WorldWideScience

Sample records for two-part epoxy resin

  1. Epoxy resins.

    Science.gov (United States)

    Bray, P G

    1999-01-01

    Epoxy resins have an extraordinarily broad range of commercial applications, especially as protective surface coatings and adhesives. Epoxy resin systems include combinations of epoxy monomers, hardeners, reactive diluents, and/or a vast array of other additives. As a result, an epoxy resin system may have a number of chemical ingredients with the potential for attendant health hazards. Most, but not all, of these health hazards arise in the occupational setting. The most frequent adverse effects are irritation or allergic mechanisms involving the dermal and respiratory systems. Sensitization usually is caused by low molecular weight or short-chain compounds. This review discusses the diagnosis, treatment, and prevention of epoxy resin-related adverse health effects.

  2. Epoxy resin

    Science.gov (United States)

    Wilson, Glenn R.; Salyer, Ival O.; Ball, III, George L.

    1976-07-13

    By mixing one part of a prepolymer containing a polyamine partially polymerized with an organic epoxide and subsequently reacted with a fatty acid containing from 8 to 32 carbon atoms, and then reacting this prepolymer mixture with 3 parts of an organic epoxide, a composition was obtained which made a gas frothable, shear-stable, room temperature curing, low density foam. A particularly advantageous prepolymer was prepared using a polyamine selected from the group consisting of diethylenetriamine, triethylenetetramine, and tetraethylenepentamine, partially polymerized with an organic epoxide having an average molecular weight of about 350 and having an epoxide equivalent of 185 to 192, and reacted with 2-10 weight percent linoleic acid. When one part of this prepolymer was reacted with about three parts of epoxy, and frothed by whipping in air or nitrogen an epoxy foam was produced which could be troweled onto surfaces and into corners or crevices, and subsequently cured, at near ambient temperature, to a strong dimensionally stable foam product.

  3. RESEARCH ON IMPROVED EPOXY RESINS.

    Science.gov (United States)

    another ’million-modulus’ epoxy resin. Cast resin properties from a series of epoxy resins hardened with several aromatic diamines are reported, but these data are sufficient to advance only speculative conclusions. (Author)

  4. Flame Retardant Epoxy Resins

    Science.gov (United States)

    Thompson, C. M.; Smith, J. G., Jr.; Connell, J. W.; Hergenrother, P. M.; Lyon, R. E.

    2004-01-01

    As part of a program to develop fire resistant exterior composite structures for future subsonic commercial aircraft, flame retardant epoxy resins are under investigation. Epoxies and their curing agents (aromatic diamines) containing phosphorus were synthesized and used to prepare epoxy formulations. Phosphorus was incorporated within the backbone of the epoxy resin and not used as an additive. The resulting cured epoxies were characterized by thermogravimetric analysis, propane torch test, elemental analysis and microscale combustion calorimetry. Several formulations showed excellent flame retardation with phosphorous contents as low as 1.5% by weight. The fracture toughness of plaques of several cured formulations was determined on single-edge notched bend specimens. The chemistry and properties of these new epoxy formulations are discussed.

  5. EPOXY RESIN TOUGHENED BY THERMOPLASTICS

    Institute of Scientific and Technical Information of China (English)

    FU Zengli; SUN Yishi

    1989-01-01

    Two kinds of tough ductile heatresisting thermoplastic, namely bisphenol A polysulfone (PSF) and polyethersulfone (PES) were used to toughen thermoset epoxy resin. A systematic study on the relationship between the molecular weight and the terminal group of the thermoplastic modifier and the fracture toughness of the modified resin was carried out. The morphology of PSF modified epoxy resin was surveyed. With the same kind of PSF the structure of the epoxy resin and the toughening effect of PSF was also investigated. The fractography of PSF, particle modified epoxy was examined in detail with SEM. The contribution of every possible energy absorption process has been discussed. Crack pinning mechanism seems to be the most important toughening mechanism for tough ductile thermoplastic PSF particle modified epoxy system.

  6. Paramagnetic epoxy resin

    Directory of Open Access Journals (Sweden)

    E. C. Vazquez Barreiro

    2017-01-01

    Full Text Available This work illustrates that macrocycles can be used as crosslinking agents for curing epoxy resins, provided that they have appropriate organic functionalities. As macrocycles can complex metal ions in their structure, this curing reaction allows for the introduction of that metal ion into the resin network. As a result, some characteristic physical properties of the metallomacrocycle could be transferred to the new material. The bisphenol A diglycidyl ether (BADGE, n = 0 and hemin (a protoporphyrin IX containing the Fe(III ion, and an additional chloride ligand have been chosen. The new material has been characterized by differential scanning calorimetry (DSC, thermogravimetric analysis (TGA, Fourier Transform Infrared (FT-IR, Nuclear Magnetic Resonance (NMR, Transmission Electron Microscopy (TEM, and magnetic susceptibility measurements. Fe(III remains in the high-spin state during the curing process and, consequently, the final material exhibits the magnetic characteristics of hemin. The loss of the chlorine atom ligand during the cure of the resin allows that Fe(III can act as Lewis acid, catalyzing the crosslinking reactions. At high BADGE n = 0/hemin ratios, the formation of ether and ester bonds occurs simultaneously during the process.

  7. Contact allergy to epoxy resin

    DEFF Research Database (Denmark)

    Bangsgaard, Nannie; Thyssen, Jacob Pontoppidan; Menné, Torkil

    2012-01-01

    . Objectives. To evaluate the prevalence of contact allergy to epoxy resin monomer (diglycidyl ether of bisphenol A; MW 340) among patients with suspected contact dermatitis and relate this to occupation and work-related consequences. Patients/methods. The dataset comprised 20 808 consecutive dermatitis...... in an educational programme. Conclusion. The 1% prevalence of epoxy resin contact allergy is equivalent to reports from other countries. The high occurrence of epoxy resin exposure at work, and the limited use of protective measures, indicate that reinforcement of the law is required....

  8. Epoxy hydantoins as matrix resins

    Science.gov (United States)

    Weiss, J.

    1983-01-01

    Tensile strength and fracture toughness of castings of the hydantoin resins cured with methylenedianiline are significantly higher than MY 720 control castings. Water absorption of an ethyl, amyl hydantoin formulation is 2.1 percent at equilibrium and Tg's are about 160 C, approximately 15 deg below the final cure temperature. Two series of urethane and ester-extended hydantoin epoxy resins were synthesized to determine the effect of crosslink density and functional groups on properties. Castings cured with methylenedianiline or with hexahydrophthalic anhydride were made from these compounds and evaluated. The glass transition temperatures, tensile strengths and moduli, and fracture toughness values were all much lower than that of the simple hydantoin epoxy resins. Using a methylene bishydantoin epoxy with a more rigid structure gave brittle, low-energy fractures, while a more flexible, ethoxy-extended hydantoin epoxy resin gave a very low Tg.

  9. Occupational exposure to epoxy resins

    NARCIS (Netherlands)

    Terwoert, J.; Kersting, K.

    2014-01-01

    Products based on epoxy resins as a binder have become popular in various settings, among which the construction industry and in windmill blade production, as a result of their excellent technical properties. However, due to the same properties epoxy products are a notorious cause of allergic skin d

  10. Occupational exposure to epoxy resins

    NARCIS (Netherlands)

    Terwoert, J.; Kersting, K.

    2014-01-01

    Products based on epoxy resins as a binder have become popular in various settings, among which the construction industry and in windmill blade production, as a result of their excellent technical properties. However, due to the same properties epoxy products are a notorious cause of allergic skin

  11. [Epoxy resin systems and contact dermatitis].

    Science.gov (United States)

    Pietranek, Jolanta Eliza

    2007-01-01

    Contact dermatitis is the major chronic skin disease that represents a global health problem. Its prevalence has been significant increasing in the latest decades. Contact dermatitis substantially alters the social life of patients and affects their work productivity. Epoxy resin systems are a frequent cause of occupational allergic contact dermatitis. Epoxy resins have an extremely wide range of commercial applications. Epoxy resin systems include combinations of epoxy monomers, hardeners, reactive diluents, and/or a vast array of other additives. In occupational settings, sensitization occurs not only to resins, but also to hardeners and reactive diluents. In this article adverse effects of epoxy resin systems are discussed.

  12. Damping Properties of Flexible Epoxy Resin

    Institute of Scientific and Technical Information of China (English)

    WANG Xiang; LIU Hanxing; OUYANG Shixi

    2008-01-01

    Amino-terminated polyethers and amino-terminated polyurethane were used as curing agent to cure the epoxy resin together and get a series of cured products. The damping properties of the composites were studied by DMA test at different measurement frequencies. Damping mechanical tests show that the flexible epoxy resin has higher loss factor than common epoxy. The highest loss factor reaches 1.57. Also the height and position of loss factor peak of the flexible epoxy resin varies by changing the content of amino-terminated polyethers. Results shows that the flexible epoxy resin can be used as damping polymer materials at room temperature or in common frequency range.

  13. Epoxy Resins Modified with Vegetable Oils

    Institute of Scientific and Technical Information of China (English)

    P.Czub

    2007-01-01

    1 Results The application of modified natural oils, nontoxic, biodegradable and renewable materials, for the modification and the synthesis of epoxy resins were presented. Firstly, the application of epoxidized vegetable oils (soybean, rapeseed, linseed and sunflower):as reactive diluents for epoxy resins was proposed and studied[1-2]. Viscosity reducing ability of epoxidized oils was tested in the compositions with Bisphenol A based low-molecular-weight epoxy resins. The rheological behaviour of the mi...

  14. [Delayed asthma bronchiale due to epoxy resin].

    Science.gov (United States)

    Authried, Georg; Al-Asadi, Haifaa; Møller, Ulla; Sherson, David Lee

    2013-10-28

    Epoxy resin is a low molecular weight agent, which can cause both acute and delayed allergic reactions. However, it is known causing skin reactions with direct or airborne contact. Rarely it can cause airway reactions like asthma bronchiale. We describe a case of a windmill worker who developed delayed asthma bronchiale due to airborne contact with epoxy resin.

  15. Advanced resin systems for graphite epoxy composites

    Science.gov (United States)

    Gilwee, W. J.; Jayarajan, A.

    1980-01-01

    The value of resin/carbon fiber composites as lightweight structures for aircraft and other vehicle applications is dependent on many properties: environmental stability, strength, toughness, resistance to burning, smoke produced when burning, raw material costs, and complexity of processing. A number of woven carbon fiber and epoxy resin composites were made. The epoxy resin was commercially available tetraglycidylmethylene dianiline. In addition, composites were made using epoxy resin modified with amine and carboxyl terminated butadiene acrylonitrile copolymer. Strength and toughness in flexure as well as oxygen index flammability and NBS smoke chamber tests of the composites are reported.

  16. Effect of epoxy resin properties on the mechanical properties of carbon fiber/epoxy resin composites

    Energy Technology Data Exchange (ETDEWEB)

    He, Hong-Wei; Gao, Feng [Taiyuan Univ. of Technology (China). College of Materials Science and Engineering; Taiyuan Univ. of Technology (China). Key Laboratory of Interface Science and Engineering in Advanced Materials; Li, Kai-Xi [Chinese Academy of Sciences, Taiyuan, Shanxi (China). Key Laboratory of Carbon Materials

    2013-09-15

    Three kinds of epoxy resins, i.e. tetraglycidyl diaminodiphenyl methane (AG80), difunctional diglycidyl ether of bisphenol-A (E51) and novolac type epoxy resin (F46) were selected as matrices for carbon fiber/epoxy composites. The objective of this work is to study the mechanical properties of fiber/epoxy composites by using these three kinds of epoxy resins with different physical and chemical performance. The results show that the composites fabricated with AG80 present the best stiffness and the composites prepared with E5 1have the best toughness. The stiffness and toughness of the composites prepared with F46 are middle values located between those for AG80/epoxy and E51/epoxy composites. Thus, the mixed epoxy resin is a promising approach for industrial production. (orig.)

  17. Structure Property Relationships of Biobased Epoxy Resins

    Science.gov (United States)

    Maiorana, Anthony Surraht

    The thesis is about the synthesis, characterization, development, and application of epoxy resins derived from sustainable feedstocks such as lingo-cellulose, plant oils, and other non-food feedstocks. The thesis can be divided into two main topics 1) the synthesis and structure property relationship investigation of new biobased epoxy resin families and 2) mixing epoxy resins with reactive diluents, nanoparticles, toughening agents, and understanding co-curing reactions, filler/matrix interactions, and cured epoxy resin thermomechanical, viscoelastic, and dielectric properties. The thesis seeks to bridge the gap between new epoxy resin development, application for composites and advanced materials, processing and manufacturing, and end of life of thermoset polymers. The structures of uncured epoxy resins are characterized through traditional small molecule techniques such as nuclear magnetic resonance, high resolution mass spectrometry, and infrared spectroscopy. The structure of epoxy resin monomers are further understood through the process of curing the resins and cured resins' properties through rheology, chemorheology, dynamic mechanical analysis, tensile testing, fracture toughness, differential scanning calorimetry, scanning electron microscopy, thermogravimetric analysis, and notched izod impact testing. It was found that diphenolate esters are viable alternatives to bisphenol A and that the structure of the ester side chain can have signifi-cant effects on monomer viscosity. The structure of the cured diphenolate based epoxy resins also influence glass transition temperature and dielectric properties. Incorporation of reactive diluents and flexible resins can lower viscosity, extend gel time, and enable processing of high filler content composites and increase fracture toughness. Incorpora-tion of high elastic modulus nanoparticles such as graphene can provide increases in physical properties such as elastic modulus and fracture toughness. The synthesis

  18. Imide modified epoxy matrix resins

    Science.gov (United States)

    Scola, D. A.

    1984-01-01

    The results of a program designed to develop tough imide modified epoxy resins cured by bisimide amine (BIA) hardeners are described. State-of-the-art epoxides MY720 and DER383 were used, and four bismide amines were evaluated. These were the BIA's derived from the 6F anhydride (4,4'-(hexafluoroisopropylidene) bis(phthalic anhydride) and the diamines 3,3'-diaminodiphynyl sulfone, 4,4'-oxygianiline, 4,4'-methylene dianiline, and 1,12-dodecane diamine. A key intermediate, designated 6F anhydride, is required for the synthesis of the bisimide amines. Reaction parameters to synthesize a precursor to the 6F anhydride (6FHC) in high yields were investigated. The catalyst trifluoromethane sulfonic acid was studied. Although small scale runs yielded the 6FHC in 50 percent yield, efforts to ranslate these results to a larger scale synthesis gave the 6FHC in only 9 percent yield. Results show that the concept of using bisimide amine as curing agents to improve the toughness properties of epoxies is valid.

  19. Flammability of Epoxy Resins Containing Phosphorus

    Science.gov (United States)

    Hergenrother, P. M.; Thompson, C. M.; Smith, J. G.; Connell, J. W.; Hinkley, J. A.

    2005-01-01

    As part of a program to develop fire-resistant exterior composite structures for future subsonic commercial and general aviation aircraft, flame-retardant epoxy resins are under investigation. Epoxies and their curing agents (aromatic diamines) containing phosphorus were synthesized and used to prepare epoxy formulations. Phosphorus was incorporated within the backbone of the epoxy resin and not used as an additive. The resulting cured neat epoxy formulations were characterized by thermogravimetric analysis, propane torch test, elemental analysis, microscale combustion calorimetry, and fire calorimetry. Several formulations showed excellent flame retardation with phosphorous contents as low as 1.5% by weight. The fracture toughness and compressive strength of several cured formulations showed no detrimental effect due to phosphorus content. The chemistry and properties of these new epoxy formulations are discussed.

  20. Epoxy resins in the construction industry.

    Science.gov (United States)

    Spee, Ton; Van Duivenbooden, Cor; Terwoert, Jeroen

    2006-09-01

    Epoxy resins are used as coatings, adhesives, and in wood and concrete repair. However, epoxy resins can be highly irritating to the skin and are strong sensitizers. Some hardeners are carcinogenic. Based on the results of earlier Dutch studies, an international project on "best practices,"--Epoxy Code--with epoxy products was started. Partners were from Denmark, Germany, the Netherlands, and the UK. The "Code" deals with substitution, safe working procedures, safer tools, and skin protection. The feasibility of an internationally agreed "ranking system" for the health risks of epoxy products was studied. Such a ranking system should inform the user of the harmfulness of different epoxies and stimulate research on less harmful products by product developers.

  1. [Allergic contact eczema from epoxy resin].

    Science.gov (United States)

    Calzado, Leticia; Ortiz-de Frutos, Francisco J; del Prado Sánchez-Caminero, María; Galera, Carmen María; Valverde, Ricardo; Vanaclocha, Francisco

    2005-11-01

    Epoxy resins are plastics that are widely used as electrical insulation, in coatings, and as adhesives and paints. They have strong sensitizing power and are one of the main causes of allergic contact eczema, both in the workplace and elsewhere. We present the case of a worker at a plastics/chemical plant, who handled aeronautical components in the process of manufacturing fuselage parts. He consulted his physician because of eczematous lesions on his fingers, hands and forearms which had developed over a two-year period and were clearly related to his work. The standard battery of skin tests was performed, along with the plastics and adhesives series and tests using the products from his workplace. Positivity was shown to epoxy resins (standard battery) and to the products from his workplace, which included different fiberglass and carbon fiber sheets impregnated with epoxy resins and epoxy adhesives.

  2. Luminous Efficient Compositions Based on Epoxy Resin

    Directory of Open Access Journals (Sweden)

    R.S. Palaiah

    2006-07-01

    Full Text Available Magnesium/sodium nitrate illuminating compositions with epoxy resin - E 605 have beenstudied for luminosity and luminous efficiency by varying fuel oxidizer ratio and binder content.The compositions have been evaluated for impact and friction sensitivities, burn rate, thermalcharacteristics, and mechanical properties. Flame temperature and combustion products areevaluated theoretically by using REAL program. Experimental results show that, luminosity,burn rate, and calorimetric value are higher for polyester resin-based compositions. The highluminous efficiency composition is achieved with magnesium/sodium nitrate ratio of 70/30 with4 per cent epoxy resin.

  3. EPOXY RESINS TOUGHENED WITH CARBOXYL TERMINATED POLYETHERS

    Institute of Scientific and Technical Information of China (English)

    YU Yunchao; LI Yiming

    1983-01-01

    Carboxyl terminated polyethers, the adducts of hydroxyl terminated polytetrahydrofuran and maleic anhydride, were used as toughener for epoxy resins. The morphology of the toughened resins was investigated by means of turbidity measurement, dynamic mechanical testing and scanning electron microscope observation. It turned out that the molecular weight and the carboxyl content of the polyether and the cure conditions are important factors, which affect the particle size of the polyether-rich domains and, in turn, the mechanical properties of the cured resin. Carboxyl terminated polytetrahydrofurans have a low glass transition temperature, and in appropriate amount they do not affect the thermal resistance of the resin. These advantages make them preferable as toughener for epoxy resins.

  4. Fluorinated Alkyl Ether Epoxy Resin Compositions and Applications Thereof

    Science.gov (United States)

    Wohl, Christopher J. (Inventor); Connell, John W. (Inventor); Smith, Joseph G. (Inventor); Siochi, Emilie J. (Inventor); Gardner, John M. (Inventor); Palmieri, Frank M. (Inventor)

    2017-01-01

    Epoxy resin compositions prepared using amino terminated fluoro alkyl ethers. The epoxy resin compositions exhibit low surface adhesion properties making them useful as coatings, paints, moldings, adhesives, and fiber reinforced composites.

  5. 40 CFR 721.3135 - Phosphorous modified epoxy resin (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Phosphorous modified epoxy resin... Specific Chemical Substances § 721.3135 Phosphorous modified epoxy resin (generic). (a) Chemical substance... phosphorous modified epoxy resin (PMNs P-00-992 and P-01-471) is subject to reporting under this section...

  6. 40 CFR 721.2752 - Epoxy resin containing phosphorus (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Epoxy resin containing phosphorus... Specific Chemical Substances § 721.2752 Epoxy resin containing phosphorus (generic). (a) Chemical substance... epoxy resin containing phosphorus (PMN P-00-912) is subject to reporting under this section for...

  7. Waterborne Epoxy Resin Modified by AMPS

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A stable epoxy emulsion was prepared with epoxy resin (EP) as raw material, 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) as modifier and benzoyl peroxide as initiator. By criterion of yield of the copolymer AMPS-EP, water-solubility, change of the acid value and intrinsic viscosity [η] along with reaction time, the copolymerization course was deduced. It is found that during the process, AMPS takes part in both the grafting copolymerization with epoxy principal chain and the ring-opening polyaddition with epoxy group. It is also discovered that the yield of AMPS-EP and water dispersing varies with reaction time. When it reaches 1.5 h,AMPS-EP can obtain good water-solubility; but the water-solubility will go bad gradually ifit exceeds 3.5 h.( )R spectrum analysis indicates that partial epoxy group partially remains and the others create sulfonic ester.

  8. Cobalt Ions Improve the Strength of Epoxy Resins

    Science.gov (United States)

    Stoakley, D. M.; St. Clair, A. K.

    1986-01-01

    Technique developed for improving mechanical strength of epoxy resins by adding cobalt ions in form of tris(acetylacetonato)cobalt (III) complex. Solid cast disks prepared from cobalt ion-containing epoxy resins tested for flexural strength and stiffness. Incorporation of cobalt ions into epoxies increased flexural strength of resins by 10 to 95 percent. Suitable resins for this technique include any liquid or solid TGMDA resins. Improved epoxy formulation proves useful as composite matrix resin, adhesive, or casting resin for applications on commercial and advanced aircraft.

  9. Chromium Ions Improve Moisure Resistance of Epoxy Resins

    Science.gov (United States)

    St. Clair, A. K.; St. Clair, T. L.; Stoakley, D. M.; Singh, J. J.; Sprinkle, D. R.

    1986-01-01

    Broad spectrum of thermosetting epoxy resins used on commercial and military aircraft, primarily as composite matrices and adhesives. In new technique, chromium-ion containing epoxy with improved resistance to moisture produced where chromium ions believed to prevent absorption of water molecules by coordinating themselves to hydroxyl groups on epoxy chain. Anticipated that improved epoxy formulation useful as composite matrix resin, adhesive, or casting resin for applications on commercial and advanced aircraft. Improvement made without sacrifice in mechanical properties of polymer.

  10. Cycloaliphatic epoxy resin coating for capillary electrophoresis.

    Science.gov (United States)

    Shah, Roopa S; Wang, Qinggang; Lee, Milton L

    2002-04-05

    Coating the interior surface of a fused-silica capillary with a polymeric material has long been used in capillary electrophoresis (CE) to reduce or eliminate electroosmotic flow and suppress adsorption. A cycloaliphatic epoxide-based resin was bonded to silane treated capillaries and crosslinked with a curing agent. The epoxy resin coating significantly reduced electroosmotic flow over a pH range of 3-10. This coating was sufficiently hydrophilic to suppress protein adsorption. The epoxy resin coated capillary was used to separate several acidic and basic proteins and peptides. Separation efficiencies greater than 400,000 theoretical plates were achieved. The relative standard deviations in migration times for proteins were methods.

  11. Investigations of toughening mechanisms of epoxy resins

    Science.gov (United States)

    Koenig, T.

    1986-01-01

    Composite material technology was applied to the solid rocket booster by the development of a carbon filament-epoxy resin case which yields a net increase of 4000 lbs. in payload in the shuttle. The question of reusability of the new composite tanks has not yet been answered and will depend on the toughness of the matrix resin. The present study was aimed at providing conditions whereby test specimens of the epoxy resin (EPON/85) and curing agents of systematically varied structures could be produced in a controlled manner. Three sets of conditions were found that might allow the isolation of the structural effects on toughness from the cure effects. The kinetic methods leading to the determination of these conditions are described.

  12. Contact allergy to epoxy resin: risk occupations and consequences.

    Science.gov (United States)

    Bangsgaard, Nannie; Thyssen, Jacob Pontoppidan; Menné, Torkil; Andersen, Klaus Ejner; Mortz, Charlotte G; Paulsen, Evy; Sommerlund, Mette; Veien, Niels Kren; Laurberg, Grete; Kaaber, Knud; Thormann, Jens; Andersen, Bo Lasthein; Danielsen, Anne; Avnstorp, Christian; Kristensen, Berit; Kristensen, Ove; Vissing, Susanne; Nielsen, Niels Henrik; Johansen, Jeanne Duus

    2012-08-01

    Epoxy resin monomers are strong skin sensitizers that are widely used in industrial sectors. In Denmark, the law stipulates that workers must undergo a course on safe handling of epoxy resins prior to occupational exposure, but the effectiveness of this initiative is largely unknown. To evaluate the prevalence of contact allergy to epoxy resin monomer (diglycidyl ether of bisphenol A; MW 340) among patients with suspected contact dermatitis and relate this to occupation and work-related consequences. The dataset comprised 20 808 consecutive dermatitis patients patch tested during 2005-2009. All patients with an epoxy resin-positive patch test were sent a questionnaire. A positive patch test reaction to epoxy resin was found in 275 patients (1.3%), with a higher proportion in men (1.9%) than in women (1.0%). The prevalence of sensitization to epoxy resin remained stable over the study period. Of the patients with an epoxy resin-positive patch test, 71% returned a questionnaire; 95 patients had worked with epoxy resin in the occupational setting, and, of these, one-third did not use protective gloves and only 50.5% (48) had participated in an educational programme. The 1% prevalence of epoxy resin contact allergy is equivalent to reports from other countries. The high occurrence of epoxy resin exposure at work, and the limited use of protective measures, indicate that reinforcement of the law is required. © 2012 John Wiley & Sons A/S.

  13. Adding Effects of Reactive Oligomers for Epoxy Resin

    OpenAIRE

    山田, 英介; 稲垣, 慎二; 岡本, 弘

    1991-01-01

    Reactive oligomers with both functional end groups were prepared by the radical telomerization and the effect of oligomers added to bisphenol-A-glycidylehter type epoxy resin was investigated by measuring mechanical properties, adhesive properties and dynamic viscoelasticities. These oligomers were high viscous liquid except the one prepared from methyl methacrylate, therefore the blend of oligomers with epoxy resin is easy. Adding oligomers, the cured epoxy resins showed the lower glass-tran...

  14. THE POLYMERIZATION OF ROOM TEMPERATURE CURING EPOXY RESINS

    Science.gov (United States)

    EPOXY RESINS , *PLASTICS, *POLYMERIZATION, AGING (PHYSIOLOGY), CHEMICAL BONDS, ELECTRICAL PROPERTIES, EMBEDDING SUBSTANCES, MONITORS, POLYMERS, RESISTANCE (ELECTRICAL), STORAGE, STRUCTURES, TEMPERATURE, TEST METHODS, VOLUME

  15. Synthesis and characterization of novel multifunctional epoxy resin

    Institute of Scientific and Technical Information of China (English)

    Jue Cheng; Jing Chen; Wan Tai Yang

    2007-01-01

    A novel multifunctional epoxy resin was synthesized by polyphenol and epichlorohydrin. The structure and molecular weight of the multifunctional epoxy were characterized by FTIR and ESI-MS. DSC and DMTA were used to investigate the thermal property of multifunctional epoxy cured by DDS. The thermal resistance of the synthesized multifunctional epoxy was much better than a standard diglycidyl ether of bisphenol-A epoxy.

  16. Epoxy-resin adhesive and method for bonding using such an epoxy resin adhesive

    NARCIS (Netherlands)

    Bhowmik, S.; Poulis, J.A.; Benedictus, R.

    2008-01-01

    The invention relates to an epoxy resin adhesive comprising a dotation of nano-substances, wherein the nano- substances are selected from the group comprising carbon-fibre nanotubes, carbon nano-fibres, silicate nano powders, and wherein the nano-substances are dispersed in the adhesive with a weigh

  17. Epoxy-resin adhesive and method for bonding using such an epoxy resin adhesive

    NARCIS (Netherlands)

    Bhowmik, S.; Poulis, J.A.; Benedictus, R.

    2008-01-01

    The invention relates to an epoxy resin adhesive comprising a dotation of nano-substances, wherein the nano- substances are selected from the group comprising carbon-fibre nanotubes, carbon nano-fibres, silicate nano powders, and wherein the nano-substances are dispersed in the adhesive with a

  18. Mechanical behaviors of hyberbranched epoxy toughened bisphenol F epoxy resin for cryogenic applications

    Science.gov (United States)

    Li, Jingwen; Wu, Zhixiong; Huang, Chuanjun; Huang, Rongjin; Li, Laifeng

    2014-01-01

    Epoxy resins have been widely employed in cryogenic engineering fields. In this work, bisphenol F epoxy resin was modified by an aromatic polyester hyperbranched epoxy resin (HTDE-2). Mechanical behaviors of the modified epoxy resins in terms of tensile properties and impact property were studied at both room and cryogenic temperatures. Moreover, the toughening mechanism was discussed by fracture surface morphology analysis. The results demonstrated that, the mechanical properties of composites initially increased until reaches the maximum value with increasing the mass content of the HTDE-2, and then decreased at both room temperature (RT) and 77K. Especially, the impact strength at 77 K was improved 40.7% compared with the pure epoxy matrix when 10 wt% HTDE-2 was introduced. The findings suggest that the HTDE-2 will be an effective toughener for the brittle bisphenol F epoxy resin for cryogenic applications.

  19. The Durability of Epoxy Resin Coating

    Institute of Scientific and Technical Information of China (English)

    ZHAO Fujun; BA Hengjing; GAO Xiaojian

    2008-01-01

    The durability of epoxy resin coating was studied under environments with relative humidity(RH) of 98%-100%, at 55 ℃ for 900 h, at 65℃ for 700 h and at 75 ℃ for 400 h, respectively. Peel strength test, dynamical mechanical thermal analysis (DMTA), infrared spectroscopy (IR) and energy dispersive X-ray spectroscopy (EDX) were employed for measurements. Peel strength indicated the development of adhesive property of the coating, DMTA indicated the development of physical property, IR revealed the development of chemical structure, and EDX showed surface element change of the coating. All these results show a good time-temperature equivalence characteristic between humidity aging time and temperature.

  20. Nonlinear time dependent behaviour of epoxy resins

    Science.gov (United States)

    Marotzke, C.; Feldmann, T.

    2016-07-01

    The nonlinear behaviour of epoxy resins is studied on standard tensile tests. A strain field measurement system is applied (Aramis) in order to monitor local strains. The residual strain is measured by recovering the specimens for up to 68 hours after unloading. The time span the specimen is exposed to load has a large influence on the creeping process and the residual strain after recovering. This is studied by comparison of instantaneous unloading with keeping the specimen under permanent load for thirty minutes. It is shown that moderate differences in the initial strain can lead to large differences in the creep behaviour as well as in the residual strain.

  1. RHEOLOGICAL BEHAVIOR OF EPOXY RESIN WATERBORNE DISPERSIONS

    Institute of Scientific and Technical Information of China (English)

    Zhen-zhong Yang; Yuan-ze Xu; De-lu Zhao

    2001-01-01

    The waterborne dispersions of epoxy resin were prepared by the phase inversion emulsification technique.Rheological behavior and its relationship with the structural change of the systems were studied. It was shown that the concentrated dispersions were highly viscoelastic and pseudoplastic, which was attributed to the formation of a physical network among the waterborne particles via hydrogen bond. The dilute dispersions were Newtonian fluids. The discrete clusters composed of small waterborne particles were found in diluted dispersions. With increasing solid content, there existed a structural transition via percolation through a cluster-cluster aggregation mode to form the physical network, which was qualitatively evidenced by the TEM morphologies.``

  2. Epoxy resins used to seal brachytherapy seed

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Natalia Carolina Camargos; Ferraz, Wilmar Barbosa; Reis, Sergio Carneiro dos; Santos, Ana Maria Matildes dos, E-mail: nccf@cdtn.br, E-mail: ferrazw@cdtn.br, E-mail: reissc@cdtn.br, E-mail: amms@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, BH (Brazil)

    2013-07-01

    Prostate cancer treatment with brachytherapy is recommended for patients with cancer at an early stage. In this treatment, small radioactive seeds are implanted directly in the prostate gland. These seeds are composed at least of one radionuclide carrier and an X-ray marker enclosed within a metallic tube usually sealed by laser process. This process is expensive and, furthermore, it can provoke a partial volatilization of the radionuclide and change the isotropy in dose distribution around the seed. In this paper, we present a new sealing process using epoxy resin. Three kinds of resins were utilized and characterized by scanning electron microscopy (SEM), energy dispersive X ray (EDS) and by differential scanning calorimetry (DSC) after immersion in simulated body fluid (SBF) and in sodium iodine solution (NaI). The sealing process showed excellent potential to replace the sealing laser usually employed. (author)

  3. Wear behaviour of epoxy resin filled with hard powders

    Science.gov (United States)

    Formisano, A.; Boccarusso, L.; Minutolo, F. Capece; Carrino, L.; Durante, M.; Langella, A.

    2016-10-01

    The development of high performance materials based on epoxy resin finds a growing number of applications in which high wear resistance is required. One major drawback in many of these applications is the relatively poor wear resistance of the epoxy resin. Therefore, in order to investigate on the possibility of increasing wear resistance of thermoset polymers filled with hard powders, sliding tests are carried out by means of a pin on disc apparatus. In particular, composite resins, constituted by an epoxy resin filled with different contents and sizes of Silicon Carbide powder, are analyzed; the wear resistance, in terms of volume loss, is measured for different abrasive counterfaces and loads.

  4. Modification of (DGEBA epoxy resin with maleated depolymerised natural rubber

    Directory of Open Access Journals (Sweden)

    2008-04-01

    Full Text Available In this work, diglycidyl ether of bisphenol A (DEGBA type epoxy resin has been modified with maleated depolymerised natural rubber (MDPR. MDPR was prepared by grafting maleic anhydride onto depolymerised natural rubber. MDPR has been characterized by Fourier transform infrared (FT-IR spectroscopy and nuclear magnetic resonance spectroscopy. MDPR was blended with epoxy resin at three different ratios (97/3, 98/2 and 99/1, by keeping the epoxy resin component as the major phase and maleated depolymerised natural rubber component as the minor phase. The reaction between the two blend components took place between the acid/anhydride group in the MDPR and the epoxide group of the epoxy resin. The proposed reaction schemes were supported by the FT-IR spectrum of the uncured Epoxy/MDPR blends. The neat epoxy resin and Epoxy/MDPR blends were cured by methylene dianiline (DDM at 100°C for three hours. Thermal, morphological and mechanical properties of the neat epoxy and the blends were investigated. Free volume studies of the cured, neat epoxy and Epoxy/MDPR blends were correlated with the morphological and mechanical properties of the same systems using Positron Annihilation Lifetime Studies.

  5. Epoxy resin developments for large superconducting magnets impregnation

    Science.gov (United States)

    Rey, J. M.; Gallet, B.; Kircher, F.; Lottin, J. C.

    The future detectors ATLAS and CMS of the Large Hadron Collider at CERN will use two huge superconducting magnets. Both are now under design, and their electrical insulation could be realized using epoxy resin and a wet impregnation technique. Because of their large dimensions, and the indirect cooling of the superconductor, the strengths of the resin and of the resin/conductor interface are of major importance. A new generation of epoxy resins for vacuum/pressure impregnation methods has been tested, and compared with some classical and well-known epoxy resins used in impregnation techniques. In order to understand the mechanical behaviour at 4 K, the complete evolution from liquid state to low temperature service condition is considered. The paper will present some results on the mechanical properties, the density and the chemical shrinkage occurring during the polymerization and the thermal contraction between room temperature and 4 K for these different types of epoxy resins.

  6. Bisphenol-A epoxy resin reinforced and toughened by hyperbranched epoxy resin

    Institute of Scientific and Technical Information of China (English)

    ZHANG Daohong; JIA Demin; HUANG Xianbo

    2007-01-01

    The study on toughening and reinforcing of bisphenol-A epoxy resin is one of important developmental direction in the field.This paper reports a one-pot synthesis of aromatic polyester hyperbranched epoxy resin HTDE-2,an effect of HTDE-2 content on the mechanical and thermal performance of the bisphenol-A (E51)/HTDE-2 hybrid resin in detail.Fourier transform infrared (FT-IR) spectrometer,scanning electronic microscopy (SEM),differential scanning calorimetry (DSC),thermogravimetric analysis (TGA),dynamic mechanical thermal analysis (DMA) and molecular simulation technology are used to study the structure of HTDE-2,performance and toughening and reinforcing mechanism of the HTDE-2/E51 hybrid resin.It has been shown that the content of HTDE-2 has an important effect on the performance of the hybrid resin,and the performance of the HTDE-2/E51 blends has maximum with the increase in HTDE-2 content.The impact strength and fracture toughness of the hybrid resin with 9 wt-% HTDE-2 are almost 3.088 and 1.749 times of E51 performance respectively,furthermore,the tensile and flexural strength can also be enhanced about 20.7% and 14.2%,respectively.The glass transition temperature and thermal degradation temperature,however,are found to decrease to some extent.

  7. Persistent photosensitivity after allergic contact dermatitis to epoxy resin.

    Science.gov (United States)

    Kwok, Tiffany; Rosen, Cheryl F; Storrs, Frances J; Lobel, Edmund; DeKoven, Joel G

    2013-01-01

    Persistent photosensitivity after allergic contact dermatitis (ACD) to epoxy resin has rarely been described. The aim of this study was to create awareness that ACD to epoxy may be a trigger for persistent photosensitivity. We present a series of 5 patients who developed ACD to epoxy resin and later a photodistributed eczematous eruption when exposed to sunlight, with a documented decrease in minimal erythema dose to UVA and UVB. The age of patients ranged from 34 to 71 years, and there were 3 men and 2 women. Each patient had occupational exposure to epoxy. Symptoms of epoxy ACD preceded photosensitivity by 5 months to 12 years in 3 cases and occurred simultaneously in 2 cases. Patch testing to epoxy resin was positive in all patients. Phototesting revealed a decreased minimal erythema dose to UVA and UVB in each of the 3 patients who were phototested. Photopatch testing was positive for epoxy resin in 1 of the 2 patients tested. All patients remained photosensitive for at least 2 years after diagnosis, with only 1 case of photosensitivity resolving with extended avoidance of epoxy. There is an association between ACD to epoxy resin and development of persistent photosensitivity. Possible mechanisms to explain the relationship between the 2 phenomena are discussed.

  8. Biobased Epoxy Resins from Deconstructed Native Softwood Lignin.

    Science.gov (United States)

    van de Pas, Daniel J; Torr, Kirk M

    2017-08-14

    The synthesis of novel epoxy resins from lignin hydrogenolysis products is reported. Native lignin in pine wood was depolymerized by mild hydrogenolysis to give an oil product that was reacted with epichlorohydrin to give epoxy prepolymers. These were blended with bisphenol A diglycidyl ether or glycerol diglycidyl ether and cured with diethylenetriamine or isophorone diamine. The key novelty of this work lies in using the inherent properties of the native lignin in preparing new biobased epoxy resins. The lignin-derived epoxy prepolymers could be used to replace 25-75% of the bisphenol A diglycidyl ether equivalent, leading to increases of up to 52% in the flexural modulus and up to 38% in the flexural strength. Improvements in the flexural strength were attributed to the oligomeric products present in the lignin hydrogenolysis oil. These results indicate lignin hydrogenolysis products have potential as sustainable biobased polyols in the synthesis of high performance epoxy resins.

  9. PREPARATION, CHARACTERIZATION AND THERMAL BEHAVIOR OF ALKYL SUBSTITUTED PHENOLIC EPOXY RESIN

    OpenAIRE

    Jyoti Chaudhary*, Supriya Dadhich, Giriraj Tailor

    2017-01-01

    The present article deals with the synthesis of phenolic epoxy resin by the reaction of phenolic resin and epichlorohydrin. The synthesis of phenolic resin was carried out by using p-ethylphenol, formaldehyde and naphthol. The structures of phenolic and epoxy resins were confirmed by spectroscopic analysis. The synthesized epoxy resin showed solubility in polar solvents like DMF, dioxane, acetone, DMSO, THF, ethyl acetate, and chloroform. Thermal characterization of epoxy resin was monitored ...

  10. Curing of Epoxy Resin Induced by Femtosecond Laser Pulse

    Institute of Scientific and Technical Information of China (English)

    LI Yubin; ZHANG Zuoguang

    2005-01-01

    The possibility of curing of epoxy resin induced by femtosecond laser beam was explored through choosing different initiators . Absorption spectroscopy, infrared spectroscopy (IR), stereomicroscopy and scanning electron microscopy (SEM) were applied to analyze the structure of epoxy resin systems after irradiation with a femtosecond laser beam. The experimental results show that the epoxy resin systems containing diaryliodonium salts can be cured by irradiation of Jemtosecond laser pulse, while the systems containing benzoin can not be cured. It is found that diaryliodonium salts decompose under the irradiation of femtosecond laser pulse through multi ( two ) -photon absorption, initiating the ring-opening polymerization of epoxy resin. And the appearance of cured area has a sheet structure consisting of many tiny lamellar structures.

  11. Properties of Graphene Oxide/Epoxy Resin Composites

    OpenAIRE

    Jijun Tang; Haijun Zhou; Yunxia Liang; Xinlan Shi; Xin Yang; Jiaoxia Zhang

    2014-01-01

    The graphene oxide (GO) was obtained by pressurized oxidation method using natural graphite as raw materials. Then the GO/epoxy resin composites were prepared by casting. The mechanical and damping properties of composites were studied. As a result, the impact intensity of GO/epoxy resin composites was prominently improved with the content of the graphene oxide increasing. The glass transition temperature decreased and the damping capacity is improved.

  12. Properties of Graphene Oxide/Epoxy Resin Composites

    OpenAIRE

    Jijun Tang; Haijun Zhou; Yunxia Liang; Xinlan Shi; Xin Yang; Jiaoxia Zhang

    2014-01-01

    The graphene oxide (GO) was obtained by pressurized oxidation method using natural graphite as raw materials. Then the GO/epoxy resin composites were prepared by casting. The mechanical and damping properties of composites were studied. As a result, the impact intensity of GO/epoxy resin composites was prominently improved with the content of the graphene oxide increasing. The glass transition temperature decreased and the damping capacity is improved.

  13. Properties of Graphene Oxide/Epoxy Resin Composites

    Directory of Open Access Journals (Sweden)

    Jijun Tang

    2014-01-01

    Full Text Available The graphene oxide (GO was obtained by pressurized oxidation method using natural graphite as raw materials. Then the GO/epoxy resin composites were prepared by casting. The mechanical and damping properties of composites were studied. As a result, the impact intensity of GO/epoxy resin composites was prominently improved with the content of the graphene oxide increasing. The glass transition temperature decreased and the damping capacity is improved.

  14. Positron Annihilation in a Rubber Modified Epoxy Resin

    DEFF Research Database (Denmark)

    Mogensen, O. E.; Jacobsen, F. M.; Pethrick, R. A.

    1979-01-01

    Positron annihilation data is reported on a rubber-modified epoxy resin. Studies of the temperature dependence of the o-positronium lifetime indicated the existence of three distinct regions; the associated transition temperatures by comparison with dilatometric data can be ascribed respectively...... to be glass transition of the epoxy phase and to that of a mixed acrylonitrile—epoxy—butadiene interfacial region....

  15. STUDY ON THE EPOXY RESIN TOUGHENED BY HYDROXY-TERMINATED BUTADIENE-ACRYLONITRILE COPOLYMER

    Institute of Scientific and Technical Information of China (English)

    HAN Xiaozu; LI Shaoying; ZHANG Qingyu

    1990-01-01

    Toughened epoxy resin with excellent properties was obtained by adding organic acid anhydride curing agent and hydroxy-terminated butadiene-acrylonitrile copolymer (HTBN), which is cheaper than CTBN. The anhydride reacts with both epoxy groups on epoxy resin and hydroxyl groups on HTBN. As a result the soft long chains of HTBN and the rigid chain of epoxy resin form one network, giving the resin toughness. Two-phase structure of the toughened resin was observed by SEM and TEM.

  16. Toughening of epoxy resins by epoxidized soybean oil

    Energy Technology Data Exchange (ETDEWEB)

    Frischinger, I.; Dirlikov, S. [Eastern Michigan Univ., Ypsilanti, MI (United States)

    1993-12-31

    Homogeneous mixtures of a liquid rubber based on prepolymers of epoxidized soybean oil with amines, diglycidyl ether of bisphenol A epoxy resins, and commercial diamines form, under certain conditions, two-phase thermosetting materials that consist of a rigid epoxy matrix and randomly distributed small rubbery soybean particles (0.1-5 {mu}m). These two-phase thermosets have improved toughness, similar to that of other rubber-modified epoxies, low water absorption, and low sodium content. In comparison to the unmodified thermosets, the two-phase thermosets exhibit slightly lower glass-transition temperatures and Young`s moduli, but their dielectric properties do not change. The epoxidized soybean oil is available at a price below that of commercial epoxy resins and appears very attractive for epoxy toughening on an industrial scale. 15 refs., 17 figs., 6 tabs.

  17. Physical aging of linear and network epoxy resins

    Science.gov (United States)

    Kong, E. S.-W.; Wilkes, G. L.; Mcgrath, J. E.; Banthia, A. K.; Mohajer, Y.; Tant, M. R.

    1981-01-01

    Network and linear epoxy resins principally based on the diglycidyl ether of bisphenol-A and its oligomers are prepared and studied using diamine and anhydride crosslinking agents. Rubber modified epoxies and a carbon fiber reinforced composite are also investigated. All materials display time-dependent changes when stored at temperatures below the glass transition temperature after quenching (sub-T/g/ annealing). Solvent sorption experiments initiated after different sub-T(g) annealing times demonstrate that the rate of solvent uptake can be indirectly related to the free volume of the epoxy resins. Residual thermal stresses and water are found to have little effect on the physical aging process, which affects the sub-T(g) properties of uniaxial carbon fiber reinforced epoxy material. Finally, the importance of the recovery phenomenon which affects the durability of epoxy glasses is considered.

  18. Thermal expansion and swelling of cured epoxy resin used in graphite/epoxy composite materials

    Science.gov (United States)

    Adamson, M. J.

    1980-01-01

    The paper presents results of experiments in which the thermal expansion and swelling behavior of an epoxy resin system and two graphite/epoxy composite systems exposed to water were measured. It was found that the cured epoxy resin swells by an amount slightly less than the volume of the absorbed water and that the swelling efficiency of the water varies with the moisture content of the polymer. Additionally, the thermal expansion of cured epoxy resin that is saturated with water is observed to be more than twice that of dry resin. Results also indicate that cured resin that is saturated with 7.1% water at 95 C will rapidly increase in moisture content to 8.5% when placed in 1 C water. The mechanism for this phenomenon, termed reverse thermal effect, is described in terms of a slightly modified free-volume theory in conjunction with the theory of polar molecule interaction. Nearly identical behavior was observed in two graphite/epoxy composite systems, thus establishing that this behavior may be common to all cured epoxy resins.

  19. PROGRESS IN PHASE INVERSION EMULSIFICATION FOR EPOXY RESIN WATERBORNE DISPERSIONS

    Institute of Scientific and Technical Information of China (English)

    Zhen-zhong Yang

    2007-01-01

    In this review,our recent work in phase inversion emulsification (PIE)for polymer(especially epoxy resin) waterborne dispersions is summarized.Based on experimental results about PIE process,the physical model is proposed which Can guide the synthesis of the waterborne dispersions such as polymer/nanoparticle composite dispersion.In the presence of a latent curing catalyst,PIE can give a crosslinkable epoxy resin waterborne dispersion.The dispersions can form cured transparent coatings with some unique properties such as UV shielding.They are promising in functional coatings,waterborne resin matrices for composites,and sizing for high performance fibers.

  20. Biphenyl liquid crystalline epoxy resin as a low-shrinkage resin-based dental restorative nanocomposite.

    Science.gov (United States)

    Hsu, Sheng-Hao; Chen, Rung-Shu; Chang, Yuan-Ling; Chen, Min-Huey; Cheng, Kuo-Chung; Su, Wei-Fang

    2012-11-01

    Low-shrinkage resin-based photocurable liquid crystalline epoxy nanocomposite has been investigated with regard to its application as a dental restoration material. The nanocomposite consists of an organic matrix and an inorganic reinforcing filler. The organic matrix is made of liquid crystalline biphenyl epoxy resin (BP), an epoxy resin consisting of cyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (ECH), the photoinitiator 4-octylphenyl phenyliodonium hexafluoroantimonate and the photosensitizer champhorquinone. The inorganic filler is silica nanoparticles (∼70-100 nm). The nanoparticles were modified by an epoxy silane of γ-glycidoxypropyltrimethoxysilane to be compatible with the organic matrix and to chemically bond with the organic matrix after photo curing. By incorporating the BP liquid crystalline (LC) epoxy resin into conventional ECH epoxy resin, the nanocomposite has improved hardness, flexural modulus, water absorption and coefficient of thermal expansion. Although the incorporation of silica filler may dilute the reinforcing effect of crystalline BP, a high silica filler content (∼42 vol.%) was found to increase the physical and chemical properties of the nanocomposite due to the formation of unique microstructures. The microstructure of nanoparticle embedded layers was observed in the nanocomposite using scanning and transmission electron microscopy. This unique microstructure indicates that the crystalline BP and nanoparticles support each other and result in outstanding mechanical properties. The crystalline BP in the LC epoxy resin-based nanocomposite was partially melted during exothermic photopolymerization, and the resin expanded via an order-to-disorder transition. Thus, the post-gelation shrinkage of the LC epoxy resin-based nanocomposite is greatly reduced, ∼50.6% less than in commercialized methacrylate resin-based composites. This LC epoxy nanocomposite demonstrates good physical and chemical properties and good biocompatibility

  1. Thermal Expansion and Swelling of Cured Epoxy Resin Used in Graphite/Epoxy Composite

    Science.gov (United States)

    Adamson, M. J.

    1979-01-01

    The thermal expansion and swelling of resin material as influenced by variations in temperature during moisture absorption is discussed. Comparison measurements using composites constructed of graphite fibers and each of two epoxy resin matrices are included. Polymer theory relative to these findings is discussed and modifications are proposed.

  2. Preparation and properties of lignin-epoxy resin composite

    Directory of Open Access Journals (Sweden)

    Quanfu Yin

    2012-11-01

    Full Text Available A cross-linked biomass-polymer composite with a lignin content of up to 60% was prepared by blending lignin with an epoxy resin and polyamine using a hot press molding process. The characteristics of the curing reaction of lignin with epoxy resin were studied using DSC and FTIR analysis. The effect of molding temperature and molding pressure on the mechanical properties and microstructure of the lignin/epoxy resin composite was also studied by SEM, DMA, and TG analyses. The results showed that the epoxy resin can be cured by lignin, and the curing temperature for the blends can be reduced by the introduction of a polyamine cure agent. The properties of the composite, such as bending strength, impact strength, glass-transition temperature, and thermal stability, were evidently influenced by the molding process. A good interfacial combination was formed between lignin and epoxy resin. Increasing the molding temperature and pressure proved beneficial to achieve a better interfacial combination for the composite, and the degree of ductile fracture was increased in the fracture surface of the composite.

  3. Interface and properties of epoxy resin modified by elastomeric nano-particles

    Institute of Scientific and Technical Information of China (English)

    HUANG Fan; LIU Yiqun; ZHANG Xiaohong; GAO Jianming; SONG Zhihai; TANG Banghui; WEI Genshuan; QIAO Jinliang

    2005-01-01

    Study on a new composite of epoxy resin/elastomeric nano-particles (ENP) is reported in this paper, which shows that, in comparison with pure epoxy resin and epoxy toughened with CTBN, the composites of epoxy resin/carboxylic nitrile-butadiene ENP and epoxy resin/styrene butadiene vinyl-pyridine ENP possess both higher toughness and heat resistance. Both ENPs used in the study have an average size of less than 100 nm. Study on the epoxy network's morphology and interface properties suggests that due to the chemical reaction between ENP and epoxy resin and more hydrogen bonds between nitrile groups of the rubber and hydroxyl groups of the epoxy resin, stronger interaction at the larger interface may lead to the observed excellent properties of the epoxy resin toughened with ENP.

  4. STUDY ON COPOLYMER EPOXY RESIN MATRIX WITHOUT SHRINKAGE PART I VOLUME CHANGE DURING CURE PROCESSES

    Institute of Scientific and Technical Information of China (English)

    HE Pingsheng; ZHOU Zhiqiang; WANG Gengchao; PAN Caiyuan; WU Renjie

    1988-01-01

    The volume change of the copolymer epoxy resins can be controlled by copolymerizing epoxy resin E51 with 3,9-di (5-norbornene-2, 2)-1, 5, 7, 11-tetraoxaspiro [5, 5] undecane (NSOC). During curing,the volume changes of copolymer epoxy resins with various amounts of NSOC were measured with a dilatometer. Cure process does not produce volume change when epoxy resin E51: NSOC is 5.88: 1 in equivalent.

  5. Thermoset Blends of an Epoxy Resin and Polydicyclopentadiene

    Energy Technology Data Exchange (ETDEWEB)

    Rohde, Brian J.; Le, Kim Mai; Krishnamoorti, Ramanan; Robertson, Megan L.

    2016-12-13

    The mechanical properties of two chemically distinct and complementary thermoset polymers were manipulated through development of thermoset blends. The thermoset blend system was composed of an anhydride-cured diglycidyl ether of bisphenol A (DGEBA)-based epoxy resin, contributing high tensile strength and modulus, and polydicyclopentadiene (PDCPD), which has a higher toughness and impact strength as compared to other thermoset polymers. Ultra-small-angle and small-angle X-ray scattering analysis explored the morphology of concurrently cured thermoset blends, revealing a macroscopically phase separated system with a surface fractal structure across blended systems of varying composition. The epoxy resin rich and PDCPD rich phases exhibited distinct glass transitions (Tg’s): the Tg observed at higher temperature was associated with the epoxy resin rich phase and was largely unaffected by the presence of PDCPD, whereas the PDCPD rich phase Tg systematically decreased with increasing epoxy resin content due to inhibition of dicyclopentadiene ring-opening metathesis polymerization. The mechanical properties of these phase-separated blends were in reasonable agreement with predictions by the rule of mixtures for the blend tensile strength, modulus, and fracture toughness. Scanning electron microscopy analysis of the tensile and fracture specimen fracture surfaces showed an increase in energy dissipation mechanisms, such as crazing, shear banding, and surface roughness, as the fraction of the more ductile component, PDPCD, increased. These results present a facile method to tune the mechanical properties of a toughened thermoset network, in which the high modulus and tensile strength of the epoxy resin can be largely retained at high epoxy resin content in the blend, while increasing the fracture toughness.

  6. MODIFICATION OF EPOXY RESINS WITH PHENOLIC HYDROXYL-TERMINATED POLYSILOXANE

    Institute of Scientific and Technical Information of China (English)

    HOU Qingpu; HUANG Ying; YU Yunzhao

    1995-01-01

    Phenolic hydroxyl-terminated polysiloxanes were incorporated into epoxy resins to reduce the internal stress owing to the mismatch in coefficient of thermal expansion (CTE).Polysiloxane-epoxy resin block copolymers were made by a pre-reaction step prior to the curing. In the cured resin, the domain size of the polysiloxane phase depended on the structure of the phenolic hydroxyl-terminated polysiloxane. It was found that the modulus of the cured resin depended largely on the level of the modifier, while the CTE was affected greatly by the structure of the polysiloxane. By means of incorporating a few percent of methylphenylsiloxane unit into the polydimethylsiloxane chain, or by introducing more compatible end-capping groups, the compounds of more effective low stress modifiers were synthesized.

  7. In-situ cure monitoring of epoxy resin systems

    OpenAIRE

    Powell, Graham

    1998-01-01

    This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University. This thesis describes the work carried out at Brunel University to develop novel optical fibre sensors capable of monitoring the cure state of an epoxy/amine resin system. The sensors were of simple construction, consisting of an optical fibre from which the silicone cladding layer had been removed over a short length. This stripped length was embedded into the curing resin system. The sensor...

  8. Can simultaneous contact allergies to phenyl glycidyl ether and epoxy resins of the bisphenol A/F-types be explained by contamination of the epoxy resins?

    Science.gov (United States)

    Pontén, Ann; Zimerson, Erik; Bruze, Magnus

    2008-11-01

    Simultaneous contact allergies to epoxy resins based on diglycidyl ether of bisphenol A (DGEBA-R) or epoxy resins of the bisphenol F-type and the reactive diluent phenyl glycidyl ether (PGE) have been reported. The reason might be cross-reactivity, exposure to an epoxy resin system with PGE as a component, or contamination by PGE in the epoxy resin. To study contamination by PGE, 20 commercial epoxy resins were analysed for the presence of PGE. To study contact allergy to PGE and its relation to epoxy resins by inserting PGE in the standard series. Among 2227 patients, 7 reacted to PGE. Of 23 (30%) patients, 7 with contact allergy to DGEBA-R and 7/19 (37%) with contact allergy to an epoxy resin of the bisphenol F-type reacted to PGE. All 7 patients with contact allergy to PGE reacted both to the DGEBA-R and to the epoxy resin of the bisphenol F-type. PGE was found in 90% of the investigated resins. The amounts of PGE ranged between 0.004% w/w and 0.18% w/w. Most probably, the presence of PGE as a contaminant in epoxy resins is of minor importance for the sensitization, but possibly the contamination of PGE might elicit contact dermatitis in individuals with a high reactivity to PGE.

  9. Chronic Dermal Toxicity of Epoxy Resins I. Skin Carcinogenic Potency and General Toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Holland, J.M.

    2001-01-16

    Epoxy resins are a diverse class of chemicals that differ in structure, physical properties, and, presumably, biological activity. The purpose of these experiments was to compare the chronic dermal toxicity and carcinogenicity of selected commercial epoxy resins and to determine the potential for positive synergistic carcinogenic interactions between different resins. This work is an extension and continuation of a Department of Energy sponsored program to evaluate epoxy resins for potential occupational health risks. The materials examined were chosen on the basis of their interest to the U.S. government. They are representative of the manufacturer's production at the time, and therefore the data are completely valid only for the specific production period. Results of the experimental exposures will be reported in two parts. This report describes the test materials, their chemical and physical characteristics and the experimental design. General (systemic) toxicity will be evaluated and the skin carcinogenicity of the materials compared. A subsequent report will provide morphological descriptions of skin and significant internal pathology induced by the various treatments.

  10. PHASE STRUCTURE AND PROPERTIES OF EPOXY RESIN MODIFIED BY POLYSILOXANE BEARING PENDANT AMINO GROUPS

    Institute of Scientific and Technical Information of China (English)

    Bing Zhang; Xiang-luan Liu; Ying Huang

    2000-01-01

    Polysiloxane-modified epoxy resins were prepared through the reaction of epoxy resin with polydimethylsiloxanes bearing pendant N-(β-aminoethyl)-γ-aminopropyl groups. The morphology and properties of the cured epoxy resins modified by the polysiloxanes were investigated. It was found that the phase structure and properties of the cured epoxy resins depend mainly on the amino group content in the polydimethylsiloxane and the level of the modifier. The change of phase structure in the cured epoxy resin systems was responsible for the dramatic change in their mechanical and surface properties.

  11. SYNTHESIS AND CHARACTERIZATION OF KRAFT LIGNIN-BASED EPOXY RESINS

    Directory of Open Access Journals (Sweden)

    Nour Eddine El Mansouri

    2011-05-01

    Full Text Available Epoxidization is an interesting way to develop a new application of lignin and therefore to improve its application potential. In this work, kraft lignin-based epoxy resins were obtained by the epoxidization reaction, using the kraft lignin recovered directly from pulping liquor and modified by a methylolation reaction. The methylolated lignins were obtained by the reaction of original kraft lignin with formaldehyde and glyoxal, which is a less volatile and less toxic aldehyde. 1H-NMR spectroscopy showed that methylolated kraft lignin has more hydroxymethyl groups than glyoxalated kraft lignin. For the epoxidization reaction we studied the influence of the lignin:NaOH (w/w ratio, temperature, and time of the reaction on the properties of the prepared epoxidized lignins. The structures of lignin-based epoxy resins were followed by epoxy index test and FTIR spectroscopy. Optimal conditions were obtained for lignin-based epoxy resin produced at lignin/NaOH = 1/3 at 70 ºC for 3h. Thermogravimetry analysis (TGA revealed that the epoxidization enhances the thermal stability of lignins and may allow a wider temperature range for applications with lignin epoxy-PF blends.

  12. Synthesis and Characterizations of Melamine-Based Epoxy Resins

    Directory of Open Access Journals (Sweden)

    Raffaele Cioffi

    2013-09-01

    Full Text Available A new, easy and cost-effective synthetic procedure for the preparation of thermosetting melamine-based epoxy resins is reported. By this innovative synthetic method, different kinds of resins can be obtained just by mixing the reagents in the presence of a catalyst without solvent and with mild curing conditions. Two types of resins were synthesized using melamine and a glycidyl derivative (resins I or by adding a silane derivative (resin II. The resins were characterized by means of chemical-physical and thermal techniques. Experimental results show that all the prepared resins have a good thermal stability, but differ for their mechanical properties: resin I exhibits remarkable stiffness with a storage modulus value up to 830 MPa at room temperature, while lower storage moduli were found for resin II, indicating that the presence of silane groups could enhance the flexibility of these materials. The resins show a pot life higher than 30 min, which makes these resins good candidates for practical applications. The functionalization with silane terminations can be exploited in the formulation of hybrid organic-inorganic composite materials.

  13. Synthesis and characterizations of melamine-based epoxy resins.

    Science.gov (United States)

    Ricciotti, Laura; Roviello, Giuseppina; Tarallo, Oreste; Borbone, Fabio; Ferone, Claudio; Colangelo, Francesco; Catauro, Michelina; Cioffi, Raffaele

    2013-09-05

    A new, easy and cost-effective synthetic procedure for the preparation of thermosetting melamine-based epoxy resins is reported. By this innovative synthetic method, different kinds of resins can be obtained just by mixing the reagents in the presence of a catalyst without solvent and with mild curing conditions. Two types of resins were synthesized using melamine and a glycidyl derivative (resins I) or by adding a silane derivative (resin II). The resins were characterized by means of chemical-physical and thermal techniques. Experimental results show that all the prepared resins have a good thermal stability, but differ for their mechanical properties: resin I exhibits remarkable stiffness with a storage modulus value up to 830 MPa at room temperature, while lower storage moduli were found for resin II, indicating that the presence of silane groups could enhance the flexibility of these materials. The resins show a pot life higher than 30 min, which makes these resins good candidates for practical applications. The functionalization with silane terminations can be exploited in the formulation of hybrid organic-inorganic composite materials.

  14. Synchrotron Radiation Investigation in Epoxy Resin Modified with Polysiloxane System

    Science.gov (United States)

    Gan, Wenjun; Li, Weizhen; Ding, Jindian; Gu, Xiaodan; Wang, Cheng

    2014-03-01

    Epoxy resins are one of the most important classes of thermosetting polymers. Epoxy resin modified with polysiloxane is expected that the siloxane moiety may exert its qualities of thermal stability, impact toughness and surface-modification properties. Our group tried to introduce polysiloxane into epoxy resin by blending diglycidyl-ether of bisphenol-A with epoxypropoxypropyl terminated polydimethyl-siloxane and polyetherimide-siloxane in different proportion. These polysiloxane modified epoxy resins have been investigated using a combination of small- and wide angle X-ray scatterings (SAXS and WAXS) and scanning transmission soft X-ray microscopy (STXM). Nano- to micro-scale domain size, distribution and chemical composition were observed with spatial and spectroscopic sensitivities offered by both hard and soft x-ray scattering/microscopy. In-situ SAXS experiments were performed to understand the mechanism of microphase separation and dynamics of nanostructure evolution. Acknowledgment: The authors thank Shanghai Municipal Education Commission (Overseas Visiting Scholar Program 2012) and Shanghai University of Engineering Science (2011xz04) for financial supports.

  15. Development of Partial Discharge Sensing Device for Epoxy Resin Bushing

    Science.gov (United States)

    Mutakamihigashi, Tatsuya; Kawasaki, Makoto; Hashiba, Yasuhito

    For the electric power equipment and the cables, prevention of accident is very important. And in substations, a lot of solid insulations using epoxy resin are introduced into cubicle-type switchgears because of its high insulation reliability and down-sizing ability. We know a phenomenon that partial discharge occur when electric installation have degraded. When void or crack exist in the polymer insulating materials or interface of conductor, partial discharge is caused and finally results in breakdown. In recent years, the feature is seen in the partial discharge generated in the epoxy resin before and after the progress of electric tree by our research. Electro-magnetic wave spectra radiated from partial discharge have specific frequency region from 200MHz to 450MHz. We developed the sensing device that can detect the electric discharge by receiving the signal by mobile antenna. We proved the performance of this equipment in operating substations; As a result, partial discharge in epoxy resin was detected by electro-magnetic wave. And then, we removed epoxy resin bushing from the cubicle and measured partial discharge by discharging current, we confirmed that presumed level is correct.

  16. Mechanisms of Interactions of Energetic Electrons with Epoxy Resins

    Science.gov (United States)

    Gupta, A.; Coulter, D. R.; Tsay, F. D.; Moacanin, J.

    1982-01-01

    The mechanism of deactivation of energy of excitation in a resin system was investigated on optical excitation as well as excitation by high energy electrons. This mechanism involves formation of excited state complexes, known as exciplexes which have a considerable charge transfer character. This mechanism will be used to develop a degradation model for epoxy matrix materials deployed in a space environment.

  17. Epoxy resin monomers with reduced skin sensitizing potency.

    Science.gov (United States)

    O'Boyle, Niamh M; Niklasson, Ida B; Tehrani-Bagha, Ali R; Delaine, Tamara; Holmberg, Krister; Luthman, Kristina; Karlberg, Ann-Therese

    2014-06-16

    Epoxy resin monomers (ERMs), especially diglycidyl ethers of bisphenol A and F (DGEBA and DGEBF), are extensively used as building blocks for thermosetting polymers. However, they are known to commonly cause skin allergy. This research describes a number of alternative ERMs, designed with the aim of reducing the skin sensitizing potency while maintaining the ability to form thermosetting polymers. The compounds were designed, synthesized, and assessed for sensitizing potency using the in vivo murine local lymph node assay (LLNA). All six epoxy resin monomers had decreased sensitizing potencies compared to those of DGEBA and DGEBF. With respect to the LLNA EC3 value, the best of the alternative monomers had a value approximately 2.5 times higher than those of DGEBA and DGEBF. The diepoxides were reacted with triethylenetetramine, and the polymers formed were tested for technical applicability using thermogravimetric analysis and differential scanning calorimetry. Four out of the six alternative ERMs gave polymers with a thermal stability comparable to that obtained with DGEBA and DGEBF. The use of improved epoxy resin monomers with less skin sensitizing effects is a direct way to tackle the problem of contact allergy to epoxy resin systems, particularly in occupational settings, resulting in a reduction in the incidence of allergic contact dermatitis.

  18. Study on Concrete Containing Recycled Aggregates Immersed in Epoxy Resin

    Directory of Open Access Journals (Sweden)

    Adnan Suraya Hani

    2017-01-01

    Full Text Available In recent decades, engineers have sought a more sustainable method to dispose of concrete construction and demolition waste. One solution is to crush this waste concrete into a usable gradation for new concrete mixes. This not only reduces the amount of waste entering landfills but also alleviates the burden on existing sources of quality natural concrete aggregates. There are too many kinds of waste but here constructions waste will be the priority target that should be solved. It could be managed by several ways such as recycling and reusing the concrete components, and the best choice of these components is the aggregate, because of the ease process of recycle it. In addition, recycled aggregates and normal aggregates were immersed in epoxy resin and put in concrete mixtures with 0%, 5%, 10% and 20% which affected the concrete mixtures properties. The strength of the concrete for both normal and recycled aggregates has increased after immersed the aggregates in epoxy resin. The percentage of water absorption and the coefficient of water permeability decreased with the increasing of the normal and the recycled aggregates immersed in epoxy resin. Generally the tests which have been conducted to the concrete mixtures have a significant results after using the epoxy resin with both normal and recycled aggregates.

  19. Influences of carbon nanofillers on mechanical performance of epoxy resin polymer

    Science.gov (United States)

    Singh, Shraddha; Srivastava, V. K.; Prakash, Rajiv

    2015-03-01

    The influence of multi-walled carbon nanotubes (MWCNTs) and graphene nanoplatelets (GnPs) on epoxy resin was investigated to compare their mechanical properties. MWCNT/epoxy resin and GnP/epoxy resin composites were compared with each other for their tensile strength, compressive strength, Charpy Impact and Izod impact energy with the variation of weight percentage ratio of nanofiller ranging from 0.5, 1.0, 2.0 and 3.0, respectively. The result shows that GnP/epoxy resin composite gave better tensile and compressive strength compared to MWCNT/epoxy resin composite whereas Izod impact energy, Charpy impact energy and dynamic fracture toughness of MWCNT/epoxy resin composite resulted in better impact resistance than the GnP/epoxy resin composite. Thermal stability and microstructural properties of composites were measured using Thermogravimetric analysis (TGA), transmission electron microscope (TEM) and scanning electron microscope (SEM).

  20. Cryogenic compressive properties of basic epoxy resin systems

    Energy Technology Data Exchange (ETDEWEB)

    Markley, F.W.; Hoffman, J.A.; Muniz, D.P.

    1985-09-01

    The compressive properties of short cylindrical samples of many different epoxy resin systems have been measured at ambient temperature and at 77/sup 0/K. These are pure resin systems of known chemistry, without the inorganic fillers or fibrous reinforcements needed in final cryogenic systems. Of course, chemically incorporated modifiers such as flexibilizing resins have been included. This data should make possible inferences about cryogenic properties from molecular structures and provide specific data useful to formulators and end users. Measurements on some other plastics such as PTFE, Polyimides, and UHMWPE have been made for comparison purposes.

  1. Development and Characterization of Novel Interpenetrating Network (IPN Foams from Epoxy Ester and Aliphatic Epoxy Resin

    Directory of Open Access Journals (Sweden)

    Kanuprasad Patel

    2009-01-01

    Full Text Available Diglycidyl ether of bisphenol-A (DGEBA was reacted with acrylate monomer at variable molar ratios. The reaction between glycerine and epichlorohydrine form glycidyl ether of polyol aliphatic epoxy resin. The resultant resins were characterized duly. Both the resins were mixed at different ratios with constant high shear stirring. The obtained mixture and suitable additives were heated at 150oC for one and half hour. The so called Interpenetrating Network (IPN transformed into foams. The performance of foams was evaluated by testing for compression in both parallel and perpendicular to rise direction. The tests were carried out at room temperature and at the elevated temperature. The compression properties showed a decreasing trend for increasing amounts of glycerine resin. The density and thermal properties of epoxy foams were also evaluated. The relation between the composition, density and properties of the foam was analyzed.

  2. Toughening mechanism in elastomer-modified epoxy resins, part 2

    Science.gov (United States)

    Yee, A. F.; Pearson, R. A.

    1984-01-01

    The role of matrix ductility on the toughenability and toughening mechanism of elastomer-modified DGEBRA epoxies was investigated. Matrix ductility was varied by using epoxide resins of varying epoxide monomer molecular weights. These epoxide resins were cured using 4,4' diaminodiphenyl sulfone (DDS) and, in some cases, modified with 10% HYCAR(r)CTBN 1300X8. Fracture roughness values for the neat epoxies were found to be almost independent on the monomer molecular weight of the epoxide resin used. However, it was found that the fracture toughness of the elastomer-modified epoxies was very dependent upon the epoxide monomer molecular weight. Tensile dilatometry indicated that the toughening mechanism, when present, is similar to the mechanisms found for the piperidine cured epoxies in Part 1. SEM and OM corroborate this finding. Dynamic mechanical studies were conducted to shed light on the toughenability of the epoxies. The time-dependent small strain behavior of these epoxies were separated into their bulk and shear components. The bulk component is related to brittle fracture, whereas the shear component is related to yielding. It can be shown that the rates of shear and bulk strain energy buildup for a given stress are uniquely determined by the values of Poisson's ratio, nu. It was found that nu increases as the monomer molecular weight of the epoxide resin used increases. This increase in nu can be associated with the low temperature beta relaxation. The effect of increasing cross-link density is to shift the beta relaxation to higher temperatures and to decrease the magnitude of the beta relaxation. Thus, increasing cross-link density decreases nu and increases the tendency towards brittle fracture.

  3. Water diffusion behavior in epoxy resins with various fluorine contents.

    Science.gov (United States)

    Li, Liang; Chen, Yin; Li, Shanjun

    2006-04-01

    In this work, novolac resin with perfluorinated side chains was synthesized and cured with o-Cresol novolac epoxy resin to obtain epoxy resins with various fluorine contents. Attenuated total reflection Fourier transform infrared spectroscopy (ATR/FT-IR) was used to monitor the in situ water diffusion process in these systems. The diffusion coefficient of water first increased and then slightly decreased with increasing fluorine content, which could be attributed to two opposite effects induced by perfluorinated side chains: enhanced hydrophobicity and increased free volume. In addition, generalized two-dimensional (2D) correlation analysis was employed to investigate both the sorption and the desorption process of water diffusion, and two kinds of water molecules, named bound and free water, were found. It was interesting to find that in the sorption process, the change in the population of bound water molecules occurs earlier than the change in the population of free water molecules, while in the desorption process, the sequence was reversed.

  4. Glass Transition Temperature Depression at the Percolation Threshold in Carbon Nanotube-Epoxy Resin and Polypyrrole-Epoxy Resin Composites

    OpenAIRE

    Barrau, Sophie; Demont, Philippe; Maraval, Céline; Bernès, Alain; Lacabanne, Colette

    2005-01-01

    The glass transition temperatures of conducting composites, obtained by blending carbon nanotubes (CNTs) or polypyrrole (PPy) particles with epoxy resin, were investigated by using both differential scanning calorimetry (DSC) and dynamical mechanical thermal analysis (DMTA). For both composites, dc and ac conductivity measurements revealed an electrical percolation threshold at which the glass transition temperature and mechanical modulus of the composites pass through a minimum.

  5. Contact allergy to reactive diluents and related aliphatic epoxy resins.

    Science.gov (United States)

    Aalto-Korte, Kristiina; Kuuliala, Outi; Henriks-Eckerman, Maj-Len; Suuronen, Katri

    2015-06-01

    Diglycidyl ether of bisphenol A resin (DGEBA-R) is the most common sensitizer in epoxy systems, but a minority of patients also develop contact allergy to reactive diluents. To analyse the frequency and clinical relevance of allergic reactions to different epoxy reactive diluents and related aliphatic epoxy resins. Test files (January 1991 to June 2014) were screened, and the clinical records of patients with allergic reactions were analysed for occupation, concomitant allergic reactions, and exposure. A total of 67 patients reacted to at least one of the compounds. The largest numbers of allergic reactions were to phenyl glycidyl ether (PGE; n = 41), 1,4-butanediol diglycidyl ether (BDDGE; n = 34), and p-tert-butylphenyl glycidyl ether (PTBPGE; n = 19). Ten of the patients did not have contact allergy to DGEBA-R. The reactions of 5 of these were related to the use of BDDGE-containing products. We found no significant exposure to PGE or PTBPGE in patients sensitized to them, but some of the patients had used cresyl glycidyl ether-containing products. Allergic reactions to reactive diluents and related aliphatic epoxy resins usually occurred together with reactions to DGEBA-R. BDDGE was the clinically most significant compound, and was the sole cause of occupational allergic contact dermatitis in 3 patients. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Homogeneous Liquid Phase Transfer of Graphene Oxide into Epoxy Resins.

    Science.gov (United States)

    Amirova, Lyaysan; Surnova, Albina; Balkaev, Dinar; Musin, Delus; Amirov, Rustem; Dimiev, Ayrat M

    2017-04-05

    The quality of polymer composite materials depends on the distribution of the filler in the polymer matrix. Due to the presence of the oxygen functional groups, graphene oxide (GO) has a strong affinity to epoxy resins, providing potential opportunity for the uniform distribution of GO sheets in the matrix. Another advantage of GO over its nonoxidized counterpart is its ability to exfoliate to single-atomic-layer sheets in water and in some organic solvents. However, these advantages of GO have not yet been fully realized due to the lack of the methods efficiently introducing GO into the epoxy resin. Here we develop a novel homogeneous liquid phase transfer method that affords uniform distribution, and fully exfoliated condition of GO in the polymer matrix. The most pronounced alteration of properties of the cured composites is registered at the 0.10%-0.15% GO content. Addition of as little as 0.10% GO leads to the increase of the Young's modulus by 48%. Moreover, we demonstrate successful introduction of GO into the epoxy matrix containing an active diluent-modifier; this opens new venues for fabrication of improved GO-epoxy-modifier composites with a broad range of predesigned properties. The experiments done on reproducing the two literature methods, using alternative GO introduction techniques, lead to either decrease or insignificant increase of the Young's modulus of the resulting GO-epoxy composites.

  7. Chemical Interpretation of the Relaxed Permittivity during Epoxy Resin Cure.

    Science.gov (United States)

    1984-11-30

    contributions of other polar groups and their time variation are included. The isothermal cure of a stoichiometric mixture of a DGEBA epoxy resin, EPON 825. with...the DGEBA molecule, and since it contains only a single epoxide. this material does not crosslink. At low temperatures and at all frequencies, the...ratios of DGEBA and DDS gave an epoxy dipole moment of 8.SE-30 C-u and an amine dipole moment of 19.8E-30 C-m [10]. The experimental data and the curves

  8. RHEOLOGICAL MODIFICATION OF EPOXY RESINS WITH NANO SILICA PREPARED BY THE SOL-GEL PROCESS

    Institute of Scientific and Technical Information of China (English)

    Xia Wang; Jiang Li; Cheng-fen Long; Yun-zhao Yu

    1999-01-01

    Nano silica-modified epoxy resins were synthesized by the sol-gel process. The materials have the morphological structure of nano particales dispersed in the epoxy matrix. The dispersed phase formed a physical network in the resin and thus influenced the rheological behavior greatly. However, the nano silica did not show a significant influence on the mechanical properties of the cured resins.

  9. [The cytogenetic activity of some brands of epoxy resins].

    Science.gov (United States)

    Iavorovskiĭ, A P; Bariliak, I R; Paustovskiĭ, Iu A

    1996-01-01

    The studies have allow us to ascertain that some epoxy resins, such as DE-500, DE-1000, DE-2000, UP-650, UP-650T, under gastric administration at the dose levels of 1/10 and 1/50 DL50 (DL50 = 5338 +/- 1134, 6644 +/- 1114, 9180 +/- 1154, 7717 +/- 586, 6980 +/- 621 mg/kg for DE-500, DE-1000, DE-2000, UP-650, UP-650T respectively) and ED-22F under inhalational exposure at 1 mg/m3 as per epichlorhydrine over three to four months, have a striking effect on the chromosomal apparatus of the laboratory animals bone marrow cells, bringing about chromosomal structural aberrations. The cytogenetic activity was found to be dependent upon the dose employed as well as duration of the exposure and chemical structure of the epoxy resins.

  10. Thermal properties of epoxy resins at cryogenic temperatures

    Science.gov (United States)

    Nakane, H.; Nishijima, S.; Fujishiro, H.; Yamaguchi, T.; Yoshizawa, S.; Yamazaki, S.

    2002-05-01

    In order to establish the design technique of epoxy resin at cryogenic temperature, its thermal contraction coefficients and dynamic Young's modulus were measured from room to cryogenic temperatures when plasticizer was both present and absent. The disappearance of the effects of the plasticizer were confirmed by measuring its thermal expansion coefficient. The process in which the addition of plasticizer reduces the glass transition temperature was clarified by measuring its dynamic Young's modulus. It was also discovered that blunt peak is caused by addition of plasticizer. The data obtained by measuring the dynamic Young's modulus clearly indicate that this peak disappears at cryogenic temperature resulting in the disappearance of the effects of the plastizer. The conclusion is that when epoxy resin is to be used at cryogenic temperature it is desirable that the addition of plastizer is kept at the minimum level.

  11. Modified Castor Oil as an Epoxy Resin Curing Agent

    Directory of Open Access Journals (Sweden)

    B. P. Patel

    2004-01-01

    Full Text Available A castor oil, an agricultural product, is an unsaturated material. Hence the castor oil is brominated by bromine liquid. The brominated castor oil (BCO was then reacted with excess of aliphatic diamines viz; ethylene diamine, 1,3-propane diamine and 1,6-hexane diamine. The resultant amino functionalized castor oil (ACO samples were then characterized by elemental analysis, IR spectral study and number of amino groups. All the three ACO samples were then employed for the curing of commercial Brominated epoxy resin. The curing of epoxy resin by ACO was monitored on differential scanning calorimeter (DSC and based on the DSC study their glass fibre reinforced composites (GRC were fabricated. The cured samples (i.e. unreinforced were also subjected to thermo gravimetric analysis (TGA. The chemical, mechanical and electrical properties of the glass fibre reinforced composites (GRC were also evaluated.

  12. Acrylate Copolymers as Impact Modiifer for Epoxy Resin

    Institute of Scientific and Technical Information of China (English)

    WANG Tao; WANG Jun; CHEN Wei; DUAN Huajun; YANG Shuang; CHEN Xi; ZHANG Bin

    2015-01-01

    P(BA-GMA) (PBG), having various molecular weights, was synthesized by in situ polymerization of butyl acrylate (BA) and glycidyl methacrylate (GMA), and further used as a modifier to improve the comprehensive properties of the epoxy curing system. The copolymers were characterized by gel permeation chromatography (GPC). The effects of various molecular weights of copolymers on the mechanical properties, thermal performance, and phase behavior of the curing system were carefully evaluated. The experimental results of differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) showed that glass transition temperature decreased and the tan δ peak shifted to a lower temperature with decreasing molecular weight of copolymer. Mechanical properties analysis of curing films showed that the impact strength and fracture toughness increased significantly upon the addition of PBG, indicating good toughness of the modified epoxy resins. From scanning electron microscopy (SEM) studies of the fracture surfaces of ER/PBG systems, the fracture behavior of epoxy matrix was changed from brittleness to toughness.

  13. On sample preparation and dielectric breakdown in nanostructured epoxy resins

    Energy Technology Data Exchange (ETDEWEB)

    Reading, M; Xu, Z; Lewin, P L; Vaughan, A S, E-mail: asv@ecs.soton.ac.uk [Tony Davies High Voltage Laboratory, University of Southampton (United Kingdom)

    2011-08-12

    There are many methods available to achieve a good dispersion of fillers within a polymeric matrix. This investigation considered several methods of dispersing three chosen fillers within an epoxy resin; the same processes were also performed on unfilled materials to investigate any effects they may have on the host material. For this investigation, the epoxy system (EP) was combined with sodium montmorillonite (MMT), micrometric silicon dioxide (SD) or nanometric silicon dioxide (NSD) as fillers. The effect of the different sample preparation routes on breakdown behaviour was then evaluated. While more thorough mixing protocols were found to lead to improved breakdown behaviour in the case of the various filled systems, surprisingly, an entirely equivalent form of behaviour was also seen in the unfilled epoxy. The influence of changes in sample geometry on the breakdown strength was established.

  14. Formation of a metal/epoxy resin interface

    Energy Technology Data Exchange (ETDEWEB)

    Kanzow, J.; Horn, P. Schulze; Kirschmann, M.; Zaporojtchenko, V.; Dolgner, K.; Faupel, F.; Wehlack, C.; Possart, W

    2005-01-15

    Interfaces between cross-linked polymers and metals play a significant role in fields like splicing and coating, metallization of plastics, microelectronics, micro system technology and nanotechnology. In this paper, we present investigations on the interface formation due to metallization (Au, Ag, Cu and Al) by evapouration of the highly cured epoxy resin system diglycidilether of bisphenol a (DGEBA)-diethylene triamine (DETA) with the focus on the structure formation at the interface. A combination of X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), atomic force microscopy (AFM) and a radiotracer technique was used to analyze the metal/epoxy interface. While a strong metal/epoxy interaction was found for Al, the noble metals Au, Ag and Cu grow in a Volmer-Weber mode due to an interplay of surface diffusion and metal cluster growth. Nevertheless, polymer bulk diffusion of these metals is negligible.

  15. Adhesive Bonding of Aluminium Alloy A5754 by Epoxy Resins

    Directory of Open Access Journals (Sweden)

    Ivan Michalec

    2013-01-01

    Full Text Available Joining thin sheets of aluminium and its alloys is a promising area in the field of joining materials. Nowadays, joining methods that do not melt the material itself are increasingly being utilised. This paper deals with adhesive bonding of aluminium alloy A5754 by two-component epoxy resins. Theresults show that joints bonded by Hysol 9466 have appropriate mechanical properties, but that joints bonded by Hysol 9492 have better thermal stability.

  16. Characterization of fracture toughness of epoxy resin after hygrothermal aging

    KAUST Repository

    Quispe, Gustavo Q.

    2013-07-01

    Characterization of fracture toughness of epoxy resin after hygrothermal ageing Gustavo Quino Quispe The aim of this work is to characterize the e ects of hygrothermal aging in the plain strain fracture toughness of the epoxy system composed by cycloaliphatic epoxy resin and diglycidyl ether of bisphenol-A (DGEBA). For this, after having been under hygrothermal aging in a climatic chamber, epoxy samples were studied using ASTM D5045 fracture toughness test, and micrography and roughness measurements of the fracture surface. It is reported a rapid decrease of GIc and KIc during the rst 2 days. Moreover, a numerical model [13] was used to simulate and see with more detail the water absorption in the aged samples. From that, it was observed the heterogeneous distribution of water. Accordingly, it was proposed that the results should be correlated with the water content at the vicinity of the crack tip. Consequently, it was possible to obtain, by quasi-static simulations, the ideal load-displacement curves of crack propagation in the heterogeneous samples. Finally, another contribution of this work is the study of the fracture surface, that gives a clue of the relationship among the fracture energy, the appearance of microcracks in the fracture surface, and the roughness (Ra).

  17. Immediate and delayed allergy from epoxy resins based on diglycidyl ether of bisphenol A.

    Science.gov (United States)

    Kanerva, L; Jolanki, R; Tupasela, O; Halmepuro, L; Keskinen, H; Estlander, T; Sysilampi, M L

    1991-06-01

    This case report presents two patients with immediate and delayed allergy to epoxy resins based on diglycidyl ether of bisphenol A (DGEBA). In patch testing, the epoxy resin (DGEBA-based) of the standard series gave allergic reactions. Both patients had a prick test reaction of histamine size or larger to the human serum albumin (HSA) conjugate of DGEBA-based epoxy resins. One had been occupationally exposed to methyl tetrahydrophthalic anhydride (MTHPA) and had a histamine-size prick test reaction to the HSA conjugate of MTHPA; the other did not react to the conjugate. Determinations of specific immunoglobulin E were carried out with HSA-DGEBA conjugates, two DGEBA-based epoxy resins, and phthalic anhydrides. The first patient had positive tests to DGEBA, the DGEBA-based epoxy resins, and two phthalic anhydrides, and the second to DGEBA and the DGEBA-based epoxy resins, but not to the phthalic anhydrides.

  18. Modification of epoxy resins with thermoplastic segmented polycarbonate-based polyurethanes

    OpenAIRE

    Pavličević Jelena; Jovičić Mirjana; Simendić Vesna; Bera Oskar; Radičević Radmila; Špírková Milena

    2014-01-01

    In this work, epoxy hybrid materials were synthesized by addition of thermoplastic segmented aliphatic polyurethanes with good elastic properties. The modified epoxy samples were obtained by curing of previously homogenized mixture of prepared polyurethane melts, epoxy resin and crosslinking agent Jeffamine D-2000. The influence of different weight content of polyurethanes (5, 10 and 15 wt. % compared to pure epoxy resin) as well the influence of different ...

  19. Viscoelastic properties of graphene-based epoxy resins

    Science.gov (United States)

    Nobile, Maria Rossella; Fierro, Annalisa; Rosolia, Salvatore; Raimondo, Marialuigia; Lafdi, Khalid; Guadagno, Liberata

    2015-12-01

    In this paper the viscoelastic properties of an epoxy resin filled with graphene-based nanoparticles have been investigated in the liquid state, before curing, by means of a rotational rheometer equipped with a parallel plate geometry. Exfoliated graphite was prepared using traditional acid intercalation followed by a sudden treatment at high temperature (900°C). The percentage of exfoliated graphite was found to be 56%. The epoxy matrix was prepared by mixing a tetrafunctional precursor with a reactive diluent which produces a significant decrease in the viscosity of the epoxy precursor so that the dispersion step of nanofillers in the matrix can easily occur. The hardener agent, the 4,4-diaminodiphenyl sulfone (DDS), was added at a stoichiometric concentration with respect to all the epoxy rings. The inclusion of the partially exfoliated graphite (pEG) in the formulated epoxy mixture significantly modifies the rheological behaviour of the mixture itself. The epoxy mixture, indeed, shows a Newtonian behaviour while, at 3 wt % pEG content, the complex viscosity of the nanocomposite clearly shows a shear thinning behaviour with η* values much higher at the lower frequencies. The increase in complex viscosity with the increasing of the partially exfoliated graphite content was mostly caused by a dramatic increase in the storage modulus. All the graphene-based epoxy mixtures were cured by a two-stage curing cycles: a first isothermal stage was carried out at the lower temperature of 125°C for 1 hour while the second isothermal stage was performed at the higher temperature of 200°C for 3 hours. The mechanical properties of the cured nanocomposites show high values in the storage modulus and glass transition temperature.

  20. Effects of colloidal nanosilica on the rheological properties of epoxy resins filled with organoclay.

    Science.gov (United States)

    Nguyen, Dinh Huong; Song, Gwang Seok; Lee, Dai Soo

    2011-05-01

    The rheological properties of epoxy resins filled with organoclay and colloidal nanosilica were investigated by employing a parallel plate rheometer in flow mode at 25 degrees C. Shear thickening and shear thinning behaviors were observed in the epoxy resins filled with a mixture of organoclay and colloidal nanosilica. Minima were observed in the relaxation time of the systems consisting of epoxy resins filled with organoclay and colloidal silica as the content of colloidal nanosilica was increased. It seems that the colloidal nanosilica increased the mobility of the filled epoxy resins and reduced the interactions between the silicate layers in the systems.

  1. Fracture behavior of silica nanoparticle filled epoxy resin

    Science.gov (United States)

    Dittanet, Peerapan

    This dissertation involves the addition of silica nanoparticles to a lightly crosslinked, model epoxy resin and investigates the effect of nanosilica content and particle size on glass transition temperature (Tg), coefficient of thermal expansion (CTE), Young's modulus (E), yield stress, and fracture toughness. This study aims to understand the influence of silica nanoparticle size, bimodal particle size distribution and silica content on the toughening behavior. The toughening mechanisms were determined using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and transmission optical microscopy (TOM). The approach identifies toughening mechanisms and develops a toughening model from unimodal-particle size systems first, then extends these concepts to various mixtures micron- and nanometer-size particles in a similar model epoxy. The experimental results revealed that the addition of nanosilica did not have a significant effect on Tg or the yield stress of epoxy resin, i.e. the yield stress and Tg remained constant regardless of nanosilica particle size. As expected, the addition of nanosilica had a significant impact on CTE, modulus and fracture toughness. The CTE values of nanosilica-filled epoxies were found to decrease with increasing nanosilica content, which can be attributed to the much lower CTE of the nanosilica fillers. Interestingly, the decreases in CTE showed strong particle size dependence. The Young's modulus was also found to significantly improve with addition of nanosilica and increase with increasing filler content. However, the particle size did not exhibit any effect on the Young's modulus. Finally, the fracture toughness and fracture energy showed significant improvements with the addition of nanosilica, and increased with increasing filler content. The effect of particle size on fracture toughness was negligible. Observation of the fracture surfaces using SEM and TOM showed evidence of debonding of nanosilica particles

  2. Glass Reinforcement of Various Epoxy Resins-Polyurea Systems

    Science.gov (United States)

    Joshi, Medha; Jauhari, Smita

    2012-07-01

    Polyureas (PUs) were prepared by the polycondensation reaction of disperse dyes containing -NH2 group and toluene 2, 4-diisocyanate. The disperse dyes have been prepared by coupling of various 2-diazobenzothiazoles with 1,3-benzenediamine. All the PUs were characterized by elemental analysis, spectral studies, number average molecular weight ( {overline{{Mn}} } ), and thermogravimetry. Further reaction of PUs was carried out with an epoxy resin (i.e., DGEBA). The curing study of prepared resins was monitored by differential scanning calorimeter (DSC). Based on DSC, thermograms glass fiber-reinforced composites have been laminated and characterized by chemical, mechanical, and electrical properties. The unreinforced cured resins were subjected to thermogravimetric analysis (TGA). The laminated composites showed excellent resistance properties against chemicals and good mechanical and electrical properties.

  3. MODIFICATION OF EPOXY RESIN WITH POLYSILOXANE BEARING PENDANT QUATERNARY AMMONIUM GROUPS

    Institute of Scientific and Technical Information of China (English)

    Zuo-xin Huang; Ying Huang; Yun-zhao Yu

    2002-01-01

    Polysiloxane bearing pendant quatemary ammonium groups (PSI) was used to modify the surface properties ofepoxy resins. In the cured resin, PSI formed the dispersed phase. Remarkable enrichment and gradient distribution ofpolysiloxane on the surface region of the epoxy resins were demonstrated by XPS analysis. The composition and propertiesof the surface of PSI-modified epoxy resin, which is in contact with the mold, are dependent on the material of the mold.Through the incorporation of PSI, epoxy resins with low surface energy and low friction coefficient were obtained.Polysiloxane with lower ionic group content shows a higher degree of enrichment on the resin surface and leads to a highercontact angle against water, while the polysiloxane having optimum compatibility with the epoxy resin shows a greater effectin reducing the static friction coefficient of the resin against glass.

  4. Novel Epoxy Resin/SiO2 Nanocomposites Preparation Method Based on Diminutive Bubbles Explosion

    Institute of Scientific and Technical Information of China (English)

    NIE Peng; ZHAO Xue-zeng; CHEN Fang; WANG Wei-jie; BAI Yong-ping

    2006-01-01

    To obtain suspended dispersion of nano-particles in liquid without any dispersant, a novel epoxy resin/SiO2 nanocomposites preparation method based on diminutive bubbles explosion is presented. And, corresponding nanocomposites preparation system was designed. The preparation system applies compressed gas as transmission medium to carry nanomaterials into epoxy resin solution. The compressed gas with nanomaterials turns into diminutive bubbles distributing in epoxy resin/SiO2. The great pressure difference between inner and outer-bubbles led to bubbles inflation and explosion. During the bubble inflation, bubble oscillation may generate. The stretching rate may reach 106 s-1, which favors more homogeneous dispersion of nanoparticles. During the bubbles explosion the released energy and the explosion shock waves disperse the nanoparticles into epoxy resin solution. By using the preparation system, epoxy resin/SiO2 nanocomposites were prepared. The SiO2 dispersed into epoxy as the configuration of 15 nm - 30 nm particles.

  5. The characteristics of epoxy resin cured by {gamma}-ray and E-beam

    Energy Technology Data Exchange (ETDEWEB)

    Nho, Y.C. E-mail: ycnho@kaeri.re.kr; Kang, Phil Hyun; Park, Jong Seok

    2004-10-01

    Epoxy resins are widely used as high-performance thermosetting resins for many industrial applications. In this study, the effect of an electron beam (E-beam) and {gamma}-ray irradiation on the curing of epoxy resins was investigated. Diglycidyl ether of bisphenol-A(DGEBA), diglycidyl ether of bisphenol-F(DGEBF) as epoxy resins, triarylsulfonium hexafluoroantimonate(TASHFA), and triarylsulfonium hexafluorophosphate(TASHFP) as initiators were used in this study. The chemical and mechanical characteristics of irradiated epoxy resins were compared after curing of E-beam and {gamma}-ray irradiation up to 50 kGy in N{sub 2} and air atmosphere. We ascertained the effect of oxygen on the radiation curing of epoxy resin. The thermal properties of cured epoxy were investigated using DMA and TGA. Mechanical properties such as flexural strength were measured. The chemical structures of cured epoxy were characterized by FT-NIR. The gel fraction and the stress at yield of epoxy resins irradiated by E-beam and {gamma}-ray in N{sub 2} atmosphere were also compared with those of epoxy resins irradiated by E-beam and {gamma}-ray in air.

  6. Cross‐Sectional Study of Respiratory Symptoms, Spirometry, and Immunologic Sensitivity in Epoxy Resin Workers

    Science.gov (United States)

    Barker, Elizabeth A.; Robinson, Maura; Knight, Vijaya; Gaitens, Joanna; Sills, Michael; Duvall, Kirby; Rose, Cecile S.

    2015-01-01

    Abstract Objectives An epoxy resin worker developed hypersensitivity pneumonitis requiring lung transplantation and had an abnormal blood lymphocyte proliferation test (LPT) to an epoxy hardener. We assessed the prevalence of symptoms, abnormal spirometry, and abnormal epoxy resin LPT results in epoxy resin workers compared to unexposed workers. Methods Participants completed questionnaires and underwent spirometry. We collected blood for epoxy resin LPT and calculated stimulation indices for five epoxy resin products. Results We compared 38 exposed to 32 unexposed workers. Higher exposed workers were more likely to report cough (OR 10.86, [1.23‐infinity], p = 0.030) or wheeze (OR 4.44, [1.00‐22.25], p = 0.049) than unexposed workers, even controlling for smoking. Higher exposed workers were more likely to have abnormal FEV1 than unexposed workers (OR 10.51, [0.86‐589.9], p = 0.071), although not statistically significant when adjusted for smoking. There were no differences in proportion of abnormal epoxy resin system LPTs between exposed and unexposed workers. Conclusions In summary, workers exposed to epoxy resin system chemicals were more likely to report respiratory symptoms and have abnormal FEV1 than unexposed workers. Use of epoxy resin LPT was not helpful as a biomarker of exposure and sensitization. PMID:26553118

  7. THE THERMAL AND ABLATIVE DEGRADATION OF SOME EPOXY RESINS CURED WITH METHYL BICYCLO(2.2.1)HEPTENE-2,3-DICARBOXYLIC ANHYDRIDE (NMA).

    Science.gov (United States)

    ABLATION), (* EPOXY RESINS , (*PYROLYSIS, EPOXY RESINS ), CYCLOALKENES, ANHYDRIDES, CATALYSTS, ADDITIVES, CROSSLINKING(CHEMISTRY), REACTION KINETICS, DEGRADATION, AGING(MATERIALS), INFRARED SPECTRA, CHROMATOGRAPHIC ANALYSIS.

  8. Impact properties of rubber-modified epoxy resin-graphite-fiber composites

    Science.gov (United States)

    Gilwee, W. J.; Nir, Z.

    1984-01-01

    To improve the impact resistance of graphite-fiber composites, a commercial and an experimental epoxy resin were modified with liquid reactive rubber and a brominated epoxy resin. The commercial epoxy was a tetrafunctional resin, and the experimental epoxy was a trifunctional resin. The reactive rubber was a carboxyl-terminated butadiene-acrylonitrile copolymer. The rubber content was varied from 0 to 25 percent (wt). The brominated epoxy resin was used at Br levels of 4, 19, and 35 percent of the resin. Composites were prepared with woven graphite cloth reinforcement. The composites were evaluated by using flexural strength in the dry state and an elevated temperature after saturation with water. The impact properties were determined by measuring shear strength after falling-ball impact and instrumented impact. The rubber-modified, trifunctional resin exhibited better properties, when tested in hot-wet conditions in a heated oven at 366 K (after boiling the material for 2 h in demineralized water), than the tetrafunctional resin. Improved impact resistance was observed with the addition of the reactive rubber to the epoxy resin. Further improvement was observed with the addition of the brominated epoxy resin.

  9. Formulation and Characterization of Epoxy Resin Copolymer for Graphite Composites

    Science.gov (United States)

    Keck, F. L.

    1983-01-01

    Maximum char yield was obtained with a copolymer containing 25% mol fraction DGEBE and 75% mol fraction DGEBA (Epon 828). To achieve the high values (above 40%), a large quantity of catalyst (trimethoxyboroxine) was necessary. Although a graphite laminate 1/8" thick was successfully fabricated, the limited life of the catalyzed epoxy copolymer system precludes commercial application. Char yields of 45% can be achieved with phenolic cured epoxy systems as indicated by data generated under NAS2-10207 contract. A graphite laminate using this type of resin system was fabricated for comparison purposes. The resultant laminate was easier to process and because the graphite prepreg is more stable, the fabrication process could readily be adapted to commercial applications.

  10. Development of Polymer Network of Phenolic and Epoxies Resins Mixed with Linseed Oil: Pilot Study

    Science.gov (United States)

    Ku, H.; Cardona, F.; Rogers, D.; Munoz, J.-C.

    2010-08-01

    Epoxy resin was mixed with phenolic resins in different percentages by weight. Composite 40/60 means the proportion by weight of epoxy resin is 40%. It was found that only composites 50/50 and 40/60 could be cured in ambient conditions. Dynamic mechanical analysis showed that only these two composites form interpenetrating polymer network. The addition of linseed oil to the two resins results also in the formation of interpenetrating network irrespective of proportion by weight of the resins; the mechanical properties will only be better when the percentage by weight of epoxy resin is higher; the aim of reducing cost and at the same time maintaining the mechanical properties cannot be fully achieved because epoxy resin is much more expensive than its counterpart.

  11. Two cases of occupational allergic contact dermatitis from a cycloaliphatic epoxy resin in a neat oil

    DEFF Research Database (Denmark)

    Jensen, Charlotte D; Andersen, Klaus E

    2003-01-01

    to a neat oil used in metal processing. Patch testing revealed that the relevant contact allergen was a cycloaliphatic epoxy resin, 1,2-cyclohexanedicarboxylic acid, bis(oxiranylmethyl) ester, added to the oil as a stabilizer. None of the patients had positive reactions to the bisphenol A-based epoxy resin...

  12. A novel epoxy methacrylate resin containing phthalazinone moiety for UV coatings

    Institute of Scientific and Technical Information of China (English)

    Yan Kou; Jin Yan Wang; Xi Gao Jian

    2007-01-01

    A novel phthalazinone modified epoxy acrylate resin for the high temperature resistant ultravioet (UV) curable coating was synthesized. The methacrylated epoxy resins obtained were utilized to UV radiation curing by taking 2.5% (wt%) of photoinitiator in combination with 20% (wt%) of diluent, and generated the interpenetraring polymer networks. The cured film had good thermal and chemical stability.

  13. Association between positive patch tests to epoxy resin and fragrance mix I ingredients

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Christensen, Lars Porskjaer; Vølund, Aage

    2009-01-01

    BACKGROUND: Both epoxy resin (diglycidyl ether of bisphenol A) and fragrance mix I are included in the European baseline series of contact allergens. A significant association between positive reactions to epoxy resin and fragrance mix has been reported by others. OBJECTIVE: To investigate and po...

  14. High energy electron beam curing of epoxy resin systems incorporating cationic photoinitiators

    Science.gov (United States)

    Janke, Christopher J.; Lopata, Vincent J.; Havens, Stephen J.; Dorsey, George F.; Moulton, Richard J.

    1999-01-01

    A mixture of epoxy resins such as a semi-solid triglycidyl ether of tris (hydroxyphenyl) methane and a low viscosity bisphenol A glycidyl ether and a cationic photoinitiator such as a diaryliodonium salt is cured by irradiating with a dosage of electron beams from about 50 to about 150 kGy, forming a cross-linked epoxy resin polymer.

  15. Two cases of occupational allergic contact dermatitis from a cycloaliphatic epoxy resin in a neat oil

    DEFF Research Database (Denmark)

    Jensen, Charlotte D; Andersen, Klaus E

    2003-01-01

    to a neat oil used in metal processing. Patch testing revealed that the relevant contact allergen was a cycloaliphatic epoxy resin, 1,2-cyclohexanedicarboxylic acid, bis(oxiranylmethyl) ester, added to the oil as a stabilizer. None of the patients had positive reactions to the bisphenol A-based epoxy resin...... product is essential....

  16. Fatigue Crack Propagation Behavior of Rubber-toughened Epoxy Resin

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Fatigue crack propagation (FCP) behaviors of mass fraction 15% CTBN (carboxyl-terminated butadiene-acrylonitrile), 15% Qishi toughening-agent toughened anhydride-cured epoxy resins (EP), and pure anhydride-cured EP were measured. The results showed that the two main toughening mechanisms, localized shear yielding and void plastics growth, which occurred near the threshold region because the rubber size is much less than the plastics size at the crack front, improved the near threshold FCP behavior and increased the threshold. The stable FCP behavior was obviously improved with the FCP rates decreased to less than 21%.

  17. Epoxy Resin Based Composites, Mechanical and Tribological Properties: A Review

    Directory of Open Access Journals (Sweden)

    S.A. Bello

    2015-12-01

    Full Text Available High fuel consumption by automobile and aerospace vehicles built from legacy alloys has been a great challenge to global design and material engineers. This has called for researches into material development for the production of lighter materials of the same or even superior mechanical properties to the existing materials in this area of applications. This forms a part of efforts to achieve the global vision 2025 i.e to reduce the fuel consumption by automobile and aerospace vehicles by at least 75 %. Many researchers have identified advanced composites as suitable materials in this regard. Among the common matrices used for the development of advanced composites, epoxy resin has attained a dominance among its counterparts because of its excellent properties including chemical, thermal and electrical resistance properties, mechanical properties and dimensional stability. This review is a reflection of the extensive study on the currently ongoing research aimed at development of epoxy resin hybrid nanocomposites for engineering applications. In this paper, brief explanation has been given to different terms related to the research work and also, some previous works (in accordance with materials within authors’ reach in the area of the ongoing research have been reported.

  18. Toughening mechanism in elastometer-modified epoxy resins: Part 1

    Science.gov (United States)

    Yee, A. F.; Pearson, R. A.

    1983-01-01

    Several plaques of Epon 828, cured with piperidine, modified with hycar(r) CTBN 1300X8, Hycar(R) CTBN 1300X13, and Hycar(R) CTBN 1300x15, and in some cases modified with biphenol A (BPA), yielded properly toughened epoxies with rubber particle diameters ranging from 0.1 to 10 microns. Fracture toughness experiments indicate that toughness was more a function of rubber content than the rubber particle size. Tensile volumetric behavior of the near resin exhibits two regions: an initial region where the increase in volume strain was due to the Poisson's effect, and a second region where a slower rate of increase in volume strain was due to shear deformation. Tensile volumetric deformation of an elastomer-modified epoxy exhibits the same type of behavior to that of the neat resin at low rates ( 3.2x0.01 sec(-1)). But at very high strain rates, which correspond more closely to the strain rates at the crack tip, there exists an increase in volume strain beyond the Poisson's effect. TEM, SEM and OM studies indicate that the rubber particles had voided. When a thin section from the deformed region is viewed under crossed-polarized light, shear bands are seen connecting voided rubber particles. From this information cavitation and enhanced shear band formation is proposed as the toughening mechanism.

  19. Cure kinetics of epoxy matrix resin by differential scanning calorimetry

    Science.gov (United States)

    Cizmecioglu, M.; Gupta, A.

    1982-01-01

    A study was made on the cure kinetics of an epoxy neat-resin (Narmco 5208) using Differential Scanning Calorimetry (DSC). Two interrelated analytical methods were applied to dynamic DSC data for evaluating the kinetic parameters, such as activation energy, E, the order of reaction, n, and the total heat of polymerization (or crosslinking), delta H sub t. The first method was proposed by Ellerstein (1968), and uses a thorough differential-integral analysis of a single DSC curve to evaluate the kinetic parameters. The second method was proposed by Kissinger (1957), and uses multiple DSC curves obtained at various heating rates to evaluate E regardless of n. Kinetic analysis of Narmco 5208 epoxy resin showed that the reaction order, n, is substantially affected by the rate of heating; i.e., n is approximately 2 at slow scan rates but is reduced to 1.5 at higher scan rates. The activation energy, E, is not affected by the scan rate, and the average value of E is 25.6 + or - 1.8 kcal/mole.

  20. Cure kinetics of epoxy matrix resin by differential scanning calorimetry

    Science.gov (United States)

    Cizmecioglu, M.; Gupta, A.

    1982-01-01

    A study was made on the cure kinetics of an epoxy neat-resin (Narmco 5208) using Differential Scanning Calorimetry (DSC). Two interrelated analytical methods were applied to dynamic DSC data for evaluating the kinetic parameters, such as activation energy, E, the order of reaction, n, and the total heat of polymerization (or crosslinking), delta H sub t. The first method was proposed by Ellerstein (1968), and uses a thorough differential-integral analysis of a single DSC curve to evaluate the kinetic parameters. The second method was proposed by Kissinger (1957), and uses multiple DSC curves obtained at various heating rates to evaluate E regardless of n. Kinetic analysis of Narmco 5208 epoxy resin showed that the reaction order, n, is substantially affected by the rate of heating; i.e., n is approximately 2 at slow scan rates but is reduced to 1.5 at higher scan rates. The activation energy, E, is not affected by the scan rate, and the average value of E is 25.6 + or - 1.8 kcal/mole.

  1. Characterization of epoxy resin containing nano clay prepared by electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jong Seok; Lee, Seung Jun; Lim, Youn Mook; Jeong, Sung In; Gwon, Hui Jeong; Shin, Young Min; Kang, Phil Hyun; Nho, Young Chan [Research Division for Industry AND Environment, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2015-02-15

    Epoxy resin is widely used as aerospace, automobile, construction and electronics due to their good mechanical and electrical properties and environmental advantages. However, the inherent flammability of epoxy resin has limited its application in some field where good flame retardancy is required. Nano clay can enhance the properties of polymers such as flames retardancy and thermal stability. In this study, we have investigated the nanoclay filled epoxy composite, which has good flame retardancy while maintaining high mechanical properties. The cured epoxy resins were obtained using an electron beam curing process. The nano clays were dispersed in epoxy acrylate solution and mechanically stirred. The prepared mixtures were irradiated using an electron beam accelerator. The composites were characterized by gel content and thermal/ mechanical properties. Moreover, the flammability of the composite was evaluated by limited oxygen index (LOI). The flame retardancy of nano clay filled epoxy composite was evidently improved.

  2. Surface modification of titanium hydride with epoxy resin via microwave-assisted ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Ning, Rong [College of Materials Science and Engineering, Hunan University, Changsha 410082 (China); Chen, Ding, E-mail: ma97chen@hotmail.com [College of Materials Science and Engineering, Hunan University, Changsha 410082 (China); Zhang, Qianxia [College of Materials Science and Engineering, Hunan University, Changsha 410082 (China); Bian, Zhibing; Dai, Haixiong; Zhang, Chi [Jiangsu Jinling Special Paint Co., Ltd., Yangzhou 225212 (China)

    2014-10-15

    Highlights: • TiH{sub 2} was modified with epoxy resin by microwave-assisted ball milling. • The epoxy ring was opened under the coupling effect of microwave and ball milling. • Microwave-assisted ball milling improved the compatibility of TiH{sub 2} with epoxy. - Abstract: Surface modification of titanium hydride with epoxy resin was carried out via microwave-assisted ball milling and the products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), thermo-gravimetry (TG) and Fourier transform infrared spectroscopy (FT-IR). A sedimentation test was performed to investigate the compatibility of the modified nano titanium hydride with the epoxy resin. The results show that the epoxy resin molecules were grafted on the surface of nano titanium hydride particles during the microwave-assisted ball milling process, which led to the improvement of compatibility between the nanoparticles and epoxy resin. According to the FT-IR, the grafting site was likely to be located around the epoxy group due to the fact that the epoxy ring was opened. However, compared with microwave-assisted ball milling, the conventional ball milling could not realize the surface modification, indicating that the coupling effect of mechanical force and microwave played a key role during the process.

  3. Adhesion at the interface in cured graphite fiber epoxy-amine resin composites

    Science.gov (United States)

    Needles, Howard L.; Alger, Kenneth W.; Okamoto, Robert

    1987-01-01

    The effect of high temperature curing on the interface between unsized or epoxy-sized graphite fiber tow and epoxy-amine resin was examined by scanning electron microscopy of compression and freeze fractured specimens. Little or no adhesion was found between the unsized graphite fiber tows and the epoxy-amine resin on curing at 165 C for 17 hrs. Epoxy-sized graphite fibers showed a similar lack of adhesion between the fiber tows and the epoxy-amine resin at 3 and 17 hr cures, although good penetration of the resin into the sized fiber tows had occurred. Interfacial bond strengths for the composites could not be effectively measured by compression fracture of specimens.

  4. Synthesis and Thermal Properties of a Novel Nitrogen-containing Epoxy Resin

    Institute of Scientific and Technical Information of China (English)

    Xing Hong ZHANG; Hong Mei WAN; Yu Qin MIN; Zuo FANG; Guo Rong QI

    2005-01-01

    A new nitrogen-containing epoxy resin (XT resin) was synthesized from chain extension of xylenephenolformaldehyde resin (XPF) and triglycidyl isocyanurate (TGIC) in the presence of base catalyst. FT-IR and 1H-NMR analysis confirmed the chemical structure of XT resin. It was cured with dicyandiamide (DICY) and diaminodiphenyl sulfone (DDS). Dynamic mechanical analysis (DMA) results showed that the introduction of triazine ring provides epoxy polymer with good thermal stability. Furthermore, high char yields at 800℃ in thermogravimetric (TGA)analysis indicated that XT resin had potential flame retardance.

  5. Electron Beam Cured Epoxy Resin Composites for High Temperature Applications

    Science.gov (United States)

    Janke, Christopher J.; Dorsey, George F.; Havens, Stephen J.; Lopata, Vincent J.; Meador, Michael A.

    1997-01-01

    Electron beam curing of Polymer Matrix Composites (PMC's) is a nonthermal, nonautoclave curing process that has been demonstrated to be a cost effective and advantageous alternative to conventional thermal curing. Advantages of electron beam curing include: reduced manufacturing costs; significantly reduced curing times; improvements in part quality and performance; reduced environmental and health concerns; and improvement in material handling. In 1994 a Cooperative Research and Development Agreement (CRADA), sponsored by the Department of Energy Defense Programs and 10 industrial partners, was established to advance the electron beam curing of PMC technology. Over the last several years a significant amount of effort within the CRADA has been devoted to the development and optimization of resin systems and PMCs that match the performance of thermal cured composites. This highly successful materials development effort has resulted in a board family of high performance, electron beam curable cationic epoxy resin systems possessing a wide range of excellent processing and property profiles. Hundreds of resin systems, both toughened and untoughened, offering unlimited formulation and processing flexibility have been developed and evaluated in the CRADA program.

  6. Screening occupational contact allergy to bisphenol F epoxy resin.

    Science.gov (United States)

    Aalto-Korte, Kristiina; Suuronen, Katri; Kuuliala, Outi; Henriks-Eckerman, Maj-Len; Jolanki, Riitta

    2014-09-01

    Epoxy resins based on diglycidyl ether of bisphenol F (DGEBF) are widely used as such in applications requiring chemical resistance, and also together with diglycidyl ether of bisphenol A resin (DGEBA-R). Concomitant patch test reactions to DGEBA-R and DGEBF resin (DGEBF-R) are common. Previous studies have yielded conflicting results on the frequency of independent DGEBF-R contact allergies. To report the results of over 11 years of screening with DGEBF-R. An in-house test substance of DGEBF-R (Epikote 862) was tested in the baseline patch test series, first at 1% and later at 0.25%. Test files were screened for allergic reactions to DGEBF-R and DGEBA-R, and the clinical records of positively reacting patients were analysed for occupation and exposure. Among 1972 patients, 66 (3.3%) reacted to DGEBF-R and 96 (4.9%) to DGEBA-R. Independent DGEBF-R allergies were seen in 5 patients only, and independent DGEBA-R allergies in 35. Specific exposure to DGEBF-R was found in 26 patients. The main occupational fields were the aircraft industry, the electrical and sports equipment industry, boat building, painting/floor coating, tile setting, and pipe relining. Independent contact allergies to DGEBF-R were rare, and screening with it was not found to be useful. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Modification of Urushiol Derivatives by Liquid Crystal Epoxy Resin

    Directory of Open Access Journals (Sweden)

    Gongwen Tang

    2015-01-01

    Full Text Available Urushiol derivatives have vast potentials for using as coating materials. However, the cured coatings are quite brittle, limiting their applications. In this study, urushiol-furfural (UFUR was chosen as an example of urushiol derivatives and a liquid crystal (LC epoxy resin, tetramethylbiphenyl diglycidyl ether (TMBPDE, was for the first time utilized to modify UFUR. Fourier transform infrared spectroscopy and solid-state 13C nuclear magnetic resonance showed the reactions between TMBPDE and UFUR after the UFUR/TMBPDE composite resin was cured. Differential scanning calorimetry analysis showed that the Tg significantly increased after the addition of TMBPDE. Thermogravimetry analysis indicated that the cured UFUR/TMBPDE composite resin exhibited increasing thermodecomposition temperature as the TMBPDE concentration increased, indicating its great potential for high temperature applications. Moreover, the presence of TMBPDE enhanced the toughness of UFUR as observed by impact test and reflected in the morphologies observed from SEM images of fracture surfaces. It would also be novel and effective to modify urushiol derivatives by the LC polymer.

  8. Non-occupational contact sensitization to epoxy resin of bisphenol A among general dermatology patients.

    Science.gov (United States)

    Majasuo, Susanna; Liippo, Jussi; Lammintausta, Kaija

    2012-03-01

    Sensitization to epoxy resins often results from occupational exposure in various fields of construction and industry. Non-occupational sensitization sources and environments have remained overlooked. To analyse non-occupational and occupational contact sensitization to epoxy resin of bisphenol A among general dermatology patients. Special attention was paid to patients sensitized from non-occupational sources. During a 10-year period, 6042 general dermatology patients were patch tested with epoxy resin (bisphenol A) in the Dermatology Clinic of Turku University Hospital. The clinical data and the sources of occupational and non-occupational exposure to epoxy resin were analysed in sensitized patients. Epoxy resin sensitization was found in 59 patients. Non-occupational sensitization was found in 21 (35%) patients, whereas the number of occupational cases was 38 (65%). The most common sources of non-occupational epoxy resin sensitization were materials used in domestic renovation and construction projects and in boat repair. Non-occupational sensitization sources account for approximately one-third of epoxy resin sensitization cases, and therefore represent an important risk among hobbies and leisure activities. © 2011 John Wiley & Sons A/S.

  9. Synthesis and Characterization of Modified Epoxy Resins by Silicic Acid Tetraethyl Ester and Nano-SiO2

    Institute of Scientific and Technical Information of China (English)

    李海燕; 张之圣

    2004-01-01

    A kind of modified epoxy resins was obtained by condensation of epoxy resin with silicic acid tetraethyl ester(TEOS) and nano-SiO2. The reactions were performed with hydrochloric acid as a catalyst at 63 °C.The structure, thermal stability and morphological characteristics of the modified epoxy resins were studied through infrared spectra(FT-IR) analysis, thermogravimetric (TG) analysis and scanning electron microscopy respectively. It has been found from the IR and TG study that modified epoxy resins have greater thermal stability than epoxy resins, and its thermal stability has been improved by the formation of inter-crosslinked network structure. The modified epoxy resins exhibit heterogeneous morphology and heterogeneity increases with more TEOS feeding, which in turn confirms the formation of inter-crosslinked network structure in modified epoxy resins.

  10. The Electrical Properties for Phenolic Isocyanate-Modified Bisphenol-Based Epoxy Resins Comprising Benzoate Group.

    Science.gov (United States)

    Lee, Eun Yong; Chae, Il Seok; Park, Dongkyung; Suh, Hongsuk; Kang, Sang Wook

    2016-03-01

    Epoxy resin has been required to have a low dielectric constant (D(k)), low dissipation factor (Df), low coefficient of thermal expansion (CTE), low water absorption, high mechanical, and high adhesion properties for various applications. A series of novel phenolic isocyanate-modified bisphenol-based epoxy resins comprising benzoate group were prepared for practical electronic packaging applications. The developed epoxy resins showed highly reduced dielectric constants (D(k)-3.00 at 1 GHz) and low dissipation values (Df-0.014 at 1 GHz) as well as enhanced thermal properties.

  11. Preparation and Property Study of Graphene Oxide Reinforced Epoxy Resin Insulation Nanocomposites with High Heat Conductivity

    Science.gov (United States)

    Shan, Xinran; Liu, Yongchang; Wu, Zhixiong; Liu, Huiming; Zhang, Zhong; Huang, Rongjin; Huang, Chuanjun; Liu, Zheng; Li, Laifeng

    2017-02-01

    In this paper, graphene oxide reinforced epoxy resin nanocomposites were successfully prepared. Compared with unmodified epoxy resin, the heat conductivity of the graphene oxide reinforced epoxy resin nanocomposites had been improved while keeping the insulation performance. The tensile strength was investigated at both room temperature (300 K) and liquid nitrogen temperature (77 K). And the fracture surfaces were examined by scanning electron microscopy (SEM). Results showed that the materials had excellent mechanical properties, which could be advantages for the applications as insulating layer in low temperature superconducting magnets.

  12. Neutron shielding material based on colemanite and epoxy resin.

    Science.gov (United States)

    Okuno, Koichi

    2005-01-01

    In recent years, there has been a need for compact shielding design such as self-shielding of a PET cyclotron or upgradation of radiation machinery in existing facilities. In these cases, high performance shielding materials are needed. Concrete or polyethylene have been used for a neutron shield. However, for compact shielding, they fall short in terms of performance or durability. Therefore, a new type of neutron shielding material based on epoxy resin and colemanite has been developed. Slab attenuation experiments up to 40 cm for the new shielding material were carried out using a 252Cf neutron source. Measurement was carried out using a REM-counter, and compared with calculation. The results show that the shielding performance is better than concrete and polyethylene mixed with 10 wt% boron oxide. From the result, we confirmed that the performance of the new material is suitable for practical use.

  13. Epoxy Resin Composite Based on Functional Hybrid Fillers

    Directory of Open Access Journals (Sweden)

    Mariusz Oleksy

    2014-08-01

    Full Text Available A study was carried out involving the filling of epoxy resin (EP with bentonites and silica modified with polyhedral oligomeric silsesquioxane (POSS. The method of homogenization and the type of filler affect the functional and canceling properties of the composites was determined. The filler content ranged from 1.5% to 4.5% by mass. The basic mechanical properties of the hybrid composites were found to improve, and, in particular, there was an increase in tensile strength by 44%, and in Charpy impact strength by 93%. The developed hybrid composites had characteristics typical of polymer nanocomposites modified by clays, with a fine plate morphology of brittle fractures observed by SEM, absence of a plate separation peak in Wide Angles X-ray Scattering (WAXS curves, and an exfoliated structure observed by TEM.

  14. Epoxy Resin Composite Based on Functional Hybrid Fillers

    Science.gov (United States)

    Oleksy, Mariusz; Szwarc-Rzepka, Karolina; Heneczkowski, Maciej; Oliwa, Rafał; Jesionowski, Teofil

    2014-01-01

    A study was carried out involving the filling of epoxy resin (EP) with bentonites and silica modified with polyhedral oligomeric silsesquioxane (POSS). The method of homogenization and the type of filler affect the functional and canceling properties of the composites was determined. The filler content ranged from 1.5% to 4.5% by mass. The basic mechanical properties of the hybrid composites were found to improve, and, in particular, there was an increase in tensile strength by 44%, and in Charpy impact strength by 93%. The developed hybrid composites had characteristics typical of polymer nanocomposites modified by clays, with a fine plate morphology of brittle fractures observed by SEM, absence of a plate separation peak in Wide Angles X-ray Scattering (WAXS) curves, and an exfoliated structure observed by TEM. PMID:28788177

  15. Cure monitoring of epoxy resin by using fiber bragg grating sensor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jin Hyuk [KEPCO, Naju (Korea, Republic of); Kim, Dae Hyun [Dept. of Mechanical and Automotive Engineering, Seoul National University of Science and Technology, Seoul (Korea, Republic of)

    2016-06-15

    In several industrial fields, epoxy resin is widely used as an adhesive for co-curing and manufacturing various structures. Controlling the manufacturing process is required for ensuring robust bonding performance and the stability of the structures. A fiber optic sensor is suitable for the cure monitoring of epoxy resin owing to the thready shape of the sensor. In this paper, a fiber Bragg grating (FBG) sensor was applied for the cure monitoring of epoxy resin. Based on the experimental results, it was demonstrated that the FBG sensor can monitor the status of epoxy resin curing by measuring the strain caused by volume shrinkage and considering the compensation of temperature. In addition, two types of epoxy resin were used for the cure-monitoring; moreover, when compared to each other, it was found that the two types of epoxy had different cure-processes in terms of the change of strain during the curing. Therefore, the study proved that the FBG sensor is very profitable for the cure-monitoring of epoxy resin.

  16. Synthesis and Characterization of Hybrid CF/MWCNTS/Epoxy Resin Composite System

    Science.gov (United States)

    Fouda, Hany; Guo, Lin; Yue, Yonghai; Chen, Ke; Elsharkawy, Karim

    2017-07-01

    In the present investigation, two methods were used for addition multiwall carbon nanotubes (MWCNTS) into carbon fiber (CF)/epoxy resin composite system. The mechanical properties of the prepared samples were compared to show the best method for addition of MWCNTS from point of view of mechanical properties. The introduction of carbon nanotubes (CNTs) into fiber reinforced polymer composites has been achieved mainly via two routes: mixing CNTs entirely throughout the matrix (matrix modification) or attaching CNTs onto reinforcing fibers (interface modification). In all previous references the addition of CNTs occur through one route from the two routes but in this research, we introduced MWCNTS into CF/epoxy resin composite through the two routes at the same time. Three CF composite samples were prepared CF/epoxy resin composite (C1), CF/1wt% MWCNTS /epoxy resin composite (C2) in which MWCNTS added via one route (epoxy resin system) and the third sample was CF/1wt% MWCNTS / epoxy resin composite (C3) in which MWCNTS added via two routes (epoxy resin and CF fabric). The result shows that the mechanical properties of C3>C2>C1, for example, the flexural strength of C3 higher than C2 by 19% and C2 higher than C1 by 51% respectively. This is because addition MWCNTS via two routes increase the ability of good mixing of CNTS with epoxy resin and good dispersion of CNTs into the CF fabric surface and this leads to improve the interface bonding between the CF and epoxy so improve the mechanical properties.

  17. Transient and steady-state currents in epoxy resin

    Energy Technology Data Exchange (ETDEWEB)

    Guillermin, Christophe [Schneider Electric Industries S.A.S., 37 quai Paul-Louis Merlin, 38050 Grenoble Cedex 9 (France); Rain, Pascal [Laboratoire d' Electrostatique et de Materiaux Dielectriques (LEMD), CNRS, 25 avenue des Martyrs, 38042 Grenoble Cedex 9 (France); Rowe, Stephen W [Schneider Electric Industries S.A.S., 37 quai Paul-Louis Merlin, 38050 Grenoble Cedex 9 (France)

    2006-02-07

    Charging and discharging currents have been measured in a diglycidyl ether of bisphenol-A epoxy resin with and without silica fillers, below and above its glass transition temperature T{sub g} = 65 deg. C. Both transient and steady-state current densities have been analysed. The average applied fields ranged from 3 to 35 kV mm{sup -1} with a sample thickness of 0.5 mm. Above T{sub g}, transient currents suggested a phenomenon of charge injection forming trapped space charges even at low fields. Steady-state currents confirmed that the behaviour was not Ohmic and suggested Schottky-type injection. Below T{sub g}, the current is not controlled by the metal-dielectric interface but by the conduction in the volume: the current is Ohmic at low fields and both transient and steady-state currents suggest a phenomenon of space-charge limited currents at high fields. The field threshold is similar in the filler-free and the filled resin. Values in the range 12-17 kV mm{sup -1} have been measured.

  18. Radiation curing of {gamma}-Al{sub 2}O{sub 3} filled epoxy resin

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Phil Hyun; Kim, Dong Jin; Nho, Young Chang [KAERI, Taejon (Korea, Republic of)

    2003-10-01

    Epoxy resins are widely utilized as high performance thermosetting resins for many industrial applications but characterized by a relatively low toughness. Recently, the incorporation with rigid inorganic was suggested to improve the mechanical properties of epoxy resins. In the present work, an attempt has been taken to disperse nano-sized {gamma}- Al{sub 2}O{sub 3} particles into diglycidyl ether of bisphenol-A (DGEBA) epoxy resins for improvement of the mechanical properties. These hybrid epoxy-alumina composites were prepared using by the {gamma}-ray curing technique that was conducted with 100kGy under nitrogen at room temperature. The composites were characterized by determining gel content, UTM (Instron model 4443), SEM, FT-IR studies.

  19. An exploration of experimental parameters in the analysis of epoxy resin by reverse phase liquid chromatography.

    Science.gov (United States)

    Twichell, J E; Walker, J Q; Maynard, J B

    1979-05-01

    Reverse phase liquid chromatographic methods have been developed for the quality control of epoxy resin formulations. The results show that different formulations require different instrumental parameters for optimun separation and detection. Operating parameters required for the analysis of complex mixtures of epoxy resins, which include curing agents and diluents, are described in this paper. Parameters found to be critical are column temperature, solvent flow rate and gradient, and detector wavelength. Microprocessor parameters required to obtain reproducible data are also discussed.

  20. PREPARATION OF MICROGEL-EPOXY RESIN TWO-PHASE POLYMERS BY IN SITU POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    YU Yunzhao; WU Xianghong; SONG Aiteng

    1991-01-01

    Microgel-epoxy resin two-phase polymers were prepared by in situ copolymerization of ethylenic monomers with unsaturated polyesters. The choice of monomers and the effect of monomer concentration on microgel particle size were discussed. Agglomeration of particles played a significant role in the early stage of polymerization. The microgel dispersion in epoxy resin was stable after the finish of polymerization. Upon curing the particles remained well dispersed.

  1. Mechanical properties of short carbon/glass fiber reinforced high mechanical performance epoxy resins

    Institute of Scientific and Technical Information of China (English)

    张竞; 黄培

    2009-01-01

    To research the relationship between epoxy and fiber inherent property and mechanical properties of composite,we prepared a series of composites using three kinds of high mechanical performance epoxy resins as matrices and reinforced by the same volume fraction(5%)of short carbon and glass fiber.Their mechanical properties were investigated from the perspective of chemical structure and volume shrinkage ratio of epoxy.We analyzed their tensile strength and modulus based on the mixing rule and Halpin-Tsai eq...

  2. Properties of two composite materials made of toughened epoxy resin and high-strain graphite fiber

    Science.gov (United States)

    Dow, Marvin B.; Smith, Donald L.

    1988-01-01

    Results are presented from an experimental evaluation of IM7/8551-7 and IM6/18081, two new toughened epoxy resin, high strain graphite fiber composite materials. Data include ply-level strengths and moduli, notched tension and compression strengths and compression-after-impact assessments. The measured properties are compared with those of other graphite-epoxy materials.

  3. Self-Healing Photocurable Epoxy/thiol-ene Systems Using an Aromatic Epoxy Resin

    Directory of Open Access Journals (Sweden)

    Ricardo Acosta Ortiz

    2016-01-01

    Full Text Available A rapid and efficient method to obtain self-healing epoxy resins is discussed. This method is based on the use of a thiol-disulfide oligomer obtained by partial oxidation of a multifunctional thiol using a hypervalent iodine (III compound as oxidant. The oligomer was characterized by Fourier transform infrared spectroscopy (FTIR, Raman and nuclear magnetic resonance spectroscopies, and gel permeation chromatography (GPC. The oligomer was a joint component of the thiol-ene system along with a tetra-allyl-functionalized curing agent. The kinetics of the photopolymerization of diglycidylether of bisphenol A (DGEBA revealed that conversions of the epoxy groups as high as 80% were achieved in only 15 minutes by increasing the concentration of the thiol-ene system in the formulation. The disulfide bonds introduced in the copolymer using the thiol-disulfide oligomer allowed the repairing of the test specimens in as little as 10 minutes when the specimens were heated at 80°C or for 500 minutes at room temperature. The analysis of the mechanical properties using dynamic mechanical analysis (DMA showed that the specimens displayed a healing efficiency up to 111% compared with the unhealed specimens, depending on the amount of polythioethers present in the copolymer.

  4. Occupational allergic contact dermatitis from epoxy resin in a golf club repairman.

    Science.gov (United States)

    Isaksson, Marléne; Möller, Halvor; Pontén, Ann

    2008-01-01

    A golfer presented with facial and hand eczema. He had exacerbations of his hand eczema prior to golf tournaments. Being an authorized golf club repairman, he had been working with a two-part glue containing an epoxy resin (ER) based on diglycidyl ether of bisphenol A (DGEBA) and the hardener diethylenetriamine (DETA) for approximately 4 years before he developed any skin problems. He was patch-tested with the standard, which contains an ER based on DGEBA (DGEBA-R), epoxy (containing DETA), and rubber glove series and had positive reactions to DGEBA-R only. Other work materials (a latex glove, a golf glove made of leather, and part of the handle of his own golf club "as is" and in a methyl tert-butyl ether extract) were tested, with negative results. Allergic contact dermatitis from ER affects the skin by direct contact; the dermatitis is usually localized to the hands and forearms. If the face and eyelids are involved, the dermatitis may be due to exposure to airborne hardeners or reactive diluents, exposure to airborne dust from residual monomers, or ectopic allergic reactions. Our repairman had sandpapered an old glued surface, which may have led to possible airborne dust formation, thus explaining the facial eczema. Therefore, a worker with contact allergy to ER may continue working provided the skin is protected from contamination.

  5. Effect of dimethylpolysiloxane liquid on the cryogenic tensile strength and thermal contraction behavior of epoxy resins

    Science.gov (United States)

    Yi, Jin Woo; Lee, Yu Jin; Lee, Sang Bok; Lee, Wonoh; Um, Moon Kwang

    2014-05-01

    Dimethylpolysiloxane liquid was blended with diglycidyl ether of bisphenol-A epoxy resin including anhydride curing agent to improve the tensile strength of the epoxy resin at 77 K without any increase in its coefficient of thermal expansion (CTE). A bifunctional polymer, silicone-modified epoxy resin (SME), was also added to the mixture as a compatibilizer. The results of UV transmittance for the blend resin showed that the incorporation of the SME could stabilize effectively spherical domains of the siloxane liquid which was immiscible with the epoxy matrix. The tensile strengths of the blend resins at both room temperature and 77 K were measured and SEM analysis for the fractured cross sections was carried out to verify the toughening behavior of the liquid droplets. The results indicated that even small amount of addition of the siloxane liquid (0.05 phr) coupled with SME (20 phr) could enhance the tensile strength at 77 K by 77.6% compared to that of the neat epoxy resin. This improvement is attributed to the fact that the solid and s droplets can disperse the localized stress and interrupt the crack propagation by cavitation mechanism followed by multiple generation of numerous micro-deformation. From the CTE measurement, the siloxane liquid has no influence on the thermal contraction behavior of the blend resin.

  6. Thermal and Mechanical Characteristics of Polymer Composites Based on Epoxy Resin, Aluminium Nanopowders and Boric Acid

    Science.gov (United States)

    Nazarenko, O. B.; Melnikova, T. V.; Visakh, P. M.

    2016-01-01

    The epoxy polymers are characterized by low thermal stability and high flammability. Nanoparticles are considered to be effective fillers of polymer composites for improving their thermal and functional properties. In this work, the epoxy composites were prepared using epoxy resin ED-20, polyethylene polyamine as a hardener, aluminum nanopowder and boric acid fine powder as flame-retardant filler. The thermal characteristics of the obtained samples were studied using thermogravimetric analysis and differential scanning calorimetry. The mechanical characteristics of epoxy composites were also studied. It was found that an addition of all fillers enhances the thermal stability and mechanical characteristics of the epoxy composites. The best thermal stability showed the epoxy composite filled with boric acid. The highest flexural properties showed the epoxy composite based on the combination of boric acid and aluminum nanopowder.

  7. KINETIC MODELING OF ESTERIFICATION OF EPOXY RESIN IN THE PRESENCE OF TRIPHENYLPHOSPHINE FOR PRODUCING VINYL ESTER RESIN: MECHANISTIC RATE EQUATION

    Institute of Scientific and Technical Information of China (English)

    M. Rafizadeh; H. Ghasemi; V. Haddadi-Asl

    2006-01-01

    Due to its mechanical properties and ease of use, vinyl ester resin is enjoying increasing consideration. This resin normally is produced by reaction between epoxy resin and unsaturated carboxylic acid. In the present study, bis-phenol A based epoxy resin and methacrylic acid was used to produce vinyl ester resin. The reaction was conducted under both stoichiometric and non-stoichiometric conditions in the presence of triphenylphosphine as catalyst. The stoichiometric and non-stoichiometric experiments were conducted at 95, 100, 105 and 110℃ and at 90 and 95℃, respectively. The first order rate equation and mechanism based rate equation were examined. Parameters are evaluated by least square method. A comparison of mechanism based rate equation and experimental data show an excellent agreement. Finally, Arrhenius equation and activation energy were presented.

  8. Testing temperature on interfacial shear strength measurements of epoxy resins at different mixing ratios

    DEFF Research Database (Denmark)

    Petersen, Helga Nørgaard; Thomason, James L.; Minty, Ross;

    2015-01-01

    The interfacial properties as Interfacial Shear Stress (IFSS) in fibre reinforced polymers are essential for further understanding of the mechanical properties of the composite. In this work a single fibre testing method is used in combination with an epoxy matrix made from Araldite 506 epoxy resin...... and triethylenetetramine (TETA) hardener. The IFSS was measured by a microbond test developed for a Thermal Mechanical Analyzer. The preliminary results indicate that IFSS has an inverse dependency of both testing temperature and the mixing ratio of hardener and epoxy resin. Especially interesting was the decreasing...

  9. Chemical analysis of monomers in epoxy resins based on bisphenols F and A.

    Science.gov (United States)

    Pontén, A; Zimerson, E; Sörensen, O; Bruze, M

    2004-05-01

    Diglycidyl ether of bisphenol A (DGEBA) is the monomer and most important contact allergen in epoxy resin(s) based on bisphenol A (DGEBA-R). Both thin-layer chromatography (TLC) and high-pressure liquid chromatography (HPLC) methods are available for the analysis of products containing DGEBA-R. With respect to detection and quantification, epoxy resins of the bisphenol F-type, i.e. epoxy resins containing the isomers of diglycidyl ethers of bisphenol F (DGEBF), are not as well investigated as DGEBA-R. The isomers of DGEBF are p,p'-DGEBF, o,p'-DGEBF and o,o'-DGEBF. Both p,p'-DGEBF and o,p'-DGEBF have been shown to be contact allergens in humans, and all 3 isomers are sensitizers in the guinea pig maximization test. We aimed (i). to develop HPLC methods for separation and purification of the individual DGEBF isomers, (ii). to detect and quantify the DGEBF isomers in epoxy resins of the bisphenol F-type and (iii). to evaluate and develop the TLC as a method for the detection of the DGEBF monomers. We found the total content of the DGEBF isomers in the investigated epoxy resins of the bisphenol F-type to vary from 17.0 to 81.7% w/w. Some of them also contained 0.1-2.4% w/w DGEBA. The HPLC method showed a sensitivity that was 2000-20 000x higher than that obtained with the TLC method for the DGEBF monomers. We concluded that the range of the DGEBF isomer content in epoxy resins of the bisphenol F-type is approximately the same as the monomer content in liquid compared to solid DGEBA-R. The relevance of contact allergy to DGEBA-R can remain unrecognized if the suspected product is an epoxy resin of the bisphenol F-type, which is analysed with the TLC method.

  10. The Effect of Gamma Irradiation on the Electrical Properties of the Epoxy Resins.

    Science.gov (United States)

    Gedeon, Sa'ad S.

    Available from UMI in association with The British Library. Requires signed TDF. This thesis is concerned primarily with the curing of epoxy resin and the effect of gamma-irradiation on the electrical properties of epoxy resin systems. The particular systems examined were a diglycidyl ether of bisphenol A (DGEBA, Ciba Geigy MY750) epoxy resin cured using one of two hardeners. These were a hydroxyalkylated polyamine (Ciba Geigy HY956) and a dodecenyl-succinicanhydride (DDSA) with an accelerator of benzyldimethylamine. Different methods of examining the curing of the epoxy resin system have been carried out including differential scanning calorimetry (DSC), infrared spectroscopy (I.R.), dielectric measurements, volume resistivity measurements and thermally stimulated discharge current. The results of dielectric relaxation measurements obtained during the curing of the epoxy resin system were interpreted on the basis of a model considering the growing polymer molecules to be in solution, the solvent being the unreacted monomer and hardener. The investigation of the effect of gamma-irradiation on the electrical properties (conduction mechanism and dielectric behaviour) of the epoxy resin system was achieved by examining the electrical properties of the fully cured epoxy resin system before and after irradiation and the results compared. To establish the electrical properties of the fully cured epoxy resin system before and after irradiation, a series of experiments which provide information about the conduction mechanism, the dielectric properties, the infrared spectra (I.R.) and the glass transition temperature (Tg) obtained from (DSC) measurements were carried out. For the epoxy resin system MY750/HY956, it was found that the D.C. conductivity, dissipation factor and capacitance values increase, whereas the glass transition temperature (Tg) and the activation energy, E, obtained from D.C. measurements decreased for the irradiated samples. Furthermore, a modification

  11. A Dielectric Study of the Time-Temperature-Transformation (TTT) Diagram of DGEBA Epoxy Resins Cured with DDS (Diaminodiphenylsulfone).

    Science.gov (United States)

    1983-12-14

    TRANSFORMATION (TTT) tDIAGRAM OF DGEBA EPOXY RESINS CURED WITH DDS by Norman F. Sheppard, Jr., Michael C. W. Coln and Stephen D. Senturia Article prepared for...DIAGRAM OF DGEBA EPOXY 6/83 - 12/83 RESINS CURED WITH DDS -6. PERFORMING ON*. REPORT NiJMUER ___________________________________Technical Report No. 7 7...Nicrodielectrometry, dielectric cure monitoring, time-temperature-transforma- tion diagram, epoxy resins, DGEBA , DDS, condictivity, permittivity, loss factor

  12. Experimental Investigation on Electrical Tracking of Epoxy Resin Compound with Silicon Rubber%Experimental Investigation on Electrical Tracking of Epoxy Resin Compound with Silicon Rubber

    Institute of Scientific and Technical Information of China (English)

    Abdul Syakur; Hamzah Berahim; Tumiran; Rochmadi

    2011-01-01

    The use of polymer materials as electrical insulators on transmission and distribution lines has been increas- ing such,as epoxy resin. Several advantages of using epoxy resin as an insulating material are its low density, better dielectric properties, and epoxy resin has higher volume resistivity than that of the glass and porcelain. However, ep- oxy resin has some disadvantages when it is used in tropical areas concerning with the humidity, high ultraviolet radia- tion, acid rain and effects of contaminants. Consequently, insulator surface will be easily damaged due to electrical tracking, which is indicated by the surface tracking. In this paper, the surface tracking on epoxy resin compound with silicon rubber has been investigated. The test was done based on the method of Inclined--Planed Tracking (IPT) IEC 587.. 1984 with NH4 C1 as contaminant. The test materials used were epoxy resins based on Diglycidyl Ether of Bisphenol A (DGEBA) and Methaphenylene Diamine (MPDA) compound with silicon rubber ( SiR ) with the dimensions of 50 mm×120 mm and the thickness of 6 mm. The flow rate of contaminant was 0.3 mL/min. The 3.5 kV AC high voltage 50 Hz was applied to the top electrodes. The experimental results show that the contact angle of hydrophobic was affected by compound of silicon rubber. The surface tracking, time to tracking and discharge current were affected by applied voltage, contamination and contact angle. By using micro--cameras, the surface damage was detected. The severest damaged sample surface on a sample had small contact angle. On the other hand, samples with the greatest contact angle needed longer time to have surface damage in the surface discharge. This shows that it is more difficult for large contact angle samples or more hydrophobic to have surface discharge. Epoxy resin compound with silicon rubber has contact angle of hydrophobic greater than epoxy resin without silicon rubber.

  13. Structural characteristics and properties of PU-modified TDE-85/MeTHPA epoxy resin

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Diglycidy1-4,5-epoxycyclohexane-1,2-dicarboxylate (TDE-85)/methyl tetrahydro-phthalic anhydride (MeTHPA) epoxy resin was modified by polyurethane(PU), and its structural characteristics and properties were studied by infrared spectrum analysis(IR), scanning electronic microscopy (SEM), mechanics testing and thermogravimetric analysis (TG). The results indicate that epoxy polymeric network Ⅰ and polyurethane polymeric network Ⅱ are formed in the PU-modified TDE-85/MeTHPA epoxy resin.Meanwhile the PU-modified TDE-85/MeTHPA resins have heterogeneous structure. The miscibility between epoxy (EP) and polyurethane (PU) as well as the phase size are dominantly determined by the mass fraction of polyurethane prepolymer (PUP) in the EP/PU blends. With the increase of PUP mass fraction, the tensile strength, impact strength and thermal stability of the PU-modified TDE-85/MeTHPA epoxy resin all firstly exhibit increasing tendency, and decrease after successively reaching their maxima. When the number-average molecular mass of PPG is 1 000 and the mass fraction of PUP is 15%, the tensile strength, impact strength and thermal stability of materials obtained, compared with TDE-85/MeTHPA epoxy resin, are improved obviously.

  14. Epoxy resin synthesis using low molecular weight lignin separated from various lignocellulosic materials.

    Science.gov (United States)

    Asada, Chikako; Basnet, Sunita; Otsuka, Masaya; Sasaki, Chizuru; Nakamura, Yoshitoshi

    2015-03-01

    A low molecular weight lignin from various lignocellulosic materials was used for the synthesis of bio-based epoxy resins. The lignin extracted with methanol from steam-exploded samples (steaming time of 5 min at steam pressure of 3.5 MPa) from different biomasses (i.e., cedar, eucalyptus, and bamboo) were functionalized by the reaction with epichlorohydrin, catalyzed by a water-soluble phase transfer catalyst tetramethylammonium chloride, which was further reacted with 30 wt% aqueous NaOH for ring closure using methyl ethyl ketone as a solvent. The glycidylated products of the lignin with good yields were cured to epoxy polymer networks with bio-based curing agents i.e., lignin itself and a commercial curing agent TD2131. Relatively good thermal properties of the bio-based epoxy network was obtained and thermal decomposition temperature at 5% weight loss (Td5) of cedar-derived epoxy resin was higher than that derived from eucalyptus and bamboo. The bio-based resin satisfies the stability requirement of epoxy resin applicable for electric circuit boards. The methanol-insoluble residues were enzymatically hydrolyzed to produce glucose. This study indicated that the biomass-derived methanol-soluble lignin may be a promising candidate to be used as a substitute for petroleum-based epoxy resin derived from bisphenol A, while insoluble residues may be processed to give a bioethanol precursor i.e., glucose.

  15. Dielectric Spectroscopy of Bisphenol A Epoxy Resin Aged in Wet and Dry Conditions

    OpenAIRE

    2009-01-01

    This thesis presents the laboratory test data on Bisphenol A epoxy insulation.This thesis work deals with electrical, mechanical and thermal analysis of Bisphenol A epoxy resin. The main aim of this thesis work was to examine if dry and wet aging changes the glass transition temperature (Tg) of the epoxies and measure the impact on the complex permittivity under different ageing conditions namely dry and wet. During ageing the samples (epoxy discs and dog bones) were kept in water at 20°C, 45...

  16. Study on Curing Kinetics of Heat-resistant Flexible Polyamide Modified Epoxy Resin Adhesive

    Directory of Open Access Journals (Sweden)

    Hua Li

    2015-04-01

    Full Text Available In order to study the effects of numerous variables affecting the reaction rate of heat-resistant flexible modified epoxy resin adhesive, the curing kinetics of polyamide modified epoxy resin was studied. The heat-resistant flexible modified epoxy resin adhesive cured at room-temperature was prepared with epoxy resin, polysulfide rubber and organosilicone as adhesive component, polyamide as main curing agent and addition of different modified filler and the curing agent containing benzene ring structure. The curing kinetics of polyamide modified epoxy resin was studied by Differential Scanning Calorimetry (DSC at different heating speeds and the characteristic temperatures of the curing process were analyzed and confirmed. the kinetics parameters of activation energy was calculated using Flynn-Wall-Ozawa equation and Kissinger equation, respectively, then the kinetic model of curing reaction was built as d&alpha/dt = 4.38×107 exp (-57740/RT (1-&alpha0.93, the results show that the two-parameter model is adequate to represent the curing reaction process, the model can well describe the curing reaction process of the studied resin. The DSC curves obtained using the experimental data show a good agreement with that theoretically calculated. The research results will provide theoretical basis for the choice of manufacturing process and the optimization of processing window.

  17. Partial discharges within two spherical voids in an epoxy resin

    Science.gov (United States)

    Illias, H. A.; Chen, G.; Bakar, A. H. A.; Mokhlis, H.; Tunio, M. A.

    2013-08-01

    A void in a dielectric insulation material may exist due to imperfection in the insulation manufacturing or long term stressing. Voids have been identified as one of the common sources of partial discharge (PD) activity within an insulation system, such as in cable insulation and power transformers. Therefore, it is important to study PD phenomenon within void cavities in insulation. In this work, a model of PD activity within two spherical voids in a homogeneous dielectric material has been developed using finite element analysis software to study the parameters affecting PD behaviour. The parameters that have been taken into account are the void surface conductivity, electron generation rate and the inception and extinction fields. Measurements of PD activity within two spherical voids in an epoxy resin under ac sinusoidal applied voltage have also been performed. The simulation results have been compared with the measurement data to validate the model and to identify the parameters affecting PD behaviour. Comparison between measurements of PD activity within single and two voids in a dielectric material have also been made to observe the difference of the results under both conditions.

  18. Dielectric relaxations investigation of a synthesized epoxy resin polymer

    Science.gov (United States)

    Jilani, Wissal; Mzabi, Nissaf; Gallot-Lavallée, Olivier; Fourati, Najla; Zerrouki, Chouki; Zerrouki, Rachida; Guermazi, Hajer

    2015-04-01

    A diglycidylether of bisphenol A (DGEBA) epoxy resin was synthesized, and cured with 3,3'-diaminodiphenyl sulfone (DDS) at a curing temperature of 120 °C. The relaxation properties of the realized polymers were studied by two complementary techniques: dielectric relaxation spectroscopy (DRS), in the temperature range 173-393K and in the frequency interval 10-1-106 Hz, and thermally stimulated depolarization current (TSDC) with a windowing polarization process. Current-voltage (I-V) measurements were also carried out to study interfacial relaxations. Dielectric data were analyzed in terms of permittivity and electric modulus variations. Three relaxation processes ( γ, β and α) have been identified. They were found to be frequency and temperature dependent and were interpreted in terms of the Havriliak-Negami approach. Relaxation parameters were determined by fitting the experimental data. The temperature dependence of the relaxation time was well fitted by the Arrhenius law for secondary relaxations, while the Vogel-Fulcher-Tamann model was found to better fit the τ( T) variations for α relaxation. We found τ 0 = 4.9 10-12 s, 9.6 10-13 s and 1.98 10-7 s for γ, β and α relaxations, respectively. The obtained results were found to be consistent with those reported in the literature. Due to the calculation of the low-frequency data of dielectric loss by the Hamon approximation, the Maxwell-Wagner-Sillars (MWS) relaxation was highlighted.

  19. STUDIES ON EPOXY RESINS MODIFIED WITH POLY (BUTYLENE TEREPHTHALATE)-b-POLY (TETRAMETHYLENE GLYCOL)

    Institute of Scientific and Technical Information of China (English)

    WANG Xia; ZHAO Binyi; LI Zhengyi; YU Yunzhao

    1997-01-01

    Poly(butylene terephthalate)-b-poly(tetramethylene glycol) (PBT-b-PTMG) was used as rheology modifier for the epoxy resin. The segmental copolymer formed spherulites in the epoxy medium. This copolymer was very effective in endowing yield stresses to the liquid resin. The PTMG segment brought in a lowering of the dissolution temperature of the spherulites in the epoxy gel. The cured resin with PBT-b-PTMG as modifier was twophase materials. The rheology modifier improved the mechanical properties of the cured resin as well. The flexible PTMG segments, however, were not in favour of the toughening effect of the modifier. This was attributed to the large domain size of the dispersed phase.

  20. [The embryotoxic and teratogenic action of some brands of epoxy resins].

    Science.gov (United States)

    Iavorovskiĭ, A P; Paustovskiĭ, Iu A

    1997-01-01

    The studies made permit stating that such epoxy resins as DE-500 with dose levels of 1/10 and 1/50 DL50, DE-1000 with 1/10, 1/50, 1/100, 1/250 DL50, UP-650, UP-650T with 1/10 DL50 administered into the stomach of pregnant females of nondescript albino rats from the 1st to the 19th day of pregnancy (DL50 being 5338 +/- 1134, 6644 +/- 1114, 9180 +/- 1154, 7717 +/- 586, 6980 +/- 621 mg/kg for the resins DE-500, DE-1000, DE-2000, UP-650, UP-650T respectively) have embryotoxic as well as teratogenic effects. The embryotoxic effect of the above epoxy resins depends on the dose administered and their chemical structure. These same embryotoxic and teratogenic effects a need to be taken into consideration in scientific substantiation/revision of hygienic regulations for polyoxipropilene diepoxides and alicyclic epoxy resins.

  1. Thermosetting epoxy resin/thermoplastic system with combined shape memory and self-healing properties

    Science.gov (United States)

    Yao, Yongtao; Wang, Jingjie; Lu, Haibao; Xu, Ben; Fu, Yongqing; Liu, Yanju; Leng, Jinsong

    2016-01-01

    A novel and facile strategy was proposed to construct a thermosetting/thermoplastic system with both shape memory and self-healing properties based on commercial epoxy resin and poly(ɛ-caprolactone)-PCL. Thermoplastic material is capable of re-structuring and changing the stiffness/modulus when the temperature is above melting temperature. PCL microfiber was used as a plasticizer in epoxy resin-based blends, and served as a ‘hard segment’ to fix a temporary shape of the composites during shape memory cycles. In this study, the electrospun PCL membrane with a porous network structure enabled a homogenous PCL fibrous distribution and optimized interaction between fiber and epoxy resin. The self-healing capability is achieved by phase transition during curing of the composites. The mechanism of the shape memory effect of the thermosetting (rubber)/thermoplastic composite is attributed to the structural design of the thermoplastic network inside the thermosetting resin/rubber matrix.

  2. Effects of Hygrothermal Cycling on the Chemical, Thermal, and Mechanical Properties of 862/W Epoxy Resin

    Science.gov (United States)

    Miller, Sandi G.; Roberts, Gary D.; Copa, Christine C.; Bail, Justin L.; Kohlman, Lee W.; Binienda, Wieslaw K.

    2011-01-01

    The hygrothermal aging characteristics of an epoxy resin were characterized over 1 year, which included 908 temperature and humidity cycles. The epoxy resin quickly showed evidence of aging through color change and increased brittleness. The influence of aging on the material s glass transition temperature (Tg) was evaluated by Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA). The Tg remained relatively constant throughout the year long cyclic aging profile. The chemical composition was monitored by Fourier Transform Infrared Spectroscopy (FTIR) where evidence of chemical aging and advancement of cure was noted. The tensile strength of the resin was tested as it aged. This property was severely affected by the aging process in the form of reduced ductility and embrittlement. Detailed chemical evaluation suggests many aging mechanisms are taking place during exposure to hygrothermal conditions. This paper details the influence of processes such as: advancement of cure, chemical degradation, and physical aging on the chemical and physical properties of the epoxy resin.

  3. CURE OF A MICROGEL-EPOXY RESIN TWO-PHASE POLYMER WITH ETHYLENE DIAMINE

    Institute of Scientific and Technical Information of China (English)

    SONG Aiteng; HUANG Wei; YU Yunzhao

    1992-01-01

    The curing of a microgel-epoxy resin two phase polymer prepared by in situ copolymerization of unsaturated polyester with acrylic monomer was studied. The unsaturated unit reacted with N- H during the cure of the resin with ethylene diamine. The Michael type reaction was ten times more rapid than the addition of N -H to epoxide .This was accounted for the lower apparent activation energy of the curing of the two phase resin.

  4. Quantitative characterization of interdiffusion at the resin-resin and resin-prepreg interphases of epoxy systems processed by model SQ-RTM

    OpenAIRE

    Ballout, Wael; Coulon, B.; Janssens, Y.-A.; Van Velthem, Pascal; Sclavons, Michel; Magnin, Delphine; Pardoen, Thomas; Bailly, Christian

    2016-01-01

    The interdiffusion between a low and a high viscosity epoxy resin was studied on model systems representing the novel composite manufacturing process called “Same Qualified-Resin Transfer Molding” (SQ-RTM). Neat resin model systems were first characterized after curing by Raman spectroscopy, energy dispersive X-ray microscopy, and nano-indentation, all methods reveal an interdiffusion distance of about 700–900 mm. Transmission electron microscopy further revealed a complex morphological gradi...

  5. Determination of Water Diffusion Coefficients and Dynamics in Adhesive/ Carbon Fiber Reinforced Epoxy Resin Composite Joints

    Institute of Scientific and Technical Information of China (English)

    WANG Chao; WANG Zhi; WANG Jing; SU Tao

    2007-01-01

    To determinate the water diffusion coefficients and dynamics in adhesive/carbon fiber reinforced epoxy resin composite joints, energy dispersive X-ray spectroscopy analysis(EDX) is used to establish the content change of oxygen in the adhesive in adhesive/carbon fiber reinforced epoxy resin composite joints. As water is made up of oxygen and hydrogen, the water diffusion coefficients and dynamics in adhesive/carbon fiber reinforced epoxy resin composite joints can be obtained from the change in the content of oxygen in the adhesive during humidity aging, via EDX analysis. The authors have calculated the water diffusion coefficients and dynamics in the adhesive/carbon fiber reinforced epoxy resin composite joints with the aid of both energy dispersive X-ray spectroscopy and elemental analysis. The determined results with EDX analysis are almost the same as those determined with elemental analysis and the results also show that the durability of the adhesive/carbon fiber reinforced epoxy resin composite joints subjected to silane coupling agent treatment is better than those subjected to sand paper burnishing treatment and chemical oxidation treatment.

  6. Effect of Epoxy Resin Mixtures on the Physical and Mechanical Properties of Sand

    Directory of Open Access Journals (Sweden)

    Costas A. Anagnostopoulos

    2014-05-01

    Full Text Available The use of new materials for soil strengthening is crucial for geotechnical engineering, especially in foundation construction. The main objective of this study was to investigate the potential use of two-component water-soluble epoxy resin to improve the physical and mechanical properties of medium sand, because the efficacy of these resins on soil strengthening has not yet been properly investigated. The experiments were conducted using resins with different epoxy resin-to-water ratios. The results of this study indicate that the epoxy resins improve the physical and mechanical properties of the sand significantly and if successfully grouted into a formation, the resins could provide a suitable solution for the stabilization of the foundation material. In separate experiments, electro osmotic treatment of sand/resin mixtures was conducted with the aim of identifying the effectiveness of electro kinetic method on the early strength development of sand/resin mixtures. From the results it was observed that the electroosmotically treated specimens appeared to have much greater strength enhancement than the one of the untreated specimens.

  7. Characterization of the surface tension and solubility parameter of epoxy resin by using inverse gas chromatography.

    Science.gov (United States)

    Shi, Fenghui; Dai, Zhishuang; Zhang, Baoyan

    2010-07-01

    Inverse gas chromatography (IGC) was used to measure the surface tension and solubility parameter of E51 epoxy resin in this work. By using the Schultz method, decane, nonane, octane and heptane were chosen as the neutral probes to calculate the dispersive surface tensions (gamma(D)). Based on the Good-van Oss equation, the specific surface tension (gamma(SP)) of E51 epoxy resin was calculated with the acidic probe of dichloromethane and the basic probe of toluene. The results showed that the gamma(D) and gamma(SP) of the E51 resin decreased linearly with the increase of temperature. According to the Flory-Huggins parameters (chi) between the resin and a series of probes, the solubility parameters (delta) of E51 resin at different temperatures were estimated using the method developed by DiPaola-Baranyi and Guillet. It was found that the values of delta of the E51 resin were 11.78, 11.57, 11.48 and 11.14 MPa1/2 at 30, 40, 50 and 60 degrees C, respectively. The dispersive component (delta(D)) and the specific component (delta(SP)) of solubility parameter at different temperatures of the E51 resin were investigated according to the relationships between surface tension, cohesion energy and solubility parameter. The results showed that the values of delta(D) were higher than those of delta(SP) for the epoxy resin, and both of them decreased with the increase of temperature.

  8. Kinetic studies of the polymerization of an epoxy resin modified with rhodamine B

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, Raquel; Fernandez d' Arlas, Borja [' Materials - Technologies' Group, Dept. of Chemical and Environmental Engineering, Polytechnic School, Universidad Pais Vasco/Euskal Herriko Unibertsitatea, Pza Europa 1, 20018 Donostia-San Sebastian (Spain); Oyanguren, Patricia A. [INTEMA Univ. Nac. de Mar del Plata-CONICET, JB Justo 4302 Mar del Plata (Argentina); Mondragon, Inaki, E-mail: inaki.mondragon@ehu.es [' Materials - Technologies' Group, Dept. of Chemical and Environmental Engineering, Polytechnic School, Universidad Pais Vasco/Euskal Herriko Unibertsitatea, Pza Europa 1, 20018 Donostia-San Sebastian (Spain)

    2009-09-10

    Novel fluorescent materials were satisfactorily synthesized. With this aim, an epoxy resin based on diglycidyl ether of bisphenol A (DGEBA) was reacted with a laser dye, rhodamine B (RB), to achieve an epoxy-based prepolymer. Then, a diamine, m-xylylenediamine (MXDA), was used as hardener with the purpose of obtaining a crosslinked polymer. The curing conditions strongly influence the intended final properties and the optimization of the curing requires a reliable kinetic model. For that reason, this work presents the kinetic study of the polymerization of the epoxy resin by differential scanning calorimetry (DSC) in isothermal mode as well as by Fourier transform infrared spectroscopy (FTIR). DSC data were fitted using a Kamal autocatalytic equation. Conversion as a function of reaction time curves obtained by means of both techniques agreed well. In addition, the synthesized epoxy-based materials were characterized by proton nuclear magnetic resonance spectroscopy ({sup 1}H NMR) and their fluorescent properties were also analysed.

  9. Electron-beam curing of epoxy resins: effect of alcohols on cationic polymerization

    Indian Academy of Sciences (India)

    N N Ghosh; G R Palmese

    2005-10-01

    Electron-beam (e-beam) induced polymerization of epoxy resins proceeds via cationic mechanism in presence of suitable photoinitiator. Despite good thermal properties and significant processing advantages, epoxy-based composites manufactured using e-beam curing suffer from low compressive strength, poor interlaminar shear strength, and low fracture toughness. A detailed understanding of the reaction mechanism involving e-beam induced polymerization is required to properly address the shortcomings associated with ebeam curable resin systems. This work investigated the effect of hydroxyl containing materials on the reaction mechanism of e-beam induced cationic polymerization of phenyl glycidyl ether (PGE). The alcohols were found to play important roles in polymerization. Compared to hydroxyl group of aliphatic alcohol, phenolic hydroxyl group is significantly less reactive with the oxonium active centre, generated during e-beam induced polymerization of epoxy resin system.

  10. Effect of Sizing on the Interfacial Shear Strength of Carbon Fiber/Epoxy Resin Monofilament Composite

    Institute of Scientific and Technical Information of China (English)

    YANG Yusong; ZHAO Yan; LI Ye; DONG Qi; CHEN Da

    2014-01-01

    The single fiber fragmentation test (SFFT) was used to measure the interfacial shear strength (IFSS) of sized and unsized CF800/epoxy resin monofilament composite in order to evaluate the effect of sizing respectively. Besides, the interfacial reinforcing mechanism was explored by analyzing the surface morphology of the carbon fibers, the wettability between the carbon fibers and the epoxy resin, and the chemical characteristics of the fiber surface. Moreover, the effect of sizing on heat and humidity resistance of interface was investigated by aging test. The results show that sizing improves IFSS of CF800/epoxy resin monofilament composite by 59% through increasing the functional groups containing oxygen and through enhancing wettability, while after sizing the heat and humidity resistance of interface is decreased.

  11. Cure Behaviors and Water Up-take Evaluation of a New Waterborne Epoxy Resin

    Institute of Scientific and Technical Information of China (English)

    WAN Tao; ZANG Tianshun; ZHANG Rui; SUN Xianchang

    2012-01-01

    Cure behaviors and water up-take evaluation of a low cost,ecofriendly and water soluble epoxy resin prepared by reaction between epichlorohydrin and PEG400,PEG600 and PEG1000,respectively,were investigated using non-isothermal differential scanning calorimetry (DSC) and gravimetrical method,respectively.Factors affecting the cure behaviors as well as water up-take of waterborne epoxy resins,such as amount of triethylenetetramine (TETA) and triethylene diamine (TEDA),PEG molecular weight,curing temperature,were systematically investigated.The prepared water soluble epoxy resins can be cured under room temperature with the shape of the curing curves similar to that expected for an autocatalytic reaction.

  12. The separation of waste printed circuit board by dissolving bromine epoxy resin using organic solvent.

    Science.gov (United States)

    Zhu, P; Chen, Y; Wang, L Y; Zhou, M; Zhou, J

    2013-02-01

    Separation of waste printed circuit boards (WPCBs) has been a bottleneck in WPCBs resource processing. In this study, the separation of WPCBs was performed using dimethyl sulfoxide (DMSO) as a solvent. Various parameters, which included solid to liquid ratio, temperature, WPCB sizes, and time, were studied to understand the separation of WPCBs by dissolving bromine epoxy resin using DMSO. Experimental results showed that the concentration of dissolving the bromine epoxy resin increased with increasing various parameters. The optimum condition of complete separation of WPCBs was solid to liquid ratio of 1:7 and WPCB sizes of 16 mm(2) at 145°C for 60 min. The used DMSO was vapored under the decompression, which obtained the regenerated DMSO and dissolved bromine epoxy resin. This clean and non-polluting technology offers a new way to separate valuable materials from WPCBs and prevent the environmental pollution of waste printed circuit boards effectively.

  13. Synthesis,Characterization and Flame-retardant Properties of Epoxy Resins and AACHH Composites

    Institute of Scientific and Technical Information of China (English)

    QIN Linqing; ZHANG Lianmeng; HUANG Zhixiong; HUANG Zhiliang; WANG Yanbing

    2009-01-01

    Flame retardant epoxy resins were prepared by a simple mixed method using am-monium aluminum carbonate hydroxy hydrate(AACHH)as a halogen-free flame retardant.The pre-pared samples were characterized by X-ray diffraction,thermogravimetric and differential scanning calorimetry,scanning electron microscope and limiting oxygen index(LOI)experiments.Effects of AACHH content on LOI of epoxy resins/AACHH composite and flame retardant mechanism were investigated and discussed.Results show that AACHH exhibites excellent flame-retardant properties in epoxy resin(EP).When the content of AACHH was 47.4%,the LOI of EP reached 32.2%.Moreover, the initial and terminal decomposition temperature of EP increased by 48 ℃and 40℃,respectively. The flame retarded mechanism of AACHH is due to the synergic flame retardant effects of diluting, cooling,decomposition resisting and obstructing.

  14. 21 CFR 177.2280 - 4,4′-Isopropyl-idenedi-phenol-epichloro-hydrin thermo-setting epoxy resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true 4,4â²-Isopropyl-idenedi-phenol-epichloro-hydrin thermo-setting epoxy resins. 177.2280 Section 177.2280 Food and Drugs FOOD AND DRUG ADMINISTRATION...,4′-Isopropyl-idenedi-phenol-epichloro-hydrin thermo-setting epoxy resins....

  15. Glass transition temperatures of epoxy resins by pulsed nuclear magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Rutenberg, A.C.; Dorsey, G.F.; Peck, C.G.

    1976-04-21

    Pulsed nuclear magnetic resonance spectroscopy has been used to measure the glass transition temperatures of cured epoxy resins. These measurements make it possible to monitor the cure and determine the glass transition temperature as a function of the curing conditions and the concentration of the components. Knowledge of the glass transition temperature of the cured epoxies allows screening of them for a number of uses, including adhesives and coatings operations.

  16. Characterization of the curing agents used in epoxy resins with TG/FT-IR technique

    OpenAIRE

    Benedita M. V. Romão; Diniz,Milton F.; Margarete F. P. Azevedo; Vera L. Lourenço; Luiz C. Pardini; Rita C.L. Dutra; Fabrice Burel

    2006-01-01

    Samples of epoxy resin (EP) based on the diglycidyl ether of bisphenol A (DGEBA), cured with nadic methyl anhydride (NMA) and mercaptan (CAPCURE 3-800), or amine-phenol (CAPCURE EH-30), respectively, SE 4 and SE 5, were prepared in the stoichiometric ratio determined by the supplier. The curing behaviour of the epoxy systems SE 4 and SE 5 was followed by DSC (Differential Scanning Calorimetry). These SE and their ingredients were analyzed using FTIR transmission techniques (KBr pellets, pyrol...

  17. Synthesis and properties of a bio-based epoxy resin with high epoxy value and low viscosity.

    Science.gov (United States)

    Ma, Songqi; Liu, Xiaoqing; Fan, Libo; Jiang, Yanhua; Cao, Lijun; Tang, Zhaobin; Zhu, Jin

    2014-02-01

    A bio-based epoxy resin (denoted TEIA) with high epoxy value (1.16) and low viscosity (0.92 Pa s, 258C) was synthesized from itaconic acid and its chemical structure was confirmed by 1H NMR and 13C NMR spectroscopy. Its curing reaction with poly(propylene glycol) bis(2-aminopropyl ether) (D230) and methyl hexahydrophthalic anhydride (MHHPA) was investigated. For comparison, the commonly used diglycidyl ether of bisphenol A (DGEBA) was also cured with the same curing agents. The results demonstrated that TEIA showed higher curing reactivity towards D230/MHHPA and lower viscosity compared with DGEBA, resulting in the better processability. Owing to its high epoxy value and unique structure, comparable or better glass transition temperature as well as mechanical properties could be obtained for the TEIA-based network relative to the DGEBA-based network. The results indicated that itaconic acid is a promising renewable feedstock for the synthesis of bio-based epoxy resin with high performance.

  18. Effect of graphene oxide sheet size on the curing kinetics and thermal stability of epoxy resins

    Science.gov (United States)

    Wang, Xiao; Jin, Jie; Song, Mo; Lin, Yue

    2016-10-01

    This work revealed the influences of graphene oxide (GO) sheet size on the curing kinetics and thermal stability of epoxy resins. A series of GO/epoxy nanocomposites were prepared by the incorporation of three different sized GO sheets, namely GO-1, GO-2 and GO-3, the average size of which was 10.79 μm, 1.72 μm and 0.70 μm, respectively. The morphologies of the nanocomposites were observed by field emission gun scanning electron microscope. The dispersion quality of each sized GO was comparable in the epoxy matrix. The curing kinetics was investigated by means of differential scanning calorimetry and analyzed based on kinetics model. Addition of a small amount of GO (0.1 wt%) exhibited strong catalytic effect on the curing reaction of epoxy resin. The activation energy was reduced by 18.9%, 28.8% and 14.6% with addition of GO-1, GO-2 and GO-3, respectively. GO-2 with medium size (1.72 μm) showed the most effective catalysis on the cure. The thermal stability of the cured resins was evaluated based on thermogravimetric analysis. GO/epoxy nanocomposites showed improved thermal stability in the range of 420 °C-500 °C, compared with the pure resin. A ˜ 4% more residue was obtained in each of the incorporated system. The variations of GO sheet size did not influence the enhancement effect on the thermal stability.

  19. Differences in interfacial bond strengths of graphite fiber-epoxy resin composites

    Science.gov (United States)

    Needles, H. L.

    1985-01-01

    The effect of epoxy-size and degree of cure on the interfacial bonding of an epoxy-amine-graphite fiber composite system is examined. The role of the fiber-resin interface in determining the overall mechanical properties of composites is poorly understood. A good interfacial adhesive bond is required to achieve maximum stress transfer to the fibers in composites, but at the same time some form of energy absorbing interfacial interaction is needed to achieve high fracture toughening. The incompatibility of these two processes makes it important to understand the nature and basic factors involved at the fiber-resin interface as stress is applied. The mechanical properties including interlaminar shear values for graphite fiber-resin composites are low compared to glass and boron-resin composites. These differences have been attributed to poor fiber-matrix adhesion. Graphite fibers are commonly subjected to post-treatments including application of organic sizing in order to improve their compatibility with the resin matrix and to protect the fiber tow from damage during processing and lay-up. In such processes, sized graphite fiber tow is impregnated with epoxy resin and then layed-up i nto the appropriate configuration. Following an extended ambient temperature cure, the graphite-resin composite structure is cured at elevated temperature using a programmed temperature sequence to cure and then cool the product.

  20. Use of 2,5-dimethyl-2,5-hexane diamine as a curing agent for epoxy resins. [Patent application

    Science.gov (United States)

    Rinde, J.A.; Newey, H.A.

    Primary diamines are prepared for use as a curing agent for epoxy resins. These curing agents can be used to form epoxy resin mixtures useful in filament winding and preimpregnated fiber molding and in formulating film adhesives, powder coatings and molding powders. The epoxy mixtures form for such uses a room temperature non-reacting, intermediate stable state which has a latent cross-linking capability.

  1. Curing Reaction Kinetics of Epoxy Resin Using Dicyandiamide Modified by Aromatic Amines

    Institute of Scientific and Technical Information of China (English)

    CHEN Lianxi; TIAN Hua; LIU Quanwen; Wang Jun

    2007-01-01

    The curing reaction and reaction mechanism of epoxy resin E-44, for which aromatic amine modified dicyandiamide was used as a curing reagent, were investigated by means of differential scanning calorimetry (DSC). The results showed that the modified dicyandiamide had better curing characteristic than ummodified dicyandiamide for epoxy resin E-44, and the curing reaction could be carried out at moderate temperature. Apparent activation energy of the curing reaction was decreased appreciably from 123.829 kJ/mol to 61.550-64.405 kJ/mol, and reaction order was decreased from 0.941 to 0.896-0.900. Curing reaction mechanism also was discussed.

  2. Epoxy Resin/Nano Ni@C Composites Exhibiting NTC Effect with Tunable Resistivity

    Institute of Scientific and Technical Information of China (English)

    Bangwen Zhang; Baowei Li; Changsheng Xie

    2009-01-01

    Epoxy resin/Ni@C nanoparticle composites with aligned microstructure were prepared by using a procedure of magnetic field assisted curing. The results show that the resistivity of composites exhibits negative temperature coefficient (NTC) effect above room temperature, and can be adjusted by varying the content filler and the magnitude of magnetic field applied. Hill's quantum tunneling model was modified to understand the electrical conduction mechanism in the composites. It shows that the NTC effect ascribes to the dominant thermal activated tunneling transport of electron across adjacent nanoparticles, as well as the low thermal expansivity of epoxy resin matrix.

  3. Studies on the Influence of Monomers on the Performance Properties of Epoxy Acrylate Resin

    Directory of Open Access Journals (Sweden)

    Amrita Sharma

    2008-01-01

    Full Text Available Twelve blend samples were prepared by physical mixing of epoxy acrylate resins with various monomers viz. ethoxylated phenol monoacrylate (EOPA, tripropylene glycol diacrylate (TPGDA and trimethylol propane tri acrylate(TMPTA, having weight ratio of epoxy acrylate resin and monomers are 50:50, 60:40, 70:30, 80:20. These samples were cured under UV radiation using 5% photo initiator by weight. These blends were evaluated for mechanical, chemical & thermal properties. It was found that the sample having mono & tri functional monomers shows better properties than the samples having di functional monomer.

  4. Tetraglycidyl epoxy resins and graphite fiber composites cured with flexibilized aromatic diamines

    Science.gov (United States)

    Delvigs, P.

    1986-01-01

    Studies were performed to synthesize new ether modified, flexibilized aromatic diamine hardeners for curing epoxy resins. The effect of moisture absorption on the glass transition temperatures of a tetraglycidyl epoxy, MY 720, cured with flexibilized hardeners and a conventional aromatic diamine was studied. Unidirectional composites, using epoxy-sized Celion 6000 graphite fiber as the reinforcement, were fabricated. The room temperature and 300 F mechanical properties of the composites, before and after moisture exposure, were determined. The Mode I interlaminar fracture toughness of the composites was characterized using a double cantilever beam technique to calculate the critical strain energy release rate.

  5. Designing of epoxy resin systems for cryogenic use

    Science.gov (United States)

    Ueki, T.; Nishijima, S.; Izumi, Y.

    2005-02-01

    The mechanical and thermal properties of several types of epoxy systems were designed based on the chemical structure, network structure and morphology aiming at cryogenic application. In this research di-epoxies or multifunctional epoxies were cured by several kinds of hardeners such as anhydride, amine or phenol and were blended with polycarbonate, carboxyl-terminated butadiene acrylonitrile copolymer or phenoxy. The mechanical properties and thermal properties of these cured epoxies were measured at room and liquid nitrogen temperature. It was found that the two-dimensional network structured linear polymer shows high performance even at cryogenic temperature. It was concluded that the controls of the structures are very important to optimize epoxy systems for cryogenic application.

  6. Synthesis and Characterization of Imide Containing Hybrid Epoxy Resin with Improved Mechanical and Thermal Properties

    Directory of Open Access Journals (Sweden)

    U. G. Rane

    2014-01-01

    Full Text Available Phosphorous containing amine, tripropyldiamine phosphine oxide (TPDAP, and hybrid monomer 4-(N-phthalimidophenyl glycidylether (PPGE were synthesized and characterized by Fourier transform infrared (FTIR spectroscopy, nuclear magnetic resonance (NMR spectroscopy, and elemental analysis (EDX. PPGE was incorporated in bisphenol A epoxy resin (BPA in various concentrations (5% to 20%, based on a weight percentage of BPA resin. Curing was carried out with the stoichiometric amount of TPDAP and 1,3-propanediamine (PDA to result in cross-link network. Various mechanical, chemical, thermal, and flame retardant properties of modified and unmodified epoxy resin were studied. The coatings obtained with the addition of PPGE were found to have improved properties as compared with those of the unmodified resin. Coatings with 15% loading of PPGE showed improved flame retardant and mechanical properties with stable thermal behaviour.

  7. Synthesis of a new hardener agent for self-healing epoxy resins

    Science.gov (United States)

    Raimondo, Marialuigia; Guadagno, Liberata; Naddeo, Carlo; Longo, Pasquale; Mariconda, Annaluisa; Agovino, Anna

    2014-05-01

    Actually, the development of smart composites capable of self-repair in aeronautical structures is still at the planning stage owing to complex issues to overcome. One of the critical points in the development of self-healing epoxy resin is related to the impossibility to employ primary amines as hardeners. In this paper, the synthesis of a new hardener for self-healing resins is shown together with applicability conditions/ranges.

  8. Flexible Epoxy Resin Formed Upon Blending with a Triblock Copolymer through Reaction-Induced Microphase Separation

    OpenAIRE

    2016-01-01

    In this study, we used diglycidyl ether bisphenol A (DGEBA) as a matrix, the ABA block copolymer poly(ethylene oxide–b–propylene oxide–b–ethylene oxide) (Pluronic F127) as an additive, and diphenyl diaminosulfone (DDS) as a curing agent to prepare flexible epoxy resins through reaction-induced microphase separation (RIMPS). Fourier transform infrared spectroscopy confirmed the existence of hydrogen bonding between the poly(ethylene oxide) segment of F127 and the OH groups of the DGEBA resin. ...

  9. [Contact allergy to epoxy resins plastics based on materials collected by the Nofer Institute of Occupational Medicine].

    Science.gov (United States)

    Kieć-Swierczyńska, Marta; Krecisz, Beata

    2003-01-01

    Of the 5604 patients examined in 1984-2001 for suspected occupational dermatitis, 160 persons (2.8%) showed allergy to epoxy resins plastics. Allergy was more frequent in men (4.9%) than in women (1.2%); in 154 persons, allergy was of occupational etiology (in a group of 160 patients with allergy to epoxy resins, the following proportions were observed: bricklayers, platelayers--17.5%; fitters, turners, machinist millers--13.8%; plastics molders--13.1%; laminators--11.3%; electrical equipment assemblers--10.6%; painters--10.0%). Having compared the frequency of allergy to components of epoxy resins in the years 1984-1993 and 1994-2001, it was found that allergy to resin, reactive diluents and plasticizers was on increase, whereas allergy to amines and acid anhydrides hardeners was on decrease. In a group of 13 chemical compounds entering into the composition of epoxy resins, epoxy resin contributed to the largest number of positive patch tests (77.5% of epoxy-allergic persons). This was followed by triethylenetetramine (23.1%), ethylenediamine (13.1%), phthalic anhydride (8.1%), diethylenetetramine (6.9%) and phenylglycidylether (6.2%). In addition, three patients reacted to both epoxy resin and cycloaliphatic resin.

  10. Free volume hole size of Cyanate ester resin/Epoxy resin interpenetrating networks and its correlations with physical properties

    Energy Technology Data Exchange (ETDEWEB)

    Zeng Minfeng [Institute of Applied Chemistry, Shaoxing University, Shaoxing 312000 (China); Lu Cuiyun [Institute of Applied Chemistry, Shaoxing University, Shaoxing 312000 (China); Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004 (China); Wang Baoyi [Institute of High Energy Physics, The Chinese Academy of Science, Beijing 100049 (China); Qi Chenze, E-mail: qichenze@usx.edu.c [Institute of Applied Chemistry, Shaoxing University, Shaoxing 312000 (China)

    2010-09-15

    Cyanate ester (CE) resin was blended with epoxy resin (EP) at different mass ratios (CE/EP: 100/0, 90/10, 70/30, 50/50, 30/70, 10/90, and 0/100). The curing process of the blend system was characterized by Fourier transform infrared spectrometry (FTIR) and differential scanning calorimetry (DSC). Examination of the mechanical properties, thermal stability, and morphology of the blend systems showed that addition of epoxy resin resulted in improved toughness but a little sacrifice in thermal stability when compared with neat CE. The free volume size of the blend system determined by positron annihilation lifetime spectroscopy (PALS) decreased with the epoxy resin content, which is consistent with the chemical structure changes for the copolymerization between CE and EP. The crosslinking units of curing products (oxazoline, oxazolidinone, and polyether network) of the blends are all smaller in size than those of triazine ring structure from neat CE. Therefore, the free volume size of the blends decreases with increase of EP content. The correlations between the free volume properties and other physical properties (thermal stability and mechanical properties) have also been discussed.

  11. A positron annihilation study on the microstructure of the interpenetration polymer networks of cyanate ester resin/epoxy resin

    Energy Technology Data Exchange (ETDEWEB)

    Qi Chenze; Li Chunqing; Zeng Minfeng; Zhang Jian [Institute of Applied Chemistry, Shaoxing University, Shaoxing 312000 (China); Wang Baoyi, E-mail: Qichenze@usx.edu.c [Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049 (China)

    2010-04-01

    Cyanate ester (CE) resin was blended with epoxy resin (EP) at different mass ratios (CE/EP: 100/0, 90/10, 70/30, 50/50, 30/70, 10/90, 0/100). The free volume size of CE/EP IPNs has been determined by positron annihilation lifetime spectroscopy (PALS). The size decreased as the epoxy resin content increased. The PALS results are consistent with the chemical structure changes for the copolymerizing between CE and EP. The crosslinking units of curing products (oxazoline, oxazolidinone, and polyether network) of the blends are all smaller in size than those of triazine ring structure from neat CE. Therefore, the free volume size of the blends decreases with increase of EP content. Examination of the mechanical properties, thermal stability, and morphology of the blend systems showed that addition of epoxy resin resulted in improved toughness but a little sacrifice in thermal stability when compared with pure CE. The correlations between the free volume properties and physical properties (thermal stability and mechanical properties) have been discussed.

  12. Modification of bifunctional epoxy resin using CO{sub 2} fixation process and nanoclay

    Energy Technology Data Exchange (ETDEWEB)

    Khoshkish, Morteza; Bouhendi, Hosein, E-mail: H.boohendi@ippi.ac.ir; Vafayan, Mehdi

    2014-10-15

    A bifunctional epoxy resin was modified by using a CO{sub 2} fixation solution process in the presence of tetra n-butyl ammonium bromide (TBAB) as catalyst and the modified treated resin was treated by cloisite 30B as nano additive. The Unmodified epoxy resin (UME), CO{sub 2} fixated modified epoxy resin (CFME), and CFME/clay nano composite (CFMEN), were cured by diethylenetriamine (DETA). A cycloaliphatic compound as a reactive diluent was used to control the viscosity of high viscose CFME. The exfoliation of organoclay in UME and CFME was investigated by X-ray diffraction and activation energy was computed using the advanced integral isoconversional method. The activation energy dependency demonstrated that the mechanism of UME curing did not change in the presence of nanoclay. In contrast, the CO{sub 2} fixation results showed a significant change in the activation energy dependency. The Thermal stability parameters include the initial degradation temperature (IDT), the temperature at the maximum rate of weight loss (T{sub max}), and the decomposition activation energy (E{sub d}) were determined by thermal gravimetry analysis. Dynamic mechanical thermal analysis measurements showed that the presence of organoclay in CFME increases the T{sub g} of nano composite in contrast to UME. The fracture roughness of UME, CFME and CFNE were determined by scanning electron microscope. The exfoliated UME/1%clay nanocomposite was confirmed by TEM image. - Highlights: • A new epoxy resin was synthesized using CO{sub 2} fixation reaction. • The synthesized epoxy resin was modified by an organo nano-clay. • CO{sub 2} fixation noticeably changed the curing mechanism. • CO{sub 2} fixation reaction consumes CO{sub 2} which is a harmful greenhouse gas.

  13. Fabrication and mechanical properties of multiwalled carbon nanotube/nanonickel reinforced epoxy resin composites

    Science.gov (United States)

    Zhang, Xiwen; Zhao, Dongyu; Luan, Dongxue; Bi, Changlong

    2016-12-01

    Nanonickel is supported on the surface of the multiwalled carbon nanotubes (MWCNTs), forming the multiwalled carbon nanotubes/nanonickel composites (MWCNTs/Ni). By using the emulsifying machine dispersing MWCNTs/Ni evenly among epoxy resin, which is prepared into epoxy resin/multiwalled carbon nanotubes/nanonickel (EP/MWCNTs/Ni) composite materials. Additionally, the observed strong interfacial interaction between MWCNTs and the epoxy resin matrix is responsible for the enhanced mechanical properties based on the analysis from scanning electron microscope. Experimental results based on the analysis from dynamic mechanical analysis (DMA) indicate a significant improvement in the glass transition temperature (Tg) by around 20 °C upon the addition of 1.5 wt% MWCNTs/Ni to the epoxy matrix. The tensile strength and the impact strength of the composites can improve around 64.8 and 176.7% compared with that of cured pure epoxy and improve with increasing MWCNTs/Ni content up to 1.3 wt%. Finally, the excellent mechanics capability of EP/MWCNTs/Ni nanocomposites will provide enormous opportunities for aerospace applications where conductive adhesive or high-performance polymer materials are necessary.

  14. SYNTHESIS AND PROPERTIES OF POLYURETHANE ACRYLATE/EPOXY RESIN INTERPENETRATING POLYMER NETWORKS

    Institute of Scientific and Technical Information of China (English)

    SHI Youheng; NIE Xuzong

    1988-01-01

    In this paper, a series of interpenetrating polymer networks (IPNs) based on polyurethane acrylate and epoxy resin was prepared by simultaneous photoinitiating by both free-radical and cationic polymerization.The effects of the polyurethane acrylate prepolymer's molecular weight, various components ratio and polymerization methods on IPN's dynamic mechanical and mechanical properties were investigated.

  15. A novel polishing technology for epoxy resin based on 355 nm UV laser

    Science.gov (United States)

    Meng, Xinling; Tao, Luqi; Liu, Zhaolin; Yang, Yi; Ren, Tianling

    2017-06-01

    The electromagnetic shielding film has drawn much attention due to its wide applications in the integrated circuit package, which demands a high surface quality of epoxy resin. However, gaseous Cu will splash and adhere to epoxy resin surface when the Cu layer in PCB receives enough energy in the process of laser cutting, which has a negative effect on the quality of the shielding film. Laser polishing technology can solve this problem and it can effectively improve the quality of epoxy resin surface. The paper studies the mechanism of Cu powder spraying on the compound surface by 355 nm ultraviolet (UV) laser, including the parameters of laser polishing process and the remains of Cu content on compound surface. The results show that minimal Cu content can be realized with a scanning speed of 700 mm/s, a laser frequency of 50 kHz and the distance between laser focus and product top surface of -1.3 mm. This result is important to obtain an epoxy resin surface with high quality. Project supported by the National Natural Science Foundation of China (Nos. 61574083, 61434001), the National Basic Research Program (No. 2015CB352100), the National Key Project of Science and Technology (No. 2011ZX02403-002), the Special Fund for Agroscientic Research in the Public Interest of China (No 201303107), the support of the Independent Research Program of Tsinghua University (No. 2014Z01006), and Advanced Sensor and Integrated System Lab of Tsinghua University Graduate School at Shenzhen (No. ZDSYS20140509172959969).

  16. PREPARATION OF WATERBORNE ULTRAFINE PARTICLES OF EPOXY RESIN BY PHASE INVERSION TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    YANG Zhengzhong; XU Yuanze; WANG Shengjie; YU Hao; CAI Weizhen

    1997-01-01

    Waterborne ultrafine particles of epoxy resin were prepared by phase inversion technique The results of SEM revealed that the particles diameter was in the range of 50 to l()am and the effects on amount of water required at phase inversion point were also dis()ed.

  17. Synthesis of Modified Epoxy Resin Undercoat for Resistor by Nano-SiO2

    Institute of Scientific and Technical Information of China (English)

    WANG Xiuyu; ZHANG Zhisheng; LI Haiyan; HU Ming

    2006-01-01

    A kind of undercoat for resistor with high temperature and humidity resistance was obtained by modifying epoxy resin with proper nano-SiO2 added at 80 ℃.The structure, thermal stability, humidity resistance, and morphological characteristics of the modified epoxy resin undercoat were studied by electrical tests, infrared spectra (IR) analysis, and scanning electron microscopy (SEM).The results show that more compact and steady inter-crosslinked network structures are formed in the modified epoxy resin undercoat added with nano-SiO2, which greatly improves the performance of modified epoxy resin undercoat.The undercoat with nano-SiO2 of about 2.71%, kept for six months at room temperature without flocculating and aggregating, is of good stability, and the surface of painted resistor is uniform, tight and without air holes on it.The varying ratio of resistance with such undercoat painted is less than one in a thousand after high temperature and humidity resistance tests.

  18. Catalytic allylation of phenols : chloride-free route towards epoxy resins

    NARCIS (Netherlands)

    Rijn, Jimmy Antonius van

    2010-01-01

    An industrially applicable process was developed for the synthesis of epoxy resin components. A catalytic reaction was explored towards allyl phenyl ethers that prevents the use of chloride-containing starting materials and thus formation of chloride-containing side products. The preferred allylatin

  19. Synthesis and application of polyepoxide cardanol glycidyl ether as biobased polyepoxide reactive diluent for epoxy resin

    Science.gov (United States)

    Polyepoxide cardanol glycidyl ether (PECGE), a novel cardanol derivative, was synthesized and used as reactive diluent for petroleum-based epoxy resin in this work. The synthetic condition was first optimized, and the resultant PECGE diluent was characterized using Fourier transform infrared spectro...

  20. Terahertz time domain spectroscopy of epoxy resin composite with various carbon inclusions

    Energy Technology Data Exchange (ETDEWEB)

    Macutkevic, J., E-mail: jan@pfi.lt [Center for Physical Sciences and Technology, A. Gostauto 11, Vilnius LT-01108 (Lithuania); Seliuta, D.; Valusis, G.; Adomavicius, R. [Center for Physical Sciences and Technology, A. Gostauto 11, Vilnius LT-01108 (Lithuania); Kuzhir, P.; Paddubskaya, A.; Shuba, M.; Maksimenko, S. [Institute for Nuclear Problem, Belarus State University, 11 Bobruiskaya St., 220030 Minsk (Belarus); Coderoni, L.; Micciulla, F.; Sacco, I.; Bellucci, S. [Frascati National Laboratory, National Institute of Nuclear Physics, via E. Fermi 40, I-00044 Frascati (Roma) (Italy)

    2012-08-24

    Highlights: Black-Right-Pointing-Pointer Epoxy resin with carbon inclusions is studied by terahertz time domain spectroscopy. Black-Right-Pointing-Pointer The resonance dielectric dispersion is observed for all investigated samples. Black-Right-Pointing-Pointer Dielectric properties are modeled by Maxwell-Garnett and nanoelectromagnetic formalism. -- Abstract: The propagation properties of terahertz waves through epoxy resin filled with small amounts (0.25-1.5 wt.%) of commercially available carbon black (CB) and CVD made single-walled and multi-walled carbon nanotubes (CNT) have been investigated by terahertz time domain spectroscopy. High electromagnetic attenuation specified substantially with absorption of THz radiation and strongly decreasing with the decrease of frequency from 0.2 to 1.5 THz has been found for both types of CNT fillers starting from 1 wt.% of nanocarbon concentration. At the same time CB in the same concentration does not make any impact to THz transmission spectrum. The resonance dielectric dispersion has been observed for all investigated samples, which can be attributed to phonon resonance in epoxy resin matrix. The availability of Maxwell-Garnett model for epoxy resin filled with 0.25-1.5 wt.% of CNT was also addressed in the paper.

  1. Occupational sensitization to epoxy resins in Northeastern Italy (1996-2010).

    Science.gov (United States)

    Prodi, Andrea; Rui, Francesca; Fortina, Anna Belloni; Corradin, Maria Teresa; Filon, Francesca Larese

    2015-01-01

    One of the main health concerns of epoxy resins is their role as skin sensitizer. This sensitization is not uncommon, because the prevalence ranges around 1-12% of the general population. Perform a cross sectional study in a patch test population from Northeastern Italy to investigate the prevalence of epoxy resins sensitization among patients with suspected contact dermatitis. Subsequently, relate findings to patients' occupation and evaluate time trend of prevalence. The final study database included 19 088 consecutive patients, tested from 1996 to 2010 in Northeastern Italy. The overall prevalence of epoxy resins sensitization was 0·89%. Dermatitis most frequently involved hands (40·25%). In both sexes, we find a significant correlation in mechanics, woodworkers, and chemical industry workers; and in males only, among farmers and fishers, construction workers, and unemployed. We found significant increase of sensitization in construction workers in the analyzed period. The overall prevalence of sensitization to epoxy resins in Northeastern Italy is in line with other European countries, but we found an increased risk of sensitization in some professions and an increasing trend of prevalence in construction workers. Better preventive actions are strongly advised in higher risk professions, with particular attentions towards building sector.

  2. Occupational sensitization to epoxy resins in Northeastern Italy (1996–2010)

    Science.gov (United States)

    Prodi, Andrea; Rui, Francesca; Fortina, Anna Belloni; Corradin, Maria Teresa; Filon, Francesca Larese

    2015-01-01

    Background: One of the main health concerns of epoxy resins is their role as skin sensitizer. This sensitization is not uncommon, because the prevalence ranges around 1–12% of the general population. Objectives: Perform a cross sectional study in a patch test population from Northeastern Italy to investigate the prevalence of epoxy resins sensitization among patients with suspected contact dermatitis. Subsequently, relate findings to patients’ occupation and evaluate time trend of prevalence. Methods: The final study database included 19 088 consecutive patients, tested from 1996 to 2010 in Northeastern Italy. Results: The overall prevalence of epoxy resins sensitization was 0·89%. Dermatitis most frequently involved hands (40·25%). In both sexes, we find a significant correlation in mechanics, woodworkers, and chemical industry workers; and in males only, among farmers and fishers, construction workers, and unemployed. We found significant increase of sensitization in construction workers in the analyzed period. Conclusions: The overall prevalence of sensitization to epoxy resins in Northeastern Italy is in line with other European countries, but we found an increased risk of sensitization in some professions and an increasing trend of prevalence in construction workers. Better preventive actions are strongly advised in higher risk professions, with particular attentions towards building sector. PMID:25633931

  3. STUDY ON THE POST-CURE KINETICS OF EPOXY RESIN IRRADIATED BY AN ELECTRON BEAM

    Institute of Scientific and Technical Information of China (English)

    Jian-wen Bao; Ye Li; Xiang-yu Zhong; Xiang-bao Chen; Feng-mei Li

    2004-01-01

    The post-cure kinetics of electron beam (EB) curing of epoxy resin initiated by diaryiodinium was investigated.The post-cure reaction fits first order reaction kinetics. The reaction rate constant increases with increasing treatment temperature of post-cure. The reaction rate of post-cure is much lower than the rate of its reaction on electron beam treatment.

  4. Imidazolium Ionic Liquid Modified Graphene Oxide: As a Reinforcing Filler and Catalyst in Epoxy Resin

    Directory of Open Access Journals (Sweden)

    Qing Lyu

    2017-09-01

    Full Text Available Surface modification of graphene oxide (GO is one of the most important issues to produce high performance GO/epoxy composites. In this paper, the imidazole ionic liquid (IMD-Si was introduced onto the surface of GO sheets by a cheap and simple method, to prepare a reinforcing filler, as well as a catalyst in epoxy resin. The interlayer spacing of GO sheets was obviously increased by the intercalation of IMD-Si, which strongly facilitated the dispersibility of graphene oxide in organic solvents and epoxy matrix. The addition of 0.4 wt % imidazolium ionic liquid modified graphene oxide (IMD-Si@GO, yielded a 12% increase in flexural strength (141.3 MPa, a 26% increase in flexural modulus (4.69 GPa, and a 52% increase in impact strength (18.7 kJ/m2, compared to the neat epoxy. Additionally the IMD-Si@GO sheets could catalyze the curing reaction of epoxy resin-anhydride system significantly. Moreover, the improved thermal conductivities and thermal stabilities of epoxy composites filled with IMD-Si@GO were also demonstrated.

  5. Synthesis and characterization of bisimide amines and bisimide amine-cured epoxy resins

    Science.gov (United States)

    Scola, D. A.

    1983-01-01

    An attempt is made to develop tough, moisture resistant, high char yield epoxy resins by means of novel bisimide amine (BIA) hardener curing agents and a state-of-the-art epoxy resin system. The BIAs are isolated as mixtures containing monomer, oligomer, and polymeric species, and then characterized by elemental analysis and high pressure liquid chromatography. The bisimide amine-cured epoxies (IMEs) were characterized with respect to moisture absorption, thermal properties, and physical and mechanical properties, as well as in the role of matrices in Celion 6000/IME composites. The relative toughness characteristics of each IME formulation was measured by the 10 deg off-axis tensile test, measuring the uniaxial tensile strength, shear strength, and shear-strain-to-failure of the composite systems.

  6. Dynamic-mechanical response of graphite/epoxy composite laminates and neat resin

    Science.gov (United States)

    Yang, P.; Carlsson, L.; Sternstein, S. S.

    1983-01-01

    Dynamic mechanical measurement results are presented for the case of carbon fiber-reinforced, epoxy matrix composite laminates subjected to loading perpendicular to the lamination plane, as well as for neat epoxy resin under the same conditions, where temperatures ranged between 20 and 200 C and deformation levels lie within the linear viscoelastic region. In-phase and out-of-phase stiffnesses are found to become superposed, forming master curves that cover a 12-decade frequency range. The application of a master curve scaling procedure shows that the in-phase stiffness has the same shape, and out-of-phase stiffness has the same dispersion, for all laminates irrespective of stacking sequence and are, in turn, nearly identical to those for the neat epoxy resin. An empirical function is found for the relaxation modulus which, when converted to a dynamic modulus, yields good overall agreement for both of the dynamic stiffness components as a function of frequency.

  7. Study of degradation of epoxy resins under the action of partial discharges. Etude de degradation des resines epoxy sous l'action des decharges partielles

    Energy Technology Data Exchange (ETDEWEB)

    Hudon, C.

    1993-09-01

    Over the past few decades, epoxy resin composites have been extensively used in the high voltage insulation systems of rotating machines, notably large electric motors and hydroelectric power turbine generators. The actual life of these epoxy materials under high alternating voltage conditions is always shorter than predicted. Degradation of the epoxy results from a complex synergistic action of ionic and electronic surface bombardment, ultraviolet radiation, and electrochemical reactions in a confined and non-vented space that is in most cases inaccessible for careful observation and analysis. A comparative study was conducted using parallel-plane epoxy-covered electrodes to investigate the interrelation between the discharge signal behavior and the associated degradation. Examination of the behavior in terms of measured amplitude of the electrical pulse component and the light emission intensity disclosed the presence of three types of discharges. It was found that as a consequence of material degradation with time, the altered conditions within the discharge gap tended to favor a transition to even-smaller discharge amplitudes, and ultimately to a glow type discharge. Detailed chemical analyses of reaction products at the specimen surface indicated that the different discharge types, though leading to formation of different degradation products, contribute significantly in various degrees to the overall degradation of the epoxy resin. A model is proposed to explain the discharge signal transition process with time. It is based mainly on the measured increase of surface conductivity resulting from formation of degradation products, mostly composed of electrically conductive organic acids and nitric acid. 122 refs., 64 figs., 12 tabs.

  8. Curing mechanism of TDE-85/MeTHPA epoxy resin modified by polyurethane

    Institute of Scientific and Technical Information of China (English)

    LI Zhi-hua; ZHENG Zi-qiao; REN Dong-yan; HUANG Yao-peng

    2007-01-01

    Diglycidyl 4,5-epoxy tetrahydro phthalate/methyl tetrahydrophthalic anhydride (TDE-85/MeTHPA) epoxy resin modified by polyurethane (PU) was prepared with 1,4-butanediol (1,4-BDO), trimethylol propane (TMP) and polyurethane prepolymer synthesized by polypropylene glycol and toluene diisocynate. Chemical reaction and curing mechanism of this system were discussed by incorporating the results of infra spectrum analysis. The results indicate that the epoxy polymeric network Ⅰ is obtained by the curing reaction between TDE-85 and MeTHPA, while the PU polymeric network Ⅱ is obtained by the chain-extended and crosslinking reaction between 1,4-BDO, TMP and polyurethane prepolymer(PUP). The graft chemical bonds are formed between polymer networks Ⅰ and Ⅱ that therefore increase the degree of blend and compatibility between epoxy polymer and PU.

  9. Thermal properties and fracture toughness of difunctional epoxy resins cured by catalytic initiators

    Energy Technology Data Exchange (ETDEWEB)

    Park, S.J.; Heo, G.Y.; Lee, J.R. [Korea Research Institute of Chemical Technology, Taejon (Korea)

    2002-05-01

    In this work, two thermal cationic latent catalysts, i.e., triphenyl benzyl phosphonium hexafluoroantimonate (TBPH) and benzyl 2-methylpyrazinium hexaluoroantimonate (BMPH) were newly synthesized. And the thermal and mechanical properties of difunctional epoxy (diglycidylether of bisphenol A, DGEBA) resins initiated by 1 phr of either TBPH or BMPH catalyst were investigated. As experimental results, the epoxy/TBPH system showed higher curing temperature and critical stress intensity factor (K{sub 1C}) than those of epoxy/BMPH. This could be interpreted in terms of slow thermal diffusion rate and bulk structure of four phenyl groups in TBPH. However, the decomposed activation energy determined from Coats-Redfern method was lower in the case of epoxy/TBPH. This result was probably due to the fact that broken short chain structure was developed by steric hindrance of TBPH. (author). 24 refs., 3 tabs., 6 figs.

  10. A biomimetic approach to enhancing interfacial interactions: polydopamine-coated clay as reinforcement for epoxy resin.

    Science.gov (United States)

    Yang, Liping; Phua, Si Lei; Teo, Jun Kai Herman; Toh, Cher Ling; Lau, Soo Khim; Ma, Jan; Lu, Xuehong

    2011-08-01

    A facile biomimetic method was developed to enhance the interfacial interaction in polymer-layered silicate nanocomposites. By mimicking mussel adhesive proteins, a monolayer of polydopamine was constructed on clay surface by a controllable coating method. The modified clay (D-clay) was incorporated into an epoxy resin, it is found that the strong interfacial interactions brought by the polydopamine benefits not only the dispersion of the D-clay in the epoxy but also the effective interfacial stress transfer, leading to greatly improved thermomechanical properties at very low inorganic loadings. Rheological and infrared spectroscopic studies show that the interfacial interactions between the D-clay and epoxy are dominated by the hydrogen bonds between the catechol-enriched polydopamine and the epoxy.

  11. γ-Ray irradiation stability and damage mechanism of glycidyl amine epoxy resin

    Science.gov (United States)

    Diao, Feiyu; Zhang, Yan; Liu, Yujian; Fang, Jun; Luan, Weilin

    2016-09-01

    Irradiation stability of triglycidyl-p-aminophenol (TGPAP) epoxy resins was evaluated according to the changes of physico-chemical and mechanical properties under 60Co γ-ray irradiation with a dose rate of 10 kGy/h. The result shows that with the increase of radiation dose, bending strength, thermal stability, free radical concentration and storage modulus of epoxy resin decrease first, then increase slightly, and decline sharply at the end with a dose of 960 kGy, due to competition effects between radiation-induced degradation and cross-linking reaction. The damage mechanism was derived by analyzing structure and composition change of AFG-90 resins after irradiation via IR and XPS. Irradiation will result in weak bond breaking such as Csbnd C and Csbnd N bond, and new bond forming like Cdbnd C and Cdbnd O.

  12. Nanostructured composites based on carbon nanotubes and epoxy resin for use as radar absorbing materials

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Valdirene Aparecida [Instituto Tecnologico de Aeronautica (ITA), Sao Jose dos Campos, SP (Brazil); Folgueras, Luiza de Castro; Candido, Geraldo Mauricio; Paula, Adriano Luiz de; Rezende, Mirabel Cerqueira, E-mail: mirabelmcr@iae.cta.br [Instituto de Aeronautica e Espaco (IAE), Sao Jose dos Campos, SP (Brazil). Div. de Materiais; Costa, Michelle Leali [Universidade Estadual Paulista Julio de Mesquita Filho (DMT/UNESP), Guaratingueta, SP (Brazil). Dept. de Materiais e Tecnologia

    2013-07-01

    Nanostructured polymer composites have opened up new perspectives for multifunctional materials. In particular, carbon nanotubes (CNTs) present potential applications in order to improve mechanical and electrical performance in composites with aerospace application. The combination of epoxy resin with multi walled carbon nanotubes results in a new functional material with enhanced electromagnetic properties. The objective of this work was the processing of radar absorbing materials based on formulations containing different quantities of carbon nanotubes in an epoxy resin matrix. To reach this objective the adequate concentration of CNTs in the resin matrix was determined. The processed structures were characterized by scanning electron microscopy, rheology, thermal and reflectivity in the frequency range of 8.2 to 12.4 GHz analyses. The microwave attenuation was up to 99.7%, using only 0.5% (w/w) of CNT, showing that these materials present advantages in performance associated with low additive concentrations (author)

  13. Preparation and Characterization of New Geopolymer-Epoxy Resin Hybrid Mortars

    Directory of Open Access Journals (Sweden)

    Raffaele Cioffi

    2013-07-01

    Full Text Available The preparation and characterization of metakaolin-based geopolymer mortars containing an organic epoxy resin are presented here for the first time. The specimens have been prepared by means of an innovative in situ co-reticulation process, in mild conditions, of commercial epoxy based organic resins and geopolymeric slurry. In this way, geopolymer based hybrid mortars characterized by a different content of normalized sand (up to 66% in weight and by a homogeneous dispersion of the organic resin have been obtained. Once hardened, these new materials show improved compressive strength and toughness in respect to both the neat geopolymer and the hybrid pastes since the organic polymer provides a more cohesive microstructure, with a reduced amount of microcracks. The microstructural characterization allows to point out the presence of an Interfacial Transition Zone similar to that observed in cement based mortars and concretes. A correlation between microstructural features and mechanical properties has been studied too.

  14. Green Preparation of Epoxy/Graphene Oxide Nanocomposites Using a Glycidylamine Epoxy Resin as the Surface Modifier and Phase Transfer Agent of Graphene Oxide.

    Science.gov (United States)

    Tang, Xinlei; Zhou, Yang; Peng, Mao

    2016-01-27

    In studies of epoxy/graphene oxide (GO) nanocomposites, organic solvents are commonly used to disperse GO, and vigorous mechanical processes and complicated modification of GO are usually required, increasing the cost and hindering the development and application of epoxy nanocomposites. Here, we report a green, facile, and efficient method of preparing epoxy/GO nanocomposites. When triglycidyl para-aminophenol (TGPAP), a commercially available glycidyl amine epoxy resin with one tertiary amine group per molecule, is used as both the surface modifier and phase transfer agent of GO, GO can be directly and rapidly transferred from water to diglycidyl ether of bisphenol A and other types of epoxy resins by manual stirring under ambient conditions, whereas GO cannot be transferred to these epoxy resins in the absence of TGPAP. The interaction between TGPAP and GO and the effect of the TGPAP content on the dispersion of GO in the epoxy matrix were investigated systematically. Superior dispersion and exfoliation of GO nanosheets and remarkably improved mechanical properties, including tensile and flexural properties, toughness, storage modulus, and microhardness, of the epoxy/GO nanocomposites with a suitable amount of TGPAP were demonstrated. This method is organic-solvent-free and technically feasible for large-scale preparation of high-performance nanocomposites; it opens up new opportunities for exploiting the unique properties of graphene or even other nanofillers for a wide range of applications.

  15. COMPARISON OF THE E44 EPOXY RESINS IN DIFFERENT CONTENTS OF CURING AGENT BY MICROWAVE AND THERMAL CURING METHODS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper discusses the fundamental principle of microwave heating, and based on the advantages of microwave heating, use maleic anhydride as curing agent.The technology of microwave curing E44 epoxy resins is investigated,the mechanical properties of cured epoxy resin samples in different contents of curing agent by microwave and thermal curing methods are measured respectively, and then some experimental results for which are obtained.At last, this paper analyses why microwave curing can improve mechanical property of epoxy resin.

  16. Etching and structure transformations in uncured epoxy resin under rf-plasma and plasma immersion ion implantation

    Science.gov (United States)

    Kondyurin, Alexey; Bilek, Marcela

    2010-05-01

    Uncured epoxy resin was spun onto silicon wafer and treated by plasma and plasma immersion ion implantation (PIII) by argon ions with energy up to 20 keV. Ellipsometry, FTIR spectroscopy and optical microscopy methods were used for analysis. The etching, carbonization, oxidation and crosslinking effects were observed. The curing reactions in modified epoxy resin are observed without a hardening agent. A model of structural transformations in epoxy resin under plasma and ion beam irradiation is proposed and discussed in relation to processes in a space environment.

  17. Preparation and Characterization of Liquid Crystalline Polyurethane/Al2O3/Epoxy Resin Composites for Electronic Packaging

    Directory of Open Access Journals (Sweden)

    Shaorong Lu

    2012-01-01

    Full Text Available Liquid crystalline polyurethane (LCPU/Al2O3/epoxy resin composites were prepared by using LCPU as modifier. The mechanical properties, thermal stability, and electrical properties of the LCPU/Al2O3/epoxy resin composites were investigated systematically. The thermal oxidation analysis indicated that LCPU/Al2O3/epoxy resin composites can sustain higher thermal decomposition temperature. Meanwhile, coefficient of thermal expansion (CTE was also found to decrease with addition of LCPU and nano-Al2O3.

  18. The effect of resin on the impact damage tolerance of graphite-epoxy laminates

    Science.gov (United States)

    Williams, J. G.; Rhodes, M. D.

    1981-01-01

    The effect of the matrix resin on the impact damage tolerance of graphite-epoxy composite laminates was investigated. The materials were evaluated on the basis of the damage incurred due to local impact and on their ability to retain compression strength in the presence of impact damage. Twenty-four different resin systems were evaluated. Five of the systems demonstrated substantial improvements compared to the baseline system including retention of compression strength in the presence of impact damage. Examination of the neat resin mechanical properties indicates the resin tensile properties influence significantly the laminate damage tolerance and that improvements in laminate damage tolerance are not necessarily made at the expense of room temperature mechanical properties. Preliminary results indicate a resin volume fraction on the order of 40 percent or greater may be required to permit the plastic flow between fibers necessary for improved damage tolerance.

  19. Rheological Behavior of an Epoxy Resin with Hollow Glass Microspheres

    Science.gov (United States)

    Costa, Cleber C.; Calado, Verônica; Tavares, Frederico W.

    2008-07-01

    An investigation was carried out on the rheological behavior of a TET/DGEBA epoxy formulations with hollow glass microspheres using different types and different volume fractions of microspheres to manufacture composites. It was proposed an equation to describe viscosity as a function of microsphere volume fracion. The fit to the experimental data was excellent.

  20. Isocyanate-terminated Polyethers Toughened Epoxy Resin: Chemical Modification, Thermal Properties, and Mechanical Strength

    Institute of Scientific and Technical Information of China (English)

    CAI Haopeng; WANG Jun; WANG Xiang; XU Renxin

    2007-01-01

    The toughening of the diglycidyl ether of bisphenol A epoxy resin with isocyanateterminated polyethers (ITPE) was investigated. The progress of the reaction and the structural changes during modification process were studied using FTIR spectroscopy. The studies support the proposition that TDI (tolylene diisocyanate) acts as a coupling agent between the epoxy and polyethers, forming a urethane linkage with the former and the latter, respectively. Me THPA-cured ER/ITPs blends were characterized using dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA). It is indicated the glass transition temperature (Tg) of systems was lower than the Tg of pure epoxy resin and overfull ITPE separated from the modified epoxy resin and formed another phase at an ITPE-content of more than 10wt%. The thermal stability was decreased by the introduction of ITPE. The impact strength and the flexural strength of the cured modifiedepoxy increased with increasing the ITPE content and a maximum plateau value of about 24.03 kJ/m2 and 130.56 MPa was measured in 10wt% ITPE. From scanning electron microscopy (SEM) studies of the fractrue surfaces of ER/ITPE systems, the nature of the micromechanisms responsible for the increases in toughness of the systems was identified.

  1. Optical fiber sensor for an on-line monitoring of epoxy resin/amine reaction

    Science.gov (United States)

    Fouchal, F.; Knight, J. A. G.; Garrington, N.; Cope, B.

    2002-05-01

    An optical fiber sensor is described; it permits a rapid determination of the state of chemical reaction in epoxy resin diglycidyl ether of bisphenol A (DGEBA), and Triethylenetetramine stoichiometric reaction. Mid infrared Fourier transform technique was used to analyze the mixture via a pair of embedded optical fibers connected to an FTIR spectrometer, which operates in the region 4000-700 cm-1 of the electromagnetic waves. An accurate monitoring of the concentration changes over time of epoxy, amine and hydroxyl groups gave a good estimate of extent of reaction and description of physical state of the produced matrix. The chemical group peaks 1130 cm-1 and 3300-3400 cm-1 where used to follow the disappearance of the epoxy, and the amine respectively, while the peak 2970 cm-1 was used as reference peak. A review of a number of other techniques used to study the curing of epoxy resins together with on-line monitoring methods applied in processing thermoset resin is referred to.

  2. Properties of Two Carbon Composite Materials Using LTM25 Epoxy Resin

    Science.gov (United States)

    Cruz, Juan R.; Shah, C. H.; Postyn, A. S.

    1996-01-01

    In this report, the properties of two carbon-epoxy prepreg materials are presented. The epoxy resin used in these two materials can yield lower manufacturing costs due to its low initial cure temperature, and the capability of being cured using vacuum pressure only. The two materials selected for this study are MR50/LTM25, and CFS003/LTM25 with Amoco T300 fiber; both prepregs are manufactured by The Advanced Composites Group. MR50/LTM25 is a unidirectional prepreg tape using Mitsubishi MR50 carbon fiber impregnated with LTM25 epoxy resin. CRS003/LTM25 is a 2 by 2 twill fabric using Amoco T300 fiber and impregnated with LTM25 epoxy resin. Among the properties presented in this report are strength, stiffness, bolt bearing, and damage tolerance. Many of these properties were obtained at three environmental conditions: cold temperature/dry (CTD), room temperature/dry (RTD), and elevated temperature/wet (ETW). A few properties were obtained at room temperature/wet (RTW), and elevated temperature/dry (ETD). The cold and elevated temperatures used for testing were -125 F and 180 F, respectively. In addition, several properties related to processing are presented.

  3. Impact of structure and functionality of core polyol in highly functional biobased epoxy resins.

    Science.gov (United States)

    Pan, Xiao; Webster, Dean C

    2011-09-01

    Highly functional biobased epoxy resins were prepared using dipentaerythritol (DPE), tripentaerythritol (TPE), and sucrose as core polyols that were substituted with epoxidized soybean oil fatty acids, and the impact of structure and functionality of the core polyol on the properties of the macromolecular resins and their epoxy-anhydride thermosets was explored. The chemical structures, functional groups, molecular weights, and compositions of epoxies were characterized using nuclear magnetic resonance (NMR) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, gel permeation chromatography (GPC), and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI MS). The epoxies were also studied for their bulk viscosity, intrinsic viscosity, and density. Crosslinked with dodecenyl succinic anhydride (DDSA), epoxy-anhydride thermosets were evaluated using differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), tensile tests, and tests of coating properties. Epoxidized soybean oil (ESO) was used as a control. Overall, the sucrose-based thermosets exhibited the highest moduli, having the most rigid and ductile performance while maintaining the highest biobased content. DPE/TPE-based thermosets showed modestly better thermosetting performance than the control ESO thermoset.

  4. Compressive Strength of Epoxy Resin Chocks Subjected to Elevated Temperatures.

    Science.gov (United States)

    1984-09-01

    9 2. Pour-In-Place Chock (PIPC) .... ............. 11 3. Atomic Model of Liquid Resin DGEBA ... ......... 18 4. Properties of CHOCKFAST...resin is known as diglycidyl ether of bisphenol A ( DGEBA ) which is the general constituent of CHOCKFAST ORANGE. Due to the confidentiality that... DGEBA occurs by reacting epichlorohydrin with bisphenol A in the presence of sodium hydroxide. The raw material epichlorohydrin is synthesized from

  5. Strain Rate Dependent Behavior of Glass/Nano Clay Filled Epoxy Resin Composite

    Directory of Open Access Journals (Sweden)

    R. Velmurugan

    2014-05-01

    Full Text Available It is believed that addition of small amount of nanoclays in the neat epoxy and fiber reinforced epoxy composite system can improve the mechanical properties. The mechanical properties of most of polymer matrix composites are sensitive to testing rate. However, most of the researches were concentrated on the behavior of the polymer matrix composites at high strain rates. The present research work is to investigate the role of clay on neat epoxy and glass–fiber reinforced epoxy composites, at low strain rates. The clay in terms of 1.5 wt%, 3 wt%, and 5 wt% are dispersed in the epoxy resin using mechanical stirring followed by sonication process. The corresponding glass/epoxy nanocomposites are prepared by impregnating the clay epoxy mixture by hand lay-up process. Characterization of the nanoclay is done by X-ray diffraction and Scanning Electron Microscopy. Tensile stress-strain curves are obtained at strain rates of 10-4 s-1, 10-3 s-1, 10-2 s-1, and 10-1 s-1 by a hydraulic machine reporting that, even at low strain rates, the longitudinal strength and stiffness increase as strain rate increases for all clay loadings. It is observed that the tensile modulus increases as the clay loading increases for both epoxy and glass/epoxy nanocomposites. It is also noticed that the longitudinal tensile strength decreases as the clay loading increases. The failed specimens show marked changes in the fracture surface with increased strain rate. Scanning electron microscopy is used to study the fiber/matrix/clay adhesion in fracture surfaces.

  6. Strain Rate Dependent Behavior of Glass/Nano Clay Filled Epoxy Resin Composite

    Directory of Open Access Journals (Sweden)

    R. Velmurugan

    2014-05-01

    Full Text Available It is believed that addition of small amount of nanoclays in the neat epoxy and fiber reinforced epoxy composite system can improve the mechanical properties. The mechanical properties of most of polymer matrix composites are sensitive to testing rate. However, most of the researches were concentrated on the behavior of the polymermatrix composites at high strain rates. The present research work is to investigate the role of clay on neat epoxy and glass–fiber reinforced epoxy composites, at low strain rates. The clay in terms of 1.5 wt%, 3 wt%, and 5 wt% are dispersed in the epoxy resin using mechanical stirring followed by sonication process. The corresponding glass/epoxy nanocomposites are prepared by impregnating the clay epoxy mixture by hand lay-up process. Characterization of the nanoclay is done by X-ray diffraction and Scanning Electron Microscopy. Tensile stress-strain curves are obtained at strain rates of 10-4 s-1, 10-3 s-1, 10-2 s-1, and 10-1 s-1 by a hydraulic  machine reporting that, even at low strain rates, the longitudinal strength and stiffness increase as strain rate increases for all clay loadings. It is observed that the tensile modulus increases as the clay loading increases for both epoxy and glass/epoxy nanocomposites. It is also noticed that the longitudinal tensile strength decreases as the clay loading increases. The failed specimens show marked changes in the fracture surface with increased strain rate. Scanning electron microscopy is used to study the fiber/matrix/clay adhesion in fracture surfaces.Defence Science Journal, Vol. 64, No. 3, May 2014, pp. 295-302, DOI:http://dx.doi.org/10.14429/dsj.64.7331

  7. Determination of the cross-linking degree of unmodified epoxy resin by cycloaliphatic polyamine and polyamidamin hardeners by ftir spectroscopy

    Directory of Open Access Journals (Sweden)

    Zlatković Saša

    2003-01-01

    Full Text Available Unmodified epoxy resin GY250 was crosslinked by the cycloaliphatic polyamino hardener HY847 and polyamidamine hardener HY848 in the different mass ratios. The degree of crosslinking of the epoxy resin and the quantity of unreacted epoxy groups were determined by a spectroscopic FTIR method. The optimal time of complete crosslinking, as a criterion of the degree, was determined by measuring the film hardness indirectly (JUS H.C8.055. The optimal stoichiometric ratio of 100:18:32 (GY250:HY847:HY848 was defined by correlating parameters which directly depend on the degree of crosslinking and the period of application of the epoxy resins, as a prerequisite for forming 2-component epoxy systems which are comparatively more elastic adhesive and waterproof.

  8. Effects of Surface Treatments of Montmorillonite Nanoclay on Cure Behavior of Diglycidyl Ether of Bisphenol A Epoxy Resin

    Directory of Open Access Journals (Sweden)

    Alfred Tcherbi-Narteh

    2013-01-01

    Full Text Available Diglycidyl ether of Bisphenol A (DGEBA based SC-15 epoxy resin was modified with three different commercially available montmorillonite (MMT nanoclay: Nanomer I.28E and Cloisite 10A and 30B. Cure behavior of nanocomposites was studied using a variety of techniques. Primary focus of this study was to investigate influence of different surface modifications of MMT nanoclay on rheological properties and cure behavior of SC-15 epoxy resin. By adding MMT to SC-15 epoxy resin, chemistry of the epoxy is altered leading to changes in rheological properties and ultimately enthalpy and activation energy of reactions. Addition of Nanomer I.28E delayed gelation, while Cloisite 10A and 30B accelerated gelation, regardless of the curing temperature. Activation energy of reaction was lower with the addition of Nanomer I.28E and Cloisite 10A and higher for Cloisite 30B compared to neat SC-15 epoxy composite.

  9. Structural and electronic properties of carbon nanotube-reinforced epoxy resins.

    Science.gov (United States)

    Suggs, Kelvin; Wang, Xiao-Qian

    2010-03-01

    Nanocomposites of cured epoxy resin reinforced by single-walled carbon nanotubes exhibit a plethora of interesting behaviors at the molecular level. We have employed a combination of force-field-based molecular mechanics and first-principles calculations to study the corresponding binding and charge-transfer behavior. The simulation study of various nanotube species and curing agent configurations provides insight into the optimal structures in lieu of interfacial stability. An analysis of charge distributions of the epoxy functionalized semiconducting and metallic tubes reveals distinct level hybridizations. The implications of these results for understanding dispersion mechanism and future nano reinforced composite developments are discussed.

  10. Thermomagnetic processing of liquid-crystalline epoxy resins and their mechanical characterization using nanoindentation.

    Science.gov (United States)

    Li, Yuzhan; Rios, Orlando; Kessler, Michael R

    2014-11-12

    A thermomagnetic processing method was used to produce a biphenyl-based liquid-crystalline epoxy resin (LCER) with oriented liquid-crystalline (LC) domains. The orientation of the LCER was confirmed and quantified using two-dimensional X-ray diffraction. The effect of molecular alignment on the mechanical and thermomechanical properties of the LCER was investigated using nanoindentation and thermomechanical analysis, respectively. The effect of the orientation on the fracture behavior was also examined. The results showed that macroscopic orientation of the LC domains was achieved, resulting in an epoxy network with an anisotropic modulus, hardness, creep behavior, and thermal expansion.

  11. HYPERBRANCHED EPOXY RESINS PREPARED BY PROTON TRANSFER POLYMERIZATION FROM AN A2 + B3 SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Li-jie Ma; Hai-qiao Wang; Li fan He; Xiao-yu Li

    2011-01-01

    Epoxy-terminated hyperbranched polymers (EHBPs) were prepared by proton transfer polymerization and characterized by FT-IR, 1H-NMR and GPC. The solution and thermal properties of the uncured samples and mechanical properties of cured samples were examined. The thermo-stable products had good solubility in polar solvents, low solution viscosity and Tgs ranging from 15℃ to 33℃ depending on their molecular weights. The mechanical properties of cured films were studied and compared with those of a bisphenol-A type epoxy resin. The films of EHBPs had good impact resistance and high gloss values without sacrificing hardness and adhesion.

  12. Method of neutralizing the corrosive surface of amine-cured epoxy resins

    Science.gov (United States)

    Lee, S. Y. (Inventor)

    1982-01-01

    The corrosive alkaline surface layer of an epoxy resin product formed by the curing of the epoxy with an aliphatic amine is eliminated by first applying a non-solvent to remove most or all of the free unreacted amine and then applying a layer of a chemical reagent to neutralize the unused amine or amine functional groups by forming a substituted urea. The surface then may be rinsed with acetone and then with alcohol. The non-solvent may be an alcohol. The neutralizing chemical reagent is a mono-isocyanate or a mono-isothiocyanate. Preferred is an aromatic mono-isocyanate such as phenyl isocyanate, nitrophenyl isocyanate and naplthyl isocyanate.

  13. Curing agent for polyepoxides and epoxy resins and composites cured therewith. [preventing carbon fiber release

    Science.gov (United States)

    Serafini, T. T.; Delvigs, P.; Vannucci, R. D. (Inventor)

    1981-01-01

    A curing for a polyepoxide is described which contains a divalent aryl radical such as phenylene a tetravalent aryl radical such as a tetravalent benzene radical. An epoxide is cured by admixture with the curing agent. The cured epoxy product retains the usual properties of cured epoxides and, in addition, has a higher char residue after burning, on the order of 45% by weight. The higher char residue is of value in preventing release to the atmosphere of carbon fibers from carbon fiber-epoxy resin composites in the event of burning of the composite.

  14. Filler content influence on the positron annihilation response in an epoxy resin composite

    Energy Technology Data Exchange (ETDEWEB)

    Salgueiro, W. [IFIMAT-UNCentro, Tandil (Argentina); Somoza, A. [Comision de Investigaciones Cientificas de la Provincia de Buenos Aires, Tandil (Argentina); Goyanes, S. [Buenos Aires Univ. (Argentina). Dept. de Fisica; Dept. de Materiales, CNEA, Buenos Aires (Argentina); Rubiolo, G. [Buenos Aires Univ. (Argentina). Dept. de Fisica; Consejo Nacional de Investigaciones Cientificas y Tecnicas (Argentina); Marzocca, A. [Buenos Aires Univ. (Argentina). Dept. de Fisica; Consolati, G. [Politecnico di Milano, Milan (Italy). Dipt. di Chimica Fisica Applicata

    2001-07-01

    Positron annihilation lifetime spectroscopy and mechanical properties tests were used to study the influence of the filler content on the epoxy resin DGEBA. Using a mechanical model recently developed by the authors of the present work, and the values of the long lifetime component it is possible to evaluate correctly the internal stresses introduced in the epoxy lattice for the filler. Additional information obtained from the analysis of the short-lived lifetime component is also presented. Specifically, in the case of the matrix charged with metallic particles, an interesting correlation between the associated intensity to this component and the filler volume fraction is shown. (orig.)

  15. Effect of Palmitic Acid on the Electrical Conductivity of Carbon Nanotubes−Epoxy Resin Composites

    OpenAIRE

    Barrau, Sophie; Demont, Philippe; Perez, Emile; Peigney, Alain; Laurent, Christophe; Lacabanne, Colette

    2003-01-01

    International audience; We found that the palmitic acid allows an efficient dispersion of carbon nanotubes in the epoxy matrix. We have set up an experimental protocol in order to enhance the CNTs dispersion in epoxy resin. Electrical conductivity is optimal using a 1:1 CNTs to palmitic acid weight ratio. The associated percolation threshold is found between 0.05 and 0.1 wt % CNTs, i.e., between 0.03 and 0.06 vol %. The SEM image shows essentially individual CNTs which is inagreement with con...

  16. Fluorinated Epoxy Resins-based Sorbent Coating Materials for Quartz Piezoelectric Crystal Detector

    Directory of Open Access Journals (Sweden)

    D. C Gupta

    2004-04-01

    Full Text Available Fluorinated epoxy resins were synthesised and evaluated as sorbent coating materials for the detection of organophosphorus compounds using quartz piezoelectric crystal detector. These resins were prepared by reacting excess of epichlorohydrin with each of or in combination of fluorinated diols, ie, a, a, a', a' tetrakis (trifluoromethyl 1,3 benzene dimethanol (TTFMBD, 4,4'bis-2-hydroxy hexafluoro isopropyl biphenyl (BHHFIBP, 4,4'dihydroxyocta fluorodiphenyl (DHOFDP and 2,2,3,3,4,4 hexafluoro 1,5 pentanediol (HFPD in the presence of sodium hydroxide at reflux temperature. These polymers were extracted in organic solvents and dried. Each of these fluoroepoxy resins were coated over quartz piezoelectric crystal by solution-casting method and tested using dimethylmethyl phosphonate (DMMP as model compound. Change in the  frequency (AF of quartz piezoelectric crystal oscillator was recorded. Sensitive and potential fluorinated epoxy resins, ie, diglycidylethers (DGE of HFPD-TTFMBD (in the molar ratio 6:4 and DGE (HFPD-BHHFIBP in the molar ratio 4:6 were characterised by viscosity, number average molecular weight (Mn, epoxy equivalent, infrared spectroscopy, and thermal stability.

  17. CHARACTERIZATION OF ALKALINE LIGNINS FOR USE IN PHENOL-FORMALDEHYDE AND EPOXY RESINS

    Directory of Open Access Journals (Sweden)

    Nour Eddine El Mansouri

    2011-05-01

    Full Text Available Besides polyurethanes and polyesters, phenolic and epoxy resins are the most prominent applications for technical lignins in thermosetting materials. To evaluate the potential application of lignin raw materials in phenol formaldehyde and epoxy resins, three types of alkaline lignins were characterized in terms of their structures and thermal properties. The lignin samples analyzed were kraft lignin (LIG-1, soda–rice straw lignin (LIG-2, and soda-wheat straw lignin (LIG-3. FTIR and 1H-NMR methods were used to determine their structure. Gel permeation chromatography (GPC was used to determine the molecular weight distribution (MWD. Differential scanning calorimetry (DSC was used to measure the glass transition temperature (Tg, and thermogravimetric analysis (TGA to determine the thermal stability of lignin samples. Results showed that kraft lignin (LIG-1 has moderate hydroxyl-group content, is rich in G-type units, and has good thermal stability. These properties make it more suitable for direct use in phenol formaldehyde resins, and it is therefore a good raw material for this purpose. The alkaline soda-rice straw lignin (LIG-2 with a high hydroxyl-group content and excellent thermal stability is most suited to preparing lignin-based epoxy resins.

  18. Thermosetting polymer for dynamic nuclear polarization: Solidification of an epoxy resin mixture including TEMPO

    Energy Technology Data Exchange (ETDEWEB)

    Noda, Yohei, E-mail: noda.yohei@jaea.go.jp [Quantum Beam Science Centre, Sector of Nuclear Science Research, Japan Atomic Energy Agency, Shirakata-Shirane, Tokai, Ibaraki 319-1195 (Japan); Kumada, Takayuki [Quantum Beam Science Centre, Sector of Nuclear Science Research, Kansai Photon Science Institute, Japan Atomic Energy Agency, Kizugawa, Kyoto 619-0215 (Japan); Yamaguchi, Daisuke; Shamoto, Shin-ichi [Quantum Beam Science Centre, Sector of Nuclear Science Research, Japan Atomic Energy Agency, Shirakata-Shirane, Tokai, Ibaraki 319-1195 (Japan)

    2015-03-11

    We investigated the dynamic nuclear polarization (DNP) of typical thermosetting polymers (two-component type epoxy resins; Araldite{sup ®} Standard or Araldite{sup ®} Rapid) doped with a (2,2,6,6-tetramethylpiperidine-1-yl)oxy (TEMPO) radical. The doping process was developed by carefully considering the decomposition of TEMPO during the solidification of the epoxy resin. The TEMPO electron spin in each two-component paste decayed slowly, which was favorable for our study. Furthermore, despite the dissolved TEMPO, the mixture of the two-component paste successfully solidified. With the resulting TEMPO-doped epoxy-resin samples, DNP experiments at 1.2 K and 3.35 T indicated a magnitude of a proton-spin polarization up to 39%. This polarization is similar to that (35%) obtained for TEMPO-doped polystyrene (PS), which is often used as a standard sample for DNP. To combine this solidification of TEMPO-including mixture with a resin-casting technique enables a creation of polymeric target materials with a precise and complex structure.

  19. Flexible Epoxy Resin Formed Upon Blending with a Triblock Copolymer through Reaction-Induced Microphase Separation

    Directory of Open Access Journals (Sweden)

    Wei-Cheng Chu

    2016-06-01

    Full Text Available In this study, we used diglycidyl ether bisphenol A (DGEBA as a matrix, the ABA block copolymer poly(ethylene oxide–b–propylene oxide–b–ethylene oxide (Pluronic F127 as an additive, and diphenyl diaminosulfone (DDS as a curing agent to prepare flexible epoxy resins through reaction-induced microphase separation (RIMPS. Fourier transform infrared spectroscopy confirmed the existence of hydrogen bonding between the poly(ethylene oxide segment of F127 and the OH groups of the DGEBA resin. Small-angle X-ray scattering, atomic force microscopy, and transmission electron microscopy all revealed evidence for the microphase separation of F127 within the epoxy resin. Glass transition temperature (Tg phenomena and mechanical properties (modulus were determined through differential scanning calorimetry and dynamic mechanical analysis, respectively, of samples at various blend compositions. The modulus data provided evidence for the formation of wormlike micelle structures, through a RIMPS mechanism, in the flexible epoxy resin upon blending with the F127 triblock copolymer.

  20. Epoxy Resins Toughened with Surface Modified Epoxidized Natural Rubber Fibers by One-Step Electrospinning.

    Science.gov (United States)

    Kim, Joo Ran; Kim, Jung J

    2017-04-27

    Epoxidized natural rubber fibers (ERFs) are developed through one-step electrospinning and directly deposited into epoxy resins without collecting and distributing of fibers. The shape of ERFs shows rough surface due to different evaporation rate of solvent mixture consisting of chloroform and dichloromethane and the average diameter of ERFs is 6.2 µm. The increase of ERFs loading from 0 to 20 wt % into the epoxy resin increases the fracture strain significantly from 1.2% to 13% and toughness from 0.3 MPa to 1.9 MPa by a factor of 7. However, the tensile strength and Young's modulus decrease about 34% from 58 MPa to 34 MPa and from 1.4 GPa to 0.9 GPa, respectively. Due to the crosslinking reactions between oxirane groups of ERFs and amine groups in the resin, surface roughness and the high aspect ratio of ERFs, ERFs result in more effective toughening effect with the minimum loss of tensile properties in epoxy resins.

  1. Curing of epoxy resins with 1-DI(2-chloroethoxyphosphinyl) methyl-2,4 and -2,6-diaminobenzene

    Science.gov (United States)

    Mikroyannidis, J. A.; Kourtides, D. A.

    1983-01-01

    Fire resistant compositions were prepared using 1-di(2-chloroethoxy-phosphinyl)methyl-2,4- and -2,6-diaminobenzene (DCEPD) as a curing agent for typical epoxy resins such as EPON 828 (Shell), XD 7342 (Dow), and My 720 (Ciba Geigy). In addition, compositions of these three epoxy resins with common curing agents such as m-phenylenediamine (MPD) or 4,4'-diaminodiphenylsulphone (DDS) were studied to compare their reactions with those of DCEPD. The reactivity of the three curing agents toward the epoxy resins, measured by differential calorimetry (DSC), was of the order MPD DCEPD DDS. The relatively lower reactivity of DCEPD toward epoxy resins was attributed to electronic effects.

  2. Curing of epoxy resins with 1-/di(2-chloroethoxyphosphinyl)methyl/-2,4- and -2,6-diaminobenzene

    Science.gov (United States)

    Mikroyannidis, J. A.; Kourtides, D. A.

    1984-01-01

    Fire resistant compositions were prepared using 1-di(2-chloroethoxy-phosphinyl)methyl-2,4- and -2,6-diaminobenzene (DCEPD) as a curing agent for typical epoxy resins such as EPON 828 (Shell), XD 7342 (Dow), and My 720 (Ciba Geigy). In addition, compositions of these three epoxy resins with common curing agents such as m-phenylenediamine (MPD) or 4,4'-diaminodiphenylsulphone (DDS) were studied to compare their reactions with those of DCEPD. The reactivity of the three curing agents toward the epoxy resins, measured by differential calorimetry (DSC), was of the order MPD DCEPD DDS. The relatively lower reactivity of DCEPD toward epoxy resins was attributed to electronic effects.

  3. Synthesis and Characterization of Liquid Crystalline Epoxy Resins

    Science.gov (United States)

    2014-01-01

    4.3.2 Sample Preparation The epoxy monomer was placed in a beaker and heated in an oil bath. Once the monomer was completely melted, the curing...83-91. [9] Carfagna C, Acierno D, Di Palma V, Amendola E, and Giamberini M. Macromolecular Chemistry and Physics 2000;201(18):2631-2638. 89...preheated to 150 ºC before the tube was inserted. Unoriented LCERs samples were prepared in the same manner, but were cured in an oil bath for

  4. Thermal investigation of tetrafunctional epoxy resin filled with different carbonaceous nanostructures

    Science.gov (United States)

    Romano, Vittorio; Naddeo, Carlo; Vertuccio, Luigi; Lafdi, Khalid; Guadagno, Liberata

    2016-05-01

    This paper presents a preliminary investigation of thermal behaviour of epoxy nanocomposites containing different types of nanofillers, such as 1-D Multiwall Carbon Nanotubes (MWCNTs) and 2-D predominant shape of Exfoliated Graphite nanoparticles (EG). The cure behavior of the different epoxy formulations (filled and unfilled) was studied by Differential Scanning Calorimetry (DSC). The DSC technique is particularly advantageous for studying the cure of reactive epoxy systems because the curing process is accompanied by the liberation of heat. For all the epoxy nanocomposites analyzed in this work, Differential Scanning Calorimetry (DSC) investigation shows curing degree (DC) values higher than 92% for the curing cycle up to 200°C, reaching up to 100% for the samples filled with Exfoliated Graphite nanoparticles (EG). The calorimetric results also show that Exfoliated Graphite nanoparticles accelerate the curing process of the epoxy resin of about 20°C. Transient Plane Source measurements of thermal conductivity show that this acceleration is directly related to the better heat conduction obtained through the incorporation in the epoxy matrix of carbonaceous nanostructures with predominantly two-dimensional shape (Exfoliated Graphite nanoparticles). The experimental results clearly demonstrate that the use of graphene sheets is very hopeful for obtaining nanocomposites characterized by high performance that are able to meet the ambitious requirements in the aeronautical field.

  5. Synthesis and characterisation of epoxy resins reinforced with carbon nanotubes and nanofibers.

    Science.gov (United States)

    Prolongo, S G; Gude, M R; Ureña, A

    2009-10-01

    Epoxy nanocomposites were fabricated using two kinds of nanofiller, amino-functionalized multi-walled carbon nanotubes (CNTs) and non-treated long carbon nanofibers (CNFs). The non-cured mixtures were analysed through viscosity measurements. The effect of the nanoreinforcement on the curing process was determined by differential scanning calorimetry. Finally, the characterisation of cured nanocomposites was carried out studying their thermo-mechanical and electrical behaviour. At room temperature, the addition of CNTs causes a viscosity increase of epoxy monomer much more marked than the introduction of CNFs due to their higher specific area. It was probed that in that case exists chemical reaction between amino-functionalized CNTs and the oxirane rings of epoxy monomer. The presence of nanoreinforcement induces a decrease of curing reaction rate and modifies the epoxy conversion reached. The glass transition temperature of the nanocomposites decreases with the contents of CNTs and CNFs added, which could be related to plasticization phenomena of the nanoreinforcements. The storage modulus of epoxy resin significantly increases with the addition of CNTs and CNFs. This augment is higher with amino-functionalized CNTs due, between other reasons, to the stronger interaction with the epoxy matrix. The electrical conductivity is greatly increased with the addition of CNTs and CNFs. In fact, the percolation threshold is lower than 0.25 wt% due to the high aspect ratio of the used nanoreinforcements.

  6. Modification of epoxy resins with thermoplastic segmented polycarbonate-based polyurethanes

    Directory of Open Access Journals (Sweden)

    Pavličević Jelena

    2014-01-01

    Full Text Available In this work, epoxy hybrid materials were synthesized by addition of thermoplastic segmented aliphatic polyurethanes with good elastic properties. The modified epoxy samples were obtained by curing of previously homogenized mixture of prepared polyurethane melts, epoxy resin and crosslinking agent Jeffamine D-2000. The influence of different weight content of polyurethanes (5, 10 and 15 wt. % compared to pure epoxy resin as well the influence of different hard segments of elastomers (20, 25 and 30 wt. % on the curing of modified epoxy systems was studied. The curing was followed by differential scanning calorimetry (DSC, in dynamic regime from 30 to 300°C, at three heating rates (5, 10 and 20°C/min. With the increase of hard segments content of polyurethanes added in higher concentration (10 and 15 wt. % into epoxy matrix, the temperature of maximum ratio of curing was shifted to lower values (from 205 to 179°C. Obtained DSC data were analyzed using two integral methods (Ozawa-Flynn-Wall and Kissinger-Akahira-Sunose and one differential kinetic model (Friedman. The significant differences were observed in the second part of the epoxy curing (for the reaction degrees higher than 60 %, where the values of activation energies remarkably increase. The addition of polyurethane elastomers retarded the curing process due to decreased mobility of reactant molecules caused by higher viscosity of reaction mixture. By detailed analysis of determined kinetic parameters, it is concluded that the influence of slow diffusion is more pronounced in the presence of thermoplastic polycarbonate-based polyurethanes, which confirmed their effect on the mechanism of epoxy curing. The highest tensile strength and hardness showed the DGEBA modified with the polyurethane with highest hard segment content. Increasing the hard segment content of polyurethane and its concentration in matrix, the tensile strength of modified epoxy was increased. The elongation at break of

  7. Fluorinated epoxy resins with high glass transition temperatures

    Science.gov (United States)

    Griffith, James R.

    1991-01-01

    Easily processed liquid resins of low dielectric constants and high glass transition temperatures are useful for the manufacture of certain composite electronic boards. That combination of properties is difficult to acquire when dielectric constants are below 2.5, glass transition temperatures are above 200 C and processability is of conventional practicality. A recently issued patent (US 4,981,941 of 1 Jan. 1991) teaches practical materials and is the culmination of 23 years of research and effort and 15 patents owned by the Navy in the field of fluorinated resins of several classes. In addition to high fluorine content, practical utility was emphasized.

  8. Mechanical and anticorrosive properties of graphene/epoxy resin composites coating prepared by in-situ method.

    Science.gov (United States)

    Zhang, Zhiyi; Zhang, Wenhui; Li, Diansen; Sun, Youyi; Wang, Zhuo; Hou, Chunling; Chen, Lu; Cao, Yang; Liu, Yaqing

    2015-01-20

    The graphene nanosheets-based epoxy resin coating (0, 0.1, 0.4 and 0.7 wt %) was prepared by a situ-synthesis method. The effect of polyvinylpyrrolidone/reduced graphene oxide (PVP-rGO) on mechanical and thermal properties of epoxy resin coating was investigated using nanoindentation technique and thermogravimetric analysis, respectively. A significant enhancement (ca. 213% and 73 °C) in the Young modulus and thermal stability of epoxy resin coating was obtained at a loading of 0.7 wt %, respectively. Furthermore, the erosion resistance of graphene nanosheets-based epoxy resin coating was investigated by electrochemical measurement. The results showed also that the Rrcco (ca. 0.3 mm/year) of graphene nanosheets-based epoxy resin coating was far lower than neat epoxy resin (1.3 mm/year). Thus, this approach provides a novel route for improving erosion resistance and mechanical-thermal stability of polymers coating, which is expected to be used in mechanical-thermal-corrosion coupling environments.

  9. Mechanical and Anticorrosive Properties of Graphene/Epoxy Resin Composites Coating Prepared by in-Situ Method

    Directory of Open Access Journals (Sweden)

    Zhiyi Zhang

    2015-01-01

    Full Text Available The graphene nanosheets-based epoxy resin coating (0, 0.1, 0.4 and 0.7 wt % was prepared by a situ-synthesis method. The effect of polyvinylpyrrolidone/reduced graphene oxide (PVP-rGO on mechanical and thermal properties of epoxy resin coating was investigated using nanoindentation technique and thermogravimetric analysis, respectively. A significant enhancement (ca. 213% and 73 °C in the Young modulus and thermal stability of epoxy resin coating was obtained at a loading of 0.7 wt %, respectively. Furthermore, the erosion resistance of graphene nanosheets-based epoxy resin coating was investigated by electrochemical measurement. The results showed also that the Rrcco (ca. 0.3 mm/year of graphene nanosheets-based epoxy resin coating was far lower than neat epoxy resin (1.3 mm/year. Thus, this approach provides a novel route for improving erosion resistance and mechanical-thermal stability of polymers coating, which is expected to be used in mechanical-thermal-corrosion coupling environments.

  10. Quantitation of buried contamination by use of solvents. Part 1: Solvent degradation of amine cured epoxy resins

    Science.gov (United States)

    Rheineck, A. E.; Heskin, R. A.; Hill, L. W.

    1972-01-01

    The solubility and/or swelling of cured epoxy resins was studied using the solubility parameter method. Determination of solubility parameters were found in order to select solvents for solvent-assisted degradation of cured epoxy polymers used in spacecraft. A method for improving recovery of seeded spores is suggested for assay of buried contaminants. Three commercial epoxy resins were cured using four different alkyl amines. For each resin-amine combination, three levels of amine were used, corresponding to 1/3, 2/3, and all of the amine required to react with the oxirane groups of the resin. The solubility parameters of the 36 resulting model compounds were determined in poorly and moderately hydrogen-bonded solvents. No strongly hydrogen-bonded solvents caused dissolution or swelling. The tolerance of cured resins is discussed in terms of polymer structure.

  11. Effect of epoxy resin and hardener containing microcapsules on healing efficiency of epoxy adhesive based metal joints

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Nazrul Islam [Department of Mechanical Engineering, National Institute of Technology Silchar, Silchar 788010, Assam (India); Halder, Sudipta, E-mail: shalder@nits.ac.in [Department of Mechanical Engineering, National Institute of Technology Silchar, Silchar 788010, Assam (India); Goyat, M.S. [Department of Physics, University of Petroleum & Energy Studies, Dehradun, Uttarakhand 248007 (India)

    2016-03-01

    Dual component microcapsules of epoxy resin and polyamine hardener with polymethyl methacrylate (PMMA) shell were synthesized using a water-oil-water emulsion solvent evaporation method. The high concentration of sodium dodecyl sulfate (SDS) was used to reduce the thickness of shell wall of dual component microcapsules. The dual microcapsules of 1:1 weight ratio were introduced in the epoxy adhesive to study the healing effect. The morphology, chemical structure and thermal characteristics of the microcapsules were characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA), respectively. The insertion of dual component microcapsules in epoxy matrix reduced the lap shear strength of adhesive joints, which may be attributed to the generation of stress concentration cites because of micron sized capsules. However, the extension and absorbed failure energy of adhesive joints under uniaxial loading increased with the increase of concentration of dual microcapsules. The viscoelastic nature of the dual microcapsules may be responsible for this enhancement. Significant enhancement in the healing efficiency (90.93%) of the joints was achieved for 10 wt% of dual microcapsules. The crack pinning and crack blunting mechanisms at the vicinity of the crack path adjacent to the microcapsules were found responsible for significant enhancement in the healing efficiency of the adhesive joints. - Highlights: • High SDS concentration was used to control the dual component microcapsules shell wall thickness. • Self-healing performance of dual component microcapsules reinforced epoxy adhesive based single lap joints was studied. • 90.93% of the damage healing was achieved for self-healing adhesive based single lap joints. • Increase in concentration of microcapsules reduces the lap shear properties of the self-healing joints.

  12. Influence of Matrixes on Microstructure and Properties of CTBN Toughened Epoxy Resins

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The influence of the type of epoxy resins (E-51, F-51) on the mechanical properties and microstructure of carboxyl-terminated butadiene nitrile rubber (CTBN) toughened epoxy resins was investigated by determination of adhesive strength and toughness as well as observation of scanning electron microstructure (SEM). The results indicate that the adhesive strength of CTBN toughened E-51 system is superior to CTBN toughened F-51 system. However, CTBN toughened E-51 system is inferior to CTBN toughened F-51 system in the toughness. This difference is related to the microstructure of two toughened systems. For CTBN toughened F-51, larger cavities and rubber particles are found in the system. The larger cavities easily cause stress concentration and result in decrease of the adhesive strength. While the larger rubber particles may better terminate the development of crazing and shear banding and result in increase of the toughness.

  13. The biocompatibility evaluation of epoxy resin-based root canal sealers in vitro.

    Science.gov (United States)

    Huang, Tsui-Hsien; Yang, Jaw-Ji; Li, Huei; Kao, Chia-Tze

    2002-01-01

    The cytotoxic and mutagenic effects of epoxy resin-based root canal sealer AH26 and AH-Plus were determined in vitro. Root canal sealers were eluted for 24 h in dimethyl sulfoxide (DMSO) and diluted in culture medium. Cytotoxic effects were assessed using the MTT [tetrazolium dye, 3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide, C18H16N5SBr] assay for mitochondrial enzyme activity and also the cell viability. Genotoxicity assays were assessed using the alkaline single cell gel electrophoresis assay (comet assay) for DNA damage measurement. Result indicated that both the AH26 and AH-Plus sealers exhibited a dose-dependent increase in astrocyte toxic effects. Additionally, dose-dependent astrocyte DNA damage was also noted for both sealers. Therefore, these epoxy resin-based sealers, AH26 and AH-Plus demonstrated both cytotoxicity and genotoxicity in vitro.

  14. Space charge behaviour in an epoxy resin: the influence of fillers, temperature and electrode material

    Energy Technology Data Exchange (ETDEWEB)

    Gallot-Lavallee, O [Laboratoire de Genie Electrique de Toulouse, Universite Paul Sabatier-118, Route de Narbonne, Toulouse 31062 (France); Teyssedre, G [Laboratoire de Genie Electrique de Toulouse, Universite Paul Sabatier-118, Route de Narbonne, Toulouse 31062 (France); Laurent, C [Laboratoire de Genie Electrique de Toulouse, Universite Paul Sabatier-118, Route de Narbonne, Toulouse 31062 (France); Rowe, S [Direction des Recherches Materiaux, Schneider Electric SA-20, Rue Henri Tarze, Grenoble 38050 (France)

    2005-06-21

    This study aims to characterize the behaviour of the space charge in an epoxy resin used as electrical insulation in systems such as transformers and bus bars. Temperature, field level, filler content and nature of the electrodes are the parameters that were considered. Space charge measurements were performed using the pulsed electro acoustic technique, in a range of field and temperature up to 40 kV mm{sup -1} and 72 deg. C, respectively, on gold-coated and un-coated samples. We discuss the possibility of performing space charge measurement on filled epoxy resin despite the piezoelectricity of quartz fillers. Under dc field we observed a quasi-symmetrical build-up of homocharges at both electrodes, followed by a substitution of the homocharges by heterocharges, mainly close to the cathode. In addition, we recorded the space charge behaviour just before breakdown on a filled sample at 72 deg. C under 12 kV mm{sup -1}.

  15. Epoxy Resin and Polyurethane Compositions from Glycolized Poly (ethylene terephthalate Wastes

    Directory of Open Access Journals (Sweden)

    Gintaras MACIJAUSKAS

    2013-09-01

    Full Text Available The possibility to use poly(ethylene terephthalate (PET bottles production waste as raw material for compositions with high adhesion ability has been investigated. PET waste was glycolyzed with polypropylene glycol and three kinds of oligoesters were formed after depolymerization reaction. The polydispersity of product formed was 1.05. The possibilities to use PET glycolysis products – oligoesters for epoxy resin and polyurethanes were studied. Two-step reaction of oligoesters with epichlorohydrin was chosen for epoxy resin synthesis, while glycolyzed PET reaction with aliphatic isocyanate was used for polyurethane synthesis. The structure and properties of the obtained polymers were investigated. DOI: http://dx.doi.org/10.5755/j01.ms.19.3.5237

  16. Study on polyethylene glycol/epoxy resin composite as a form-stable phase change material

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Yutang; Kang, Huiying; Wang, Weilong; Liu, Hong; Gao, Xuenong [The Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education, South China University of Technology, Guangzhou 510640 (China)

    2010-12-15

    Form-stable polyethylene glycol (PEG)/epoxy resin (EP) composite as a novel phase change material (PCM) was prepared using casting molding method. In this new material, PEG acts as the latent heat storage material and EP polymer serves as the supporting material, which provides structural strength and prevents the leakage of the melted PEG. The structure and morphology of the novel composite were observed using Fourier transformation infrared spectroscope (FTIR) and scanning electronic microscope (SEM). The thermo-mechanical property and transition behavior were characterized by polarizing optical microscope (POM), static thermo-mechanical analysis (TMA) and differential scanning calorimeter (DSC). The experimental results show that, as a result of the physical tangled function of the epoxy resin carrier to the PEG segment, the composite macroscopically presents the solid-solid phase change characteristic. (author)

  17. Study on polyethylene glycol/epoxy resin composite as a form-stable phase change material

    Energy Technology Data Exchange (ETDEWEB)

    Fang Yutang, E-mail: ppytfang@scut.edu.c [Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education, South China University of Technology, Guangzhou 510640 (China); Kang Huiying; Wang Weilong; Liu Hong; Gao Xuenong [Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education, South China University of Technology, Guangzhou 510640 (China)

    2010-12-15

    Form-stable polyethylene glycol (PEG)/epoxy resin (EP) composite as a novel phase change material (PCM) was prepared using casting molding method. In this new material, PEG acts as the latent heat storage material and EP polymer serves as the supporting material, which provides structural strength and prevents the leakage of the melted PEG. The structure and morphology of the novel composite were observed using Fourier transformation infrared spectroscope (FTIR) and scanning electronic microscope (SEM). The thermo-mechanical property and transition behavior were characterized by polarizing optical microscope (POM), static thermo-mechanical analysis (TMA) and differential scanning calorimeter (DSC). The experimental results show that, as a result of the physical tangled function of the epoxy resin carrier to the PEG segment, the composite macroscopically presents the solid-solid phase change characteristic.

  18. Epoxy Resin and Polyurethane Compositions from Glycolized Poly (ethylene terephthalate Wastes

    Directory of Open Access Journals (Sweden)

    Gintaras MACIJAUSKAS

    2013-09-01

    Full Text Available The possibility to use poly(ethylene terephthalate (PET bottles production waste as raw material for compositions with high adhesion ability has been investigated. PET waste was glycolyzed with polypropylene glycol and three kinds of oligoesters were formed after depolymerization reaction. The polydispersity of product formed was 1.05. The possibilities to use PET glycolysis products – oligoesters for epoxy resin and polyurethanes were studied. Two-step reaction of oligoesters with epichlorohydrin was chosen for epoxy resin synthesis, while glycolyzed PET reaction with aliphatic isocyanate was used for polyurethane synthesis. The structure and properties of the obtained polymers were investigated. DOI: http://dx.doi.org/10.5755/j01.ms.19.3.5237

  19. Effect of Hyperbranched Polyester on Modification of Epoxy Resins Cured with Anhydride

    Institute of Scientific and Technical Information of China (English)

    Xiu Xia WANG; Zhi Gang JIANG; Yi Feng ZHANG

    2006-01-01

    The synthesis and characterization of hyperbranched polyester (HBP) with different molecular weight are studied. The effect of HBP on the modification of epoxy resins cured with anhydride is mainly discussed. The characteristics of HBP and the morphologies of cured system are determined by nuclear magnetic resonance spectroscopy (NMR), gel permeation chromatography (GPC) and scanning electron microscope (SEM). The impact strength of cured system is detected and Fourier transform infrared (FTIR) measurements were used to pursue the curing process. The investigation shows that HBP can improve the toughness by forming copolymer networks between epoxy resins, HBP and anhydride. Moreover, when the molecular weight of HBP is 1342g/mol the toughening effect is the best, and the changes of toughness are small with the increase of molecular weight of HBP to 3500 g/mol.

  20. Effect of cure cycle on curing process and hardness for epoxy resin

    Directory of Open Access Journals (Sweden)

    2009-09-01

    Full Text Available A 3-dimensional finite element model is developed to simulate and analyze the temperature and degree of cure field of epoxy casting part during cure process. The present model based on general finite element software ABAQUS is verified by literature example and experimental data. The numerical results show good agreement with literature example and measured data, and are even more accurate than the simulation of literature. After modeling successfully, the influence of temperature cure cycle ramps have on the temperature and degree of cure gradient is investigated. Moreover, the effect of non-uniform temperature and degree of cure field within epoxy casting part on hardness is demonstrated. The present model provides an accurate and novel method that allows further insight into the process of cure for epoxy resin.

  1. Synthesis and Characterization of Polyurethane and Epoxy Resin Interpenetrating Polymer Network

    Institute of Scientific and Technical Information of China (English)

    WU Xiao-yan; YANG Xiao-hui; LIU Yun-hang; WANG Xin-ling

    2005-01-01

    A series of Polyurethane (PU)/bisphenol A based Epoxy Resin (EP) Interpenetrating Polymer Networks (IPN) were synthesized and characterized by SEM, DSC, TGA and DMTA. It was found that IPN shows the best compatibility and damping properties when the ratio of PU/EP is 80 to 20. The results show that chain-extender and higher molecular weight of PPG are able to improve the properties of compatibility, damping and thermal properties.

  2. Isothermal curing of polymer layered silicate nanocomposites based upon epoxy resin by means of anionic homopolymerisation

    OpenAIRE

    Román Concha, Frida Rosario; Calventus Solé, Yolanda; Colomer Vilanova, Pere; Hutchinson, John M.

    2013-01-01

    The use of an initiator, 4-(dimethylamino) pyridine (DMAP), to promote an anionic homopolymerisation reaction for the isothermal cure of polymer layered silicate (PLS) nanocomposites based on an epoxy resin, as well as the effect of the nanoclay content, have been studied by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dielectric relaxation spectroscopy (DRS) and transmission electron microscopy (TEM). The vitrification phenomenon was observed during the isotherm...

  3. Reduced sensitizing capacity of epoxy resin systems: a structure-activity relationship study.

    Science.gov (United States)

    Niklasson, Ida B; Broo, Kerstin; Jonsson, Charlotte; Luthman, Kristina; Karlberg, Ann-Therese

    2009-11-01

    Epoxy resins can be prepared from numerous chemical compositions. Until recently, alternatives to epoxy resins based on diglycidyl ethers of bisphenol A (DGEBA) or bisphenol F (DGEBF) monomers have not received commercial interest, but are presently doing so, as epoxy resins with various properties are desired. Epoxy resin systems are known to cause allergic contact dermatitis because of contents of uncured monomers, reactive diluents, and hardeners. Reactive diluents, for example, glycidyl ethers, which also contain epoxide moieties, are added to reduce viscosity and improve polymerization. We have investigated the contact allergenic properties of a series of six analogues to phenyl glycidyl ether (PGE), all with similar basic structures but with varying carbon chain lengths and degrees of saturation. The chemical reactivity of the compounds in the test series toward the hexapeptide H-Pro-His-Cys-Lys-Arg-Met-OH was investigated. All epoxides were shown to bind covalently to both cysteine and proline residues. The percent depletion of nonreacted peptide was also studied resulting in 88% depletion when using PGE and 46% when using butyl glycidyl ether (5) at the same time point, thus revealing a large difference between the fastest and the slowest reacting epoxide. The skin sensitization potencies of the epoxides using the murine local lymph node assay (LLNA) were evaluated in relation to the observed physicochemical and reactivity properties. To enable determination of statistical significance between structurally closely related compounds, a nonpooled LLNA was performed. It was found that the compounds investigated ranged from strong to weak sensitizers, congruent with the reactivity data, indicating that even small changes in chemical structure result in significant differences in sensitizing capacity.

  4. Thermo-mechanical properties of commercially available epoxy resins for structural applications

    OpenAIRE

    2015-01-01

    Externally bonded (EB) or Near-Surface-Mounted (NSM) composite reinforcements are often bonded to a cementitious substrate by means of commercially available epoxies. These twocomponent- resins are generally ‘cold-curing’ (at room temperature), having however the ability to cure faster under elevated temperatures. One application requesting such an accelerated curing process is the gradient anchorage for strengthening of concrete structures with prestressed CFRP laminates, based o...

  5. Synthesis of a novel siloxane-containing diamine for increasing flexibility of epoxy resins

    Energy Technology Data Exchange (ETDEWEB)

    Park, Soo-Jin [Advanced Materials Division, Korea Research Institute of Chemical Technology, P.O. Box 107, Yusong, Daejeon 305-600 (Korea, Republic of)]. E-mail: psjin@krict.re.kr; Jin, Fan-Long [Advanced Materials Division, Korea Research Institute of Chemical Technology, P.O. Box 107, Yusong, Daejeon 305-600 (Korea, Republic of); Park, Jun-Ha [School of Chemical Engineering, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Kim, Kong-Soo [School of Chemical Engineering, Chungbuk National University, Cheongju 361-763 (Korea, Republic of)

    2005-06-15

    A new siloxane-containing curing agent (ETSO-DDM) was synthesized from epoxy-terminated siloxane oligomer (ETSO) and 4,4'-diaminodiphenyl methane (DDM) with a hot-melt method. And its structure was characterized by means of FT-IR, {sup 1}H NMR, and {sup 13}C NMR spectra. The thermal stabilities and the mechanical behaviors of diglycidylether of bisphenol A (DGEBA) epoxy resins cured with ETSO-DDM were examined. The thermal stability factors, such as the initial decomposition temperature (IDT), temperature of maximum rate of degradation (T {sub max}), and decomposition activation energy (E {sub t}), of the DGEBA/ETSO-DDM systems were increased with increasing the ETSO content up to 5 wt% ETSO. The mechanical properties were increased and the internal stress of the cured epoxy resins was decreased as the ETSO content increased. This could be interpreted in terms of the introduction of soft siloxane segment into the epoxy network, which can be attributed to the increasing of the flexibility or decreasing of the internal stress in the DGEBA/ETSO-DDM systems.

  6. Production of the Large-area Plastic Scintillator for Beta-ray Detection using Epoxy Resin

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Jong Soo; Choi, Yong Seok; Hong, Sang Bum; Seo, Bum Kyung; Moon, Jei Kwon; Choi, Jong Won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    In this study, we prepared a plastic scintillator whose manufacturing process is simple and can be freely shaped. A thin plate of the plastic scintillator was manufactured using epoxy resin as a polymer. The plastic scintillator was made by mixing epoxy resin and organic scintillators under various conditions. The optimal mixture ratio to prepare the plastic scintillator was derived from the above results. Using the derived results, we made the large-area plastic scintillator which can quickly measure the contamination site and evaluated characteristics of the large-area plastic scintillator in the laboratory. A thin plate of a plastic scintillator with a simple preparation process can be freely shaped using epoxy resin and organic scintillators such as PPO and POPOP. PPO emits scintillation of light in the ultraviolet range, and POPOP is a wave shifter for moving the wavelength responsible for the PMT. The mixture ratio of PPO and POPOP was determined using their emission spectra. The optimal weight percentage of PPO and POPOP in an organic scintillator was determined to be 0.2 wt%:0.01 wt%. Based on the above results, the large-area plastic scintillator of the window size of a typical pancake-type αβ surface contamination counter was prepared. We want to evaluate the characteristics of the large-area plastic scintillator. However, there were the difficulties in evaluating characteristics of the large-area plastic scintillator. The cross-sectional area of the large-area plastic scintillator is significantly different to PMT.

  7. [Immunological variants and free radical characteristics of workers exposed to epoxy resins].

    Science.gov (United States)

    Iavorovskiĭ, A P; Kuiun, L A; Afonina, G B; Paustovskiĭ, Iu A; Veremeĭ, M I

    2001-01-01

    Workers on exposure to epoxy resins (ER) have been shown to reveal several variants of immunogrammes of blood, expression of Fas-ligands and oxygen-dependent metabolism of phagocytes. These are as follows: the immune deficiency variant (38.1%), the autoimmune one (33.3%), the state of norm (28.6%). The blood phagocyte oxygen-dependent metabolism tends towards activation but the phagocyte functional reserve is reduced which facts suggest depression of metabolism and phagocytic defence in the organism. Identified in the study are several variants of kinetic parameters of the blood serum chemiluminescence suggesting activation/inhibition of process of free radical oxidation, strengthening/weakening of the blood antioxidant defence, which events can be regarded as early diagnostic and prognostic criteria of adverse effects of epoxy resins on the organism of those handling them. These data suggest to us an insufficient reliability of the existing maximum permissible concentration of epoxy resins in the air of the working zone and attest to the need for its reconsideration.

  8. Physicochemical and mechanical interfacial properties of trifluorometryl groups containing epoxy resin cured with amine

    Energy Technology Data Exchange (ETDEWEB)

    Park, Soo-Jin [Advanced Materials Division, Korea Research Institute of Chemical Technology, PO Box 107, Yusong, Daejeon 305-600 (Korea, Republic of)]. E-mail: psjin@krict.re.kr; Jin, Fan-Long [Advanced Materials Division, Korea Research Institute of Chemical Technology, PO Box 107, Yusong, Daejeon 305-600 (Korea, Republic of); Shin, Jae-Sup [Department of Chemistry, Chungbuk National University, Chongju 361-763 (Korea, Republic of)

    2005-01-15

    A phenyl-trifluoromethyl (-Ph-CF{sub 3}) groups modified epoxy resin, diglycidylether of bisphenol A-fluorine (DGEBA-F), was synthesized and the physical properties, such as curing behaviors, thermal stabilities, and dielectric constant of the DGEBA-F/4,4'-diaminodiphenyl methane (DDM) system were investigated and compared with commercial DGEBA/DDM system. For the mechanical behaviors of the specimens, the fracture toughness and impact tests were performed, and their fractured surfaces were examined by using a scanning electron microscope (SEM). The dielectric constant values of the DGEBA-F/DDM system were lower than those of the DGEBA/DDM system and the mechanical properties of the casting DGEBA-F specimens were higher than those of the DGEBA specimens. This was probably due to the fact that the introduction of the -Ph-CF{sub 3} groups into the side chain of the epoxy resin resulted in improving the electrical properties and toughness of the cured DGEBA-F epoxy resin.

  9. Optimization of the rheological properties of epoxy resins for glass and carbon reinforced plastics

    Science.gov (United States)

    Phyo Maung, Pyi; Malysheva, G.; Romanova, I.

    2016-10-01

    Vacuum assisted resin transfer moulding (VARTM) offers advantages such as simplicity, low cost of consumables, and the ability to carry out the impregnation process and curing without using expensive equipment and tooling. In the VARTM process, rheological properties of resin have a critical impact on the impregnation and curing process. In this article, the experimental results of viscosity are presented, including the glass transition temperature, and the tensile and bending strength of the epoxy binders with the amine hardener, which depend on the quantity of its active solvent composition. The active solvent used is diethylene glycol. It shows that for an increase in the content of the active solvent, a reduction in the viscosity and a reduction of the glass transition temperature and strength occurs. The optimum composition of the binder is selected by using the Pareto optimization criteria and the Cayley - Smorodinskaya method. By using the epoxy binder, the active solvent should not exceed 10-15% by weight. This approach helps to optimize the amount of active solvent added to the epoxy resins for the criterion of viscosity, strength, and heat resistance.

  10. Development of microwave absorbing materials prepared from a polymer binder including Japanese lacquer and epoxy resin

    Science.gov (United States)

    Iwamaru, T.; Katsumata, H.; Uekusa, S.; Ooyagi, H.; Ishimura, T.; Miyakoshi, T.

    Microwave absorption composites were synthesized from a poly urushiol epoxy resin (PUE) mixed with one of microwave absorbing materials; Ni-Zn ferrite, Soot, Black lead, and carbon nano tube (CNT) to investigate their microwave absorption properties. PUE binders were specially made from Japanese lacquer and epoxy resin, where Japanese lacquer has been traditionally used for bond and paint because it has excellent beauty. Japanese lacquer solidifies with oxygen contained in air's moisture, which has difficulty in making composite, but we improved Japanese lacquer's solidification properties by use of epoxy resin. We made 10 mm thickness composite samples and cut them into toroidal shape to measure permittivity, permeability, and reflection loss in frequencies ranging from 50 Hz to 20 GHz. Electric magnetic absorber's composites synthesized from a PUE binders mixed either with Soot or CNT showed significantly higher wave absorption over -27 dB than the others at frequencies around 18 GHz, although Japanese lacquer itself doesn't affect absorption. This means Japanese lacquer can be used as binder materials for microwave absorbers.

  11. Effect of toughened epoxy resin on partial discharge at solid-solid interface

    Science.gov (United States)

    Manping, Li; Kai, Wu; Zhao, Zhang; Yonghong, Cheng

    2017-02-01

    A series of solid-solid interfaces, consisting of ceramic-epoxy resin interface samples with a tip-plate electrode, were investigated by performing partial discharge tests and real-time electrical tree observations. A toughening agent was added to the epoxy resin at different ratios for comparison. The impact strength, differential scanning calorimetry (DSC) and dielectric properties of the cured compositions and ceramic were tested. The electric field strength at the tip was calculated based on Maxwell’s theory. The test results show that the addition of a toughener can improve the impact strength of epoxy resin but it decreases the partial discharge inception voltage (PDIV) of the interface sample. At the same time, toughening leads to complex branches of the electrical tree. The simulation result suggests that this reduction of the PDIV cannot be explained by a change of permittivity due to the addition of a toughening agent. The microstructural change caused by toughening was considered to be the key factor for lower PDIV and complex electrical tree branches. Supported by China Academy of Engineering Physics (Project 2014B05005).

  12. Drinking water contaminants from epoxy resin-coated pipes: A field study.

    Science.gov (United States)

    Rajasärkkä, Johanna; Pernica, Marek; Kuta, Jan; Lašňák, Jonáš; Šimek, Zdenĕk; Bláha, Luděk

    2016-10-15

    Rehabilitation of aged drinking water pipes is an extensive renovation and increasingly topical in many European cities. Spray-on-lining of drinking water pipes is an alternative cost-effective rehabilitation technology in which the insides of pipes are relined with organic polymer. A commonly used polymer is epoxy resin consisting of monomer bisphenol A (BPA). Leaching of BPA from epoxy lining to drinking water has been a concern among public and authorities. Currently epoxy lining is not recommended in some countries. BPA leaching has been demonstrated in laboratory studies but the behavior and ageing process of epoxy lining in situ is not well known. In this study 6 locations with different age epoxy linings of drinking water pipes done using two distinct technologies were studied. While bisphenol F, 4-n-nonylphenol, and 4-t-octylphenol were rarely found and in trace concentrations, BPA was detected in majority of samples. Pipes lined with the older technology (LSE) leached more BPA than those with more recent technology (DonPro): maxima in cold water were 0.25 μg/L and 10 ng/L, respectively. Incubation of water in pipes 8-10 h prior to sampling increased BPA concentration in cold water 1.1-43-fold. Hot water temperature caused even more BPA leaching - at maximum 23.5 μg/L. The influence of ageing of epoxy lining on BPA leaching on could be shown in case of LSE technology: locations with 8-9 years old lining leached 4-20-fold more BPA compared to a location with 2-year-old lining. Analysis of metals showed that epoxy lining can reduce especially iron concentration in water. No significant burden to water could be shown by the analyzed 72 volatile organic compounds, including epichlorhydrin, precursor used in epoxy resin. Estrogenicity was detected in water samples with the highest BPA loads. Comparable responses of two yeast bioreporters (estrogen receptor α and BPA-targeted) indicated that bisphenol-like compounds were the main cause of estrogenicity

  13. Dermatosis profesional por resina epoxi: Presentación de un caso clínico Professional dermatosis for epoxy resin: A clinical case report

    Directory of Open Access Journals (Sweden)

    S Gaviola

    2008-06-01

    Full Text Available Mostramos un caso de dermatosis profesional originado por plásticos (resinas epoxi y la importancia de la detección precoz. Las resinas epoxi son de gran utilización en todo tipo de industrias (artes graficas, construcción, electrónica, componentes de prótesis traumatológicas, prótesis odontológicas, etc. y sus componentes pueden ser causa de dermatitis de contacto irritativa y por sensibilización.We describe a case of professional dermatosis caused by exposition to plastic products (epoxy resin and importance of early detection. The epoxy resins are widely used in all types of industries (graphics arts, construction, electronics, traumathological and odontological prothesis, etc. and their components may be the cause of contact dermatitis and sensitivity. Risk factors at work with epoxy resins are present during the production base resins, hardening agents, plasticizers and dilutants increase the risk of exposition at work. This requires preventive measures and early diagnosis.

  14. Tensile Properties of Unsaturated Polyester and Epoxy Resin Reinforced with Recycled Carbon-Fiber-Reinforced Plastic

    Science.gov (United States)

    Okayasu, Mitsuhiro; Kondo, Yuta

    2017-08-01

    To better understand the mechanical properties of recycled carbon-fiber-reinforced plastic (rCFRP), CFRP crushed into small pieces was mixed randomly in different proportions (0-30 wt%) with two different resins: unsaturated polyester and epoxy resin. Two different sizes of crushed CFRP were used: 0.1 mm × 0.007 mm (milled CFRP) and 30 mm × 2 mm (chopped CFRP). The tensile strength of rCFRP was found to depend on both the proportion and the size of the CFRP pieces. It increased with increasing proportion of chopped CFRP, but decreased with increasing proportion of milled CFRP. There was no clear dependence of the tensile strength on the resin that was used. A low fracture strain was found for rCFRP samples made with chopped CFRP, in contrast to those made with milled CFRP. The fracture strain was found to increase with increasing content of milled CFRP up to 20 wt%, at which point, coalescence of existing microvoids occurred. However, there was a reduction in fracture strain for rCFRP with 30 wt% of milled CFRP, owing to the formation of defects (blow holes). Overall, the fracture strain was higher for rCFRPs based on epoxy resin than for those based on unsaturated polyester with the same CFRP content, because of the high ductility of the epoxy resin. The different tensile properties reflected different failure characteristics, with the use of chopped CFRP leading to a complicated rough fracture surface and with milled CFRP causing ductile failure through the presence of tiny dimple-like fractures. However, for a high content of milled CFRP (30 wt%), large blow holes were observed, leading to low ductility.

  15. Electron beam curing of acrylated epoxy resins for anisotropic conductive film application

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Tae gyu; Lee, Inhyuk; Lee, Jungmin [Department of Physics and Institute of Nanoscience and Nanotechnology, Hanyang University, Seoul, 133-791 (Korea, Republic of); Hwang, Jinyoung; Chung, Hoeil [Department of Chemistry, Hanyang University, Seoul, 133-791 (Korea, Republic of); Shin, Kwanwoo [Department of Chemistry and Interdisciplinary Program of Integrated Biotechnology, Institute of Biological Interfaces, Sogang University, Seoul 121-742 (Korea, Republic of); Seo, Young soo [Department of Nanoscience Technology, Sejong University, Seoul, 143-747 (Korea, Republic of); Kim, Jaeyong, E-mail: kimjy@hanyang.ac.kr [Department of Physics and Institute of Nanoscience and Nanotechnology, Hanyang University, Seoul, 133-791 (Korea, Republic of)

    2013-11-29

    Radiation curable acrylated epoxy oligomer was found to be an effective resin system for application to electron beams (EB) on curing of anisotropic conducting film. To study curing degree as a function of EB dosage, we irradiated bisphenol-A type acrylate epoxy oligomer samples with doses of 5 to 600 kGy of EB. To investigate the effect of a metal barrier for potential industrial application, a 3 mm thick Al plate was placed in front of the samples, and the curing parameters were compared with the ones irradiated without an Al plate. As the dosage of the EB irradiation was increased, the glass transition temperature of the sample ranged from 46.8 to 62.2 °C for the epoxy composites without placing an Al plate, and from 46.4 to 64.1 °C for their counterparts with a 3 mm thick Al plate. These results confirm that enhancement of the curing degree with increasing EB irradiation is possible even in the presence of a metal plate. The scanning electron microscope images of the fracture surfaces are presented as evidence of the morphological changes of the EB cured epoxy samples. - Highlights: ► Acrylated epoxy oligomer was cured by irradiation of the electron beam. ► Curing degree was increased with increasing dosage of the electron beam. ► Electron beam can be used for the bonding of anisotropic conducting films.

  16. The Influence of Nano-Al2O3 Additive on the Adhesion between Epoxy Resin and Steel Substrate

    Institute of Scientific and Technical Information of China (English)

    ZHAILan-lan; LINGGuo-ping

    2004-01-01

    The influence of nano-A1203 additive on the adhesion between epoxy resin and steel substrate has been investigated. The results of tensile testing indicated that the adhesion strength was increased dramatically by addition of Al2O3 nanoparticles in epoxy resin compared with that of the unmodified resin. The highest adhesion strength was obtained with 1 wt% nano-Al2O3 added in epoxy adhesive, more than two times higher than that of the unmodified. Scanning electronic microscope (SEM) revealed that a boundary layer exists between epoxy and steel substrate, energy spectrum analysis indicates there is enrichment of the nano-Al2O3 particle. Those results confirmed that the nano-Al2O3 additive was closely related to the change of interface morphology and the improvement of adhesion strength. The reason for adhesion improvement was also be discussed.

  17. The Influence of Nano-Al2O3 Additive on the Adhesion between Epoxy Resin and Steel Substrate

    Institute of Scientific and Technical Information of China (English)

    ZHAI Lan-lan; LING Guo-ping

    2004-01-01

    The influence of nano-Al2O3 additive on the adhesion between epoxy resin and steel substrate has been investigated. The results of tensile testing indicated that the adhesion strength was increased dramatically by addition of Al2O3 nanoparticles in epoxy resin compared with that of the unmodified resin. The highest adhesion strength was obtained with 1 wt% nano-Al2O3 added in epoxy adhesive, more than two times higher than that of the unmodified. Scanning electronic microscope (SEM) revealed that a boundary layer exists between epoxy and steel substrate, energy spectrum analysis indicates there is enrichment of the nano-Al2O3 particle. Those results confirmed that the nano-Al2O3 additive was closely related to the change of interface morphology and the improvement of adhesion strength. The reason for adhesion improvement was also be discussed.

  18. The overall effect of reactive rubber nanoparticles and nano clay on the mechanical properties of epoxy resin

    Directory of Open Access Journals (Sweden)

    Mona A. Ahmed

    2015-10-01

    Full Text Available Epoxy resin, a thermoset polymer matrix used for technical applications; exhibit some outstanding properties such as high modulus, high chemical resistance and high dimension stability. However, the high crosslink density of epoxy makes this material brittle with low impact strength and poor resistance to crack propagation, which limits their many end use applications. It is an important objective to explore new routes toward toughening of epoxy resins without affecting stiffness, strength, and glass temperature. The main objective of this work is to incorporate reactive rubber nanoparticles (RRNP and organically modified nanoclay (Cloisite-30B into epoxy matrix with the aim of obtaining improved material with higher toughness without compromising the other desired mechanical properties. Epoxy hybrids nanocomposites containing RRNP, Cloisite-30B and RRNP/Cloisite-30B mixture were synthesized and characterized to compare the different properties which normally result from the use of single filler and hence aiming to improve toughness/stiffness balance.

  19. Analysis of tissue reactions to methacrylate resin-based, epoxy resin-based, and zinc oxide-eugenol endodontic sealers.

    Science.gov (United States)

    Scarparo, Roberta Kochenborger; Grecca, Fabiana Soares; Fachin, Elaine Vianna Freitas

    2009-02-01

    The purpose of this study was to investigate the reaction of the subcutaneous connective tissue of rats to methacrylate resin-based sealer (EndoREZ), epoxy resin-based sealer (AH Plus), and zinc oxide-eugenol sealer (EndoFill). Polyethylene tubes containing the test materials were implanted in 18 rats. After 7, 30, and 60 days, tissues were collected for biopsy and fixed and processed for histologic evaluation. Observations were made of the cellular inflammatory component, the fibrous condensation, and the abscess formation. Comparisons between groups and times were made with the Friedman and Kruskall-Wallis tests. EndoREZ and EndoFill sealers showed a more intense and longer-lasting inflammation. With AH Plus, the inflammatory reaction showed a tendency to diminish over time. The only group to show a statistically significant reduction in inflammation during the 60-day period was the control group. None of the materials tested proved to have ideal characteristics for biocompatibility.

  20. Recyclable epoxy resins: An example of green approach for advanced composite applications

    Science.gov (United States)

    Cicala, Gianluca; Rosa, Daniela La; Musarra, Marco; Saccullo, Giuseppe; Banatao, Rey; Pastine, Stefan

    2016-05-01

    Automotive composite applications are increasingly growing due to demand for lightweight structures to comply to the requirements for fuel reduction. HP-RTM is gaining relevance as one of the preferred production technologies for high volume applications. The BMW i3 life module being a notable example of HP-RTM application. The key aspects of HP-RTM are the short injection times (i.e. less than 1min) and the fast curing of the thermoset resins (i.e. less than 10min). The choice of using thermosets poses relevant issues for their limited recycling options. The standard recycling solution is the incineration but, this solution poses some concerns in terms of global environmental impact. Novel solutions are presented in this work based on the use of recyclable epoxy systems. In our work the results of experimentation carried out by our group with cleavable ammines by Connora Technologies and bioepoxy resins by Entropy Resins will be discussed. The multiple uses of recycled matrices obtained treating the recyclable epoxy resins are discussed in the framework of a "cradle" to "crave" approach. Finally, Life Cycle Assessment (LCA) is used to evaluate the environmental benefits of the proposed approach.

  1. Aminophenoxycyclotriphosphazene cured epoxy resins and the composites, laminates, adhesives and structures thereof

    Science.gov (United States)

    Kumar, Devendra (Inventor); Fohlen, George M. (Inventor); Parker, John A. (Inventor)

    1977-01-01

    Aminophenoxy cyclotriphosphazenes such as hexakis (4-aminophenoxy) cyclotriphosphazene and tris (4-aminophenoxy)-tris phenoxy cyclotriphosphazene are used as curing agents for epoxy resins. These 1,2-epoxy resins are selected from di- or polyepoxide containing organic moieties of the formula (CH2-CHO-CH2) m-W-R-W- (CH2CH-CH2O)m where R is diphenyl dimethylmethane, diphenylmethane; W is a nitrogen or oxygen atom; and m is 1 when W is oxygen and 2 when W is nitrogen. The resins are cured thermally in stages at between about 110 to 135 C for between about 1 and 10 min, then at between about 175 to 185 C for between 0.5 to 10 hr and post cured at between about 215 and 235 C for between 0.1 and 2 hr. These resins are useful for making fire resistant elevated temperature stable composites, laminates, molded parts, and adhesives and structures, usually for aircraft secondary structures and for spacecraft construction.

  2. Effect of resin on impact damage tolerance of graphite/epoxy laminates

    Science.gov (United States)

    Williams, J. G.; Rhodes, M. D.

    1982-01-01

    Twenty-four different epoxy resin systems were evaluated by a variety of test techniques to identify materials that exhibited improved impact damage tolerance in graphite/epoxy composite laminates. Forty-eight-ply composite panels of five of the material systems were able to sustain 100 m/s impact by a 1.27-cm-diameter aluminum projectile while statically loaded to strains of 0.005. Of the five materials with the highest tolerance to impact, two had elastomeric additives, two had thermoplastic additives, and one had a vinyl modifier; all the five systems used bisphenol A as the base resin. An evaluation of test results shows that the laminate damage tolerance is largely determined by the resin tensile properties, and that improvements in laminate damage tolerance are not necessarily made at the expense of room-temperature mechanical properties. The results also suggest that a resin volume fraction of 40 percent or greater may be required to permit the plastic flow between fibers necessary for improved damage tolerance.

  3. Syringaresinol: A Renewable and Safer Alternative to Bisphenol A for Epoxy-Amine Resins.

    Science.gov (United States)

    Janvier, Marine; Hollande, Louis; Jaufurally, Abdus Samad; Pernes, Miguel; Ménard, Raphaël; Grimaldi, Marina; Beaugrand, Johnny; Balaguer, Patrick; Ducrot, Paul-Henri; Allais, Florent

    2017-02-22

    A renewable bisepoxide, SYR-EPO, was prepared from syringaresinol, a naturally occurring bisphenol deriving from sinapic acid, by using a chemo-enzymatic synthetic pathway. Estrogenic activity tests revealed no endocrine disruption for syringaresinol. Its glycidylation afforded SYR-EPO with excellent yield and purity. This biobased, safe epoxy precursor was then cured with conventional and renewable diamines for the preparation of epoxy-amine resins. The resulting thermosets were thermally and mechanically characterized. Thermal analyses of these new resins showed excellent thermal stabilities (Td5 % =279-309 °C) and Tg ranging from 73 to 126 °C, almost reaching the properties of those obtained with the diglycidylether of bisphenol A (DGEBA), extensively used in the polymer industry (Td5 % =319 °C and Tg =150 °C for DGEBA/isophorone diamine resins). Degradation studies in NaOH and HCl aqueous solutions also highlighted the robustness of the syringaresinol-based resins, similar to bisphenol A (BPA). All these results undoubtedly confirmed the potential of syringaresinol as a greener and safer substitute for BPA. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Surface Coating Studies of Polyurethane Derived from [(Alkyd-(Epoxy Resin Treated Castor Oil] Using Isophorene Diisocynate - II

    Directory of Open Access Journals (Sweden)

    Dinesh. P. Patel

    2012-07-01

    Full Text Available Castor oil (C was reacted with profitable epoxy resin (E (diglycidylether of bisphenol-A, DGEBF at a range of mole ratios. The consequential products (Castor oil- Epoxy resin were nominated as CEs. Isocyanate terminated castor oil Polyurethane (ICOPU was prepared by reaction of castor oil and various proportion of Isophoren diisocyanate. A commercial alkyd resin was blended with various proportions of CEs and ICOPU. A unique solvent system, which shows a one – phase clear solution and a clear coat of binder system, was used. All the blends were applied on mild steel panels and characterized for drying time, adhesion, flexibility, hardness, impact resistance and chemical resistance properties.

  5. Synthesis of a Novel Phosphorus-Containing Flame Retardant Curing Agent and Its Application in Epoxy Resins.

    Science.gov (United States)

    Zhang, Hongkun; Xu, Miaojun; Li, Bin

    2016-03-01

    A novel phosphorus-containing compound diphenyl-(2,5-dihydroxyphenyl)-phosphine oxide defined as DPDHPPO was synthesized and used as flame retardant and curing agent for epoxy resins (EP). The chemical structure was well characterized by Fourier transform infrared (FTIR) spectroscopy, 1H, 13C and 31P nuclear magnetic resonance. The flame retardant properties, combusting performances and thermal degradation behaviors of the cured epoxy resins were investigated by limiting oxygen index (LOI), vertical burning tests (UL-94), cone calorimeter and thermogravimetric analysis (TGA) tests. The morphologies and chemical compositions of char residues for cured epoxy resins were investigated by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), respectively. The water resistant properties were evaluated by putting the samples into distilled water at 70 degrees C for 168 h. The results revealed that the EP/40 wt% DPDHPPO/60 wt% PDA thermosets successfully passed UL-94 V-0 flammability rating and the LOI value was as high as 31.9%. The cone tests results revealed that the incorporation of DPDHPPO efficiently reduced the combustion parameters of epoxy resins thermosets, such as heat release rate (HRR), total heat release (THR) and so on. The TGA results indicated that the introduction of DPDHPPO promoted epoxy resins matrix decomposed ahead of time compared with that of pure EP and led to a higher char yield and thermal stability at high temperature. The morphological structures and analysis of XPS of char residues revealed that DPDHPPO benefited to the formation of a sufficient, compact and homogeneous char layer with rich flame retardant elements on the epoxy resins materials surface during combustion. After water resistance tests, EP/40 wt% DPDHPPO/60 wt% PDA thermosets still remained excellent flame retardancy, the moisture absorption of epoxy resins thermosets decreased with the increase of DPDHPPO contents in the thermosets due to the existing

  6. Role of Interphase in the Mechanical Behavior of Silica/Epoxy Resin Nanocomposites

    Directory of Open Access Journals (Sweden)

    Yi Hua

    2015-06-01

    Full Text Available A nanoscale representative volume element has been developed to investigate the effect of interphase geometry and property on the mechanical behavior of silica/epoxy resin nanocomposites. The role of interphase–matrix bonding was also examined. Results suggested that interphase modulus and interfacial bonding conditions had significant influence on the effective stiffness of nanocomposites, while its sensitivities with respect to both the thickness and the gradient property of the interphase was minimal. The stiffer interphase demonstrated a higher load-sharing capacity, which also increased the stress distribution uniformity within the resin nanocomposites. Under the condition of imperfect interfacial bonding, the effective stiffness of nanocomposites was much lower, which was in good agreement with the documented experimental observations. This work could shed some light on the design and manufacturing of resin nanocomposites.

  7. Dynamic Mechanical Properties and Thermal Effect of an Epoxy Resin Composite, Encapsulation's Element of a New Electronic Component

    Science.gov (United States)

    Rmili, W.; Deffarges, M. P.; Chalon, F.; Ma, Z.; Leroy, R.

    2013-11-01

    Epoxy resin is used in many industrial applications principally in the microelectronic field to protect integrated circuits. However, these components are subject to various environments such as moisture and thermal fluctuations during packaging. Consequently, mechanical, physical and chemical properties of the resin can be affected. For an epoxy resin composite designed for a future application, an evaluation of the relevant properties was carried out using a dynamic mechanical analyzer and a thermogravimetric analysis (TGA) instrument. The surface morphology was investigated using scanning electron microscopy to examine the impact of post-cured treatment through evolution of the rigidity and of the glass transition temperature. Subsequently, a temperature classification was proposed to define the temperature limit for safe use of the material. Finally, temperature degradation was observed and confirmed by TGA tests. Results from all of these analyses bring understanding to the phenomenon of thermal degradation and its influence on the stability of the epoxy resin composite.

  8. Structural characteristics and properties of polyurethane modified TDE-85/MeTHPA epoxy resin with interpenetrating polymer networks

    Institute of Scientific and Technical Information of China (English)

    LI Zhi-hua; HUANG Yao-peng; REN Dong-yan; ZHENG Zi-qiao

    2008-01-01

    Diglycidyl-4,5-epoxycyciohexane-1,2-dicarboxylate(TDE-85)/methyl tetrahydrophthalic anhydride (MeTHPA) epoxy resin was modified with polyurethane(PU) and the interpenetrating polymer networks(IPNs) of PU-modified TDE-85/MeTHPA resin were prepared. The structural characteristics and properties of PU-modified TDE-85/MeTHPA resin were investigated by Fourier transform infrared (FTIR) spectrum, emission scanning electron microscopy (SEM) and thermogravimetry (TG). The results indicate that epoxy polymer network (Ⅰ) and polyurethane polymer network (Ⅱ) of the modified resin can be obtained and the networks (Ⅰ) and (Ⅱ) interpenetrate and tangle highly each other at the phase interface. The micro morphology presents heterogeneous structure. The integrative properties of PU-modified TDE-85/MeTHPA epoxy resin are improved obviously. The PU-modified TDE-85/MeTHPA resin's tensile strength reaches 69.39 MPa, the impact strength reaches 23.56 kJ/m, the temperature for the system to lose 1% mass (t1%) is 300℃, and that for the system to lose 50% mass (t50%) is 378℃. Compared with those of TDE-85/MeTHPA resin, the tensile strength, impact strength, t1% and t50% of the PU-modified resin increases by 48%,115%,30℃,11℃, respectively. The PU-modified TDE-85/MeTHPA resin has the structure characteristics and properties of interpenetrating polymer networks.

  9. Damping of Ni-Mn-Ga epoxy resin composites

    Institute of Scientific and Technical Information of China (English)

    Wei Liang; He Yu; Liu Yufeng; Yang Naibin

    2013-01-01

    By combining the advantages of efficient damping and high mechanical properties, Ni-Mn-Ga particle composites have a very good prospect for applications in damping structure design. In this paper, a ferromagnetic shape memory alloy Ni-Mn-Ga composite is prepared. Ni-Mn-Ga particle/bisphenol-A epoxy composite cantilever beam vibration tests under a magnetic field and without the magnetic field are conducted to analyze the structural damping ratios n. Meanwhile, the damping characteristics of the Ni-Mn-Ga composite are studied through the axial loading-unloading method and the acoustic emission signals method. The damping coefficient of the composite for different Ni-Mn-Ga volume fractions is obtained. The interface properties of the composite are discussed by micro examination and axial loading. The relationships between the damping of the composite and that of the component materials are discussed. The specific damping capacity (SDC) and acoustic emission counts diagram of different specimens with different Ni-Mn-Ga volume fractions are analyzed.

  10. Efficientcy of corrosion protection properties of epoxy resin/cashew nut shell liquid alloy reinforced with titanium dioxide

    Directory of Open Access Journals (Sweden)

    Wilaivan Loonpooht

    2014-12-01

    Full Text Available The cure behavior of epoxy resin containing cashew nut shell liquid (CNSL and corrosion protective performance of epoxy alloy reinforced with titanium dioxide (TiO2 have been investigated. According to FTIR spectra obtained from epoxy alloys, the CNSL can be employed as a curing agent. The curing process occurred when amount of CNSL was as low as 20%wt. It was found experimentally that the CNSL used for epoxy curing should not be higher than 40%wt.in order to minimize amount CNSL left after reaction. The corrosion protective performance of epoxy alloy on aluminum sheets was carried out. The results revealed that the ability of corrosion resistance increased with the amount of TiO2 introduced into the Epoxy/CNSL film investigated. In this work, the highest corrosion resistance value was found when the TiO2 concentration of 1.5 %wt was reached.

  11. The effect of mechanical relaxation on ultra-fast charge pulses in flexible epoxy resin nanocomposites

    Science.gov (United States)

    Montanari, G. C.; Xu, M.; Fabiani, D.; Dissado, L. A.

    2012-06-01

    Previously we have reported the existence of small-amplitude charge pulses in crosslinked Polyethylene (XLPE) and epoxy resin with a mobility several orders of magnitude higher than that found for the incoherent charge transport relevant to the steady state current. Here the relationship of this phenomenon to mechanical relaxation in the material is investigated by using a series of epoxy resin nanocomposites based on a resin that has its flexibility increased above that of the fully cured glassy epoxy network by the addition of a suitable flexibilizing chemical. Differential Scanning Calorimetry (DSC) measurements show that the stiffness of the nanocomposite is progressively increased as the nanoparticle concentration increases. Pulsed Electro-Acoustic (PEA) measurements reveal that both positive and negative fast charge pulses exist in the unfilled epoxy at 45 and 70°C under a field of 10 kV/mm with mobility 5×10-10 to 9×10-10 m2 V-1 s-1, amplitude between 2×10-5 and 3.6×10-5 C m-2 and repetition rates between 8 and 12 s-1. These values are reduced progressively as the nanoparticle concentration is increased from 0% in the unfilled epoxy. A β-mode mechanical relaxation is identified in the loss modulus by Dynamical Mechanical Analysis (DMA), whose activation energy moves to higher values with increasing nanoparticle concentration. It is shown that the repetition rates of both positive and negative pulses have similar values and are correlated with the β-mode activation energy; a similar correlation is found for the activation energy of the mobility of positive pulses. The correlation of the activation energy of the mobility of negative pulses and that of the β-mode is weaker although both show a progressive increase with nanoparticle concentration. The modification of the fast charge pulse properties by the mechanical stiffness of the epoxy nanocomposite is discussed in terms of the theory presented previously for their formation and transport.

  12. Thermal, mechanical, and electrical properties of fluorine-containing epoxy resins

    Energy Technology Data Exchange (ETDEWEB)

    Park, S.J.; Jin, F.L.; Lee, J.R. [Korea Research Institute of Chemical Technology, Taejeon (Korea); Shin, J.S. [Chungbuk National University, Chongju (Korea)

    2002-05-01

    The dielectric constants of fluorine-containing epoxy resins, 2-diglycidylether of benzotrifluoride(FER)/4,4'-diamino-diphenyl methane (DDM) and diglycidylether of bisphenol-A( DGEBA) DDM systems were evaluated by dielectric spectrometer. Glass transition temperature and thermal stability factors, including initial decomposed temperature, temperatures of maximum rate of degradation, and decomposition activation energy of the cured specimens were investigated by dynamic mechanical analysis and thermogravimetric analysis. For the mechanical properties of the casting specimens, The fracture toughness, flexural, and impact tests were performed, and their fractured surfaces were examined by scanning electron microscope. The dielectric constant of FER/DDM system was lower than that of commercial DGEBA/DDM system, and the mechanical properties of the cured specimens showed higher values than those of DGEBA/DDM system, This was probably due to the introduction of trifluoromethyl(CF{sub 3}) group into the side chain of the epoxy resins, resulting in improving the electric and mechanical properties of the epoxy cure system studied. (author). 22 refs., 2 tabs., 7 figs.

  13. Biodeterioration of epoxy resin: a microbial survey through culture-independent and culture-dependent approaches.

    Science.gov (United States)

    Pangallo, Domenico; Bučková, Maria; Kraková, Lucia; Puškárová, Andrea; Šaková, Nikoleta; Grivalský, Tomaš; Chovanová, Katarina; Zemánková, Milina

    2015-02-01

    During the 20th century, synthetic polymers were greatly used in the field of art. In particular, the epoxy resins were used for both conservation and for creating sculptures. The biodeterioration of these polymers has not been adequately studied. The aim of this investigation was to examine the microflora responsible for the deterioration of an epoxy statue exposed to outdoor conditions. Fungal and bacterial microflora were isolated from the art object, clustered by fluorescence-ITS (internal transcribed spacer), identified by ITS and 16S rRNA sequencing and tested for their lipolytic abilities by three agar assays. Different algal, bacterial, cyanobacterial and fungal clone libraries were constructed. The surrounding airborne microflora was analyzed using culture-dependent and culture-independent approaches. The results indicated the presence, on the statue surface, of an interesting and differentiate microbial community composed of rock-inhabiting members, algal photobionts (Trebouxia spp., Chloroidium ellipsoideum and Chlorella angustoellipsoidea), Cyanobacteria (Leptolyngbya sp., Phormidium sp., Cylindrospermum stagnale, Hassallia byssoidea and Geitlerinema sp.), black yeasts related to the species Friedmanniomyces endolithicus, Pseudotaeniolina globosa, Phaeococcomyces catenatus and Catenulostroma germanicum and several plant-associated fungi. This investigation provides new information on the potential microfloral inhabitants of epoxy resin discovering a new ecological niche, occupied mainly by several members of rock-colonizing microbial species.

  14. Graphite Nanoplatelet Modified Epoxy Resin for Carbon Fibre Reinforced Plastics with Enhanced Properties

    Directory of Open Access Journals (Sweden)

    Yan Li

    2017-01-01

    Full Text Available A simple approach to deliver graphene or graphite nanoplatelets (GNPs into carbon fibre reinforced plastic (CFRPs to enhance the multifunctional properties of carbon/epoxy laminates was demonstrated. GNPs improved the typically low interlaminar mechanical, thermal, and electrical properties of CFRPs after direct vacuum infusion of GNP doped resin obtained via in situ exfoliation by three-roll milling (TRM. Compared to high shear mixing or probe ultrasonication, TRM produces higher shear rates and stresses to exfoliate and finely disperse GNP particles within an epoxy matrix. This environmentally friendly and industrial scalable process does not require the use of solvents, additives, or chemical treatments. The flexural modulus and interlaminar shear strength (ILSS of CFRPs was increased by 15% and by 18%, respectively, with the addition of 5 wt.% in situ exfoliated GNP in the doped epoxy resin. Out-of-plane electrical and thermal conductivity, at the same filler content, were, respectively, improved by nearly two orders of magnitude and 50%.

  15. Organo-modified bentonites as new flame retardant fillers in epoxy resin nanocomposites

    Science.gov (United States)

    Benelli, Tiziana; D'Angelo, Emanuele; Mazzocchetti, Laura; Saraga, Federico; Sambri, Letizia; Franchini, Mauro Comes; Giorgini, Loris

    2016-05-01

    The present work deals with two organophilic bentonites, based on nitrogen-containing compounds: these organoclays were synthesized via an ion exchange process starting from pristine bentonite with 6-(4-butylphenyl)-1,3,5-triazine-2,4-diamine (BFTDA) and 11-amino-N-(pyridine-2yl)undecanamide (APUA) and then used for the production of epoxy-based flame retardant nanocomposites. The amount of organic modifier in the organoclays Bento-BFTDA and Bento-APUA was determined with a TGA analysis and is around 0.4mmol/g for both samples. The effect of the organoclays on a commercial epoxy resin nanocomposite's thermo-mechanical and flammability properties was investigated. Composites containing 3wt% and 5wt% of the nanofillers were prepared by solventless addition of each organoclay to the epoxy resin, followed by further addition of the hardener component. For the sake of comparison a similar nanocomposite with the plain unmodified bentonite was produced in similar condition. The nanocomposites's thermo-mechanical properties of all the produced samples were measured and they resulted slightly improved or practically unaffected. On the contrary, when the flame behaviour was assessed in the cone-calorimeter, an encouraging decrease of 17% in the peak heat released rate (pHRR) was obtained at 3wt% loading level with Bento-APUA. This is a promising result, assessing that the APUA modified organoclay might act as flame retardant.

  16. Ultrasonic Characterisation of Epoxy Resin/Polyethylene Terephthalate (PET Char Powder Composites

    Directory of Open Access Journals (Sweden)

    Imran ORAL

    2016-11-01

    Full Text Available This study is carried out in order to determine the elastic properties of the Epoxy Resin (ER / Polyethylene terephthalate (PET Char Powder Composites by ultrasonic wave velocity measurement method. Plastic waste was recycled as raw material for the preparation of epoxy composite materials. The supplied chars were mixed with epoxy resin matrix at weight percentages of 10 %, 20 % and 30 % for preparing ER/PET Char Powder (PCP composites. The effect of PET char powder on the elastic properties of ER/PCP composites were investigated by ultrasonic pulse-echo method. According to the obtained results, the composition ratio of 80:20 is the most appropriate composition ratio, which gave the highest elastic constants values for ER/PCP composites. On the other hand, the best electrical conductivity value was obtained for 70:30 composition ratio. It was observed that ultrasonic shear wave velocity correlated more perfectly than any other parameters with hardness.DOI: http://dx.doi.org/10.5755/j01.ms.22.4.12190

  17. Syntheses of silsesquioxane (POSS)-based inorganic/organic hybrid and the application in reinforcement for an epoxy resin.

    Science.gov (United States)

    Ni, Caihua; Ni, Guifeng; Zhang, Liping; Mi, Jiaquan; Yao, Bolong; Zhu, Changping

    2011-10-01

    A new inorganic/organic hybrid material containing silsesquioxane was prepared by the reaction of caged octa (aminopropyl silsesquioxane) (POSS-NH(2)) with n-butyl glycidyl ether (nBGE) and 1,4-butanediol diglycidyl ether (BDGE). The copolymers of POSS, nBGE, and BDGE could be obtained with varied feed ratio of POSS-NH(2), nBGE, and BDGE in the preparation. The hybrid material was added into an epoxy resin (E51) for enhancing the toughening and thermal properties of the epoxy resin. The results showed that the toughening and the thermal properties of the cured epoxy resin were greatly improved by the addition of the hybrid. The enhancement was ascribed to nano-scale effect of the POSS structure and the formation of anchor structure in the cured network. The investigation of kinetics for the curing process of the hybrid-modified epoxy resin revealed that two kinds of curing reactions occurred in different temperature ranges. They were attributed to the reactions between amino groups of the curing agent with epoxy groups of E51 and with residue epoxy groups in the hybrid. The reacting activation energies were calculated based on Kissinger's and Flynn-Wall-Ozawa's methods, respectively.

  18. The Effects of in Situ-Formed Silver Nanoparticles on the Electrical Properties of Epoxy Resin Filled with Silver Nanowires

    Directory of Open Access Journals (Sweden)

    Gwang-Seok Song

    2016-04-01

    Full Text Available A novel method for preparing epoxy/silver nanocomposites was developed via the in situ formation of silver nanoparticles (AgNPs within the epoxy resin matrix while using silver nanowires (AgNWs as a conductive filler. The silver–imidazole complex was synthesized from silver acetate (AgAc and 1-(2-cyanoethyl-2-ethyl-4-methylimidazole (imidazole. AgNPs were generated in situ during the curing of the epoxy resin through the thermal decomposition of the AgAc–imidazole complex, which was capable of reducing Ag+ to Ag by itself. The released imidazole acted as a catalyst to cure the epoxy. Additionally, after the curing process, the in situ-generated AgNPs were stabilized by the formed epoxy network. Therefore, by using the thermal decomposition method, uniformly dispersed AgNPs of approximately 100 nm were formed in situ in the epoxy matrix filled with AgNWs. It was observed that the nanocomposites containing in situ-formed AgNPs exhibited isotropic electrical properties in the epoxy resins in the presence of AgNWs.

  19. Enhanced actuation performance of piezoelectric fiber composites induced by incorporated BaTiO3 nanoparticles in epoxy resin

    Science.gov (United States)

    Wu, Mingliang; Yuan, Xi; Luo, Hang; Chen, Haiyan; Chen, Chao; Zhou, Kechao; Zhang, Dou

    2017-05-01

    Piezoelectric fiber composites (PFCs) have attracted much interest owing to their flexibility and toughness compared with conventional monolithic piezoceramic wafers. The free strain values and actuation property of PFCs strongly depend on the active electric field applied in Pb(Zr1 - xTix)O3 (PZT) fibers. Reducing the dielectric constant mismatch between PZT fiber and the assembling epoxy resin would greatly increase the active electric field in PZT fiber. Therefore, BaTiO3 (BT) nanoparticles were introduced into the epoxy resin to enhance the dielectric constant. Homogeneous dispersion of BT nanoparticles and tight adhesion with the epoxy resin were achieved through a surface modification by dopamine. The maximum dielectric constant of dopamine modified BT/epoxy (BT@Dop/epoxy) nanocomposites was 10.38 with 12 wt% BT@Dop content at 1 kHz. The maximum free strain of PFCs reached 1820 ppm with 6 wt% BT@Dop content, while PFCs assembled by pure epoxy showed 790 ppm at the same processing condition. The tip displacement of cantilever beam actuated by PFCs reached the peak of 19 mm at the resonance frequency with 6 wt% BT@Dop, which was improved by 90% comparing to PFCs with pure epoxy.

  20. Temperature dependence of isothermal curing reaction of epoxy resin studied by modulated differential scanning calorimetry and infrared spectroscopy

    Science.gov (United States)

    Yamasaki, Hideki; Morita, Shigeaki

    2016-11-01

    The isothermal curing reaction of bisphenol A diglycidyl ether epoxy (BADGE) resin with dimethyl diamino methane (DDM) hardener was investigated by means of modulated differential scanning calorimetry (MDSC) and infrared (IR) spectroscopy at 90, 100 and 120 °C. It was confirmed that the behavior of the bands assigned to the epoxy group, ether group, secondary amine and tertiary amine were different depending on temperature. At stoichiometric amounts of DDM and BADGE, the reaction at 90 and 100 °C compared with that at 120 °C, the oxirane or glycidyl group of epoxy resin and the secondary amine group were left even if reached at the end point of the reaction, and those reaction proceed as diffusion control continues longer. The reaction between 90 and 100 °C, it was different from the reactivity of the epoxy resin, various amino groups and ether group. Hence, the cured epoxy resin had a different composition. Moreover, it was also verified that the reactivity of the various amino groups and the etherification were difference, therefore, it was suggested that the cross-linkage construction of the cured resin at different temperature was different.

  1. The stability of new transparent polymeric materials: The epoxy trimethoxyboroxine system. Part 1: The preparation, characterization and curing of epoxy resins and their copolymers

    Science.gov (United States)

    Pearce, E.; Lin, S. C.

    1981-01-01

    The effects of resin composition, curing conditions fillers, and flame retardant additives on the flammability of diglycidyl ether of bisphenol-A (DGEBA) as measured by the oxygen index is examined. The oxygen index of DGEBA cured with various curing agents was between 0.198 to 0.238. Fillers and flame retardant additives can increase the oxygen index dependent on the material and the amount used. Changes in the basic cured resin properties can be anticipated with the addition of noncompatible additives. High flame resistant epoxy resins with good stability and mechanical properties are investigated.

  2. Surface modification of an epoxy resin with polyamines and polydopamine: Adhesion toward electroless deposited copper

    Energy Technology Data Exchange (ETDEWEB)

    Schaubroeck, David, E-mail: David.Schaubroeck@elis.ugent.be [Center for Microsystems Technology (CMST), IMEC and Ghent University, Technologiepark 914A, B-9052 Ghent (Belgium); Mader, Lothar [Center for Microsystems Technology (CMST), IMEC and Ghent University, Technologiepark 914A, B-9052 Ghent (Belgium); Dubruel, Peter [Polymer Chemistry and Biomaterials Research Group, Ghent University, Krijgslaan 281 S4 bis, B-9000 Ghent (Belgium); Vanfleteren, Jan [Center for Microsystems Technology (CMST), IMEC and Ghent University, Technologiepark 914A, B-9052 Ghent (Belgium)

    2015-10-30

    Highlights: • Surface modifications of epoxy resins with polydopamine and grafted polyamines can significantly increase the adhesion toward electroless deposited copper. • A clear characterization of the copper/epoxy interphase is provided by SEM analyses of cross sections. • Tailored conditions such as etching time (roughness) and electroless deposition temperature are needed to increase the adhesion of the modified surfaces. - Abstract: In this paper the influence of the epoxy roughness, surface modifications and ELD (electroless copper deposition) temperatures on the adhesive strength of the copper is studied. Good adhesion at low roughness values is targeted due to their applicability in high density electronic circuits. Roughened epoxy surfaces are modified with adsorbed polyamines, polydopamine and polyamines grafted to polydopamine. Next the, adhesive strength of ELD copper is determined with peel strength measurements and the interphases are examined with SEM (scanning electron microscopy). Polydopamine and polyamines grafted to polydopamine can lead to increased adhesive strength at lower roughness values compared to the non-modified samples at specific plating temperatures.

  3. Curing and toughening of epoxy resins with phosphorus containing monomers and polymers

    Energy Technology Data Exchange (ETDEWEB)

    Park, Y.R.; Park, I.Y.; Yoon, T.H. [Kwangji Inst. of Science and Technology, Kwangju (Korea, Republic of)] [and others

    1996-12-31

    Epoxy resins have been utilized in many areas, from house holds to airplanes, for the past several decades due to some exceptional properties such as low cost, good mechanical properties and excellent adhesive properties. However, low fracture toughness and flame resistance of epoxy resins have limited their applicability. Therefore, enhancing those properties have been of great interest to many researchers and scientists. As introduced by McGrath and co-workers in 1980s, the reactive thermoplastic polymers have proven to be an excellent toughener for improving not only fracture toughness but also adhesive properties without sacrificing thermo-mechanical properties and chemical resistance. Flame retardency could be improved by adding flame retardent additives which are divided into two groups; additives and reactives. However, among the additives, halogen compounds are known to be toxic gas generator and ozone depleter. Moreover, additives could be potentially leached out of the material, while reactives are inferior to additives. Recently, a reactive type phosphine oxide containing flame retardants have been introduced by McGrath and co-workers and proven to be an excellent flame retardant. In this paper, phospine oxide containing monomers were prepared and utilized as curing agents for expoxy resins, and starting materials for the polymers.

  4. NMR detection of thermal damage in carbon fiber reinforced epoxy resins.

    Science.gov (United States)

    Brady, Steven K; Conradi, Mark S; Vaccaro, Christopher M

    2005-02-01

    Composite materials of epoxy resins reinforced by carbon fibers are increasingly being used in the construction of aircraft. In these applications, the material may be thermally damaged and weakened by jet blast and accidental fires. The feasibility of using proton NMR relaxation times T1, T1rho, and T2 to detect and quantify the thermal damage is investigated. In conventional spectrometers with homogeneous static magnetic fields, T1rho is readily measured and is found to be well correlated with thermal damage. This suggests that NMR measurements of proton T1rho may be used for non-destructive evaluation of carbon fiber-epoxy composites. Results from T1rho measurements in the inhomogeneous static and RF magnetic fields of an NMR-MOUSE are also discussed.

  5. Basic failure mechanisms in advanced composites. [composed of epoxy resins reinforced with carbon fibers

    Science.gov (United States)

    Mazzio, V. F.; Mehan, R. L.; Mullin, J. V.

    1973-01-01

    The fundamental failure mechanisms which result from the interaction of thermal cycling and mechanical loading of carbon-epoxy composites were studied. This work was confined to epoxy resin uniderictionally reinforced with HTS carbon fibers, and consists of first identifying local fiber, matrix and interface failure mechanisms using the model composite specimen containing a small number of fibers so that optical techniques can be used for characterization. After the local fracture process has been established for both mechanical loading and thermal cycling, engineering composite properties and gross fracture modes are then examined to determine how the local events contribute to real composite performance. Flexural strength in high fiber content specimens shows an increase in strength with increased thermal cycling. Similar behavior is noted for 25 v/o material up to 200 cycles; however, there is a drastic reduction after 200 cycles indicating a major loss of integrity probably through the accumulation of local cleavage cracks in the tensile region.

  6. Food contamination from epoxy resins and organosols used as can coatings: analysis by gradient NPLC.

    Science.gov (United States)

    Biedermann, M; Grob, K

    1998-07-01

    Normal phase LC with gradient elution enabled the analysis of a broadened range of oligomers of BADGE (Bisphenol-A diglycidyl ether) and Novolak compounds in canned foods, such as sea foods in oil, meat products and soups. A major component released from Bisphenol-A resins was identified as the cyclo-(Bisphenol-A monoglycidyl ether) dimer and was commonly present in foods at concentrations of around 1 mg/kg. For the epoxy Novolaks, concentrations of the three- to six-ring compounds often far exceeded those of BFDGE (Bisphenol-F diglycidyl ether) and reached 20 mg/kg in foods. A two-step acylation is proposed for the detection of epoxy components.

  7. Fabrication of SiC-C composite from poycarbosilane, epoxy and polyvinyl butyral resin mixture

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Jin Wook; Park, Dong Won; Jeun, Joon Pyo; Kang, Phil Hyun [Korea Atomic Energy Research Institte, Jeongeup (Korea, Republic of)

    2009-06-15

    Silicon carbide (SiC) has wide application in various industrial fields because of their good high strength and modulus, low density, oxidation resistance and thermal stability. In this study, SiC-C composites were prepared from mixture of polycarbosilane (PCS), epoxy resin, and polyvinyl butyral (PVB) with weight ration of 2/1/1. PCS/epoxy/PVB mixture was cured by electron beam irradiation at 5,000 kGy. The cured composite was pyrolyzed by heat treatment in flowing argon at 1,300 .deg. C for 1 hr. As the result of TGA analysis, the oxidation resistance showed 95.2% residue at 1,500 .deg. C under air.

  8. Reaction-induced phase separation in rubber-modified epoxy resin

    Institute of Scientific and Technical Information of China (English)

    张剑文; 张红东; 严栋; 周红卫; 杨玉良

    1997-01-01

    The phase separation mechanism,and structure development during curing of epoxy with a novel liquid rubber-ZR were investigated by time-resolved light scattering,optical microscope and differential scanning calonmetry (DSC) The mixture loaded with curing agent was a single-phase system in the early stage of curing.When the cure reaction proceeded,phase separation took place via the spinodal decomposition induced by polymerization of epoxy resin.This was supported by the characteristic change of light scattering profile with curing time.Cure reaction plays an important role in the progress of phase separation.The bigger the cure reaction rate is,the longer periodic distance will be.The overall two-phase structure was basically locked in when the conversion approached 80% estimated by DSC,and finally the co-continuous two-phase structure was successfully obtained.

  9. Characterization of the curing agents used in epoxy resins with TG/FT-IR technique

    Directory of Open Access Journals (Sweden)

    Benedita M. V. Romão

    2006-06-01

    Full Text Available Samples of epoxy resin (EP based on the diglycidyl ether of bisphenol A (DGEBA, cured with nadic methyl anhydride (NMA and mercaptan (CAPCURE 3-800, or amine-phenol (CAPCURE EH-30, respectively, SE 4 and SE 5, were prepared in the stoichiometric ratio determined by the supplier. The curing behaviour of the epoxy systems SE 4 and SE 5 was followed by DSC (Differential Scanning Calorimetry. These SE and their ingredients were analyzed using FTIR transmission techniques (KBr pellets, pyrolysis without control and controlled pyrolysis-FT-IR, the CONTROLPIR/FT-IR for characterizing the curing agents (CA. The temperature range used for samples pyrolysis was found from TG (thermogravimetry. Thus, the FT-IR bands of liquid pyrolysate obtained by CONTROLPIR/FT-IR were evaluated, in comparison to the reference spectrum of CA. The characterization of CA was also possible, by the analysis of such SE with the TG/FT-IR technique.

  10. Temperature measurements for shocked polymethylmethacrylate, epoxy resin, and polytetrafluoroethylene and their equations of state

    Science.gov (United States)

    Bordzilovskii, S. A.; Karakhanov, S. M.; Merzhievskii, L. A.; Voronin, M. S.

    2016-10-01

    This paper presents the results of computational and experimental studies of the temperature along the shock adiabat for three polymers. Measurements of the brightness temperatures of shock-compressed epoxy resin and polymethylmethacrylate and the brightness and color temperatures of shock-compressed polytetrafluoroethylene were carried out. The temperatures of the shock-compressed polymethylmethacrylate were determined in the range 1390-1900 K for shock pressures of 22-39 GPa. Similar measurements performed for epoxy resin in the pressure range of 18-40 GPa showed values of 940-1900 K, and the temperatures of polytetrafluoroethylene in the pressure range of 30-50 GPa were equal to 2000-3200 K. The equation of state for the three polymers with a nonspherical strain tensor was constructed to describe shock-wave and high-temperature processes in a wide range of thermodynamic parameters. In the proposed model, two Grüneisen parameters were used: the thermodynamic parameter corresponding to intrachain vibrations and the lattice parameter representing the contribution of interchain vibrations. The brightness temperatures of shocked-compressed polymethylmethacrylate and epoxy resin showed a good agreement with calculations using the proposed model and with the results of earlier calculation methods. Time dependences of the observed intensity of light were used to determine the absorption coefficients of the shocked polymers and estimate the effective thickness of the radiating layer. A typical feature of all the polymers is the width of the radiating layer of 0.8 to 2.5 mm, depending on the material and shock pressure.

  11. Mobility restrictions and glass transition behaviour of an epoxy resin under confinement.

    Science.gov (United States)

    Djemour, A; Sanctuary, R; Baller, J

    2015-04-07

    Confinement can have a big influence on the dynamics of glass formers in the vicinity of the glass transition. Already 40 to 50 K above the glass transition temperature, thermal equilibration of glass formers can be strongly influenced by the confining substrate. We investigate the linear thermal expansion and the specific heat capacity cp of an epoxy resin (diglycidyl ether of bisphenol A, DGEBA) in a temperature interval of 120 K around the glass transition temperature. The epoxy resin is filled into controlled pore glasses with pore diameters between 4 and 111 nm. Since DGEBA can form H-bonds with silica surfaces, we also investigate the influence of surface silanization of the porous substrates. In untreated substrates a core/shell structure of the epoxy resin can be identified. The glass transition behaviours of the bulk phase and that of the shell phase are different. In silanized substrates, the shell phase disappears. At a temperature well above the glass transition, a second transition is found for the bulk phase - both in the linear expansion data as well as in the specific heat capacity. The cp data do not allow excluding the glass transition of a third phase as being the cause for this transition, whereas the linear expansion data do so. The additional transition temperature is interpreted as a separation between two regimes: above this temperature, macroscopic flow of the bulk phase inside the porous structure is possible to balance the mismatch of thermal expansion coefficients between DGEBA and the substrate. Below the transition temperature, this degree of freedom is hindered by geometrical constraints of the porous substrates. Moreover, this second transition could also be found in the linear expansion data of the shell phase.

  12. Curing behaviour of epoxy resin/graphite composites containing ionic liquid

    Energy Technology Data Exchange (ETDEWEB)

    Guo Baochun; Wan Jingjing; Lei Yanda; Jia Demin, E-mail: psbcguo@scut.edu.c [Department of Polymer Materials and Engineering, South China University of Technology, Guangzhou 510640 (China)

    2009-07-21

    By adopting the isoconversional method, subtle changes in the curing activation energy (E{sub {alpha}}) among epoxy resin/graphite composites by the inclusion of expanded graphite (EG), ionic liquid of 1-butyl-3-methyl-imidazolium hexafluorophosphate ([BMIm]PF{sub 6}) or their combination are shown in the whole conversion range. At lower concentrations (1 phr) of EG, compared with the E{sub {alpha}} of the neat epoxy resin, the composite with EG has a lower E{sub {alpha}} before the gelation, and a higher E{sub {alpha}} after the gelation. At higher concentrations of EG, however, in the whole conversion range, the composite with EG shows a higher E{sub {alpha}} compared with the neat epoxy resin. As the curing proceeded, a peculiar increase in E{sub {alpha}} is found in systems containing [BMIm]PF{sub 6}. Due to the formation of hydrogen bonding between [BMIm]PF{sub 6} and the hardener (Jeffamine), the reactivity of Jeffamine is considerably decreased, leading to a much higher E{sub {alpha}} in [BMIm]PF{sub 6}-containing systems, especially at higher conversion. In systems containing a combination of [BMIm]PF{sub 6} and EG, due to the interactions between EG and [BMIm]PF{sub 6}, the shielding effect provided by the well-dispersed EG sheets constrains the formation of the hydrogen bonding between [BMIm]PF{sub 6} and Jeffamine, leading to lowered E{sub {alpha}} compared with that for the system containing [BMIm]PF{sub 6} only.

  13. High-performance epoxy casting resins for SMD-LED packaging

    Science.gov (United States)

    Bogner, Georg; Debray, Alexandra; Hoehn, Klaus

    2000-04-01

    In order to come up with high volume SMD-LED production encompassing 1.9 billion devices for current fiscal year we did basic exploratory work to establish structure-processing- property relations for robust epoxy casting resin packages with identical ppm level of one. Bisphenol A-based epoxy casting resins (DGEBA) with acidic ester modified Hexahydrophthalic anhydride (HHPA) hardeners using strictly controlled high-grade raw materials were formulated and thermally transferred to highly transparent polyester networks. For 1 mm thick samples transparency in the 400 to 800 nm region is above 90%. Thermal aging tests for 6 weeks at 120 degrees Celsius reveal only slight discoloration with a color distance of 2. To avoid significant light losses within the LED operating life of 100,000 hrs stress on mechanically sensitive light-emitting chips was reduced by matching glass transition temperature Tg and E-modulus to 115 degrees Celsius and 2,800 MPa, respectively. Total chloride content below 1,000 ppm imply low corrosion potential. Further, resin composition, epoxy-hardener mixing ratio as well as curing profile were adapted to materialize fast curing for demand quantities while introducing effective low stress moieties in the final structure. Low internal stress, superior thermal shock and crack resistance were derived from supreme fracture toughness: KIC and GIC values were 1.350 MPam1/2 and 560 J/m2. With favorable water absorption behavior LED-packages withstand all soldering processes including TTW (through the wave) soldering. Thus, SMD-LEDs fulfill electronic industry standard JEDEC LEVEL 2.

  14. DEVELOPMENT OF A METHOD STATISTICAL ANALYSIS ACCURACY AND PROCESS STABILITY PRODUCTION OF EPOXY RESIN ED-20

    Directory of Open Access Journals (Sweden)

    N. V. Zhelninskaya

    2015-01-01

    Full Text Available Statistical methods play an important role in the objective evaluation of quantitative and qualitative characteristics of the process and are one of the most important elements of the quality assurance system production and total quality management process. To produce a quality product, one must know the real accuracy of existing equipment, to determine compliance with the accuracy of a selected technological process specified accuracy products, assess process stability. Most of the random events in life, particularly in manufacturing and scientific research, are characterized by the presence of a large number of random factors, is described by a normal distribution, which is the main in many practical studies. Modern statistical methods is quite difficult to grasp and wide practical use without in-depth mathematical training of all participants in the process. When we know the distribution of a random variable, you can get all the features of this batch of products, to determine the mean value and the variance. Using statistical control methods and quality control in the analysis of accuracy and stability of the technological process of production of epoxy resin ED20. Estimated numerical characteristics of the law of distribution of controlled parameters and determined the percentage of defects of the investigated object products. For sustainability assessment of manufacturing process of epoxy resin ED-20 selected Shewhart control charts, using quantitative data, maps of individual values of X and sliding scale R. Using Pareto charts identify the causes that affect low dynamic viscosity in the largest extent. For the analysis of low values of dynamic viscosity were the causes of defects using Ishikawa diagrams, which shows the most typical factors of the variability of the results of the process. To resolve the problem, it is recommended to modify the polymer composition of carbon fullerenes and to use the developed method for the production of

  15. Shape and size effects of ceria nanoparticles on the impact strength of ceria/epoxy resin composites

    Institute of Scientific and Technical Information of China (English)

    Xiaoqiang He; Dengsong Zhang; Hongrui Li; Jianhui Fang; Liyi Shi

    2011-01-01

    Ceria nanoparticles with various shapes (rods,cubes,and plates) and sizes were controllably synthesized and then introduced into epoxy resin. Subsequently,we investigated correlations between the shape and size of ceria nanostructures and the mechanical performance of composites. The samples were characterized by transmission electron microscopy,scanning electron microscopy,and X-ray diffraction. Compared with commercial ceria filled composites,the composites made with morphology-controlled ceria nanostructures show a higher impact strength. It is found that epoxy resins made with high-aspect-ratio ceria nanorods show the highest impact strength,up to 17.27 kJ/m2,which is about four times that of the neat epoxy resin.

  16. Cold-Curing Structural Epoxy Resins: Analysis of the Curing Reaction as a Function of Curing Time and Thickness

    Directory of Open Access Journals (Sweden)

    Carola Esposito Corcione

    2014-09-01

    Full Text Available The curing reaction of a commercial cold-curing structural epoxy resin, specifically formulated for civil engineering applications, was analyzed by thermal analysis as a function of the curing time and the sample thickness. Original and remarkable results regarding the effects of curing time on the glass transition temperature and on the residual heat of reaction of the cold-cured epoxy were obtained. The influence of the sample thickness on the curing reaction of the cold-cured resin was also deeply investigated. A highly exothermal reaction, based on a self-activated frontal polymerization reaction, was supposed and verified trough a suitable temperature signal acquisition system, specifically realized for this measurement. This is one of the first studies carried out on the curing behavior of these peculiar cold-cured epoxy resins as a function of curing time and thickness.

  17. Shielding properties of composite materials based on epoxy resin with graphene nanoplates in the microwave frequency range

    Science.gov (United States)

    Volynets, N. I.; Bychenok, D. S.; Lyubimov, A. G.; Kuzhir, P. P.; Maksimenko, S. A.; Baturkin, S. A.; Klochkov, A. Ya.; Mastrucci, M.; Micciulla, F.; Bellucci, S.

    2016-12-01

    Analysis of the electromagnetic properties of composite materials based on epoxy resin with the addition of 0.5 wt % graphene nanoplates in the frequency range of 26-37 GHz is performed. The influence of types of epoxy resin with different viscosities and the type of solvent used (ethanol, acetone) on the electromagnetic response in this frequency range are determined. It is established that the least viscous epoxy resin, Epikote 828, and solvent ethanol are most effective for creation of a shielding covering in the microwave range. Composite materials with optimal composition provide attenuation of the electromagnetic signal at a level at least 10 dB in power for a film thickness of 1.1 mm.

  18. Cold-Curing Structural Epoxy Resins: Analysis of the Curing Reaction as a Function of Curing Time and Thickness.

    Science.gov (United States)

    Corcione, Carola Esposito; Freuli, Fabrizio; Frigione, Mariaenrica

    2014-09-22

    The curing reaction of a commercial cold-curing structural epoxy resin, specifically formulated for civil engineering applications, was analyzed by thermal analysis as a function of the curing time and the sample thickness. Original and remarkable results regarding the effects of curing time on the glass transition temperature and on the residual heat of reaction of the cold-cured epoxy were obtained. The influence of the sample thickness on the curing reaction of the cold-cured resin was also deeply investigated. A highly exothermal reaction, based on a self-activated frontal polymerization reaction, was supposed and verified trough a suitable temperature signal acquisition system, specifically realized for this measurement. This is one of the first studies carried out on the curing behavior of these peculiar cold-cured epoxy resins as a function of curing time and thickness.

  19. MICRO-PHASE SAEPARATION IN EPOXY RESIN WATERBORNE PARTICLES DURING CURING PROCESS

    Institute of Scientific and Technical Information of China (English)

    Xi-yan Liu; Dong Qiu; Mei-li Guo; Zhen-zhong Yang

    2005-01-01

    Sub-micron sized phenolic epoxy resin waterborne particles were prepared by phase inversion emulsification.Micro-phase separation occurred during the curing process at high temperature. The as-prepared samples possessed one glass transition temperature (Tg) and two exothermal processes during DSC heating scannings. After being thermally treated above the exothermal peak temperature, they possessed two glass transition temperatures with the disappearance of exothermal peaks, whilst a core/shell structure was formed. This was likely related with the outward diffusion of reactive oligomers to the outer layer of particles.

  20. A novel chain-extended urea containing hyperbranched polymer used as toughening modifier for epoxy resin

    Institute of Scientific and Technical Information of China (English)

    LU Shao-rong; WEI Chun; YANG Xiao-wang

    2006-01-01

    A new kind of reactive toughening accelerator for epoxy resin,amine-teminated hyperbranched polymer (H2O-NMe2) was synthesized and characterized by FT-IR spectroscopy. Dynamic mechanical analysis (DMA) was used to study the glass transition temperature (Tg),loss factor (tanδ) and activation energy (Ea) by using multiplexing frequency. The results show that the Ea at glassy relaxation process of modified system is about 70-80 kJ/mol higher than that of unmodified system,and the high modulus and good thermal properties are still maintained.

  1. Recent Developments in Halogen Free Flame Retardants for Epoxy Resins for Electrical and Electronic Applications

    Directory of Open Access Journals (Sweden)

    Manfred Döring

    2010-08-01

    Full Text Available The recent implementation of new environmental legislations led to a change in the manufacturing of composites that has repercussions on printed wiring boards (PWB. This in turn led to alternate processing methods (e.g., lead-free soldering, which affected the required physical and chemical properties of the additives used to impart flame retardancy. This review will discuss the latest advancements in phosphorus containing flame retardants for electrical and electronic (EE applications and compare them with commercially available ones. The mechanism of degradation and flame retardancy of phosphorus flame retardants in epoxy resins will also be discussed.

  2. ULTRASONIC BEHAVIOR OF EPOXY RESINS/POLY (ETHYLENE OXIDE)BLENDS CURED WITH PHTHALIC ANHYDRIDE

    Institute of Scientific and Technical Information of China (English)

    ZHENG Sixun; WANG Haiqian; LUO Xiaolie; ZHANG Naibin; MA Dezhu; ZHU Changfei; HU Jiankai

    1995-01-01

    By means of ultrasonic attenuation apparatus, the ultrasonic velocity and attenuation of anhydride-cured epoxy resins (EP)/poly(ethylene oxide)(PEO)blends were measured on the basis of pulse-echo method. It was found that the sonic velocity of the blends decreased as the temperature increased, but attenuation coefficient increased and possessed a peak value. Larger velocity and smaller attenuation coefficient(α)can be obtained from perfect crosslinking network structures of pure DGEBA cured with phthalic anhydride (PA). As for cured DGEBA/PEO blend systems,sonic velocity decreased as a function of PEO concentration,but attenuation coefficient (α) increased.

  3. On-line Monitoring of Epoxy Resin Exposed to Acid Solution

    Institute of Scientific and Technical Information of China (English)

    Yuyan LIU; M.Kubouchi; H.Sembokuya; K.Tsuda; T.Tomiyama

    2006-01-01

    In this study, a new on-line health monitoring technology for the determination of the penetration of environment solution into epoxy resin was pursued. A corrosion sensor including plastic optical fiber and pH indicator was fabricated. The color-change layer of this sensor appeared after immersion in sulfuric acid solution, which could be examined by using optical fiber and spectrophotometer. The results showed that the penetration of sulfuric acid was detected by adding bromophenol blue (BPB) in the corrosion sensor. This system could be applied to on-line health monitoring of chemical equipment structures.

  4. Impact and dynamic mechanical thermal properties of textile silk reinforced epoxy resin composites

    Science.gov (United States)

    Yang, K.; Guan, J.

    2016-07-01

    Silk fabric reinforced epoxy resin composites (SFRPs) were prepared using simple techniques of hand lay-up, hot-press and vacuum treatment, and a series of volume fractions of silk reinforcements were achieved. The impact properties and dynamic mechanical properties of SFRPs were investigated using a pendulum impact testing method and dynamic mechanical thermal analysis (DMTA). The results suggest that silk reinforcement could greatly enhance the mechanical performances of SFRPs. The impact strength reached a maximum of 71 kJ/m2 for 60%-silk SFRP, which demonstrated a potential of silk composites for defence and impact- resistant materials.

  5. Surface characterization and stability of an epoxy resin surface modified with polyamines grafted on polydopamine

    Energy Technology Data Exchange (ETDEWEB)

    Schaubroeck, David, E-mail: David.Schaubroeck@elis.ugent.be [Center for Microsystems Technology (CMST), imec and Ghent University, Technologiepark 914A, B-9052 Ghent (Belgium); Vercammen, Yannick; Van Vaeck, Luc [Biomolecular and Analytical Mass Spectrometry, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk (Belgium); Vanderleyden, Els; Dubruel, Peter [Polymer Chemistry and Biomaterials Research Group, Ghent University, Krijgslaan 281 S4 bis, B-9000 Ghent (Belgium); Vanfleteren, Jan [Center for Microsystems Technology (CMST), imec and Ghent University, Technologiepark 914A, B-9052 Ghent (Belgium)

    2014-06-01

    This paper reports on polydopamine and polyamine surface modifications of an etched epoxy cresol novolac (ECN) resin using the ‘grafting to’ method. Three different polyamines are used for the grafting reactions: branched polyethyleneimine (B-PEI), linear polyethyleneimine (L-PEI) and diethylenetriamine (DETA). These modifications are compared to control materials prepared via direct deposition of polyamines. The stability of the modifications toward a concentrated hydrochloric acid (HCl) environment is evaluated. The modified surfaces are characterized with scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and time-of-flight static secondary ion mass spectroscopy (TOF-S-SIMS).

  6. Construction of an amperometric ascorbate biosensor using epoxy resin membrane bound Lagenaria siceraria fruit ascorbate oxidase.

    Science.gov (United States)

    Pundir, C S; Chauhan, Nidhi; Jyoti

    2011-06-01

    Ascorbate oxidase purified from Lagenaria siceraria fruit was immobilized onto epoxy resin "Araldite" membrane with 79.4% retention of initial activity of free enzyme. The biosensor showed optimum response within 15s at pH 5.8 and 35°C, which was directly proportional to ascorbate concentration ranging from 1-100μM. There was a good correlation (R(2) = 0.99) between serum ascorbic acid values by standard enzymic colorimetric method and the present method. The enzyme electrode was used for 200 times without considerable loss of activity during the span of 90 days when stored at 4°C.

  7. Properties of unidirectional GFRPs based on an epoxy resin modified with polysulphone or an epoxyurethane oligomer

    Science.gov (United States)

    Solodilov, V. I.; Gorbatkina, Yu. A.

    2006-11-01

    The mechanical properties of unidirectional GFRPs based on an ED-22 epoxy resin were investigated. The resin was modified with a PSK-1 polysulphone or a PEF-3a epoxyurethane oligomer. Triethanolaminotitanate or diaminodiphenilsulphone was used as a hardener. The modification did not improve the mechanical properties of GFRPs in quasi-static loading; but in a low-speed impact loading, the shear strength of epoxypolysulphone GFRPs with 20 wt.% PSK-1 increased by 20-25%. For all the GFRPs investigated, the shear strength grew linearly with the logarithm of loading rate. The introduction of the modifiers increased the fracture toughness considerably: by 100 and 70% for GFRPs modified with 20 wt.% PSK-1 and 50 wt.% PEF-3a, respectively.

  8. Hyperbranched Acrylated Aromatic Polyester Used as a Modifier in UV-Curable Epoxy Acrylate Resins

    Institute of Scientific and Technical Information of China (English)

    KOU,Hui-Guang; ASIF,Anila; SHI,Wen-Fang

    2003-01-01

    The viscosity, the shrinkage degree and the photoplymerization rate of the epoxy acrylate (EB600 ) blended with hyperbranched acrylated aromatic polyester ( HAAPE ) were investigated. The addition of HAAPE into EB600 largely reduces the viscosity of the blend formulation and the shrinkage degree. For example, EB600resin with 50% weight fraction of HAAPE has the 1250 cps of the viscosity and 2.0% of shrinkage degree, while the pure EB600 resin has 3000 cps of the viscosity and 10.5% of shrinkage degree. The photopolymerization rate of the rein is also promoted by HAAPE addition. The good miscibility between HAAPE and EB600 was also observed from the dynamic mechanical analysis. The tensile, flexural and compressive strength, and the thermal properties of the UVcured films are greatly improved.

  9. Genotoxicity and cytotoxicity of the epoxy resin-based root canal sealer AH plus.

    Science.gov (United States)

    Leyhausen, G; Heil, J; Reifferscheid, G; Waldmann, P; Geurtsen, W

    1999-02-01

    Previous studies with four rapid in vitro and in vivo test systems have shown that the epoxy resin-based root canal sealer AH26 may be genotoxic and cytotoxic (9). The purpose of this study was to determine the cytotoxic and genotoxic effects of the new resinous root canal sealer AH Plus by means of the growth inhibition test with primary human periodontal ligament fibroblasts and permanent 3T3 monolayers, the procaryotic umu test, the eucaryotic DNA synthesis inhibition test, and the in vivo alkaline filter elution test. In addition, Ames tests were performed with extracts from AH Plus. AH Plus caused only slight or no cellular injuries. Furthermore, no genotoxicity and mutagenicity were revealed by AH Plus. These data should be taken into consideration when deciding about a root canal sealer.

  10. Influence of Electrolytical Oxidising of Silumine Surfaces on the Quality of Bonding with Epoxy Resin

    Directory of Open Access Journals (Sweden)

    Posmyk A.

    2016-09-01

    Full Text Available The article presents the preparation process of AC-AlSi12 aluminum alloy surface by application of anodic oxidation method. The method enables the formation of a porous oxide layer (Al2O3 which generates the substrate of durable adhesive bond with an epoxy resin. It also presents the influence of the form of silicon precipitates in the modified alloy upon anodizing process, uniform structure and thickness of the oxide layer as well as the topography of its surface which is expected to improve adhesion of the resin and silumin. The paper describes how the position of oxidized surface against the negative electrode influences the coating structure. The studied silumins are intended to form the material for casting of 3 dimensional objects whose parts will change the distribution of electric field strength that may cause non-uniform structure of the coating.

  11. Delamination on GFRP laminates impacted at room and lower temperatures: Comparison between epoxy and vinylester resins

    Science.gov (United States)

    Lopresto, Valentina; Langella, Antonio; Papa, Ilaria

    2016-10-01

    Low velocity impact tests at three different impact energy values and three different temperatures, were performed on glass fibre composite laminates made by infusion technology. Two different resins, epoxy and vinylester, were considered to impregnate the fibres: the first is mainly of aeronautical interest whereas the second one is mainly applied in Naval field. The specimens were first completely destroyed to obtain the complete load-displacement curve. The latter allowed the evaluation of the increasing impact energies, 5, 10 and 20J, used to investigate about the start and propagation of the damage inside the laminates. The delamination was investigated by the very commonly used Ultra Sound technique and the results obtained on the different materials at different temperatures were compared. A general better behaviour of vinylester resin was noted.

  12. PREPARATION OF BISPHENOL A EPOXY RESIN WATERBORNE DISPERSIONS BY THE PHASE INVERSION EMULSIFICATION TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    Zhen-zhong Yang; De-lu Zhao

    2000-01-01

    The phase inversion emulsification technique (PIET) is an effective physical method for preparing waterborne dispersions of polymer resins. Some results concerning the preparation of bisphenol A epoxy resin waterborne dispersions by PIET in our laboratory were summarized. Electrical properties, rheological behavior and morphological evolution during phase inversion progress were systematically characterized. The effects of the emulsifier concentration and emulsification temperature on phase inversion progress and the structural features of the waterborne particles were studied as well. The deformation and break up of water drops in a shear field were analyzed in terms of micro-rheology, while the interaction and coalescence dynamics of water drops were discussed in terms of DLVO theory and Smoluchowski effective collision theory,respectively. Based on the experimental results and theoretical analysis, a physical model of phase inversion progress was suggested, by which the effects of the parameters on phase inversion progress and the structural features of the waterborne particles were interpreted and predicted.

  13. Influence of epoxy resin as encapsulation material of silicon photovoltaic cells on maximum current

    Directory of Open Access Journals (Sweden)

    Acevedo-Gómez David

    2017-01-01

    Full Text Available This work presents an analysis about how the performance of silicon photovoltaic cells is influenced by the use of epoxy resin as encapsulation material with flat roughness. The effect of encapsulation on current at maximum power of mono-crystalline cell was tested indoor in a solar simulator bench at 1000 w/m² and AM1.5G. The results show that implementation of flat roughness layer onto cell surface reduces the maximum current inducing on average 2.7% less power with respect to a cell before any encapsulation. The losses of power and, in consequence, the less production of energy are explained by resin light absorption, reflection and partially neutralization of non-reflective coating.

  14. Halohydrination of epoxy resins using sodium halides as cationizing agents in MALDI-MS and DIOS-MS.

    Science.gov (United States)

    Watanabe, Takehiro; Kawasaki, Hideya; Kimoto, Takashi; Arakawa, Ryuichi

    2008-12-01

    Halohydrination of epoxy resins using sodium halides as cationizing agents in matrix-assisted laser desorption/ionization (MALDI) and desorption ionization on porous silicon mass spectrometry (DIOS-MS) were investigated. Different mass spectra were observed when NaClO(4) and NaI were used as the cationizing agents at the highest concentration of 10.0 mM, which is much higher than that normally used in MALDI-MS. MALDI mass spectra of epoxy resins using NaI revealed iodohydrination to occur as epoxy functions of the polymers. The halohydrination also occurred using NaBr, but not NaCl, due to the differences in their nucleophilicities. On the basis of the results of experiments using deuterated CD(3)OD as the solvent, the hydrogen atom source was probably ambient water or residual solvent, rather than being derived from matrices. Halohydrination also occurred with DIOS-MS in which no organic matrix was used; in addition, reduction of epoxy functions was observed with DIOS. NaI is a useful cationizing agent for changing the chemical form of epoxy resins due to iodohydrination and, thus, for identifying the presence of epoxy functions.

  15. Rheological and electrical properties of hybrid nanocomposites of epoxy resins filled with graphite nanoplatelets and carbon black.

    Science.gov (United States)

    Truong, Quang-Trung; Lee, Seon-Suk; Lee, Dai-Soo

    2011-02-01

    Graphite nanoplatelets (GNP) were prepared by microwave irradiation of natural graphites intercalated with ferric chloride in nitromethane (GIC). Intercalated structure of GIC was confirmed by X-ray diffraction patterns. SEM images of GIC after microwave irradiation showed the exfoliation of GIC, the formation of GNPs. Hybrid nanocomposites of bisphenol-A type epoxy resins filled with GNP and a conductive carbon black (CB) were prepared and rheological and electrical properties of the nanocomposites were investigated. Viscosity and electrical surface resistivity of the nanocomposites showed minima at certain mixtures of GNP and CB in the epoxy resins.

  16. AFM and XRD characterization of silver nanoparticles films deposited on the surface of DGEBA epoxy resin by ion sputtering

    OpenAIRE

    José Elisandro de Andrade; Rogério Machado; Marcelo Andrade Macêdo; Frederico Guilherme Carvalho Cunha

    2013-01-01

    In this work, silver atoms were deposited by ion sputtering on the surface of diglycidyl ether of bisphenol A (DGEBA) epoxy resin cured at 150 °C for 6 hours in air. The films of DGEBA and its precursors were characterized by Raman spectroscopy to identify the main functional groups and their relationship with the deposited silver atoms. Silver thin films of 5, 10, 15 and 20 nm were deposited on the epoxy resin at room temperature. Both the initial film of DGEBA and the subsequent silver thin...

  17. Leakage Current Phenomenon on Ceramics and Epoxy Resin as 20 kV Outdoor Insulator at Tropical Environment

    Directory of Open Access Journals (Sweden)

    Valdi Rizki Yandri

    2011-01-01

    Full Text Available This paper explains the research results of  leakage current, hydrophobicity and flashover voltage comparison on ceramics and epoxy  resin 20 kV outdoor insulator in a  chamber at tropical climate conditions. The waveform of leakage current (LC was measured using a digital oscilloscope. The digital data was transferred to a personal computer using a RS-232 cable. The digital data was analyzed using Fast Fourier Transform. The result showed that LC was affected by various environment conditions like temperature, humidity and pollution. LC of ceramics insulator was higher than epoxy resin insulator in low temperature, high humidity and high pollution condition.

  18. The role of the epoxy resin: Curing agent ratio in composite interfacial strength by single fibre microbond test

    DEFF Research Database (Denmark)

    Minty, Ross; Thomason, James L.; Petersen, Helga Nørgaard

    2015-01-01

    This paper focuses on an investigation into the role of the epoxy resin: curing agent ratio in composite interfacial shear strength of glass fibre composites. The procedure involved changing the percentage of curing agent (Triethylenetetramine [TETA]) used in the mixture with several different...... percentages used, ranging from 4% up to 30%, including the stoichiometric ratio. It was found by using the microbond test, that there may exist a relationship between the epoxy resin to curing agent ratio and the level of adhesion between the reinforcing fibre and the polymer matrix of the composite....

  19. High solids loading of aluminum nitride powder in epoxy resin: Dispersion and thermal conductivity

    Science.gov (United States)

    Lee, Eunsung

    Most semiconductor devices are now packaged in an epoxy polymer composite, which includes a silica powder filler for reducing the thermal expansion coefficient. However, increased heat output from near-future semiconductors will require higher thermal conductivity fillers such as aluminum nitride powder, instead of silica. This thesis research is intended to apply improved dispersant chemistry, in order to achieve a high volume percentage of AlN powder in epoxy, increasing the thermal conductivity of the composite without causing excessive viscosity before the epoxy monomer is crosslinked. In initial experiments, the dispersibility of aluminum oxide in epoxy monomer resin was better than that of AlN, because of the weaker basicity of oxide surfaces compared with nitride. To improve the dispersibility of AlN, its surface was modified by pretreatment with silane coupling agents. Silane molecules with different head groups were investigated. In those experiments, methylsilane gave lower viscosities than chloro- or methoxysilane, while pretreatments using organic acids increased the viscosity of the AlN dispersion. The viscosity changes and FTIR peak intensity trends suggested that the silane molecules could be adsorbed on AlN surfaces in the form of a monolayer during optimization experiments, and the best silane monolayer coverage on the AlN powder surfaces was achieved with 2 wt% amounts in a 3 hour treatment. A particular phosphate ester was a good second layer dispersant for the AlN-plus-epoxy system. When that dispersant was added onto the silane-treated filler surfaces, the degree of viscosity reduction was dependent on the types of silane coupling agent functional groups. In the optimized results, silane pretreatment followed by dispersant addition was better than either alone. High solids loading, up to 57 vol.%, was achieved with a wide particle size distribution of powder, and the viscosity of that dispersion was 60,000 to 90,000 cps, which easily flowed by

  20. Effect of Curing Agent and Temperature on the Rheological Behavior of Epoxy Resin Systems

    Directory of Open Access Journals (Sweden)

    Lei Zhao

    2012-07-01

    Full Text Available The effect of curing agent (6610 content and temperature on the rheological behavior of the epoxy resin CYD-128 was studied by DSC analysis and viscosity experiments. The results show that the resin system meets the requirements of processing technology. A complete reaction occurs when the curing agent content (40 parts per hundred resin, phr is a little higher than the theoretical value (33.33 phr, while the degree of reaction of the resin system is reduced when the curing agent content is lower (25.00 phr than theoretical value. However, excessive curing agent (50.00 phr results in a lower reaction rate. Curing agent content has little influence on gel time when curing agent content exceeded 33.33 phr and the temperature was less than 70 °C. The isothermal viscosity-time curves shift towards the –x axis when the temperature rises from 50 °C to 80 °C. Meanwhile, higher temperature results in higher reaction rates.

  1. Effect of curing agent and temperature on the rheological behavior of epoxy resin systems.

    Science.gov (United States)

    Zhao, Chenhui; Zhang, Guangcheng; Zhao, Lei

    2012-07-17

    The effect of curing agent (6610) content and temperature on the rheological behavior of the epoxy resin CYD-128 was studied by DSC analysis and viscosity experiments. The results show that the resin system meets the requirements of processing technology. A complete reaction occurs when the curing agent content (40 parts per hundred resin, phr) is a little higher than the theoretical value (33.33 phr), while the degree of reaction of the resin system is reduced when the curing agent content is lower (25.00 phr) than theoretical value. However, excessive curing agent (50.00 phr) results in a lower reaction rate. Curing agent content has little influence on gel time when curing agent content exceeded 33.33 phr and the temperature was less than 70 °C. The isothermal viscosity-time curves shift towards the -x axis when the temperature rises from 50 °C to 80 °C. Meanwhile, higher temperature results in higher reaction rates.

  2. Properties of photocured epoxy resin materials for application in piezoelectric ultrasonic transducer matching layers.

    Science.gov (United States)

    Trogé, Alexandre; O'Leary, Richard L; Hayward, Gordon; Pethrick, Richard A; Mullholland, Anthony J

    2010-11-01

    This paper describes the acoustic properties of a range of epoxy resins prepared by photocuring that are suitable for application in piezoelectric ultrasonic transducer matching layers. Materials, based on blends of diglycidyl ether of Bisphenol A and 1,4-cyclohexanedimethanol diglycidyl ether, are described. Furthermore, in order to vary the elastic character of the base resin, samples containing polymer microspheres or barium sulfate particles are also described. The acoustic properties of the materials are determined by a liquid coupled through transmission methodology, capable of determining the velocity and attenuation of longitudinal and shear waves propagating in an isotropic layer. Measured acoustic properties are reported which demonstrate materials with specific acoustic impedance varying in the range 0.88-6.25 MRayls. In the samples comprising blends of resin types, a linear variation in the acoustic velocities and density was observed. In the barium sulfate filled samples, acoustic impedance showed an approximately linear variation with composition, reflecting the dominance of the density variation. While such variations can be predicted by simple mixing laws, relaxation and scattering effects influence the attenuation in both the blended and filled resins. These phenomena are discussed with reference to dynamic mechanical thermal analysis and differential scanning calorimetry of the samples.

  3. Research on epoxy resin modified by boron phenolic resin%硼酚醛树脂对环氧树脂的改性研究

    Institute of Scientific and Technical Information of China (English)

    田鑫; 廖登雄; 李玲

    2016-01-01

    在环氧树脂中加入 BPF 进行改性,按照不同配比将 BPF /EP 配成稳定、均一的试样。对试样的凝胶时间和环氧值进行了测定,并计算出不同配比试样的反应活化能,探讨了不同配比对凝胶时间和环氧值的影响。对不同配比固化试样的氧指数和冲击强度进行了测试,结果显示,BPF 的加入能够明显改善环氧树脂的阻燃性能和冲击强度。当 BPF 的含量为40%(质量分数)时,固化物的氧指数为25.0。当 BPF /EP 固化比例为3∶7时,冲击强度最高,为40.3 kJ/m2。%Epoxy resin was modified by boron phenolic resin.The boron phenolic resin and epoxy resin were prepared to be stable and uniform samples according to different ratio.The gel time and epoxy value of the samples were measured and the activation energy of the samples were calculated.At the same time, the influence of different ratios on the gel time and epoxy value was discussed.The oxygen index and the impact strength of cured samples were tested which have different ratios.Results show that the flame re-tardant and impact strength of epoxy resin are improved with addition of boron phenolic resin.When the content of boron phenolic resin is 40% (mass fraction),the oxygen index of the cured was 25.0.When the curing rate of boron phenolic resin and epoxy resin is 3 ∶7,the highest impact strength is obtained which is 40.3 kJ/m2 .

  4. Synthesis, properties and applications of interacting blends of acrylated novalac epoxy resin based poly(ester-amides and vinyl ester

    Directory of Open Access Journals (Sweden)

    Pragnesh N. Dave

    2016-09-01

    Full Text Available Epoxy resin based unsaturated poly(ester-amide resins (UPEAs were prepared by the reported method. These UPEAs were then treated with acryloyl chloride to afford acrylated UPEAs resin (i.e. AUPEAs. Interacting blends of equal proportional AUPEAs and vinyl ester epoxy (VE resin were prepared. APEAs and AUPEAs were characterized by elemental analysis, molecular weight determined by vapor pressure osmometer and by IR spectral study and by thermogravimetry. The curing of interacting blends was monitored on differential scanning calorimeter (DSC. Based on DSC data in situ glass reinforced composites of the resultant blends have been prepared and characterized for mechanical, electrical and chemical properties. Unreinforced blends were characterized by thermogravimetry (TGA.

  5. Study on Strength of Hybrid Mortar Synthesis with Epoxy Resin, Fly Ash and Quarry Dust Under Extreme Conditions

    Science.gov (United States)

    Sudheer, P.; Muni Reddy, M. G., Dr.; Adiseshu, S., Dr.

    2017-08-01

    Blend and characterization of Bisphenol-A diglycidyl ether based thermosetting polymer mortar comprising an epoxy resin, Fly ash and Quarry dust are presented here for the strength study. The specimens have been prepared by means of an innovative process in Extreme conditions of commercial epoxy resin, Fly ash and Quarry dust based paste. In this way, thermosetting based hybrid mortars characterized by a different contents of normalized Fly ash and Quarry dust by a homogeneous distribution of the resin have been attained. Once hardened, these new composite materials show improved compressive strength and toughness in respect to both the Fly ash and Rock sand pastes since the Resin provides a more cohesive microstructure, with a reduced number of micro cracks. The micro structural characterization allows pointing out the presence of an Interfacial Transition Zone similar to that observed in cement based mortars. A correlation between micro-structural features and mechanical properties of the mortar has also been studied in Extreme conditions.

  6. Dissolution of brominated epoxy resins by dimethyl sulfoxide to separate waste printed circuit boards.

    Science.gov (United States)

    Zhu, Ping; Chen, Yan; Wang, Liangyou; Qian, Guangren; Zhang, Wei Jie; Zhou, Ming; Zhou, Jin

    2013-03-19

    Improved methods are required for the recycling of waste printed circuit boards (WPCBs). In this study, WPCBs (1-1.5 cm(2)) were separated into their components using dimethyl sulfoxide (DMSO) at 60 °C for 45 min and a metallographic microscope was used to verify their delamination. An increased incubation time of 210 min yielded a complete separation of WPCBs into their components, and copper foils and glass fibers were obtained. The separation time decreased with increasing temperature. When the WPCB size was increased to 2-3 cm(2), the temperature required for complete separation increased to 90 °C. When the temperature was increased to 135 °C, liquid photo solder resists could be removed from the copper foil surfaces. The DMSO was regenerated by rotary decompression evaporation, and residues were obtained. Fourier transform infrared spectroscopy (FT-IR), thermal analysis, nuclear magnetic resonance, scanning electron microscopy, and energy-dispersive X-ray spectroscopy were used to verify that these residues were brominated epoxy resins. From FT-IR analysis after the dissolution of brominated epoxy resins in DMSO it was deduced that hydrogen bonding may play an important role in the dissolution mechanism. This novel technology offers a method for separating valuable materials and preventing environmental pollution from WPCBs.

  7. Non-destructive evaluation by terahertz spectroscopy for penetration of acid solutions into epoxy resin

    Directory of Open Access Journals (Sweden)

    M. Kusano

    2016-11-01

    Full Text Available Epoxy resins are used as high-performance thermosetting linings to protect substrates under corrosive environments. However, in a severe corrosive chemical solution, such protective layers may degrade with long time due to penetrations of solvent and solute molecules into resin network. In this regard, the terahertz time-domain spectroscopy (THz-TDS is a promising tool for non-destructive evaluation of the penetrant amounts due to high transparency of such plastic materials and high sensitivity to the molecular vibrations in terahertz spectral range. In this work, the complex refractive indexes n and κ of epoxy specimens were measured after immersion into sulfuric acid solutions and compared with penetrated mass fractions of water and acid ions. It was found that n and κ depended linearly with water and sulfuric acid mass fraction in specimens, and κ of sulfuric acid immersed specimens was lager at higher frequency. While the calculated Δκ agreed well with THz-TDS measurement by THz-TDS, the calculated Δn was higher than the measurement. The difference may be attributed to the water and sulfuric states in the specimen.

  8. Cure kinetics characterization and monitoring of an epoxy resin for thick composite structures

    Science.gov (United States)

    Hardis, Ricky

    The use of fiber-reinforced polymers (FRPs) is increasing for numerous industrial applications. In-situ cure monitoring is very important to directly observe the cure process of FRPs during the manufacturing process. In this work, the possible use for in-situ cure monitoring of an epoxy resin was investigated by means of Raman spectroscopy and dielectric analysis (DEA). The cure behavior was first characterized using differential scanning calorimetry (DSC) as a baseline comparison, and the best-fit phenomenological reaction model was determined to describe the cure behavior of the epoxy resin as well as the kinetic parameters. The relationship between T g and degree of cure was also established. The degree of cure obtained from the Raman spectroscopy and DEA under isothermal conditions was compared to the one obtained from the DSC. A good agreement was observed among the three methods, supporting in-situ cure monitoring during manufacturing. An implementation plan for in-plant monitoring was also discussed.

  9. Rheological behavior of novel polyamide 6/silica nanocomposites containing epoxy resins

    Institute of Scientific and Technical Information of China (English)

    赵才贤; 张平; 陈广兵; 王霞瑜

    2008-01-01

    A novel polyamide 6/silica nanocomposite containing epoxy resins(EPA6N) was prepared via in situ polymerization using tetraethoxysilane(TEOS) as the precursor of silica.The dynamic rheological properties of pure PA6 and EPA6N at temperatures of 225 and 235 ℃ were investigated.The results of transmission electron microscopy(TEM) and atomic force microscopy(AFM) indicate that the silica particles are well dispersed in the polyamide 6 matrix on about 30 nm in diameter,which demonstrates that this method can effectively avoid agglomeration of the inorganic particles.The rheological results suggest that pure PA6 shows Newtonian behavior.However,the novel EPA6N exhibits a solid-like rheological behavior,which is due to the small size,large surface of silica particles and the stronger polyamide 6-silica chemical bond formed through the reactions of epoxy resins with end groups of PA6 molecular chains.The EPA6N also exhibits higher melt viscosity,storage modulus and loss modulus than those of pure PA6.

  10. Synthesis of nanosized barium titanate/epoxy resin composites and measurement of microwave absorption

    Indian Academy of Sciences (India)

    M Murugan; V K Kokate; M S Bapat; A M Sapkal

    2010-12-01

    Barium titanate/epoxy resin composites have been synthesized and tested for microwave absorption/transmission. Nanocrystalline barium titanate (BaTiO3 or BT) was synthesized by the hydrothermal method and the composites of BT/epoxy resin were fabricated as thin solid slabs of four different weight ratios. BT was obtained in the cubic phase with an average particle size of 21 nm, deduced from the X-ray diffraction data. The reflection loss (RL) and transmission loss (TL) of the composite materials were measured by the reflection/transmission method using a vector network analyser R&S: ZVA40, in the frequency range 8.0–18.5 GHz (X and Ku-bands). The RL was found to be better than −10 dB over wide frequency bands. The higher RL for lower concentration of BT could be due to increase in impedance matching effects. Low TL values indicate that the absorption by BT is quite low. This could be due to formation of BT in the cubic paraelectric phase.

  11. PROMOTION EFFECT OF MELAMINE ON FLAME RETARDANCY OF EPOXY RESINS CONTAINING CAGED BICYCLIC PHOSPHATE

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Caged bicyclic phosphate (CBP) and its dimelamine salt (PDS) were synthesized and added to epoxy resins to obtain the flame retarded epoxy resin composites. The flammability of the composites was characterized by the limiting oxygen index (LOI) and cone calorimeter tests. The LOI values of flame retarded composites increase consistently with the increase of flame retardant amounts, and they are almost the same when the loading of CBP is the same as that of PDS,although the phosphorus content of PDS is much lower than that of CBP. The total heat release increases in the order of CBP30/ER < PDS30/ER < PDS15/ER < CBP15/ER, whereas that of specific extinction area is CBP15/ER > CBP30/ER > PDS30/ER ≌ PDS15/ER. PDS exhibits more effective inhibition of oxidation of combustible gases. In the tests of thermogravimetric analyses (TG) and Fourier transform infrared spectroscopy (FT-IR), it is found that the degradation of the composites is influenced greatly by the addition of flame retardants. By scanning electron microscopy (SEM), a thick and tight char-layer is observed for PDS30/ER, resulting from the interaction of nitrogen species with phosphorus species.Therefore, the combination of CBP with melamine in the flame retarded system can improve the flame retardancy greatly.

  12. Mechanical properties of composites made of hybrid fabric impregnated with silica nanoparticles and epoxy resin

    Science.gov (United States)

    Kordani, N.; Alizadeh, M.; Lohrasby, F.; Khajavi, R.; Baharvandi, H. R.; Rezanejad, M.; Ahmadzadeh, M.

    2017-09-01

    In this study, the mechanical properties of composites will be examined which were made from Kenaf and hybrid fabric with a simple structure that was coated with epoxy resin and nano silica particles. This fabric cotton has a different situation in terms of yarn score and the type of fiber that is used in textiles. Nano silica particles of 200 nm, polyethylene glycol with 200 molecular weights and ethanol with mechanical weight molecular with ratio of 6:1 will be mixed. Suspension of 60% was chosen according to the silica particles. The D6264 standard test for concentrated force was carried out through the cone edge to determine the strength of each of the samples. Increasing of resistance against penetration in the Kenaf samples from the raw until impregnated with the shear thickening fluid is less than the hybrid samples. Slippage of the fibers with the change of round edge indenter to cone edge indenter has changed. Penetration by cone edge to the cloth is done with lower force and it shows the effect of slippage of fibers on the resistance of the penetration. Samples impregnated with the shear thickening fluid in comparison with epoxy resin have lower resistance. Slippage of natural fibers in comparison with synthetic fibers is lower and on the other hand the average of friction between fibers in the natural fibers is more than synthetic fibers.

  13. Study on the Characteristics of a Scintillator for Beta-ray Detection using Epoxy Resin

    Science.gov (United States)

    Nam, Jong Soo; Choi, Yong Seok; Hong, Sang Bum; Seo, Bum Kyung; Moon, Jei Kwon; Choi, Jong Won

    2017-09-01

    A thin plate of a plastic scintillator for detecting a beta-ray was developed. The plastic scintillator was made using epoxy resin and organic scintillators such as 2.5-diphenyloxazole (PPO) and 1,4-bis [5-phenyl-2-oxazole] benzene (POPOP). The mixture ratio of epoxy resin and the organic scintillators was determined using their absorbance, transmittance, emission spectra, and transparency. Their optimal weight percentage of PPO and POPOP in the organic scintillators was adjusted to 0.2 wt%:0.01 wt%. The prepared plastic scintillator was used to measure the standard source of Sr-90. The pulse height spectra and total counts of the prepared plastic scintillator were similar to a commercial plastic scintillator. Based on the above results, a large-area plastic scintillator was prepared for rapid investigation of a site contaminated with Sr-90. The prepared large-area plastic scintillator was evaluated for the characteristics in the laboratory. The evaluation results are expected to be usefully utilized in the development of a large-area plastic scintillation detector. The large-area plastic scintillation detector developed on the basis of the evaluation results is expected to be utilized to quickly measure the contamination of Sr-90 in the grounds used as a nuclear power facility.

  14. Physicochemical Properties of Epoxy Resin-Based and Bioceramic-Based Root Canal Sealers

    Science.gov (United States)

    Lee, Ju Kyung; Kwak, Sang Won; Ha, Jung-Hong; Lee, WooCheol

    2017-01-01

    Three bioceramic sealers (EndoSequence BC sealer, EndoSeal MTA, and MTA Fillapex) and three epoxy resin-based sealers (AH-Plus, AD Seal, and Radic-Sealer) were tested to evaluate the physicochemical properties: flow, final setting time, radiopacity, dimensional stability, and pH change. The one-way ANOVA and Tukey's post hoc test were used to analyze the data (P = 0.05). The MTA Fillapex sealer had a highest flow and the BC Sealer presented a flow significantly lower than the others (P MTA Fillapex samples were not set in humid incubator condition even after one month. EndoSeal MTA had the longest setting time among the measurable materials and Radic-Sealer and AD Seal showed shorter setting time than the AH-Plus (P MTA showed statistically higher values and MTA Fillapex showed statistically lower radiopacity (P MTA presented a significant increase of pH over experimental time for 4 weeks. In conclusion, the bioceramic sealer and epoxy resin-based sealers showed clinical acceptable physicochemical properties, but BC Sealer and MTA Fillapex were not set completely. PMID:28210204

  15. Experimental investigations of mechanical and electrical characteristics of a nanomodified epoxy resin DER-330

    Science.gov (United States)

    Brusentseva, T. A.

    2016-11-01

    Technique preparation of a composite material based on epoxy resin DER-330 and 5 different nanopowders has been developed. The modifiers exert a positive effect on the elastic modulus, flexural strength, and dielectric permittivity of the epoxy-anhydride polymers. Weight content of nanoadditives in the matrix ranged from 0% to 4%. Dependences between mechanical properties of epoxy composites and concentration and nature of the filler were investigated in a three-point bending. Morphology of the fracture surface was studied. The complex analysis of nanofillers allowed us optimum fillers and concentrations when a significant increase of elastic and strength characteristics is achieved. It was showed that addition of silica fume nanoparticles A-380 to the matrix increases fracture stress on 30%. Composites with nanoparticles of aluminum nitride showed the best mechanical values in case of jointly investigated parameters. Growth of the elastic modulus is 12% and increase of the fracture stress is 7%. Adding alumina nanoparticles and nanofibers in the range of investigated concentration does not lead to significant changes in the mechanical characteristics of the composite

  16. Optical and dielectric properties of nanocomposites systems based on epoxy resins and reactive polyhedral oligosilsquioxanes

    Science.gov (United States)

    Eed, H.; Hassouneh, O.; Ramadin, Y.; Zihlif, A.; Ragosta, G.; Elimat, Z. M.

    2013-01-01

    An epoxy network structure made of diglycidylether of bisphenol-A and diamino diphenylsulfone was modified by adding various amounts of an epoxy functionalized polyhedral oligomeric silsesquioxane. The obtained nanocomposites were characterized in terms of optical and dielectric properties. The UV-absorption spectra were collected in the wavelength range of 400-800 nm. The optical data were analyzed in terms of absorption formula for non-crystalline materials. The optical energy gap and other basic constants, such as energy tails, dielectric constants, refractive index and optical conductivity, were determined and showed a clear dependence on the POSS concentration. It was found that the optical energy gap for the neat epoxy resin is less than for nanocomposites, and it decreases with increase in the POSS content. The refractive index of nanocomposites was determined from the calculated values of absorption and reflectance. It was found that the refractive index and the dielectric constants increased with increase in the POSS concentration. The optical conductivity, which is a measure of the optical absorption, increased with the POSS content. Furthermore, it was found that the glass transition temperature and the optical energy gap correlate well with the POSS filler concentration.

  17. Enhanced actuation performance of piezoelectric fiber composites induced by incorporated BaTiO{sub 3} nanoparticles in epoxy resin

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Mingliang; Yuan, Xi [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083 (China); Luo, Hang, E-mail: xtluohang@163.com [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083 (China); College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan 410083 (China); Chen, Haiyan; Chen, Chao; Zhou, Kechao [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083 (China); Zhang, Dou, E-mail: dzhang@csu.edu.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083 (China)

    2017-05-18

    Piezoelectric fiber composites (PFCs) have attracted much interest owing to their flexibility and toughness compared with conventional monolithic piezoceramic wafers. The free strain values and actuation property of PFCs strongly depend on the active electric field applied in Pb(Zr{sub 1−x}Ti{sub x})O{sub 3} (PZT) fibers. Reducing the dielectric constant mismatch between PZT fiber and the assembling epoxy resin would greatly increase the active electric field in PZT fiber. Therefore, BaTiO{sub 3} (BT) nanoparticles were introduced into the epoxy resin to enhance the dielectric constant. Homogeneous dispersion of BT nanoparticles and tight adhesion with the epoxy resin were achieved through a surface modification by dopamine. The maximum dielectric constant of dopamine modified BT/epoxy (BT@Dop/epoxy) nanocomposites was 10.38 with 12 wt% BT@Dop content at 1 kHz. The maximum free strain of PFCs reached 1820 ppm with 6 wt% BT@Dop content, while PFCs assembled by pure epoxy showed 790 ppm at the same processing condition. The tip displacement of cantilever beam actuated by PFCs reached the peak of 19 mm at the resonance frequency with 6 wt% BT@Dop, which was improved by 90% comparing to PFCs with pure epoxy. - Highlights: • The effect of dielectric mismatch on effective electric field in piezoceramic fibers was explained by a model. • The dispersibility and adhesion of BaTiO{sub 3} nanoparticles in epoxy was improved by the dopamine modification. • The actuation performance increased firstly and then decreased with adding BaTiO{sub 3} nanoparticles. • The maximum free strain and displacement of cantilever beam were up to 1820 ppm and 19 mm, respectively.

  18. Mechanical and thermal properties of oxazolidone modified epoxy resin%噁唑烷酮改性环氧树脂的性能

    Institute of Scientific and Technical Information of China (English)

    黄丽; 石萌萌; 王成忠

    2013-01-01

    Oxazolidone ring was introduced into epoxy resin by reacting 4,4’-diphenylmethane diisocyanate (MDI) with epoxy resin composed of bisphenol A epoxy resin and aliphatic epoxy resin. The viscosity of modified epoxy resin,mechanical and thermal properties of cured resin were studied by changing the content of aliphatic epoxy resin which was used as reactive diluent and MDI. The viscosity of oxazolidone modified epoxy resin could be reduced effectively when modification ratio was decreased and content of diluent was increased. When modification ratio was 4∶1,tensile strength and bending strength of cured resin reached 75.4 MPa and 158.2 MPa. The values were increased by 64%and 57%respectively compared with those of bisphenol A epoxy resin cured samples. Elongation and impact strength were also greatly improved. Oxazolidone modified epoxy resin exhibited high strength and toughness. Diluent content indicated a small influence on glass transition temperature (Tg). The Tg of oxazolidone modified epoxy resin was between 108 ℃ and 118 ℃. Oxazolidone modified epoxy resin possessed thermal resistance as bisphenol A epoxy resin.%采用4,4-二苯基甲烷二异氰酸酯(MDI)对双酚A环氧树脂和脂肪族环氧树脂进行唑烷酮化共改性,研究了MDI及作为活性稀释剂的脂肪族环氧用量对改性产物黏度及树脂固化物力学性能、耐热性的影响。结果表明,低改性比和稀释剂可以有效降低唑烷酮改性环氧树脂黏度,当改性比为4∶1时,树脂固化物拉伸强度、弯曲强度达到75.4 MPa和158.2 MPa,分别比环氧树脂固化物提高了64%和57%,断裂延伸率和冲击强度有较大提高,具有高强高韧的特点。稀释剂含量对Tg影响较小,各改性树脂Tg在108~118℃之间,与纯环氧树脂的耐热性相当。

  19. High contrast ultrasonic imaging of resin-rich regions in graphite/epoxy composites using entropy

    Science.gov (United States)

    Hughes, Michael S.; McCarthy, John E.; Bruillard, Paul. J.; Marsh, Jon N.; Wickline, Samuel A.

    2016-02-01

    This study compares different approaches for imaging a near-surface resin-rich defect in a thin graphite/epoxy plate using backscattered ultrasound. The specimen was created by cutting a circular hole in the second ply; this region filled with excess resin from the graphite/epoxy sheets during the curing process. Backscat-tered waveforms were acquired using a 4 in. focal length, 5MHz center frequency broadband transducer, scanned on a 100 × 100 grid of points that were 0.03 × 0.03 in. apart. The specimen was scanned with the defect side closest to the transducer. Consequently, the reflection from the resin-rich region cannot be gated from the large front-wall echo. At each point in the grid 256 waveforms were averaged together and subsequently used to produce peak-to-peak, Signal Energy (sum of squared digitized waveform values), as well as entropy images of two different types (a Renyi entropy, and a joint entropy). As the figure shows, all of the entropy images exhibit better border delineation and defect contrast than the either the peak-to-peak or Signal Energy. The best results are obtained using the joint entropy of the backscattered waveforms with a reference function. Two different references are examined. The first is a reflection of the insonifying pulse from a stainless steel reflector. The second is an approximate optimum obtained from an iterative parametric search. The joint entropy images produced using this reference exhibit three times the contrast obtained in previous studies.

  20. Microwave and thermal curing of an epoxy resin for microelectronic applications

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, K. [Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Pavuluri, S.K.; Leonard, M.T.; Desmulliez, M.P.Y. [MIcroSystems Engineering Centre (MISEC), Institute of Signals, Sensors and Systems, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Arrighi, V., E-mail: v.arrighi@hw.ac.uk [Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom)

    2015-09-20

    Graphical abstract: - Highlights: • Thermal and microwave curing of a commercial epoxy resin EO1080 are compared. • Microwave curing increases cure rate and does not adversely affect properties. • The curing of EO1080 is generally autocatalytic but deviates at high conversion. • Microwave radiation has a more complex effect on curing kinetics. - Abstract: Microwave curing of thermosetting polymers has a number of advantages to natural or thermal oven curing and is considered a cost-effective alternative. Here we present a detailed study of a commercially available epoxy resin, EO1080. Samples that are thermally cured are compared to curing using a recently developed modular microwave processing system. For commercial purposes it is crucial to demonstrate that microwave curing does not adversely affect the thermal and chemical properties of the material. Therefore, the kinetics of cure and various post cure properties of the resin are investigated. Attenuated Total Reflectance Fourier-Transform Infrared (ATR-FTIR) analysis shows no significant difference between the conventionally and microwave cured samples. Differential scanning calorimetry (DSC) is used to monitor the kinetics of the curing reaction, as well as determine the thermal and ageing properties of the material. As expected, the rate of curing is higher when using microwave energy and we attempt to quantify differences compared to conventional thermal curing. No change in glass transition temperature (T{sub g}) is observed. For the first time, enthalpy relaxation measurements performed on conventional and microwave cured samples are reported and these indicate similar ageing properties at any given temperature under T{sub g}.

  1. Influence of Coating with Some Natural Based Materials on the Erosion Wear Behavior of Glass Fiber Reinforced Epoxy Resin

    Directory of Open Access Journals (Sweden)

    Aseel Basim Abdul Hussein

    2015-06-01

    Full Text Available In the present study, composites were prepared by Hand lay-up molding. The composites constituents were epoxy resin as a matrix, 6% volume fractions of glass fibers (G.F as reinforcement and 3%, 6% volume fractions of preparation natural material (Rice Husk Ash, Carrot Powder, and Sawdust as filler. Studied the erosion wear behavior and coating by natural wastes (Rice Husk Ash with epoxy resin after erosion. The results showed the non – reinforced epoxy have lower resistance erosion than natural based material composites and the specimen (Epoxy+6%glass fiber+6%RHA has higher resistance erosion than composites reinforced with carrot powder and sawdust at 30cm , angle 60°, grin size of sand 425µm , temperature 30Ċ , 300 gm salt content in 2liter of water and 15 hour. Coating specimen with mixed epoxy resin -RHA with particles size in the range (1.4-4.2 µm improves erosion wear resistance characteristics of the coated specimen, coating thickness was (16 ± 1 μm and after erosion at (15 hour the thickness was (10 μm .

  2. EPOXY RESIN FOR APG AND ITS CURING CHARACTERISTICS%APG用环氧树脂及其固化特性

    Institute of Scientific and Technical Information of China (English)

    何愈

    2001-01-01

    In this paper,general features,curing characteristics and application process of epoxy resin for APG and the relation between property and curing shrinkage or processing condition were discussed.%讨论了APG用环氧树脂特征、应用工艺以及工艺与固化收缩和性能的关系。

  3. Effect of borates on thermal degradation and flame retardancy of epoxy resins using polyhedral oligomeric silsesquioxane as a curing agent

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Hongyu [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); Department of Building and Construction, City University of Hong Kong and USTC-CityU Joint Advanced Research Centre, Suzhou (China); Suzhou Key Laboratory of Urban Public Safety, Suzhou Institute of University of Science and Technology of China, Suzhou (China); Wang, Xin; Yu, Bin; Song, Lei [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); Hu, Yuan, E-mail: yuanhu@ustc.edu.cn [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); Suzhou Key Laboratory of Urban Public Safety, Suzhou Institute of University of Science and Technology of China, Suzhou (China); Yuen, Richard K.K. [Department of Building and Construction, City University of Hong Kong and USTC-CityU Joint Advanced Research Centre, Suzhou (China)

    2012-05-10

    Highlights: Black-Right-Pointing-Pointer Flame retarded epoxy resins with borates were prepared using POSS as a curing agent. Black-Right-Pointing-Pointer Borates and POSS exhibited a synergistic effect on flame retardancy of epoxy resins. Black-Right-Pointing-Pointer Incorporation of borates and POSS significantly reduced the heat release rate. - Abstract: A series of flame-retardant epoxy resins containing boron and silicon were obtained through a crosslinking reaction, using tris (2-hydroxypropyl) borate (THPB) together with octaaminophenyl POSS (OapPOSS) as the curing agents. The limiting oxygen index (LOI) reached 30.5% when the contents of boron and silicon in the cured system were 1.5% and 0.5%, respectively, indicating that THPB and OapPOSS exhibited good flame retardant effect on epoxy resins (EP). Microscale combustion calorimetry (MCC) results indicated that the peak heat release rate (PHRR) and total heat release (THR) of the cured systems were reduced by 69% and 46%, respectively, compared to those of pure EP. Moreover, the thermal degradation process and flame retardant mechanism of the composites were investigated by TGA, real time FTIR and TG-FTIR. The chemical components of the char residues were explored by XPS.

  4. Evaluation of the use of inorganic pigments and fillers in cure of epoxy resins by microwave irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kersting, Daniel, E-mail: daniel.kersting@usp.br [Universidade de Sao Paulo (USP), SP (Brazil). Escola Politecnica. Dept. de Engenharia Metalurgica e de Materiais; Centro Tecnologico da Marinha (CTMSP), SP (Brazil); Wiebeck, Helio, E-mail: hwiebeck@usp.br [Universidade de Sao Paulo (USP), SP (Brazil). Escola Politecnica. Dept. de Engenharia Metalurgica e de Materiais

    2013-07-01

    The use of microwave in chemical processes began soon after the WW II. The mechanism of curing via microwave heating is independent of the thermal conductivity of the irradiated material and offers a good solution to operate with materials that do not have a good thermal conductivity, such as polymers. Despite these advantages, the use of multimode microwave ovens, the main source used today, indicates some challenges to overcome. Associated with the use of epoxy resins in various applications, the use of pigments and inorganic fillers has added more variables to be studied. Much of the inorganic fillers used commercially are good absorbers of microwave providing changes in the amount of radiation absorbed, and thus the amount of heat transferred to the epoxy resin curing process. After selecting the key fillers and pigments traditionally used in the production of parts with epoxy resins they were subjected to the same microwave irradiation for evaluation of their behavior alone. In order to observe the effect of mixtures 1, 2, and 5% by weight of filler were added to epoxy resin, and it was verified these effects in the curing process. The preliminary results are promising, because for the same cure cycle for different types of fillers added separately, gains in curing time were obtained, making the process of cure via microwave quick and efficient without substantial losses in thermal properties of the final products obtained. (author)

  5. SYNTHESIS AND APPLICATION OF EPOXY RESIN%环氧树脂的合成与应用

    Institute of Scientific and Technical Information of China (English)

    汪多仁

    2001-01-01

    Synthetic process,production development,properties,application and consumption rospect of epoxy resin was presented in this paper.%介绍了环氧树脂的合成工艺、生产发展、性能、应用与市场前景。

  6. Effect of gamma-irradiation on the colorimetric properties of epoxy-resin films: Potential use in dosimetric application

    Energy Technology Data Exchange (ETDEWEB)

    Hosni, F., E-mail: ali_hosni2001@yahoo.fr [Unité de Recherche Maîtrise des Techniques Nucléaires à Caractère Pacifique, Centre National des Sciences et Technologie Nucléaires, 2020 Sidi-Thabet (Tunisia); Academie Militaire de Fondouk Jedid, 8012 Nabeul (Tunisia); Farah, K. [Unité de Recherche Maîtrise des Techniques Nucléaires à Caractère Pacifique, Centre National des Sciences et Technologie Nucléaires, 2020 Sidi-Thabet (Tunisia); Institut Supérieur du Transport et de la Logistique, 12 Rue Abdallah Ibn Ezzoubeier 40000, Université de Sousse (Tunisia); Kaouach, H. [Institut National de Recherche Scientifique et Technique, B.P. 95, Hammam-Lif 2050 (Tunisia); Louati, A. [Academie Militaire de Fondouk Jedid, 8012 Nabeul (Tunisia); Chtourou, R. [Institut National de Recherche Scientifique et Technique, B.P. 95, Hammam-Lif 2050 (Tunisia); Hamzaoui, A.H. [Laboratoire de Valorisation des Matériaux Utiles, Centre National de Recherche en Sciences des Matériaux, Technopôle de Borj Cedria, B.P. 95, Hammam-Lif 2050 (Tunisia)

    2013-09-15

    The present paper reports the results of the colorimetric study of gamma-irradiated epoxy-resin films. Epoxy-resin samples were irradiated by gamma-rays with doses varying from 1 to 50 kGy. Color changes of epoxy-resin were observed and studied by the measurements of the variation of the L{sup ∗}, a{sup ∗}, b{sup ∗} as function of dose and post-irradiation time. Where L{sup ∗} is a measure of the magnitude of brightness from black to white, parameter a{sup ∗} describe the relative amounts of red and green, and parameter b{sup ∗} describes the relative amounts of yellow and blue color. Color changes (ΔE) were also calculated. They indicated a marked dependence of the absorbed doses showing the optical activation of the color centers. It was found that color changes (ΔE) due to absorbed dose increase from 6 to 50. Color change showed a low variability which did not exceed 3% for the measurements carried out between 1 and 72 h. The obtained results revealed that epoxy-resin films can be used as a new routine dosimeter or irradiation indicator in dose range 1–50 kGy.

  7. PROGRESS OF BISPHENOL-S EPOXY RESIN%双酚S环氧树脂的研究进展

    Institute of Scientific and Technical Information of China (English)

    李燕芳; 高俊刚

    2001-01-01

    The synthesis reaction kinetics,curing mechanism,properties,application and development of bisphenol-S epoxy resin were reviewed with 23 references.%概述了双酚S环氧树脂的合成方法、固化机理、性能及应用进展。

  8. Characteristics of epoxy resin/SiO2 nanocomposite insulation: effects of plasma surface treatment on the nanoparticles.

    Science.gov (United States)

    Yan, Wei; Phung, B T; Han, Zhao Jun; Ostrikov, Kostya

    2013-05-01

    The present study compares the effects of two different material processing techniques on modifying hydrophilic SiO2 nanoparticles. In one method, the nanoparticles undergo plasma treatment by using a custom-developed atmospheric-pressure non-equilibrium plasma reactor. With the other method, they undergo chemical treatment which grafts silane groups onto their surface and turns them into hydrophobic. The treated nanoparticles are then used to synthesize epoxy resin-based nanocomposites for electrical insulation applications. Their characteristics are investigated and compared with the pure epoxy resin and nanocomposite fabricated with unmodified nanofillers counterparts. The dispersion features of the nanoparticles in the epoxy resin matrix are examined through scanning electron microscopy (SEM) images. All samples show evidence that the agglomerations are smaller than 30 nm in their diameters. This indicates good dispersion uniformity. The Weibull plot of breakdown strength and the recorded partial discharge (PD) events of the epoxy resin/plasma-treated hydrophilic SiO2 nanocomposite (ER/PTI) suggest that the plasma-treated specimen yields higher breakdown strength and lower PD magnitude as compared to the untreated ones. In contrast, surprisingly, lower breakdown strength is found for the nanocomposite made by the chemically treated hydrophobic particles, whereas the PD magnitude and PD numbers remain at a similar level as the plasma-treated ones.

  9. New structure of diamine curing agent for epoxy resins with self-restoration ability: Synthesis and spectroscopy characterization

    Science.gov (United States)

    Raimondo, Marialuigia; Guadagno, Liberata; Naddeo, Carlo; Longo, Pasquale; Mariconda, Annaluisa; Agovino, Anna

    2017-02-01

    The development of smart materials in aeronautical structures consisting of compounds based on epoxy resins having self-repair capability has been hampered by some criticalities. One of the main critical points is related to the impossibility to use primary amines (e.g.: 4,4‧-diaminodiphenyl sulfone, DDS) as hardeners, because they can poison the catalyst responsible for the healing mechanisms. In this paper, the synthesis, characterization and some tests of applicability of a new hardener, the tetramethylated diaminodiphenyl sulfone (tm-DDS), are shown. The tm-DDS is able to rapidly react with epoxy resin, giving a composite material having some characteristics significantly better than composites hardened with different tertiary amines. The new hardener is able to increase the glass transition temperature (Tg) of about 90 °C with respect to the more common hardener, ancamine K54, already used in self-healing epoxy formulations.

  10. Epoxy sheathing

    National Research Council Canada - National Science Library

    1992-01-01

    ... their vessels using polyester resins. In May 1990, several fishermen applied to the Vessel Upgrading Program for assistance to fiberglass their vessels using epoxy resin for the purpose of extending fishing vessel life...

  11. Effects of Processing Conditions on the Properties of Epoxy Resin Microcapsule

    Institute of Scientific and Technical Information of China (English)

    CAI Xiulan; FU Datian; QU Ailan

    2015-01-01

    In order to improve the healing performance and increase the service life of the polymer matrix composites, microcapsules were prepared by interfacial polymerization process with urea formaldehyde resin and epoxy resin E-51 as the wall material and core material separately. The effects of core/shell mass ratio and emulsiifer on the distribution, topography and encapsulation rate of microcapsules were investigated. By optimizing the conditions, microcapsules with little particle size, well dispersion and compact surface were prepared. The distribution, topography, stability and compositions of the microcapsules were characterized using Nano-2s, optical microscope, scanning electron microscopy, thermal analysis and Fourier transform infrared spectroscopy. The osmosis performance of the microcapsules was evaluated. The experimental results showed that the ratio of core/shell materials (1:1) and 1% DBS as emulsifier were optimum preparation conditions and the encapsulation rate was 62.5%. The microcapsules can be synthesized successfully with mean diameter 548.6 nm and exhibit a good chemical stability below 225℃. The FTIR result indicated that urea-formaldehyde resin was formed and the core materials were successfully encapsulated in urea-formaldehyde shell. Osmosis performance evaluation showed that the microcapsules were well coated and slowly osmosed.

  12. Preparation and Characterization of Epoxy Resin Cross-Linked with High Wood Pyrolysis Bio-Oil Substitution by Acetone Pretreatment

    Directory of Open Access Journals (Sweden)

    Yi Liu

    2017-03-01

    Full Text Available The use of cost effective solvents may be necessary to store wood pyrolysis bio-oil in order to stabilize and control its viscosity, but this part of the production system has not been explored. Conversely, any rise in viscosity during storage, that would occur without a solvent, will add variance to the production system and render it cost ineffective. The purpose of this study was to modify bio-oil with a common solvent and then react the bio-oil with an epoxy for bonding of wood without any loss in properties. The acetone pretreatment of the bio-oil/epoxy mixture was found to improve the cross-linking potential and substitution rate based on its mechanical, chemical, and thermal properties. Specifically, the bio-oil was blended with epoxy resin at weight ratios ranging from 2:1 to 1:5 and were then cured. A higher bio-oil substitution rate was found to lower the shear bond strength of the bio-oil/epoxy resins. However, when an acetone pretreatment was used, it was possible to replace the bio-oil by as much as 50% while satisfying usage requirements. Extraction of the bio-oil/epoxy mixture with four different solvents demonstrated an improvement in cross-linking after acetone pretreatment. ATR-FTIR analysis confirmed that the polymer achieved a higher cross-linked structure. DSC and TGA curves showed improved thermal stability with the addition of the acetone pretreatment. UV-Vis characterization showed that some functional groups of the bio-oil to epoxy system were unreacted. Finally, when the resin mixture was utilized to bond wood, the acetone pretreatment coupled with precise tuning of the bio-oil:epoxy ratio was an effective method to control cross-linking while ensuring acceptable bond strength.

  13. Testing Penetration of Epoxy Resin and Diamine Hardeners through Protective Glove and Clothing Materials.

    Science.gov (United States)

    Henriks-Eckerman, Maj-Len; Mäkelä, Erja A; Suuronen, Katri

    2015-10-01

    Efficient, comfortable, yet affordable personal protective equipment (PPE) is needed to decrease the high incidence of allergic contact dermatitis arising from epoxy resin systems (ERSs) in industrial countries. The aim of this study was to find affordable, user-friendly glove and clothing materials that provide adequate skin protection against splashes and during the short contact with ERS that often occurs before full cure. We studied the penetration of epoxy resin and diamine hardeners through 12 glove or clothing materials using a newly developed test method. The tests were carried out with two ERS test mixtures that had a high content of epoxy resin and frequently used diamine hardeners of different molar masses. A drop (50 µl) of test mixture was placed on the outer surface of the glove/clothing material, which had a piece of Fixomull tape or Harmony protection sheet attached to the inner surface as the collection medium. The test times were 10 and 30 min. The collecting material was removed after the test was finished and immersed into acetone. The amounts of diglycidyl ether of bisphenol A (DGEBA), isophorone diamine (IPDA), and m-xylylenediamine (XDA) in the acetone solution were determined by gas chromatography with mass spectrometric detection. The limit for acceptable penetration of XDA, IPDA, and DGEBA through glove materials was set at 2 µg cm(-2). Penetration through the glove materials was 1.4 µg cm(-2) or less. The three tested chemical protective gloves showed no detectable penetration (<0.5 µg cm(-2)). Several affordable glove and clothing materials were found to provide adequate protection during short contact with ERS, in the form of, for example, disposable gloves or clothing materials suitable for aprons and as additional protective layers on the most exposed parts of clothing, such as the front of the legs and thighs and under the forearms. Every ERS combination in use should be tested separately to find the best skin protection material

  14. On adhesive properties of perlite and sewage sludge ash with epoxy resin bonded single-strap repairs

    Science.gov (United States)

    Bulut, Mehmet; Erkliğ, Ahmet; Furkan Doğan, Nurettin

    2017-08-01

    In this study, the tensile properties of epoxy adhesive with the inclusion of micro-scale perlite and sewage sludge ash (SSA) particles were investigated for glass-epoxy laminates adhesively bonded single-strap repairs. Particle fillers were incorporated in the epoxy resin as an additive material at different ratios by weight, namely, 5, 10, 15 wt% for perlite; 5, 10, 15 and 20 wt% for SSA as well as unfilled composites. Composite samples were weakened by opening a circular cutout at the center of them, and then repaired by the circular patches produced from the same material. The repairing performances of samples were explored for two different patch ratios (D/d  =  2 and 3). Results indicated that the inclusion of perlite and SSA particles in the epoxy adhesive contributed to a significant increase in load carrying capacity at a weight content of 10 wt%.

  15. Effects of postcuring on mechanical properties of pultruded fiber-reinforced epoxy composites and the neat resin

    Science.gov (United States)

    Long, Edward R., Jr.; Long, Sheila Ann T.; Funk, Joan G.; Collins, William D.; Gray, Stephanie L.

    1989-01-01

    The effects of postcuring on mechanical properties of pultruded fiber-reinforced epoxy-resin composites have been investigated. Composites with carbon, glass, and aramid reinforcement fibers were individually studied. The epoxy was a commercially-available resin that was especially developed for pultrusion fabrication. The pultrusions were conducted at 400 F with postcures at 400, 450, 500, and 550 F. Measurements of the flexural, shear, and interlaminar fracture-toughness properties showed that significant postcuring can occur during the pultrusion process. All three mechanical properties were degraded by the higher (500 and 550 F) temperatures; photomicrographs suggest that the degradation was caused at the fiber-resin interface for all three fiber types.

  16. Concomitant contact allergy to the resins, reactive diluents and hardener of a bisphenol A/F-based epoxy resin in subway construction workers.

    Science.gov (United States)

    Chu, Chia-Yu; Pontén, Ann; Sun, Chee-Ching; Jee, Shiou-Hwa

    2006-03-01

    An outbreak of suspected contact dermatitis among subway construction workers was suspected to be due to a new bisphenol A/F-based epoxy resin system (ERS). The construction workers used ERSs during the insertion of iron bars into concrete walls. The objective of the study was to determine the components (if any) of the ERS responsible for the contact allergy. Patch testing was performed on 20 of the 22 construction workers who had had contact with the ERS, and to the various subcomponents of component A on 5 of the 7 who reacted to this component. 9 patients (9/22, 40.9%) had clinical symptoms and signs of suspected contact dermatitis at presentation. 7 of these 9, but none of the 11 asymptomatic individuals, were positive to component A, while all were negative to component B. Of the 5 cases receiving further patch testing, all reacted to m-xylylene diamine, 4 to 1,6-hexanediol diglycidyl ether, 3 to epoxy resins of the bisphenol F-type and trimethylolpropane triglycidyl ether 0.25% petrolatum, and only 1 to epoxy resins of the bisphenol A-type. Contact allergy to ERSs may involve hardeners and diluents as well as resins, and patch testing for reaction to all components should be performed.

  17. Free volumes and gas transport in polymers: amine-modified epoxy resins as a case study.

    Science.gov (United States)

    Patil, Pushkar N; Roilo, David; Brusa, Roberto S; Miotello, Antonio; Aghion, Stefano; Ferragut, Rafael; Checchetto, Riccardo

    2016-02-07

    The CO2 transport process was studied in a series of amine-modified epoxy resins having different cross-linking densities but the same chemical environment for the penetrant molecules. Positron Annihilation Lifetime Spectroscopy (PALS) was used to monitor the free volume structure of the samples and experimentally evaluate their fractional free volume fh(T) and its temperature evolution. The analysis of the free volume hole size distribution showed that all the holes have a size large enough to accommodate the penetrant molecules at temperatures T above the glass transition temperature Tg. The measured gas diffusion constants at T > Tg have been reproduced in the framework of the free volume theory of diffusion using a novel procedure based on the use of fh(T) as an input experimental parameter.

  18. Nondestructive approach for measuring temperature-dependent dielectric properties of epoxy resins.

    Science.gov (United States)

    Akhtar, M Jaleel; Feher, Lambert E; Thumm, Manfred

    2008-01-01

    A practical method for measuring the complex relative permittivity of epoxy resins and other viscous liquids over a wide temperature range in S-band is presented. The method involves inserting a hot glass tube, filled with the liquid-under-test (LUT), into a length of WR-340 rectangular waveguide connected between two ports of a Vector Network Analyzer, which measures the reflection and transmission coefficients at 2.45 GHz. The heating arrangement consists of a temperature-controlled glycol bath, where the LUT-filled glass tube is placed. The dielectric properties are determined using an optimization routine, which minimizes the error between the theoretical and measured scattering coefficient data. The theoretical values of the scattering coefficient data are computed with the help of a numerical 3-D electromagnetic field simulator, the CST Microwave Studio. The dielectric properties of the empty glass tube (required by the simulation code) are also measured using the above methodology.

  19. Treatment by gliding arc of epoxy resin: preliminary analysis of surface modifications

    Science.gov (United States)

    Faubert, F.; Wartel, M.; Pellerin, N.; Pellerin, S.; Cochet, V.; Regnier, E.; Hnatiuc, B.

    2016-12-01

    Treatments with atmospheric pressure non-thermal plasma are easy to implement and inexpensive. Among them gliding arc (GlidArc) remains rarely used in surface treatment of polymers. However, it offers economic and flexible way to treat quickly large areas. In addition the choice of carrier gas makes it possible to bring the active species and other radicals allowing different types of grafting and functionalization of the treated surfaces, for example in order to apply for anti-biofouling prevention. This preliminary work includes analysis of the surface of epoxy resins by infrared spectroscopy: the different affected chemical bonds were studied depending on the duration of treatment. The degree of oxidation (the C/O ratio) is obtained by X-ray microanalysis and contact angle analysis have been performed to determinate the wettability properties of the treated surface. A spectroscopic study of the plasma allows to determine the possible active species in the different zones of the discharge.

  20. IR study on hydrogen bonding in epoxy resin-silica nanocomposites

    Institute of Scientific and Technical Information of China (English)

    Wei Zhang; Abbas A. Dehghani-Sanij; Richard S. Blackburn

    2008-01-01

    The chemical and physical interactions between ingredients in composites play an important role in the improvement of service prop-sity loss of isocyanate absorption band in conjunction with the intensity growth of carboxyl absorption band indicates the progress of reaction. FT-IR spectroscopy was also adopted to examine the intermolecular hydrogen bonding of epoxy resin with silica as well as intramolecular one within polymer matrix. The vibration frequency of carboxyl group (-C=O) and hydroxyl group (-OH) shifts from 1736 to 1728 cm-1and 3420 to 3414 cm-1, respectively, indicating the occurrence of hydrogen bonding between -C=O and -OH. The vibration frequency of Si-OH moves from 3435 to 3414 cm -1, suggesting the involvement of silica. Whereas the vibration frequency of pending -OH in polymer chain moves from 3435 to 3420 cm-1 or 3414 cm-1, proposing that this kind of interaction can also happen within polymer matrix.

  1. The effects of alumina nanoparticle on the properties of an epoxy resin system

    Energy Technology Data Exchange (ETDEWEB)

    Omrani, Abdollah [Faculty of Chemistry, University of Mazandaran, P.O. Box 453, Babolsar, Mazandaran (Iran, Islamic Republic of)], E-mail: omrani@umz.ac.ir; Simon, Leonardo C. [Department of Chemical Engineering, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1 (Canada); Rostami, Abbas A. [Faculty of Chemistry, University of Mazandaran, P.O. Box 453, Babolsar, Mazandaran (Iran, Islamic Republic of)

    2009-03-15

    The aim of this investigation is to determine the reinforcing effects of alumina nanoparticle in a diglycidyl ether of bisphenol A (DGEBA) type epoxy resin using different approaches based on in situ Fourier transform infrared spectroscopy, differential scanning calorimetry (DSC), dynamic mechanical, mechanical and microstructure measurements. From the kinetic analysis using the Avrami equation, it has been seen that the kinetic parameters are influenced by the presence of nanoparticle and the used curing temperatures. Differential scanning calorimetry was used to probe the changes in reactivity by analyzing the reaction heat and the glass transition temperature values of the cured composites owing to the presence of nanoparticle and due to the diamine hardener. It was also found that a relatively low concentration of Al{sub 2}O{sub 3} nanoparticle led to an impressive improvement of dynamic mechanical, mechanical, and thermal properties. The scanning electron microscopy (SEM) photographs showed that the surface roughness increased with the addition of nanoalumina.

  2. Gamma-rays initiated cationic polymerization of epoxy resins and their carbon nanotubes composites

    Science.gov (United States)

    Przybytniak, Grażyna; Nowicki, Andrzej; Mirkowski, Krzysztof; Stobiński, Leszek

    2016-04-01

    Epoxy resins based on diglycidyl ether of bisphenol A (DGEBA) in the presence cationic initiator in the form of iodonium salt were exposed to gamma-rays in order to initiate curing process. The influence of the initiator concentration, dose rate, chemical structure of monomers and the presence of carbon nanotubes were determined on the basis of the recorded on-line thermal effects. The induction time of radiation curing increased with lowering concentration of the initiator and oxirane groups as well as with decreasing dose rates. As was confirmed by SEM images, carbon nanotubes were uniformly distributed over the matrix and closely surrounded by the macromolecules. Such a structure resulted from adsorption of the initiator on the filler surface what allowed to begin polymerization around nanoparticles and facilitated their incorporation into the matrix. As a consequence, the mechanical properties of the nanocomposites were improved.

  3. The glass transition temperature and microstructure of polyurethane/epoxy resin interpenetrating polymer networks nanocomposites

    Institute of Scientific and Technical Information of China (English)

    JIA Qingming; ZHENG Maosheng; SHEN Renjie; CHEN Hongxiang

    2006-01-01

    Nanocomposites with various contents of organophilic montmorillonite (oMMT) have been prepared by adding oMMT to interpenetrating polymer networks (IPNs) of polyurethane and epoxy resin (PU/EP) which had been prepared by a sequential polymeric technique. DSC experiment indicates a novel phenomenon that the glass transition temperature (Tg) of the nanocomposites increases with the oMMT content up to 3 %, then decreases with further increasing oMMT content. In order to explain this phenomenon, crosslink density, hydrogen bonding in the hard segments, crystallization of the nanocomposites and the exfoliation degree of oMMT in the nanocomposites have been investigated by swelling method, FT-IR, XRD, SEM and TEM, respectively. The results indicate that the crosslink density and the hydrogen bonding index of the nanocomposites increase, but the crystallization degree of the nanocomposites decreases with increasing oMMT content. In addition, oMMT improves the network structure of PU/EP.

  4. Low Temperature Mechanical Testing of Carbon-Fiber/Epoxy-Resin Composite Materials

    Science.gov (United States)

    Nettles, Alan T.; Biss, Emily J.

    1996-01-01

    The use of cryogenic fuels (liquid oxygen and liquid hydrogen) in current space transportation vehicles, in combination with the proposed use of composite materials in such applications, requires an understanding of how such materials behave at cryogenic temperatures. In this investigation, tensile intralaminar shear tests were performed at room, dry ice, and liquid nitrogen temperatures to evaluate the effect of temperature on the mechanical response of the IM7/8551-7 carbon-fiber/epoxy-resin system. Quasi-isotropic lay-ups were also tested to represent a more realistic lay-up. It was found that the matrix became both increasingly resistant to microcracking and stiffer with decreasing temperature. A marginal increase in matrix shear strength with decreasing temperature was also observed. Temperature did not appear to affect the integrity of the fiber-matrix bond.

  5. Investigation on peak frequency of the microwave absorption for carbonyl iron/epoxy resin composite

    Energy Technology Data Exchange (ETDEWEB)

    Wang Bochong; Wei Jianqiang; Yang Yong; Wang Tao [Institute of Applied Magnetics, Key Laboratory of Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou 730000 (China); Li Fashen, E-mail: lifs@lzu.edu.c [Institute of Applied Magnetics, Key Laboratory of Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou 730000 (China)

    2011-04-15

    Microwave absorbing characteristics of carbonyl iron/epoxy resin composite with various volume concentrations were investigated in 0.1-18 GHz. According to the electromagnetic parameters and thicknesses of the sample, numerical calculation and experiment have demonstrated that the frequency dependence of the microwave absorption comply with the quarter-wavelength ({lambda}/4) matching model that may explain not only the peak frequency but also the number of the peaks. It implies that the quarter-wavelength condition can be successfully applied to understand and predict the peak frequency of the microwave absorption for ferromagnetic metal-based composites. - Research highlights: > The dip in RL complies with the quarter-wavelength condition. > Two dips appear simultaneously when the sample thickness is thicker than the critical thickness t{sub c}{sup 3/4}. > The peak frequency of the dips can be manipulated by changing the sample thickness.

  6. Nuclear characteristics of epoxy resin as a space environment neutron shielding

    Energy Technology Data Exchange (ETDEWEB)

    Adeli, Ruhollah [Nuclear Science and Technology Research Institute, Yazd (Iran, Islamic Republic of). Central Iran Research Complex; Shirmardi, Seyed Pezhman [Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of). Radiation Application Research School; Mazinani, Saideh [Amirkabir Nanotechnology Research Institute, Tehran (Iran, Islamic Republic of); Ahmadi, Seyed Javad [Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of). Nuclear Fuel Cycle Research School

    2017-03-15

    In recent years many investigations have been done for choosing applicable light neutron shielding in space environmental applications. In this study, we have considered the neutron radiation-protective characteristics of neat epoxy resin, a thermoplastic polymer material and have compared it with various candidate materials in neutron radiation protection such as Al 6061 alloy and Polyethylene. The aim of this investigation is the effect of type of moderator for fast neutron, notwithstanding neutron absorbers fillers. The nuclear interactions and the effective dose at shields have been studied with the Monte Carlo N-Particle transport code (MCNP), using variance reductions to reduce the relative error. Among the candidates, polymer matrix showed a better performance in attenuating fast neutrons and caused a lower neutron and secondary photon effective dose.

  7. Barium ferrite/epoxy resin nanocomposite system: Fabrication, dielectric, magnetic and hydration studies

    Directory of Open Access Journals (Sweden)

    A. Kanapitsas

    2016-03-01

    Full Text Available Composite systems of epoxy resin and barium ferrite nanoparticles have been prepared, and studied varying the content of the inclusions. Morphology of prepared samples has been examined via scanning electron microscopy and X-ray diffraction spectra, while electrical and magnetic properties were investigated by means of broadband dielectric spectroscopy, and magnetization tests respectively. Finally, water vapor sorption measurements were conducted in order to study the water sorption dynamics of the system. Electron microscopy images revealed the successful fabrication of nanocomposites. Dielectric permittivity increases with filler content, while three relaxation processes were detected in the relative spectra. These processes are attributed to interfacial polarization, glass to rubber transition of the matrix, and re-orientation of polar side groups of the polymer’s chain. Magnetization and magnetic saturation increase with magnetic nano-powder content. Nanocomposites absorb a small amount of water, not exceeding 1.7 wt%, regardless filler content, indicating their hydrophobic character.

  8. Friction and wear behavior of nanosilica-filled epoxy resin composite coatings

    Energy Technology Data Exchange (ETDEWEB)

    Kang Yingke [Key Laboratory of Ministry of Education for Special Functional Materials, Henan University, Kaifeng 475004 (China); Chen Xinhua, E-mail: xuc0374@163.com [College of Chemistry and Chemical Engineering, Xuchang University, Xuchang 461000 (China); Song Shiyong; Yu Laigui [Key Laboratory of Ministry of Education for Special Functional Materials, Henan University, Kaifeng 475004 (China); Zhang Pingyu, E-mail: pingyu@henu.edu.cn [Key Laboratory of Ministry of Education for Special Functional Materials, Henan University, Kaifeng 475004 (China)

    2012-06-15

    Hydrophilic silica nanoparticles (abridged as nano-SiO{sub 2}) surface-capped with epoxide were dispersed in the solution of epoxy resin (abridged as EP) in tetrahydrofuran under magnetic stirring. Resultant suspension of nano-SiO{sub 2} in EP was then coated onto the surface of glass slides and dried at 80 Degree-Sign C in a vacuum oven for 2 h, generating epoxy resin-nanosilica composite coatings (coded as EP/nano-SiO{sub 2}). EP coating without nano-SiO{sub 2} was also prepared as a reference in the same manner. A water contact angle meter and a surface profiler were separately performed to measure the water contact angles and surface roughness of as-prepared EP/nano-SiO{sub 2} composite coatings. The friction and wear behavior of as-prepared EP/nano-SiO{sub 2} composite coatings sliding against steel in a ball-on-plate contact configuration under unlubricated condition was evaluated. Particularly, the effect of coating composition on the friction and wear behavior of the composite coatings was highlighted in relation to their microstructure and worn surface morphology examined by means of scanning electron microscopy. Results indicate that EP/nano-SiO{sub 2} composite coatings have a higher surface roughness and water contact angle than EP coating. The EP-SiO{sub 2} coatings doped with a proper amount of hydrophilic SiO{sub 2} nanoparticles show lower friction coefficient than EP coating. However, the introduction of surface-capped nanosilica as the filler results in inconsistent change in the friction coefficient and wear rate of the filled EP-matrix composites; and it needs further study to achieve well balanced friction-reducing and antiwear abilities of the composite coatings for tribological applications.

  9. Cure Behaviors of epoxy resin initiated by methylanilinium slats as latent cationic curing agent.

    Energy Technology Data Exchange (ETDEWEB)

    Park, S.J.; Kim, T.J.; Lee, C.J.; Lee, J.R. [Korea Research Institute of Chemical Technology, Taejeon (Korea); Park, J.K.; Shin, J.H. [Seoul National University, Seoul (Korea)

    2001-03-01

    The effect of novel N-crotyl-N, N-dimethyl-4-methylanilinium hexafluoroantimonate (CMH) curing agent as a thermal latent initiator on thermal behaviors, rheological properties, and thermal stability of diglycidylether of bisphenol A (DGEBA) epoxy cationic system was investigated. From DSC measurements of DGEBA/CMH system, it was shown that this system exhibits an excellent thermal latent characteristic at a given temperature. The conversion and conversion rate of DGEBA/CMH system increased with increasing the concentration of initiator, due to high activity of CMH. Rheological properties of the system were investigated under isothermal condition using a rheometer. The gelation time was obtained from the analysis of storage modulus (G'), loss modulus (G''), and damping factor (tan {delta}). As a result, the reduction of gelation time was affected by high curing temperature and concentration of CMH, resulting in high degree of network formation in cationic polymerization, due to difference of activity. The thermal stability of the cured epoxy resin was discussed in terms of the activation energy for decomposition and thermal factors determined from TGA measurements. (author). 29 refs., 3 tabs., 10 figs.

  10. Thermo-mechanical characterization of siliconized E-glass fiber/hematite particles reinforced epoxy resin hybrid composite

    Science.gov (United States)

    V. R., Arun prakash; Rajadurai, A.

    2016-10-01

    In this present work hybrid polymer (epoxy) matrix composite has been strengthened with surface modified E-glass fiber and iron(III) oxide particles with varying size. The particle sizes of 200 nm and surface modification process has been done on both fiber and filler by an amino functional silane 3-Aminopropyltrimethoxysilane (APTMS). Crystalline and functional groups of siliconized iron(III) oxide particles were characterized by XRD and FTIR spectroscopy analysis. Fixed quantity of surface treated 15 vol% E-glass fiber was laid along with 0.5 and 1.0 vol% of iron(III) oxide particles into the matrix to fabricate hybrid composites. The composites were cured by an aliphatic hardener Triethylenetetramine (TETA). Effectiveness of surface modified particles and fibers addition into the resin matrix were revealed by mechanical testing like tensile testing, flexural testing, impact testing, inter laminar shear strength and hardness. Thermal behavior of composites was evaluated by TGA, DSC and thermal conductivity (Lee's disc). The scanning electron microscopy was employed to found shape and size of iron(III) oxide particles adhesion quality of fiber with epoxy matrix. Good dispersion of fillers in matrix was achieved with surface modifier APTMS. Tensile, flexural, impact and inter laminar shear strength of composites was improved by reinforcing surface modified fiber and filler. Thermal stability of epoxy resin was improved when surface modified fiber was reinforced along with hard hematite particles. Thermal conductivity of epoxy increased with increase of hematite content in epoxy matrix.

  11. Influence of the molecular structure on hydrolyzability of epoxy resins; Influence de la structure moleculaire sur l`hydrolysabilite des resines epoxyde

    Energy Technology Data Exchange (ETDEWEB)

    Pays, M.F.

    1996-12-31

    EDF has decided to use glass reinforced composites for certain pipework in Pressurized Water Reactors (service water, emergency-supplied service water, fine pipe works, etc...) as a replacement for traditional materials. In practice, steel is prone to rapid corrosion in these circuits; introducing composites could prove economically viable if their long term behaviour can be demonstrated. However, composite materials can undergo deterioration in service through hydrolysis of the resin or the fibre-matrix interface. Different resins can be chosen depending on the programmed use. A first study has covered the hydrolyzability of polyester and vinyl ester resins. The present document undertakes the resistance to hydrolysis of epoxy resins, concentrating on those reputed to withstand high temperatures. This research uses model monomer, linking the molecular structure of the materials to their resistance to hydrolysis. (author).

  12. THE STUDIES OF THE CURING OF AN EPOXY RESIN ON COPPER WIRE BY FTIR EXTERNAL REFLECTION SPECTROSCOPY

    Institute of Scientific and Technical Information of China (English)

    XUE Gi; LIU Shiying; JIANG Shangen

    1988-01-01

    The epoxy coating on copper wire has been studied by a modified sampling technique using Fourier transform infrared (FTIR) diffuse reflectance attachment. As the wire axis was parallel to the incident plane, a reflection spectrum of thin layer coating on a copper wire can be obtained. The study found that imidazole, especially the acetic acid treated imidazole, can be used as an effective curing catalyst of the epoxy resin on copper. This is the first report about the IR study of coatings on metal wires.

  13. Surface modification of an epoxy resin with polyamines and polydopamine: The effect on the initial electroless copper deposition

    Science.gov (United States)

    Schaubroeck, David; Mader, Lothar; De Geyter, Nathalie; Morent, Rino; Dubruel, Peter; Vanfleteren, Jan

    2014-06-01

    This paper describes the influence of polydopamine and polyamine surface modifications of an etched epoxy cresol novolak (ECN) resin on the initial electroless copper deposition. Three different strategies to introduce polyamines on a surface in aqueous environment are applied: via polyethyleneimine adsorption (PEI), via polydopamine and via polyamines grafted to polydopamine. Next, the influence of these surface modifications on the catalytic palladium activation is investigated through X-ray photoelectron spectroscopy (XPS) analysis. Finally, the initial electroless copper deposition on modified epoxy surfaces is evaluated using SEM and Energy Dispersive Spectroscopy (EDS). Grafted polyamines on polydopamine surface modifications result in a large increase of the initial deposited copper.

  14. Manufacturing of REBCO coils strongly bonded to cooling members with epoxy resin aimed at its application to Maglev

    Energy Technology Data Exchange (ETDEWEB)

    Mizuno, Katsutoshi, E-mail: mizuno.katsutoshi.14@rtri.or.jp; Ogata, Masafumi; Hasegawa, Hitoshi

    2014-11-15

    Highlights: • Paraffin has a risk of losing thermal coupling during cooling down. • We propose an epoxy impregnated REBCO coil co-wound with PTFE tape. • The coil is tightly bonded to cooling members by epoxy resin without the degradation. • We made a REBCO racetrack coil with the same outer dimension as the Maglev magnet. - Abstract: The REBCO coated conductor has been attracted attention because of its high current density in the presence of high magnetic field. If the coated conductor is applied to Maglev, the operational temperature of the on-board magnets will be over 40 K and energy consumption of cryocoolers will be reduced. That high operational temperature also means the absence of liquid helium. Therefore, reliable thermal coupling is desirable for cooling the coils. We propose an epoxy impregnated REBCO coil co-wound with PTFE tape. While the PTFE tape prevents the performance degradation of the coil, the epoxy resin bonds the coil to cooling members. We carried out three experiments to confirm that the coil structure which we propose has robust thermal coupling without the degradation. First, thermal resistances of paraffin and epoxy were measured varying the temperature from room temperature to 10 K. The measurement result indicates that paraffin has a risk of losing thermal coupling during cooling down. In another experiment, PTFE (polytetrafluoroethylene) tape insulator prevented performance degradation of a small epoxy impregnated REBCO coil, while another REBCO coil with polyimide tape showed clear performance degradation. Finally, we produced a racetrack REBCO coil with the same outer dimension as a Maglev on-board magnet coil. Although the racetrack coil was installed in a GFRP coil case and tightly bonded to the case by epoxy impregnation, any performance degradation was not observed.

  15. Thermo-mechanical characterization of siliconized E-glass fiber/hematite particles reinforced epoxy resin hybrid composite

    Energy Technology Data Exchange (ETDEWEB)

    Arun Prakash, V.R., E-mail: vinprakash101@gmail.com; Rajadurai, A., E-mail: rajadurai@annauniv.edu.in

    2016-10-30

    Highlights: • Particles dimension have reduced using Ball milling process. • Importance of surface modification was explored. • Surface modification has been done to improve adhesion of fiber/particles with epoxy. • Mechanical properties has been increased by adding modified fiber and particles. • Thermal properties have been increased. - Abstract: In this present work hybrid polymer (epoxy) matrix composite has been strengthened with surface modified E-glass fiber and iron(III) oxide particles with varying size. The particle sizes of 200 nm and <100 nm has been prepared by high energy ball milling and sol-gel methods respectively. To enhance better dispersion of particles and improve adhesion of fibers and fillers with epoxy matrix surface modification process has been done on both fiber and filler by an amino functional silane 3-Aminopropyltrimethoxysilane (APTMS). Crystalline and functional groups of siliconized iron(III) oxide particles were characterized by XRD and FTIR spectroscopy analysis. Fixed quantity of surface treated 15 vol% E-glass fiber was laid along with 0.5 and 1.0 vol% of iron(III) oxide particles into the matrix to fabricate hybrid composites. The composites were cured by an aliphatic hardener Triethylenetetramine (TETA). Effectiveness of surface modified particles and fibers addition into the resin matrix were revealed by mechanical testing like tensile testing, flexural testing, impact testing, inter laminar shear strength and hardness. Thermal behavior of composites was evaluated by TGA, DSC and thermal conductivity (Lee’s disc). The scanning electron microscopy was employed to found shape and size of iron(III) oxide particles adhesion quality of fiber with epoxy matrix. Good dispersion of fillers in matrix was achieved with surface modifier APTMS. Tensile, flexural, impact and inter laminar shear strength of composites was improved by reinforcing surface modified fiber and filler. Thermal stability of epoxy resin was improved

  16. Dry entrapment of enzymes by epoxy or polyester resins hardened on different solid supports.

    Science.gov (United States)

    Barig, Susann; Funke, Andreas; Merseburg, Andrea; Schnitzlein, Klaus; Stahmann, K-Peter

    2014-06-10

    Embedding of enzymes was performed with epoxy or polyester resin by mixing in a dried enzyme preparation before polymerization was started. This fast and low-cost immobilization method produced enzymatically active layers on different solid supports. As model enzymes the well-characterized Thermomyces lanuginosus lipase and a new threonine aldolase from Ashbya gossypii were used. It was shown that T. lanuginosus lipase recombinantly expressed in Aspergillus oryzae is a monomeric enzyme with a molecular mass of 34kDa, while A. gossypii threonine aldolase expressed in Escherichia coli is a pyridoxal-5'-phosphate binding homotetramer with a mass of 180kDa. The enzymes were used freeze dried, in four different preparations: freely diffusing, adsorbed on octyl sepharose, as well as cross-linked enzyme aggregates or as suspensions in organic solvent. They were mixed with standard two-component resins and prepared as layers on solid supports made of different materials e.g. metal, glass, polyester. Polymerization led to encapsulated enzyme preparations showing activities comparable to literature values.

  17. Mechanical behavior of quartz fiber reinforced epoxy resins for teeth restoration.

    Science.gov (United States)

    Visco, A M; Calabrese, L; Campo, N; Torrisi, L; Oteri, G; Lo Giudice, G; Cicciù, D

    2006-01-01

    In this work composite materials, based on quartz fibers and epoxy resins, were employed with the aim to restore damaged teeth. The composite materials were chosen because they show biomechanical features very similar to that of the dentine, the main constituent of the tooth. Extracted teeth were rebuilt with two different restorative procedures: in the first, the composite material was pre-formed in a conical trunk shape abutment (PA) and then bonded to a fiber quartz post with a dental bonder. In the second rebuilt system the abutment was prepared by cross linking the resin on the fiber quartz post with a halogen lamp (CRA). The restored teeth were then mechanically tested and observed with a Scanning Electron Microscope (SEM) with the aim to study the interaction between the reconstructive materials. Wetting and roughness measurements were also carried out in order to study the interface adhesion between the post and the abutments. Characterization analysis evidenced that the CRA restorative procedure improves the adhesion between the substitutive materials and shows higher fracture strength than the PA ones. Anyway both the rebuilt systems are able to support the masticator load. An explanation of the interfacial post-abutment interaction phenomenon is discussed.

  18. Accurate Cure Modeling for Isothermal Processing of Fast Curing Epoxy Resins

    Directory of Open Access Journals (Sweden)

    Alexander Bernath

    2016-11-01

    Full Text Available In this work a holistic approach for the characterization and mathematical modeling of the reaction kinetics of a fast epoxy resin is shown. Major composite manufacturing processes like resin transfer molding involve isothermal curing at temperatures far below the ultimate glass transition temperature. Hence, premature vitrification occurs during curing and consequently has to be taken into account by the kinetic model. In order to show the benefit of using a complex kinetic model, the Kamal-Malkin kinetic model is compared to the Grindling kinetic model in terms of prediction quality for isothermal processing. From the selected models, only the Grindling kinetic is capable of taking into account vitrification. Non-isothermal, isothermal and combined differential scanning calorimetry (DSC measurements are conducted and processed for subsequent use for model parametrization. In order to demonstrate which DSC measurements are vital for proper cure modeling, both models are fitted to varying sets of measurements. Special attention is given to the evaluation of isothermal DSC measurements which are subject to deviations arising from unrecorded cross-linking prior to the beginning of the measurement as well as from physical aging effects. It is found that isothermal measurements are vital for accurate modeling of isothermal cure and cannot be neglected. Accurate cure predictions are achieved using the Grindling kinetic model.

  19. Isothermal curing of polymer layered silicate nanocomposites based upon epoxy resin by means of anionic homopolymerisation

    Energy Technology Data Exchange (ETDEWEB)

    Román, Frida, E-mail: roman@mmt.upc.edu; Calventus, Yolanda, E-mail: calventus@mmt.upc.edu; Colomer, Pere, E-mail: colomer@mmt.upc.edu; Hutchinson, John M., E-mail: hutchinson@mmt.upc.edu

    2013-12-20

    Highlights: • The nanocomposite with low content of clay displayed improved thermal properties. • The vitrification was observed in the isothermal curing. • Dielectric relaxations outside and inside of the clay galleries were detected. - Abstract: The use of an initiator, 4-(dimethylamino) pyridine (DMAP), to promote an anionic homopolymerisation reaction for the isothermal cure of polymer layered silicate (PLS) nanocomposites based on an epoxy resin, as well as the effect of the nanoclay content, have been studied by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dielectric relaxation spectroscopy (DRS) and transmission electron microscopy (TEM). The vitrification phenomenon was observed during the isothermal cure process, and it was found that the nanocomposite with a low clay content (2 wt%), denoted EDM2, shows improved thermal properties with respect to the unreinforced resin (denoted ED), while the nanocomposite with a higher clay content (5 wt%), denoted EDM5, displayed inferior properties. The cure kinetics were analysed by different methods, and it was observed that the activation energy and kinetic parameters of EDM2 were lower compared to the other two systems. Examination of the nanostructure of the cured EDM2 nanocomposite showed partial exfoliation, while the EDM5 system retains an intercalated nanostructure. In the DRS studies of the curing process of the EDM2 system, two dielectric relaxations were detected, which are associated with the molecular mobility in the curing reaction which takes place both outside and inside the clay galleries.

  20. Optical techniques for determination of the state of cure of epoxy resin based systems

    Science.gov (United States)

    Michie, W. C.; Thursby, G.; Johnstone, W.; Culshaw, B.

    1993-03-01

    Determination of the state of cure of epoxy resin based systems is of considerable interest to manufacturers of large carbon fiber reinforced plastic and glass reinforced plastic structures. Optical methods designed to indicate the cure state have been developed using a loss mechanism which is a function of the refractive index of the curing system. Such techniques are however subject to corruption from losses arising from other influences and consequently are limited in their measurement resolution. In this paper, two techniques which are able to provide a high degree of accuracy of measurement of refractive index are investigated as a means of performing cure measurements. The methods investigated involve the interaction of the evanescent field of a side polished optical fiber with an overlay waveguide or a surface plasmon. Coupling between the fiber and the overlay waveguide (or plasmon) is strongly influenced by the refractive index of the bulk superstrate above the overlay (in this case the curing resin system). Both sensing schemes are self referencing and are not influenced by loss.

  1. Preparation and Characterization of Carboxyl-terminated Poly (butadiene-co-acrylonitrile)-epoxy Resin Prepolymers for Fusion-bonded-epoxy Powder Coating

    Institute of Scientific and Technical Information of China (English)

    LIU Jingcheng; JIA Xiuli; ZHANG Shengwen; LIU Ren; LIU Xiaoya

    2012-01-01

    Liquid carboxyl-terminated poly(butadiene-co-acrylonitrile)(CTBN)-epoxy resin(EP)prepolymers were prepared with different contents of CTBN.The chemical reactions between EP and CTBN were characterized by Fourier ransform infrared (FTIR) spectroscopy and gel permeation chromatography (GPC).The scanning electron micrograph (SEM) and dynamic mechanical analysis (DMA) of curing films showed phase separation,and the rubber particles were finely dispersed in the epoxy matrix.Mechanical properties analysis of curing films showed that impact strength and elongation at break increased significantly upon the addition of CTBN,indicating good toughness of the modified epoxy resins.Thermogravimetric analysis (TGA) showed that the incorporation of CTBN had little effect on the thermal stability of EP.Fusion-bondedepoxy (FBE) powder coatings modified with CTBN-EP prepolymers were prepared.The experimental results demonstrate the ability of CTBN-EP prepolymers,toughening technology to dramatically enhance the flexibility and impact resistance of FBE coatings without compromising other key properties such as corrosion protection.

  2. Microwave processing of epoxy resins and synthesis of carbon nanotubes by microwave plasma chemical vapor deposition

    Science.gov (United States)

    Zong, Liming

    Microwave processing of advanced materials has been studied as an attractive alternative to conventional thermal processing. In this dissertation, work was preformed in four sections. The first section is a review on research status of microwave processing of polymer materials. The second section is investigation of the microwave curing kinetics of epoxy resins. The curing of diglycidyl ether of bisphenol A (DGEBA) and 3, 3'-diaminodiphenyl sulfone (DDS) system under microwave radiation at 145 °C was governed by an autocatalyzed reaction mechanism. A kinetic model was used to describe the curing progress. The third section is a study on dielectric properties of four reacting epoxy resins over a temperature range at 2.45 GHz. The epoxy resin was DGEBA. The four curing agents were DDS, Jeffamine D-230, m-phenylenediamine, and diethyltoluenediamine. The mixtures of DGEBA and the four curing agents were stoichiometric. The four reacting systems were heated under microwave irradiation to certain cure temperatures. Measurements of temperature and dielectric properties were made during free convective cooling of the samples. The cooled samples were analyzed with a Differential Scanning Calorimeter to determine the extents of cure. The Davidson-Cole model can be used to describe the dielectric data. A simplified Davidson-Cole expression was proposed to calculate the parameters in the Davidson-Cole model and describe the dielectric properties of the DGEBA/DDS system and part of the dielectric data of the other three systems. A single relaxation model was used with the Arrhenius expression for temperature dependence to model the results. The evolution of all parameters in the models during cure was related to the decreasing number of the epoxy and amine groups in the reactants and the increasing viscosity of the reacting systems. The last section is synthesis of carbon nanotubes (CNTs) on silicon substrate by microwave plasma chemical vapor deposition of a gas mixture of

  3. Novel high glass temperature sugar-based epoxy resins: Characterization and comparison to mineral oil-based aliphatic and aromatic resins

    OpenAIRE

    Niedermann, P.; G. Szebenyi; A. Toldy

    2015-01-01

    Curing and rheological behaviour, glass transition temperature, mechanical and thermal properties of two newly synthesized glucopyranoside- (GPTE) and glucofuranoside- (GFTE) based renewable epoxy resin (EP) components were investigated and compared to aromatic and aliphatic EPs. The glucose-based EPs can be successfully cured with amine and anhydride type curing agents, their gel times are suitable for processing and can be well-adopted to the needs of the common composite preparation method...

  4. 环氧改性硅树脂的研究进展%Reseach Progress on Epoxy-Modified Organosilicone Resin

    Institute of Scientific and Technical Information of China (English)

    李霞; 谢琴; 康乃文

    2016-01-01

    综述了近年来环氧改性硅树脂的方法及研究现状,展望了环氧改性硅树脂在高新技术领域的应用。%The paper reviews the methods of epoxy modified silicone resin and research status, and pros-pects the epoxy modified silicone resin in high and new technology in the field of application.

  5. Food-contact epoxy resin: co-variation between migration and degree of cross-linking. Part II.

    Science.gov (United States)

    Lambert, C; Larroque, M; Subirats, J T; Gérard, J F

    1998-04-01

    The study of epoxy resin composed of bisphenol A diglycidylether (BADGE), bisphenol F diglycidylether (BFDGE) (base), and primary aliphatic polyamines (hardener), has confirmed the interest of measuring certain physical parameters in order to evaluate the density of cross-linking of the network and thus predict the risks of resin molecules migrating into foodstuffs. This suggestion had been made in a preceding study on an epoxy resin composed of bisphenol A diglycidylether (BADGE) and primary aromatic polyamines. Samples with different densities of cross-linking, obtained by subjecting the resin to different curing temperatures (5, 20, 50 and 90 degrees C) for 7 days, were studied. The density of cross-linking increased with curing temperature, as indicated by the increase in glass transition temperature, the increased stability of the rubber storage modulus E'rub (increase in cross-link nodes), the fall in relaxation enthalpies (reduction in physical ageing) and the decreased amplitude of the loss-factor tan delta (reduction in chain mobility). Maximum cross-linking was obtained in the resin cured at 90 degrees C (temperature above Tg infinity). Concurrently, tests of migration into different liquid food simultants (distilled water, distilled water/ethanol/acetic acid, distilled water/ethanol) revealed a considerable reduction in specific migrations of BADGE and BFDGE, and of unidentified peaks.

  6. Effects of Core-Shell Rubber (CSR) Nanoparticles on the Fracture Toughness of an Epoxy Resin at Cryogenic Temperatures

    Science.gov (United States)

    Wang, J.; Cannon, S. A.; Schneider, J. A.

    2008-01-01

    This study investigates the effects of core-shell rubber (CSR) nanoparticles on the fracture toughness of an epoxy resin at liquid nitrogen (LN2) temperatures. Varying amounts of Kane Ace (Registered TradeMark) MX130 toughening agent were added to a commercially available EPON 862/W epoxy resin. Resulting fracture toughness was evaluated by the use of Charpy impact tests conducted on an instrumented drop tower. The size and distribution of the CSR nanoparticles were characterized using Transmission Electric Microscopy (TEM) and Small Angle X-ray Scattering (SAXS). Up to nominal 4.6% addition of the CSR nanoparticles, resulted in a nearly 5 times increase in the measured breaking energy. However, further increases in the amount of CSR nanoparticles had no appreciable affect on the breaking energy.

  7. Epigallocatechin-3-gallate increased the push out bond strength of an epoxy resin sealer to root dentin.

    Science.gov (United States)

    Pheenithicharoenkul, Suthida; Panichuttra, Anchana

    2016-12-01

    This study aimed to investigate the effect of epigallocatechin-3-gallate (EGCG) from green tea extract on the push out bond strength of an epoxy resin sealer to root dentin. Seventy single root canal premolars were decoronated and instrumented. The roots were randomly irrigated with different final irrigation protocols (n=16): 17%EDTA (EDTA), 17%EDTA followed by 2.5%NaOCl (EDTA+NaOCl), 17%EDTA followed by 1 mg/mL EGCG (EDTA+EGCG) and 1 mg/mL EGCG (EGCG). Other six root canals were received only 2.5%NaOCl as a control group. One root from each group (n=1) was excluded and prepared for SEM investigation. All root canals were then obturated and horizontally sectioned to perform the push out test. EDTA+EGCG group had the highest bond strength (pbond strength than EDTA group (pbond strength of an epoxy resin sealer to root dentin.

  8. Influence of Copper Layer Content in the Elastic and Damping Behavior of Glass-Fiber/Epoxy-Resin Composites

    Science.gov (United States)

    Carneiro, V. H.; Capela, P.; Teixeira, J. C.; Teixeira, S.; Cerqueira, F.; Macedo, F.; Ribas, L.; Soares, D.

    2016-12-01

    The impact in the elastic behavior and internal friction, caused by the introduction of Copper layers in Glass-Fiber/Epoxy Resin composites and temperature effects, were studied and evaluated recurring to Dynamic Mechanical Analysis. It is shown that the introduction of Copper layers increases the storage modulus of the composites and delays their glass transition temperature, however, it allows a faster transformation. Additionally, it is concluded that the introduction of Copper layers elevates the internal friction during the glass transition phase by the inversion of the deformation mechanism due to thermal expansion and increase in the Poisson's ratio of the epoxy resin to a value near 0.5 where its deformation is approximately isochoric. This increase in damping capacity is relevant in application with cyclic fatigue and mechanical vibration.

  9. Analogues of the epoxy resin monomer diglycidyl ether of bisphenol F: effects on contact allergenic potency and cytotoxicity.

    Science.gov (United States)

    O'Boyle, Niamh M; Delaine, Tamara; Luthman, Kristina; Natsch, Andreas; Karlberg, Ann-Therese

    2012-11-19

    Diglycidyl ethers of bisphenol A (DGEBA) and bisphenol F (DGEBF) are widely used as components in epoxy resin thermosetting products. They are known to cause occupational and nonoccupational allergic contact dermatitis. The aim of this study is to investigate analogues of DGEBF with regard to contact allergy and cytotoxicity. A comprehensive knowledge of the structural features that contribute to the allergenic and cytotoxic effects of DGEBF will guide the development of future novel epoxy resin systems with reduced health hazards for those coming into contact with them. It was found that the allergenic effects of DGEBF were dependent on its terminal epoxide groups. In contrast, it was found that the cytotoxicity in monolayer cell culture was dependent not only on the presence of epoxide groups but also on other structural features.

  10. Quantitative Analysis of Curing Mechanisms of Epoxy Resin by Mid- and Near- Fourier Transform Infra Red Spectroscopy

    Directory of Open Access Journals (Sweden)

    Sagar T. Cholake

    2014-05-01

    Full Text Available This article informs the essence of major work done by a number of researchers on the analysis of two-step curing mechanism of diglycidyl ether of bisphenol A (DGEBA epoxy resin in presence of amine curing agents using near- and mid-IR technology. Various peaks used as a marker for resin formation are discussed and their implementation is comprehensively studied. In addition to this, a wide range of information about the importance of reference peaks in both near-IR (NIR and mid-IR (MIR regions are congregated and their accuracy is audited. Also discrepancies observed by researchers in epoxy conversion (α in NIR and MIR regions are reviewed to highlight the comparative advantages of both regions, one over the other.Defence Science Journal, Vol. 64, No. 3, May 2014, pp. 314-321, DOI:http://dx.doi.org/10.14429/dsj.64.7326

  11. Kinetic study of polymerization/curing of filament-wound composite epoxy resin systems with aromatic diamines

    Science.gov (United States)

    Golub, M. A.; Lerner, N. R.; Hsu, M. S.

    1986-01-01

    The kinetics of polymerization/curing of a filament-wound composite epoxy resin consisting of an 80/20 DGEBA/DGEBD blend and an MDA/m-PDA blend (Tonox 60/40) was studied at various temperatures and at amine epoxy ratios between 1.1 and 4.4 by means of Fourier-transform (FT) IR and bulk viscosity measurements. The activation energy for the polymerization/curing reaction using an amine/epoxy ratio of 1.1 was 11.9 kcal/mole, in agreement with a previous value. The FT-IR conversion-time plots were fitted to a kinetic expression containing two rate constants with activation energies of 13.7 and 10.0 kcal/mole. The bulk viscosity followed the Williams et al. (1955) equation, with a Di Benedetto (1965) expression for the glass transition temperature.

  12. Preparation, curing kinetic and properties of a novel amine with flexible polyoxypropylene side chain curing agent for epoxy resin

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Guiyou, E-mail: guiyouwang@ecust.edu.cn; Jiang, Guanlan; Zhang, Jie

    2014-08-10

    Highlights: • Novel amines with different length of flexible polyoxypropylene side chain (AFPE) were synthesized. • The non-isothermal curing kinetics of DGEBA/AFPEs were studied in detail. • Structure, morphology and physical properties of AFPEs modified diethylenetriamine/DGEBA systems were studied, and results showed that AFPE was a novel and effective toughening agent for epoxy resins. - Abstract: A novel amine with flexible polyoxypropylene side chain (AFPE) was synthesized and characterized with FT-IR and NMR. Then, AFPEs with different molecular weight were used as a curing agent for diglycidyl ether of bisphenol A (DGEBA), and non-isothermal reaction was detected with DSC. The kinetic parameters of the curing process were determined by Málek method. A two-parameter (m, n) autocatalytic model (Šesták–Berggren equation) was found to be adequate to describe the reaction-controlled kinetics of the studied epoxy resins, yet was insufficient in depicting the diffusion-controlled kinetics of the epoxy resins. The values of E{sub a} depended on the molecular weight of AFPEs, and increased with longer polyoxypropylene chain length in the AFPE. Dynamic mechanical analysis of AFPEs modified DGEBA/diethylenetriamine systems found that with the increasing molecular weight of AFPEs, α relaxation temperature, β relaxation temperature and crosslinking density decreased, while impact strength and elongation at break improved. From scanning electron microscope, tensile surfaces were rougher and sizes of cavities in the surface became larger with the increasing molecular weight of AFPEs. Our study showed that AFPE was a novel and effective toughening agent for epoxy resins.

  13. Study of the anode plasma dynamics under the action of a high-power electron beam on epoxy resin

    Science.gov (United States)

    Ananyev, S. S.; Bagdasarov, G. A.; Gasilov, V. A.; Dan'ko, S. A.; Demidov, B. A.; Kazakov, E. D.; Kalinin, Yu. G.; Kurilo, A. A.; Ol'khovskaya, O. G.; Strizhakov, M. G.; Tkachenko, S. I.

    2017-07-01

    Results are presented from experimental studies of plasma dynamics in a diode gap under the action of a high-current relativistic electron beam on epoxy resin at energy densities in the range of 170-860 J/cm2. The plasma expansion was studied by means of an optical streak camera. Three-dimensional numerical simulations in the one-temperature hydrodynamic approximation were also performed. The experimental data are compared with the results of numerical simulations.

  14. Research Progress in Oxazolidone Epoxy Resin%噁唑烷酮环氧树脂的研究进展

    Institute of Scientific and Technical Information of China (English)

    王成忠; 石萌萌; 黄丽

    2012-01-01

    含噁唑烷酮结构的树脂具有优良的耐热性、电性能及物理机械性能等。将噁唑烷酮环引入环氧树脂,可提高固化物的玻璃化转变温度、粘结性、介电性和阻燃性等。本文综述了噁唑烷酮环氧树脂的一般合成方法,探讨了原料配比、反应温度、催化剂种类及用量对噁唑烷酮环氧树脂合成过程的影响,分析了固化剂与噁唑烷酮环氧树脂固化产物性能之间的联系,对噁唑烷酮环氧树脂在绝缘材料、涂料、粘合剂、印刷电路板以及高性能树脂基体等领域的应用情况进行了详细介绍,并对其发展前景予以展望。%The resin with oxazolidone structure exhibits excellent heat resistance, electrical insulation, physical and mechanical properties and so on. Add oxazolidone ring to epoxy, the glass transition temperatures, the adhesive force, the dielectrical property and the flame retardant of cured products were improved. The research progresses on general synthesis method of oxazolidone epoxy resin, explores influence on synthesis reaction of oxazolidone epoxy resin including ratio of raw materials, reaction temperature, catalyst type and dosage, analyse the connection between curing agent and the property of cured products, In a process for producing application in kinds of fields of oxazolidone epoxy resin in details, including insulation, paint, bond, print circuit board, resin matrix and the like,and take a outlook of oxazolidone epoxy resin.

  15. Curing behavior and kinetic analysis of epoxy resin/multi-walled Carbon nanotubes composites

    Institute of Scientific and Technical Information of China (English)

    FANG Zhengping; WANG Jianguo; GU Aijuan; TONG Lifang

    2007-01-01

    The effect of multi-walled carbon nanotubes (MWNTs).both amino-functionalized(f-MWNTs) and unfunctionalized (p-MWNTs) on the curing behavior of epoxy resin (EP) cured with triethanolamine (TEA),was investigated using differential scanning calorimetry(DSC).Because the triethylenetetramine (TETA) grafted on the f-MWNTs could act as curing agent and the produced tertiary amine as negative ionic catalysts of curing reaction of EP so the activation energy of the EP/TEA system was decreased by the addition of f-MWNTs.Viscosity played a key role in the curing behavior of the EP/TEA/MWNTs system,for high viscosity of the EP/TEA/MWNTs system could hinder the motion of the functional grows.The curing heat in EP/TEA/f-MWNTs (weight ratio 1/0.1/0.01) system was higher than the neat EP/TEA(weight ratio 1/0.1) system,while the curing heat in EP/TEA/p-MWMTs (weight ratio 1/0.1/0.01) was lower than the neat system.When the content of f-MWNTs was increased to 2 phr(weight ratio of 1/0.1/0.02).the curing heat became lower than that of the neat EP/TEA system,which was the result of the higher viscosity of the EP/f-MWNTs/TEA system.Since the curing heat indicated the curing degree of the system generally,the addition of the f-MWNTs was thought to increase the curing degree of the epoxy matrix at a relatively low content.

  16. The epoxy resin variation effect on microstructure and physical properties to improve bonded NdFeB flux magnetic density

    Science.gov (United States)

    Rusnaeni, N.; Sarjono, Priyo; Muljadi; Noer, Nasrudin

    2016-11-01

    NdFeB magnets have been fabricated from a mixture of powder NdFeB (MPQ-B+) and epoxy resins (ER) with a variation of 0% wt, 2% wt, 4% wt and 6% wt. The pellets samples were made by pressing 4 tons of the mixture powder at room temperature before curing at 100°C for 1 hour. The SEM-EDX results showed the microstructure with ER were evenly smeared the NdFeB magnetic particles due to higher percent C and lower transition metals value. Sample with 2% wt epoxy resin was able to achieve the highest density of 5.35 g/cm3 and the highest magnetic flux of 2121 Gauss. The magnetic properties characterization using the permagraph indicates that the sample pellets with 2% wt epoxy resin has a value of remanence (Br) = 4.92 kG, coercivity (Hc) = 7.76 kOe, and energy product (Bhmax) = 4.58 MGOe. Despite low remanence value in the pellet samples, the resistance to demagnetization value was still acceptable.

  17. Synthesis of Highly Elastic Epoxy Resin%高弹性环氧树脂的合成

    Institute of Scientific and Technical Information of China (English)

    刘佳; 程显明; 王艳; 王波

    2015-01-01

    Epoxy resin has been widely used in many fields because of it's good comprehensive me-chanical properties and excellent adhesion.But the epoxy resin has highly crosslinking density and largly in-ternal stress after curing,leading to brittlness,poor fatigue resistance and poor impacting toughness,and their applications are subject to certain restrictions.This paper reviewed the theories and methods for synthe-sis of high elastic epoxy resin.%环氧树脂具有良好的综合力学性能、优异的粘接性,在诸多领域得到了广泛的应用。但是固化后的环氧树脂交联密度高,内应力大,因而质脆、耐疲劳性与抗冲击韧性差,而使其应用受到一定的限制。综述了合成高弹性环氧树脂的理论和方法,并探讨了高弹性环氧树脂的应用前景。

  18. Influence of radiopaque fillers on physicochemical properties of a model epoxy resin-based root canal sealer

    Directory of Open Access Journals (Sweden)

    Fabricio Mezzomo COLLARES

    2013-12-01

    Full Text Available Objective: To verify the influence of radiopaque fillers on an epoxy resin-based sealer. Material and Methods: Experimental sealers were formulated by adding 20%, 40%, 60%, 80%, 100% and 120% of calcium tungstate, ytterbium trifluoride or barium sulphate by weight to an epoxy-resin-base. Setting time, flow, film thickness, radiopacity, sorption, solubility, pH and push-out bond strength were evaluated. Results: The setting time ranged from 373 to 612.66 min, the flow varied from 13.81±0.49 to 22.49±0.37 mm, and the film thickness ranged from 16.67±5.77 to 33.33±11.54 µm. The lowest pH was 5.47±0.53, and the highest was 6.99±0.03. Radiopacity varied from 0.38±0.04 to 2.57±0.21 mmAl and increased with the amount of filler. Calcium tungstate sealers had a higher sorption and solubility than other sealers. There was no significant difference in the push-out bond strength among the fillers at the 120% concentration. CONCLUSION: The inorganic fillers evaluated and their concentrations affect the physicochemical properties of an epoxy resin-based root canal sealer.

  19. Investigation of the shear thinning behavior of epoxy resins for utilization in vibration assisted liquid composite molding processes

    Science.gov (United States)

    Meier, R.; Kirdar, C.; Rudolph, N.; Zaremba, S.; Drechsler, K.

    2014-05-01

    Efficient production and consumption of energy are of greatest importance for contemporary industries and their products. This has led to an increasing application of lightweight materials in general and of Carbon Fiber Reinforced Plastics (CFRP) in particular. However, broader application of CFRP is often limited by high costs and manual labor production processes. These constraints are addressed by Liquid Composite Molding (LCM) processes. In LCM a dry fibrous preform is placed into a cavity and infiltrated mostly by thermoset resins; epoxy resins are wide spread in CFRP applications. One crucial parameter for a fast mold filling is the viscosity of the resin, which is affected by the applied shear rates as well as temperature and curing time. The work presented focuses on the characterization of the shear thinning behavior of epoxy resins. Furthermore, the correlation with the conditions in vibration assisted LCM processes, where additional shear rates are created during manufacture, is discussed. Higher shear rates result from high frequencies and/or high amplitudes of the vibration motions which are created by a vibration engine mounted on the mold. In rheological investigations the shear thinning behavior of a representative epoxy resin is studied by means of rotational and oscillatory experiments. Moreover, possible effects of shear rates on the chemical curing reaction are studied. Here, the time for gelation is measured for different levels of shear rates in a pre-shearing phase. Based on the rheological studies, the beneficial effect of vibration assistance in LCM processes with respect to mold filling can further be predicted and utilized.

  20. Studies on Glass Reinforced Epoxy Resin Using Vulkadur- A as Crosslinking Agent both in Presence and Absence of Carbon Black and other Non black Fillers

    Directory of Open Access Journals (Sweden)

    T. K. Ghosh

    1974-04-01

    Full Text Available Epoxy resin can be reinforced with glass (fabric form in presence of Vulkadur-A, a phenol formaldehyde resin containing a hardening agent. Overall enhancement in mechanical properties has been found stocks cured with Vulkadur-A containing 2.5 parts of carbon black as filler.

  1. Manufacturing of REBCO coils strongly bonded to cooling members with epoxy resin aimed at its application to Maglev

    Science.gov (United States)

    Mizuno, Katsutoshi; Ogata, Masafumi; Hasegawa, Hitoshi

    2014-11-01

    The REBCO coated conductor has been attracted attention because of its high current density in the presence of high magnetic field. If the coated conductor is applied to Maglev, the operational temperature of the on-board magnets will be over 40 K and energy consumption of cryocoolers will be reduced. That high operational temperature also means the absence of liquid helium. Therefore, reliable thermal coupling is desirable for cooling the coils. We propose an epoxy impregnated REBCO coil co-wound with PTFE tape. While the PTFE tape prevents the performance degradation of the coil, the epoxy resin bonds the coil to cooling members. We carried out three experiments to confirm that the coil structure which we propose has robust thermal coupling without the degradation. First, thermal resistances of paraffin and epoxy were measured varying the temperature from room temperature to 10 K. The measurement result indicates that paraffin has a risk of losing thermal coupling during cooling down. In another experiment, PTFE (polytetrafluoroethylene) tape insulator prevented performance degradation of a small epoxy impregnated REBCO coil, while another REBCO coil with polyimide tape showed clear performance degradation. Finally, we produced a racetrack REBCO coil with the same outer dimension as a Maglev on-board magnet coil. Although the racetrack coil was installed in a GFRP coil case and tightly bonded to the case by epoxy impregnation, any performance degradation was not observed.

  2. Research progress in microencapsulation technology of epoxy resin%环氧树脂微胶囊化技术研究进展

    Institute of Scientific and Technical Information of China (English)

    林广沅; 孔振武

    2012-01-01

    The status and progress in microencapsulation technology of epoxy resin were reviewed on the preparation techniques,influence factors and characterization methods of microencapsulated epoxy resins and curing agents.The common core and shell materials for the preparation of single composition microencapsulated epoxy resin system and the application status and prospect of microencapsulated epoxy system were introduced briefly.%从环氧树脂/固化剂微胶囊的制备技术、影响因素及表征方法等方面综述了环氧树脂微胶囊化技术的现状及其进展;同时简要介绍了用微胶囊技术制备单组分环氧树脂体系常用的芯材、壳材,以及微胶囊化环氧树脂体系的应用现状及前景。

  3. Quantitative characterization of solid epoxy resins using comprehensive two dimensional liquid chromatography coupled with electrospray ionization-time of flight mass spectrometry.

    Science.gov (United States)

    Julka, Samir; Cortes, Hernan; Harfmann, Robert; Bell, Bruce; Schweizer-Theobaldt, Andreas; Pursch, Matthias; Mondello, Luigi; Maynard, Shawn; West, David

    2009-06-01

    A comprehensive multidimensional liquid chromatography system coupled to Electrospray Ionization-Mass Spectrometry (LCxLC-ESI-MS) was developed for detailed characterization and quantitation of solid epoxy resin components. The two orthogonal modes of separation selected were size exclusion chromatography (SEC) in the first dimension and liquid chromatography at critical conditions (LCCC) in the second dimension. Different components present in the solid epoxy resins were separated and quantitated for the first time based on the functional groups and molecular weight heterogeneity. Coupling LCxLC separations with mass spectrometry enabled the identification of components resolved in the two-dimensional space. Several different functional group families of compounds were separated and identified, including epoxy-epoxy and epoxy-alpha-glycol functional oligomers, and their individual molecular weight ranges were determined. Repeatability obtained ranged from 0.5% for the main product to 21% for oligomers at the 0.4% concentration level.

  4. Processing-property relationships in epoxy resin/titanium dioxide nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Polyzos, Georgios [ORNL; Tuncer, Enis [ORNL; Sauers, Isidor [ORNL; More, Karren Leslie [ORNL

    2010-01-01

    In situ precipitated titanium dioxide nanoparticles improve the physical properties of polymer composites. Since the pioneering work at Toyota Research Center on exfoliated montmorillonite nanoparticles in a nylon matrix, extensive studies have been performed on polymer nanocomposites in an effort to better integrate organic and inorganic phases. Inorganic fillers, such as silicon and titanium oxides, are widely used because of their remarkable enhancement of the mechanical, electrical, barrier, and flame-retardancy properties of organic polymers. The dispersion and size of the fillers determine the performance of nanocomposites and, despite numerous methods and processing conditions reported in the literature, a universally simple method to scale up the distribution of nanofillers remains a challenge. A significant part of our research involves formulation of novel nanodielectrics that can withstand high electric fields and exhibit superior mechanical performance. Focusing on nanocomposites operating at cryogenic temperatures, our group developed an in situ method for nucleating titanium dioxide (TiO{sub 2}) nanoparticles in polyvinyl alcohol. We also applied this method to a variety of polymer matrices. Here, we present our recent work on a cryogenic resin filled with TiO{sub 2} nanoparticles. Using a particle-precursor solution from which TiO{sub 2} precipitates, we nucleated nanoparticles within the cryogenic epoxy resin Araldite 5808 (Huntsman Advanced Materials Inc., USA). We fabricated nanocomposite films at low weight percentages ({approx}2.5%) to avoid formation of large aggregates and interfaces. The morphology and dispersion of the in situ synthesized nanoparticles are shown by low- and high-magnification transmission-electron-microscopy (TEM) images. The TiO{sub 2} particles ({le}5nm in diameter) are uniformly nucleated and form evenly distributed nanometer-sized clusters in the polymer matrix. This morphology differs significantly from nanocomposites

  5. Synthesis and Characterization of Liquid Natural Rubber as Impact Modifier for Epoxy Resin

    Science.gov (United States)

    Saleh, A. B. Ben; Ishak, Z. A. Mohd; Hashim, A. S.; Kamil, W. A.; Ishiaku, U. S.

    Liquid natural rubber (LNR) with a molecular weight Mn =16×103 was prepared by the depolymerization of deproteinized natural rubber latex (DPNR). The liquid natural rubber (LNR) was characterized by FTIR and H'NMR spectroscopic analysis. LNR was premixed with the epoxy resin (EP) and cured with a diamine curing agent for 1 h at 100 °C and post cured at 110 °C, for 2 h in air oven. The modified EP containing different contents of LNR (5, 10, 15 and 20 phr) were evaluated. Thermal, mechanical and morphology properties were determined. The fracture toughness (KIC) of both unmodified and modified EPs were determined on static loaded single edge notched (SEN-B) specimens at room temperature. The glass transition temperatures (Tg) of the modified EPs were decreased with increasing LNR content. The strengths and modulus of EPs were slightly reduced with the incorporation of LNR. The effect was also reflected in the significant increase in the tensile strain of modified EP. Fracture toughness of the EP was observed to increase with the presence of LNR. The toughening effect became more apparent as the testing speeds were increased from 1 to 500 mm/min. Fracture surface analysis by scanning electron microscopy (SEM) revealed the presence of a two-phase morphology.

  6. Linear and nonlinear mechanical properties of a series of epoxy resins

    Science.gov (United States)

    Curliss, D. B.; Caruthers, J. M.

    1987-01-01

    The linear viscoelastic properties have been measured for a series of bisphenol-A-based epoxy resins cured with the diamine DDS. The linear viscoelastic master curves were constructed via time-temperature superposition of frequency dependent G-prime and G-double-prime isotherms. The G-double-prime master curves exhibited two sub-Tg transitions. Superposition of isotherms in the glass-to-rubber transition (i.e., alpha) and the beta transition at -60 C was achieved by simple horizontal shifts in the log frequency axis; however, in the region between alpha and beta, superposition could not be effected by simple horizontal shifts along the log frequency axis. The different temperature dependency of the alpha and beta relaxation mechanisms causes a complex response of G-double-prime in the so called alpha-prime region. A novel numerical procedure has been developed to extract the complete relaxation spectra and its temperature dependence from the G-prime and G-double-prime isothermal data in the alpha-prime region.

  7. Aging Characteristics on Epoxy Resin Surface Under Repetitive Microsecond Pulses in Air at Atmospheric Pressure

    Science.gov (United States)

    Xie, Qing; Liu, Xiong; Zhang, Cheng; Wang, Ruixue; Rao, Zhangquan; Shao, Tao

    2016-03-01

    Research on aging characteristics of epoxy resin (EP) under repetitive microsecond pulses is important for the design of insulating materials in high power apparatus. It is because that very fast transient overvoltage always occurs in a power system, which causes flashover and is one of the main factors causing aging effects of EP materials. Therefore, it is essential to obtain a better understanding of the aging effect on an EP surface resulting from flashover. In this work, aging effects on an EP surface were investigated by surface flashover discharge under repetitive microsecond pulses in atmospheric pressure. The investigations of parameters such as the surface micro-morphology and chemical composition of the insulation material under different degrees of aging were conducted with the aid of measurement methods such as atomic force microscopy (AFM), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). Results showed that with the accumulation of aging energy on the material surface, the particles formed on the material surface increased both in number and size, leading to the growth of surface roughness and a reduction in the water contact angle; the surface also became more absorbent. Furthermore, in the aging process, the molecular chains of EP on the surface were broken, resulting in oxidation and carbonisation. supported by the Natural Science Foundation of Hebei Province (No. E2015502081), National Natural Science Foundation of China (Nos. 51222701, 51307060), and the National Basic Research Program of China (No. 2014CB239505-3)

  8. Structure, thermal and fracture mechanical properties of benzoxazine-modified amine-cured DGEBA epoxy resins

    Directory of Open Access Journals (Sweden)

    2011-03-01

    Full Text Available First, traditional diamine hardeners of epoxy resins (EP were checked as potential accelerators for the benzoxazine (BOX homopolymerization. It was established that the acceleration effect depends on both the type and amount of the diamine compounds. In the follow-up work amine-curable diglycidyl ether bisphenol A (DGEBA type EP was modified with BOX keeping the EP/BOX ratio constant (75/25 wt.%. The amine hardeners, added in the EP in stoichiometric amounts, were of aliphatic and aromatic nature, viz. diethylenetriamine (DETA, 4,4'-diaminodiphenyl methane (DDM, and their 1/1 mixture. The thermal, viscoelastic, flexural and fracture mechanical properties of the EP/BOX hybrids were determined and compared to those of the reference EPs. Based on dynamic-mechanical thermal analysis and atomic force microscopy the formation of co-network between EP and BOX was concluded. Homopolymerized BOX was built in the network in nanoscaled inclusions and it was associated with internal antiplasticization. Incorporation of BOX improved the charring, enhanced the flexural modulus and strength, and reduced the glass transition of the parent EP. The fracture toughness and energy were not improved by hybridization with BOX.

  9. Effects of gamma-ray irradiation on a cyanate ester/epoxy resin

    Science.gov (United States)

    Idesaki, Akira; Uechi, Hiroki; Hakura, Yoshihiko; Kishi, Hajime

    2014-05-01

    Effects of γ-ray irradiation on a cyanate ester/epoxy resin composed of dicyanate ester of bisphenol A (DCBA) and diglycidyl ether of bisphenol A (DGEBA) were investigated by changes in physicochemical and mechanical properties after the γ-ray irradiation with dose of 100 MGy as maximum at around 40 °C under vacuum. After the irradiation, gases of hydrogen, carbon monoxide and carbon dioxide were evolved, glass transition temperature decreased, and flexural strength also decreased. It was concluded that ether linkages bonded to cyanurate, isocyanurate and oxazolidinone structures are mainly decomposed by the irradiation. After 100 MGy irradiation, the flexural strength of DCBA/DGEBA was maintained more than 170 MPa which is 90% of initial value of 195 MPa. Flexural modulus and density slightly increased to the values of 3.9 GPa and 1.211 g/cm3 from initial values of 3.4 GPa and 1.199 g/cm3, respectively.

  10. Thermoset nanocomposites from waterborne bio-based epoxy resin and cellulose nanowhiskers.

    Science.gov (United States)

    Wu, Guo-min; Liu, Di; Liu, Gui-feng; Chen, Jian; Huo, Shu-ping; Kong, Zhen-wu

    2015-01-01

    Thermoset nanocomposites were prepared from a waterborne terpene-maleic ester type epoxy resin (WTME) and cellulose nanowhiskers (CNWs). The curing behaviors of WTME/CNWs nanocomposites were measured with rotational rheometer. The results show that the storage modulus (G') of WTME/CNWs nanocomposites increased with the increase of CNWs content. Observations by scanning electron microscopy (SEM) demonstrate that the incorporation of CNWs in WTME matrix caused microphase separation and destroyed the compactness of the matrix. This effect leads to the glass transition temperatures (Tg) of WTME/CNWs nanocomposites slightly decrease with the increase of CNWs content, which were confirmed by both DSC and DMA tests. The mechanical properties of WTME/CNWs nanocomposites were investigated by tensile testing. The Yong's modulus (E) and tensile strength (σb) of the nanocomposites were significantly reinforced by the addition of CNWs. These results indicate that CNWs exhibit excellent reinforcement effect on WTME matrix, due to the formation and increase of interfacial interaction by hydrogen bonds between CNWs nano-filler and the WTME matrix.

  11. HYDRODYNAMIC AND THERMODYNAMIC EFFECTS IN PHASE INVERSION EMULSIFICATION PROCESS OF EPOXY RESIN IN WATER

    Institute of Scientific and Technical Information of China (English)

    Yuan-ze Xu; Yu-zhe Wu; Jian-mao Yang

    2006-01-01

    The mechanism of phase inversion emulsification process (PIE) was studied for waterborne dispersion of highly viscous epoxy resin using non-ionic polymeric surfactants. Drop deformation and breakup, rheological properties,conductivity, and particle size measurements reveal the micro-structural transition amid emulsification. It is revealed that strong flow causes water drop to burst with the formation of droplets and huge interface. Phase inversion corresponds to an abrupt rheological transition from a type of viscous melt with weak elasticity to a highly elastic type of aqueous gel. This implies that the phase inversion equivalent to a curvature inversion. Based on this, a geometric model is postulated to correlate process variables to the particle size. The coverage and conformation of the surfactant plays key role for the particle size of the final emulsion. The interactions of thermodynamic and hydrodynamic effects are also discussed. It is concluded that the thermodynamics control the PIE while the hydrodynamics drives the creation of interface and involves every step of PIE.

  12. Simultaneous measurement of refractive index and temperature using an epoxy resin-based interferometer.

    Science.gov (United States)

    Wang, Jian; Wu, Shengli; Ren, Wenyi

    2014-11-20

    A fiber-optics reflection probe based on fiber Fabry-Perot interference (FFPI) is proposed and experimentally demonstrated. The sensing structure comprises an epoxy resin (ER)-based cap on the end-face of the single-mode fiber. A well-defined interference spectrum is obtained by the reflective beams of two surfaces of the ER cap. The simultaneous measurements, including fringe contrast-referenced for the surrounding refractive index (SRI) and wavelength-referenced for temperature, have been achieved via selective interference dips monitoring. Experimental results indicate that the proposed FFPI presents an SRI sensitivity of 57.69 dB/RIU in the measurement range of 1.33-1.40 RIU and a temperature sensitivity of 0.98  pm·μm-1·°C-1 with per unit cavity length in the range of 30°C-70°C. The proposed sensor has advantages of being compact and robust, making it an alternative candidate as a smart sensor in chemical and biological applications.

  13. SPEEK/epoxy resin composite membranes in situ polymerization for direct methanol fell cell usages

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Tiezhu; Zhao, Chengji; Zhong, Shuangling; Zhang, Gang; Shao, Ke; Zhang, Haiqiu; Wang, Jing; Na, Hui [Alan G. MacDiarmid Institute, College of Chemistry, Jilin University, Qianwei Road 2699, Changchun 130012 (China)

    2007-03-20

    Sulfonated poly(ether ether ketone) (SPEEK)/4,4'-diglycidyl(3,3',5,5'-tetramethylbiphenyl) epoxy resin (TMBP) composite membranes in situ polymerization were prepared for the purpose of improving the methanol resistance and mechanical properties of SPEEK membranes with high ion-exchange capacities (IEC) for the usage in the direct methanol fuel cells (DMFCs). The effects of introduction of TMBP content on the properties of the composite membranes were investigated in detail. The composite membranes have good mechanical, thermal properties, lower swelling ratio, lower water diffusion coefficient (0.87 x 10{sup -5} cm{sup 2} s{sup -1} at 80 C) and better methanol resistance (5.26 x 10{sup -7} cm{sup 2} s{sup -1} at 25 C) than SPEEK membranes. The methanol diffusion coefficients of the composite membranes are much lower than that of SPEEK membrane (17.5 x 10{sup -7} cm{sup 2} s{sup -1} at 25 C). Higher selectivity was been found for the composite membranes in comparison with SPEEK. Therefore, the SPEEK/TMBP composite membranes show a good potential in DMFCs usages. (author)

  14. Effect of the surface roughness on interfacial properties of carbon fibers reinforced epoxy resin composites

    Energy Technology Data Exchange (ETDEWEB)

    Song Wei [College of Chemistry, Chemical Engineering and Materials Science, Department of Materials Science and Engineering, Soochow University, Suzhou, Jiangsu 215123 (China); Gu Aijuan, E-mail: ajgu@suda.edu.cn [College of Chemistry, Chemical Engineering and Materials Science, Department of Materials Science and Engineering, Soochow University, Suzhou, Jiangsu 215123 (China); Liang Guozheng, E-mail: lgzheng@suda.edu.cn [College of Chemistry, Chemical Engineering and Materials Science, Department of Materials Science and Engineering, Soochow University, Suzhou, Jiangsu 215123 (China); Yuan Li [College of Chemistry, Chemical Engineering and Materials Science, Department of Materials Science and Engineering, Soochow University, Suzhou, Jiangsu 215123 (China)

    2011-02-15

    The effect of the surface roughness on interfacial properties of carbon fibers (CFs) reinforced epoxy (EP) resin composite is studied. Aqueous ammonia was applied to modify the surfaces of CFs. The morphologies and chemical compositions of original CFs and treated CFs (a-CFs) were characterized by Atomic Force Microscopy (AFM), and X-ray Photoelectron Spectroscopy (XPS). Compared with the smooth surface of original CF, the surface of a-CF has bigger roughness; moreover, the roughness increases with the increase of the treating time. On the other hand, no obvious change in chemical composition takes place, indicating that the treating mechanism of CFs by aqueous ammonia is to physically change the morphologies rather than chemical compositions. In order to investigate the effect of surface roughness on the interfacial properties of CF/EP composites, the wettability and Interfacial Shear Strength (IFSS) were measured. Results show that with the increase of the roughness, the wettabilities of CFs against both water and ethylene glycol improves; in addition, the IFSS value of composites also increases. These attractive phenomena prove that the surface roughness of CFs can effectively overcome the poor interfacial adhesions between CFs and organic matrix, and thus make it possible to fabricate advanced composites based on CFs.

  15. Electrochemical surface functionalization of carbon fibers for chemical affinity improvement with epoxy resins

    Science.gov (United States)

    Kainourgios, Panayiotis; Kartsonakis, Ioannis A.; Dragatogiannis, Dimitrios A.; Koumoulos, Elias P.; Goulis, Panagiotis; Charitidis, Costas A.

    2017-09-01

    The purpose of this study is to increase the wetting properties of carbon fibers in order to improve the adhesion force between the fiber and the polymer matrix. Commercial carbon fibers were surface functionalized through cyclic voltammetry together with potentiostatic conditions in aqueous electrolyte solutions of H2SO4, in the presence of acrylic acid, methacrylic acid, acrylonitrile and N-vinylpyrrolidone monomers. The anodic and cathodic peaks were correlated with oxide formation and their partial reduction, respectively. The produced surface modified carbon fibers were wetted with epoxy resin so that to produce dumbbell type composites for tensile strength testing. The nature of oxygen containing groups on the fibers surface was determined by Fourier-transform infrared and Raman spectroscopy. Moreover, the wetting properties of the treated carbon fibers were evaluated via contact angle measurements whereas the morphology of the coated fibers was investigated via scanning electron microscopy. Finally, the mechanical performance of the composites was evaluated by means of tensile testing and strength measurements.

  16. In Situ Exfoliation of Graphene in Epoxy Resins: A Facile Strategy to Efficient and Large Scale Graphene Nanocomposites.

    Science.gov (United States)

    Li, Yan; Zhang, Han; Crespo, Maria; Porwal, Harshit; Picot, Olivier; Santagiuliana, Giovanni; Huang, Zhaohui; Barbieri, Ettore; Pugno, Nicola M; Peijs, Ton; Bilotti, Emiliano

    2016-09-14

    Any industrial application aiming at exploiting the exceptional properties of graphene in composites or coatings is currently limited by finding viable production methods for large volumes of good quality and high aspect ratio graphene, few layer graphene (FLG) or graphite nanoplatelets (GNP). Final properties of the resulting composites are inherently related to those of the initial graphitic nanoparticles, which typically depend on time-consuming, resource-demanding and/or low yield liquid exfoliation processes. In addition, efficient dispersion of these nanofillers in polymer matrices, and their interaction, is of paramount importance. Here we show that it is possible to produce graphene/epoxy nanocomposites in situ and with high conversion of graphite to FLG/GNP through the process of three-roll milling (TRM), without the need of any additives, solvents, compatibilisers or chemical treatments. This readily scalable production method allows for more than 5 wt % of natural graphite (NG) to be directly exfoliated into FLG/GNP and dispersed in an epoxy resin. The in situ exfoliated graphitic nanoplatelets, with average aspect ratios of 300-1000 and thicknesses of 5-17 nm, were demonstrated to conferee exceptional enhancements in mechanical and electrical properties to the epoxy resin. The above conclusions are discussed and interpreted in terms of simple analytical models.

  17. Mechanical properties of reactively flame retarded cyanate ester/epoxy resin blends and their carbon fibre reinforced composites

    Directory of Open Access Journals (Sweden)

    A. Toldy

    2016-12-01

    Full Text Available Cyanate ester/epoxy resin (CE/EP carbon fibre reinforced composites consisting of diglycidyl ether of bisphenol A (DGEBA and novolac type cyanate ester (CE were prepared and reactively flame retarded using epoxy functional adduct of DGEBA and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO. Effect of cyanate ester and flame retardant (FR ratio was determined on matrix viscosity, matrix and composite glass transition temperature (Tg, as well as composite mechanical properties including storage modulus, tensile, bending, interlaminar shear and Charpy impact properties. Although the epoxy resin (EP and FR decreased the Tg, even the flame retarded CE/EP blends had at least 22 °C higher Tg than the benchmark DGEBA composite. As for the mechanical properties, as a result of higher interlaminar shear strength suggesting better fibre-matrix adhesion, the CE/EP blends managed to over-perform the reference CE in most cases: The 2% phosphorus (P-containing CE/EP composite had 25% higher tensile strength than the CE reference. The bending strength of the blends remained in the same range as the reference, while the impact resistance significantly increased in comparison to CE, especially in flame retarded composites.

  18. Surface and buried interfacial structures of epoxy resins used as underfills studied by sum frequency generation vibrational spectroscopy.

    Science.gov (United States)

    Vázquez, Anne V; Holden, Brad; Kristalyn, Cornelius; Fuller, Mike; Wilkerson, Brett; Chen, Zhan

    2011-05-01

    Flip chip technology has greatly improved the performance of semiconductor devices, but relies heavily on the performance of epoxy underfill adhesives. Because epoxy underfills are cured in situ in flip chip semiconductor devices, understanding their surface and interfacial structures is critical for understanding their adhesion to various substrates. Here, sum frequency generation (SFG) vibrational spectroscopy was used to study surface and buried interfacial structures of two model epoxy resins used as underfills in flip chip devices, bisphenol A digylcidyl ether (BADGE) and 1,4-butanediol diglycidyl ether (BDDGE). The surface structures of these epoxies were compared before and after cure, and the orientations of their surface functional groups were deduced to understand how surface structural changes during cure may affect adhesion properties. Further, the effect of moisture exposure, a known cause of adhesion failure, on surface structures was studied. It was found that the BADGE surface significantly restructured upon moisture exposure while the BDDGE surface did not, showing that BADGE adhesives may be more prone to moisture-induced delamination. Lastly, although surface structure can give some insight into adhesion, buried interfacial structures more directly correspond to adhesion properties of polymers. SFG was used to study buried interfaces between deuterated polystyrene (d-PS) and the epoxies before and after moisture exposure. It was shown that moisture exposure acted to disorder the buried interfaces, most likely due to swelling. These results correlated with lap shear adhesion testing showing a decrease in adhesion strength after moisture exposure. The presented work showed that surface and interfacial structures can be correlated to adhesive strength and may be helpful in understanding and designing optimized epoxy underfill adhesives.

  19. Morphology and contact angle studies of poly(styrene-co-acrylonitrile modified epoxy resin blends and their glass fibre reinforced composites

    Directory of Open Access Journals (Sweden)

    2007-06-01

    Full Text Available In this study, the surface characteristics of blends and composites of epoxy resin were investigated. Poly(styrene-co-acylonitrile (SAN was used to modify diglycedyl ether of bisphenol-A (DGEBA type epoxy resin cured with diamino diphenyl sulfone (DDS and the modified epoxy resin was used as the matrix for fibre reinforced composites (FRP’s. E-glass fibre was used as the fibre reinforcement. The scanning electron micrographs of the fractured surfaces of the blends and composites were analyzed. Morphological analysis revealed different morphologies such as dispersed, cocontinuous and phase-inverted structures for the blends. Contact angle studies were carried out using water and methylene iodide at room temperature. The solid surface energy was calculated using harmonic mean equations. Blending of epoxy resin increases its contact angle. The surface free energy, work of adhesion, interfacial free energy, spreading coefficient and Girifalco-Good’s interaction parameter were changed significantly in the case of blends and composites. The incorporation of thermoplastic and glass fibre reduces the wetting and hydrophilicity of epoxy resin.

  20. 纯环氧VPI浸渍树脂的研制及性能测试%Research and Properties Test of Epoxy VPI Impregnation Resin

    Institute of Scientific and Technical Information of China (English)

    郭胜智; 吴梦艳; 徐雄鹰; 刘艳婷; 施德俊; 夏宇

    2014-01-01

    介绍了一种无酸酐无易挥发性稀释剂的纯环氧VPI浸渍树脂。通过优选环氧活性稀释剂及自制固化剂,制备一种黏度适中、不易吸潮、储存稳定,且具有优异的电气性能和机械性能的纯环氧VPI浸渍树脂。该树脂性能与环氧酸酐树脂性能相当,是环氧酸酐VPI浸渍树脂理想的替代品。%An epoxy VPI resin without anhydride and volatile thinner was introduced. By optimally selecting active epoxy diluting agent and self-made curing agent, the epoxy VPI resin with moderate viscosity, moisture resistance, good storage stability, excellent electrical and mechanical properties was prepared. The performance of the resin as mentioned is equal to that of epoxy anhydride resin, it is an ideal substitute of epoxy anhydride VPI resin.

  1. Research progress in bio-based epoxy resins%生物基环氧树脂的研究进展

    Institute of Scientific and Technical Information of China (English)

    马松琪; 刘小青; 朱锦

    2014-01-01

    In oder to solve the unsustainability and toxicity problems of the traditional bisphenol A type epoxy resins,one of the best solutions is synthesizing the epoxy resins with the bio-based raw materials.Our researchers in the bio-based polymer material research group of Ningbo Institute of Materials Technology&Engineering (Chinese Academy of Science) have done a lot of work in preparation of the bio-based epoxy resins.Based on the progress in home and abroad,this paper introduced the research work in preparing the bio-based epoxy resins with rosin, itaconic acid and gallic acid as the raw materials,and presented the raises prospect of future development in the bio-based epoxy resins.%以生物基原料合成环氧树脂是目前解决双酚A环氧树脂原料不可持续性和毒性问题最切实可行的方案。在综述国内外生物基环氧树脂研究进展的基础上,对最近几年我们基于松香、衣康酸、没食子酸合成生物基环氧树脂方面的研究进展进行了介绍,在此基础上进行了总结和展望。

  2. Rapid bonding of polydimethylsiloxane (PDMS) to various stereolithographically (STL) structurable epoxy resins using photochemically cross-linked intermediary siloxane layers

    Science.gov (United States)

    Wilhelm, Elisabeth; Neumann, Christiane; Sachsenheimer, Kai; Länge, Kerstin; Rapp, Bastian E.

    2014-03-01

    In this paper we present a fast, low cost bonding technology for combining rigid epoxy components with soft membranes made out of polydimethylsiloxane (PDMS). Both materials are commonly used for microfluidic prototyping. Epoxy resins are often applied when rigid channels are required, that will not deform if exposed to high pressure. PDMS, on the other hand, is a flexible material, which allows integration of membrane valves on the chip. However, the integration of pressure driven components, such as membrane valves and pumps, into a completely flexible device leads to pressure losses. In order to build up pressure driven components with maximum energy efficiency a combination of rigid guiding channels and flexible membranes would be advisable. Stereolithographic (STL) structuring would be an ideal fabrication technique for this purpose, because complex 3D-channels structures can easily be fabricated using this technology. Unfortunately, the STL epoxies cannot be bonded using common bonding techniques. For this reason we propose two UV-light based silanization techniques that enable plasma induced bonding of epoxy components. The entire process including silanization and corona discharge bonding can be carried out within half an hour. Average bond strengths up to 350 kPa (depending on the silane) were determined in ISO-conform tensile testing. The applicability of both techniques for microfluidic applications was proven by hydrolytic stability testing lasting more than 40 hours.

  3. Sifat fisik hidroksiapatit sintesis kalsit sebagai bahan pengisi pada sealer saluran akar resin epoxy (Physical properties of calcite synthesized hydroxyapatite as the filler of epoxy-resin-based root canal sealer

    Directory of Open Access Journals (Sweden)

    Ema Mulyawati

    2013-12-01

    Full Text Available Background: The filler addition to resin based sealers will enhance the physical properties of the polymer. Because of its biological properties, the synthetic hydroxyapatite (HA has been proposed as filler for dental material such as composite resin. The calcite synthesized HA is the HA produced of calcite minerals that came from many Indonesian mining. Purpose: The aim of study was to determine the effect of different concentration of calcite synthesized HA as the filler of the epoxy-resin-based root canal sealer on the physical properties such as its contact angle, the film thickness and the microhardness. Methods: The crystal of the calcite synthesized hydroxyapatite with the size between 77.721-88.710 nm and the ratio of Ca/P 1.6886 were synthesized at Ceramic Laboratory, Mechanical Engineering, using wet method of hydrothermal microwave. The powders of the epoxy- resin were prepared by added the synthesized hydroxyapatite crystal in 5 different weight ratios (e.g.: HA-10%, HA-20%, HA-30%, HA-40% and HA-50%. Each of these was mixed with the paste of 3:1 ratio using spatula on a glass plate until homogen and then measuring the contact angle and the film thickness. Microhardness test was conducted after the mixture of experimental sealer was stored for 24 hrs at 37 oC to reach perfect polymerization. Results: All of contact angles were <90o and were not significantly different to each other (p= 0.510. All groups had a film thickness in accordance with ISO 6876 (<50 um and with no statistical difference (p= 0.858. In the HA of 10%, 20%, 30% seen that the microhardness were increased, while in the HA-50% was decreased and in the HA-40% has the same microhardness to the control groups (HA-0%. Conclusion: Calcite synthesized HA as the filler did not affect contact angle and film thickness of the sealer. Microhardness of the epoxy-resin based sealer could be increased using maximum 30% of the calcite synthesized HA as the filler.Latar belakang

  4. Effect of titania particles on the microstructure and properties of the epoxy resin coatings on sintered NdFeB permanent magnets

    Energy Technology Data Exchange (ETDEWEB)

    Xu, J.L., E-mail: jlxu@nchu.edu.cn; Huang, Z.X.; Luo, J.M.; Zhong, Z.C., E-mail: zzhong.2006@yahoo.com.cn

    2014-04-15

    The nanometer titania particles enhanced epoxy resin composite coatings were prepared on the sintered NdFeB permanent magnets by cathodic electrophoretic deposition. The effects of titania particle concentrations on the microstructure and properties of the epoxy coatings were investigated by surface and cross-sectional morphologies observation, surface roughness and microhardness measurement, H{sub 2}SO{sub 4} solution immersion test, neutral salt spray test and magnetic properties measurement. The results showed that the thickness of epoxy coatings with and without the titania particles addition was about 40 μm. The titania particles could be uniformly dispersed and embedded in the epoxy matrix if the titania particles concentration was lower than 40 g/l. With increasing titania particle concentrations, the number of the particles embedded in the epoxy matrix increased and the surface roughness and microhardness of the composite coatings increased. At the same time, the weight loss of the coated samples immersed in H{sub 2}SO{sub 4} solution decreased and the neutral salt spray time of the coated samples prolonged. It could be concluded that the titania particles did not change the thickness of the epoxy coatings and did not deteriorate the magnetic properties of NdFeB substrates, but could greatly improve the microhardness and corrosion resistance of the epoxy coatings. - Highlights: • The titania particles enhanced epoxy resin coatings were prepared on sintered NdFeB by cathodic electrophoretic deposition. • The titania particles could be uniformly dispersed and embedded in the epoxy resin matrix. • With increasing titania concentrations, the surface roughness and the microhardness of composite coatings increased. • The addition of titania particles greatly improved the corrosion resistance of the epoxy coatings. • The composition coatings did not deteriorate the magnetic properties of NdFeB substrates.

  5. Advances of Epoxy Resin Toughening by Inorganic Nano-particles%无机纳米粒子增韧环氧树脂研究进展

    Institute of Scientific and Technical Information of China (English)

    李媛媛; 戴红旗; 雷文

    2012-01-01

    Epoxy resin is a kind of thermosetting resin that is wildly applied in many fields.It is mainly used as strengthening agent or modifier in paper making industry.However,its further application is restricted because of its rigid property.Adding inorganic nano-particles to epoxy resin matrix is an important method to toughen epoxy resin.In this paper,dispersion methods of inorganic nano-particles in epoxy resin as well as effects of inorganic nano-particles on epoxy resin properties were assembled.In addition,effects of inorganic nano-particle size,content and shape on modified epoxy resin property were analysed,and toughening mechanisms were summarized.%环氧树脂是一类广泛应用的热固性树脂,在造纸工业中主要用作增强剂或者改性剂。然而其质脆,限制了它的进一步开发应用。在环氧树脂基体里添加无机纳米粒子是增韧环氧树脂的一种重要手段。本文综述了无机纳米粒子在环氧树脂基体内的分散方法、无机粒子增韧环氧树脂对环氧树脂的各种性能影响,分析了粒子粒径大小、含量及形态对增韧环氧树脂性能的影响并阐述了无机粒子增韧环氧树脂的机理。

  6. Biodegradation Study of Nanocomposites of Phenol Novolac Epoxy/Unsaturated Polyester Resin/Egg Shell Nanoparticles Using Natural Polymers

    Directory of Open Access Journals (Sweden)

    S. M. Mousavi

    2015-01-01

    Full Text Available Nanocomposite materials refer to those materials whose reinforcing phase has dimensions on a scale from one to one hundred nanometers. In this study, the nanocomposite biodegradation of the phenol Novolac epoxy and the unsaturated polyester resins was investigated using the egg shell nanoparticle as bioceramic as well as starch and glycerin as natural polymers to modify their properties. The phenol Novolac epoxy resin has a good compatibility with the unsaturated polyester resin. The prepared samples with different composition of materials for specified time were buried under soil and their biodegradation was studied using FTIR and SEM. The FTIR results before and after degradation showed that the presence of the hydroxyl group increased the samples degradation. Also adding the egg shell nanoparticle to samples had a positive effect on its degradation. The SEM results with and without the egg shell nanoparticle also showed that use of the egg shell nanoparticle increases the samples degradation. Additionally, increasing the amount of starch, and glycerol and the presence of egg shell nanoparticles can increase water adsorption.

  7. Effects of wheat starch on erosive wear of E-glass fibre reinforced epoxy resin composite materials

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, V.K. [Department of Mechanical Engineering, Institute of Technology, Banaras Hindu University, Varanasi 221005 (India)]. E-mail: vk_sa@yahoo.co.in

    2006-11-05

    Erosive wear tests were carried out to study the effects of particle, impingement angle and particle velocity on the solid particle erosion behaviour of E-glass fibre reinforced epoxy resin (GFRP) composites. The erosive wear of wheat flour powder filled composites is evaluated at different impingement angles from 30 deg. to 90 deg. and at three different velocities of 24, 35 and 52 m s{sup -1}. The erodent used is silica sand with the size range 150-250 {mu}m of irregular shapes. The result shows erosive wear rates of GFRP composite with 2 g wheat flour, as filler is the lowest. This restricts fiber-matrix debonding. Pure glass epoxy without any filler shows the highest erosion rate due to weak bonding strength. The morphologies of eroded surface were examined by the scanning electron microscope.

  8. Thermal Conductivity of Epoxy Resin Composites Filled with Combustion Synthesized h-BN Particles.

    Science.gov (United States)

    Chung, Shyan-Lung; Lin, Jeng-Shung

    2016-05-20

    The thermal conductivity of epoxy resin composites filled with combustion-synthesized hexagonal boron nitride (h-BN) particles was investigated. The mixing of the composite constituents was carried out by either a dry method (involving no use of solvent) for low filler loadings or a solvent method (using acetone as solvent) for higher filler loadings. It was found that surface treatment of the h-BN particles using the silane 3-glycidoxypropyltrimethoxysilane (GPTMS) increases the thermal conductivity of the resultant composites in a lesser amount compared to the values reported by other studies. This was explained by the fact that the combustion synthesized h-BN particles contain less -OH or active sites on the surface, thus adsorbing less amounts of GPTMS. However, the thermal conductivity of the composites filled with the combustion synthesized h-BN was found to be comparable to that with commercially available h-BN reported in other studies. The thermal conductivity of the composites was found to be higher when larger h-BN particles were used. The thermal conductivity was also found to increase with increasing filler content to a maximum and then begin to decrease with further increases in this content. In addition to the effect of higher porosity at higher filler contents, more horizontally oriented h-BN particles formed at higher filler loadings (perhaps due to pressing during formation of the composites) were suggested to be a factor causing this decrease of the thermal conductivity. The measured thermal conductivities were compared to theoretical predictions based on the Nielsen and Lewis theory. The theoretical predictions were found to be lower than the experimental values at low filler contents ( 60 vol %).

  9. Effect of root canal filling techniques on the bond strength of epoxy resin-based sealers.

    Science.gov (United States)

    Rached-Júnior, Fuad Jacob Abi; Souza, Angélica Moreira; Macedo, Luciana Martins Domingues; Raucci-Neto, Walter; Baratto-Filho, Flares; Silva, Bruno Marques; Silva-Sousa, Yara Teresinha Corrêa

    2016-01-01

    The aim of this study was to evaluate the effects of different root canal filling techniques on the bond strength of epoxy resin-based sealers. Sixty single-rooted canines were prepared using ProTaper (F5) and divided into the following groups based on the root filling technique: Lateral Compaction (LC), Single Cone (SC), and Tagger Hybrid Technique (THT). The following subgroups (n = 10) were also created based on sealer material used: AH Plus and Sealer 26. Two-millimeter-thick slices were cut from all the root thirds and subjected to push-out test. Data (MPa) was analyzed using ANOVA and Tukey's test (α = 0.05). The push-out values were significantly affected by the sealer, filling technique, and root third (p < 0.05). AH Plus (1.37 ± 1.04) exhibited higher values than Sealer 26 (0.92 ± 0.51), while LC (1.80 ± 0.98) showed greater bond strength than THT (1.16 ± 0.50) and SC (0.92 ± 0.25). The cervical (1.45 ± 1.14) third exhibited higher bond strength, followed by the middle (1.20 ± 0.72) and apical (0.78 ± 0.33) thirds. AH Plus/LC (2.26 ± 1.15) exhibited the highest bond strength values, followed by AH Plus/THT (1.32 ± 0.61), Sealer 26/LC (1.34 ± 0.42), and Sealer 26/THT (1.00 ± 0.27). The lowest values were obtained with AH Plus/SC and Sealer 26/SC. Thus, it can be concluded that the filling technique affects the bond strength of sealers. LC was associated with higher bond strength between the material and intra-radicular dentine than THT and SC techniques.

  10. Thermal Conductivity of Epoxy Resin Composites Filled with Combustion Synthesized h-BN Particles

    Directory of Open Access Journals (Sweden)

    Shyan-Lung Chung

    2016-05-01

    Full Text Available The thermal conductivity of epoxy resin composites filled with combustion-synthesized hexagonal boron nitride (h-BN particles was investigated. The mixing of the composite constituents was carried out by either a dry method (involving no use of solvent for low filler loadings or a solvent method (using acetone as solvent for higher filler loadings. It was found that surface treatment of the h-BN particles using the silane 3-glycidoxypropyltrimethoxysilane (GPTMS increases the thermal conductivity of the resultant composites in a lesser amount compared to the values reported by other studies. This was explained by the fact that the combustion synthesized h-BN particles contain less –OH or active sites on the surface, thus adsorbing less amounts of GPTMS. However, the thermal conductivity of the composites filled with the combustion synthesized h-BN was found to be comparable to that with commercially available h-BN reported in other studies. The thermal conductivity of the composites was found to be higher when larger h-BN particles were used. The thermal conductivity was also found to increase with increasing filler content to a maximum and then begin to decrease with further increases in this content. In addition to the effect of higher porosity at higher filler contents, more horizontally oriented h-BN particles formed at higher filler loadings (perhaps due to pressing during formation of the composites were suggested to be a factor causing this decrease of the thermal conductivity. The measured thermal conductivities were compared to theoretical predictions based on the Nielsen and Lewis theory. The theoretical predictions were found to be lower than the experimental values at low filler contents (< 60 vol % and became increasing higher than the experimental values at high filler contents (> 60 vol %.

  11. Study of the mechanical properties of photo-cured epoxy resin fabricated by stereolithography process

    Directory of Open Access Journals (Sweden)

    Nattapon Chantarapanich

    2013-02-01

    Full Text Available Stereolithography process enables various freeform geometries to be manufactured, which are beneficial to manyresearch and development fields, particularly on medicine. The mechanical properties of stereolithography models can begenerally but not only influenced by the material characteristics, but also by the method of manufacturing. Since thestereolithography process involves building three dimensional objects by depositing material layer-by-layer as well as thepost-curing by ultraviolet light, it is therefore possible for stereolithography models to exhibit a directional dependence of themechanical properties. The objectives of the study focused on the influence of build orientations and ultraviolet post-curingperiod on the mechanical properties. In the experiments, Watershed 11122 commercial epoxy photo-curable resin was used.The in-house developed stereolithography machine of the National Metal and Materials Technology Center of Thailand wasused to fabricate tensile test specimens (American Society for Testing Materials Standard D638 with different build orientations. Main build orientations included flat and edge. Each main build orientation contained three sub-build orientationswhich were 0 degree, 45 degrees, and 90 degrees to the x-axis. The mechanical properties including elastic modulus, ultimatetensile strength, elongation at ultimate tensile strength, and elongation at break were evaluated by tensile test with a universal testing machine. The results indicated that the mechanical properties of specimens were slightly different among thesub-build orientations. The larger differences of mechanical properties of specimens were found between main build orientations. The mechanical strength of specimens improved corresponding to the increase of UV post-curing period ranged from0 to 4 hours whereas the post-curing period using 4 hours onward, the mechanical properties of specimens were nearlyconstant.

  12. Modification of epoxy resin, silicon and glass surfaces with alkyl- or fluoroalkylsilanes for hydrophobic properties

    Science.gov (United States)

    Marczak, Jacek; Kargol, Marta; Psarski, Maciej; Celichowski, Grzegorz

    2016-09-01

    Preparation of superhydrophobic materials inspired by nature has attracted a great scientific interest in recent decades. Some of these materials have hierarchical lotus-like structures, i.e. micro- and nano-objects coated by hydrophobic compounds. A major challenge of applying the superhydrophobic surfaces for the self-cleaning coatings preparation is their improved efficiency in varying atmospheric conditions, e.g. UV light. The objective of this research work was to investigate the effect of the different chemical structure and the surface free energy on the hydrophobic and tribological properties of the alkylsilanes and fluoroalkylsilanes deposited on silicon wafers, glass slides and epoxy resin. Tribological and hydrophobic properties of the modified surfaces were correlated with their chemical structures. Chemical structures of the deposited materials were examined by using Fourier transform infrared (FT-IR) spectroscopy and hydrophobic properties were investigated by water contact angle (WCA) and surface free energy (SFE) measurements. The modified surfaces exhibited water contact angles of above 100° for the selected modifiers. It was noticed that the replacement of hydrogen atoms by fluorine atoms in alkyl chain caused an increase in the water contact angle values and a decrease in friction coefficients. The obtained results showed that the carbon chain length of a modifier and its chemical structure can strongly affect the hydrophobic and tribological properties of the modified surfaces. The highest values of WCA, lowest values of SFE and coefficient of friction were obtained for samples covered by fluorinated compounds. Moreover, some preliminary aging test was performed to give an insight into the effectiveness of deposited alkylsilanes and fluoroalkylsilanes coatings. After accelerated UV exposure, no significant changes in the chemical structure, hydrophobic and tribological properties of the modified surfaces were noticed. The samples degradation

  13. Polybutylacrylate/poly (methyl methacrylate) Core-Shell Elastic Particles as Epoxy Resin Toughener:Part II Toughness on DGEBA/DDM system

    Institute of Scientific and Technical Information of China (English)

    Jianli WANG; Myonghoon LEE; Kejian YAO; Jianbin JI; Xiaomei YU

    2004-01-01

    Mechanical properties of epoxy resin were investigated by adding core-shell elastic particles (CSEP). The results indicated that optimized core-shell ratio was 60/40 and the loading volume of CSEP was 10 phr (per hundred parts of epoxy resin by weight). The impact strength of modified systems increased apparently with the decrease of core sizes. However, the shearing strength changed gently with the particle sizes. CSEP with lightly crosslinked rubbery core showed more effectiveness on toughness than others. With solution blending, CSEP could be dispersed in epoxy matrix well, and the morphologies of dispersed rubber domains were controlled perfectly by CSEP whose structure was predesigned. A cavitation-shearing band toughness mechanism was observed from the SEM micrographs of fracture surface. It also was found that the deforming temperature (DT) of modified epoxy did not decline apparently.

  14. Novel high glass temperature sugar-based epoxy resins: Characterization and comparison to mineral oil-based aliphatic and aromatic resins

    Directory of Open Access Journals (Sweden)

    P. Niedermann

    2015-02-01

    Full Text Available Curing and rheological behaviour, glass transition temperature, mechanical and thermal properties of two newly synthesized glucopyranoside- (GPTE and glucofuranoside- (GFTE based renewable epoxy resin (EP components were investigated and compared to aromatic and aliphatic EPs. The glucose-based EPs can be successfully cured with amine and anhydride type curing agents, their gel times are suitable for processing and can be well-adopted to the needs of the common composite preparation methods. GPTE showed the highest glass transition temperature (Tg among all investigated resins, followed by GFTE and DGEBA. Below the Tg there was no significant difference between the storage modulus values of the EP systems. The glucose-based EPs had lower tensile and bending strength, but their tensile modulus values are not significantly different from the mineral oil based EPs. The thermal stability of the synthesized GPTE and GFTE is between DGEBA and the aliphatic resins. In applications where bending stresses are dominant over the tensile ones, and outstanding Tg is required, these glucose-based resins offer a feasible renewable option.

  15. Chromatographic analysis of water and wine samples for phenolic compounds released from food-contact epoxy resins.

    Science.gov (United States)

    Lambert, C; Larroque, M

    1997-02-01

    Food-contact epoxy resins can release phenolic compounds such as phenol, m-cresol, bisphenol F, bisphenol A, 4-tert-butylphenol, bisphenol F diglycidyl ether (BFDGE), and bisphenol A diglycidyl ether (BADGE) into foodstuffs. A validated high-performance liquid chromatographic method with fluorometric detection is described for the simultaneous analysis of these compounds in wine and mineral water. Sample preparation by solid-liquid extraction enables detection limits of 2.5 micrograms/L in wine and 0.25 microgram/L in mineral water to be achieved. Recovery rates are close to 100%, except for BFDGE and BADGE (around 60% in wine and 75% in mineral water).

  16. Statistical deduction and experimental verification on kinetic equations for the curing reactions of epoxy resins/amines

    Institute of Scientific and Technical Information of China (English)

    CHEN Ping; LU Zu-shun; YU Da-shu; HU Li-jiang

    2005-01-01

    Based on three typical mechanisms (second-order, third-order and competitive mechanisms) for the curing reactions of the epoxy resins with amines, a pair of the kinetic equations (for primary and secondary aminations) was presented to explain the uniformity and relationship among the three different kinetic mechanisms of the reactions. The presented macro-equations were deduced from the kinetic micro-equations by the statistics method. And the constitutive equations were verified by experimental data at different reaction times and temperatures (95℃, 60℃ and 39℃), taking diglycidyl ether of bisphenol A (DGEBA) /ethyleneamine (EA) as a model.

  17. Occupational allergic airbone contact dermatitis and delayed bronchial asthma from epoxy resin revealed by bronchial provocation test.

    Science.gov (United States)

    Kanerva, L; Estlander, T; Keskinen, H; Jolanki, R

    2000-08-01

    Diglycidyl ether of bisphenol A (DGEBA) epoxy resins belong to the most common causes of occupational allergic contact dermatitis. DGEBA has on rare occasions caused occupational asthma. Here we present a patient who first developed occupational allergic contact dermatitis (ACD) caused by a single accidental exposure to DGEBA. Then, on continued occupational exposure to DGEBA, the patient developed occupational asthma from DGEBA, in addition to ACD. A bronchial provocation test with DGEBA caused a 36% drop in the peak expiratory flow, reflecting a delayed type of occupational asthma. This bronchial provocation test caused a strong dermatitis of the exposed skin of the face, in accordance with airborne ACD from DGEBA.

  18. Application of epoxy resin to a solid-foam pelvic model: creating a dry-erase pelvis.

    Science.gov (United States)

    Weaver, Michael J; Brubacher, Jacob W; Vrahas, Mark S

    2014-11-01

    The value of preoperative planning and templating has been well-established in fracture surgery. We have found that using 3-dimensional (3-D) models in preoperative planning aids in the understanding of anatomy, fracture-reduction techniques, and fixation methods, particularly in pelvic and acetabular fractures. To facilitate the correction of errors and reuse for future cases, we coat pelvic models with dry-erase epoxy resin. Fracture lines and planned implants are drawn onto the models with dry-erase markers. The creation of 3-D planning tools is useful in understanding the anatomy of pelvic and acetabular fractures.

  19. Influence of aromatic amine hardeners in the cure kinetics of an epoxy resin used in advanced composites

    Directory of Open Access Journals (Sweden)

    Michelle Leali Costa

    2005-03-01

    Full Text Available Composite structures for aerospace applications are mainly made by the well-known prepreg technology. In order to achieve adequate prepreg processing schedules, and consequently maximum fiber strength utilization, one has to know in deep the cure kinetics of matrix, which held the fibers together. This work describes a procedure to study the cure kinetic and has as example how aromatic amine hardeners influence the cure kinetics of an epoxy resin used in advanced composites. The investigation was carried out by using the DSC technique and it was found that depending on the system used the cure kinetics of the formulation obeys order n or autocatalytic order.

  20. 环氧树脂的热性能研究进展%Research Progress on Thermal Properties of Epoxy Resin

    Institute of Scientific and Technical Information of China (English)

    秦飞宇; 李文慧

    2016-01-01

    环氧树脂是含有环氧基团的有机物小分子低聚物。在一定条件下,与固化剂反应交联成三维立体网状结构。环氧树脂具有各项优良性能,如,化学稳定性,优良的绝缘性,优良的粘结性,低固化收缩率,高强度,高模量,价格低廉等特点。环氧树脂广泛用于国民经济中的各个方面。本文主要综述了环氧树脂的应用,优缺点,以及近年来围绕热性能改性的方法。简易介绍了芳香基环氧树脂及酚醛环氧。%Epoxy resins are organic small molecule oligomers containing epoxy groups .Under certain conditions , the crosslinking reaction with a curing agent works into a three -dimensional network structure .An epoxy resin has the excellent properties such as chemical stability , good insulation , good adhesion , low cure shrinkage , high strength , high modulus, low price, and so on.Epoxy resins are widely used in all aspects of the national economy .The applications, advantages and disadvantages , as well as methods in recent years around the thermal properties of modified epoxy resin were reviewed.The aromatic epoxy resin and phenolic epoxy were introduced .

  1. Evaluation of Nanomaterial Approaches to Damping in Epoxy Resin and Carbon Fiber/Epoxy Composite Structures by Dynamic Mechanical Analysis

    Science.gov (United States)

    Miller, G.; Heimann, Paula J.; Scheiman, Daniel A.; Duffy, Kirsten P.; Johnston, J. Chris; Roberts, Gary D.

    2013-01-01

    Vibration mitigation in composite structures has been demonstrated through widely varying methods which include both active and passive damping. Recently, nanomaterials have been investigated as a viable approach to composite vibration damping due to the large surface available to generate energy dissipation through friction. This work evaluates the influence of dispersed nanoparticles on the damping ratio of an epoxy matrix. Limited benefit was observed through dispersion methods, however nanoparticle application as a coating resulting in up to a three-fold increase in damping.

  2. Nanocomposite of photocurable epoxy-acrylate resin and carbon nanotubes: dynamic-mechanical, thermal and tribological properties

    Directory of Open Access Journals (Sweden)

    Marcos Nunes dos Santos

    2013-04-01

    Full Text Available In this study, the thermal, dynamic-mechanical and tribological behavior of nanocomposites of a photocurable epoxy-acrylate resin and multiwalled carbon nanotubes (MWCNT are investigated. A route consisting of a combination of sonication, mechanical and magnetic stirring is used to disperse 0.25-0.75 wt. (% MWCNT into the resin. Two photocuring cycles using 12 hours and 24 hours of UV-A radiation are studied. The storage modulus, the loss modulus and the tan delta are obtained by dynamic mechanical analysis. Thermal stability is investigated by thermogravimetry, morphology by transmission electronic microscopy (TEM and tribological performance using a pin-on-disk apparatus. The results indicate an increase in stiffness and higher ability to dissipate energy, as well as a shift in the glass transition temperature for the nanocomposites. The addition of nanofillers also decreased friction coefficient and wear rate of the nanocomposites but did not change the observed wear mechanisms.

  3. 21 CFR 175.380 - Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins.

    Science.gov (United States)

    2010-04-01

    ... required in the production of the resins or added to impart desired physical and technical properties. The optional adjuvant substances may include resins produced by the condensation of allyl ether of mono-, di... percent (by volume) ethyl alcohol in distilled water at 160 °F for 4 hours yields total extractives not...

  4. Effects of benzoxazine resin on property enhancement of shape memory epoxy: A dual function of benzoxazine resin as a curing agent and a stable network segment

    Directory of Open Access Journals (Sweden)

    T. Tanpitaksit

    2015-09-01

    Full Text Available An ability of bisphenol-A/aniline based benzoxazine resin (BA-a to simultaneously acts as a curing agent and a stable or rigid network segment for shape memory epoxy, i.e. a two component system, is demonstrated. This significantly simplifies a formulation of present shape memory epoxy systems, i.e. a three or four component system. A suitable content of BA-a in the aliphatic epoxy (NGDE/polybenzoxazine (PBA-a samples for good shape memory performance is in a range of 30 to 50 mol%. The storage modulus of the obtained NGDE/PBA-a shape memory polymers (SMPs was increased from 3.57 GPa for 30 mol% BA-a content to 4.50 GPa for 50 mol% BA-a content. Glass transition temperature of the sample was also substantially increased with increasing BA-a fraction, i.e. from 51°C to 140°C. Flexural modulus and strength at room temperature of the samples at 50 mol% BA-a were found to be as high as 3.97 GPa and 132 MPa compared to the maximum values of 2.54 GPa and 100 MPa of SMP based on cyanate ester-epoxy. All samples exhibited a high value of shape fixity close to 100%. A presence of the BA-a in the samples also imparted a greater recovery stress ranging from 0.25 to 1.59 MPa. Consequently, the obtained NGDE/PBA-a copolymers are highly attractive for shape memory materials to be used in a broader range of applications particularly at elevated temperature and a higher recovery stress value.

  5. 提高环氧树脂胶黏剂耐热性能的途径%Research Progress for Heat Resistance of Epoxy Resin Adhesives

    Institute of Scientific and Technical Information of China (English)

    梁西良; 王旭; 王文博

    2015-01-01

    环氧树脂胶黏剂具有优异的黏结性能,被广泛应用,但是其耐热性能较差,需对其进行改进,以适应于高性能领域的要求。本文对近年来环氧树脂胶黏剂耐热改性方面的工作进行了综述,主要改性方法包括环氧结构改性、耐热型固化剂、耐热型树脂、无机纳米材料等,设计合成新型耐热结构环氧树脂和无机纳米材料改性环氧树脂是研究的热点。%Epoxy resin adhesive, which has excellent adhesive properties, has been widely used, but its use in the high-performance area was limited by its poor thermal resistance, it should be improved. In this paper, several major methods about the modification of epoxy resin adhesives to improve its heat-resistant were reviewed. The methods included structural adjustment, heat-resistant curing agent, heat-resistant resin, inorganic nanoparticles, etc. The novel heat resistance epoxy resin and inorganic nano-materials modified epoxy resin had been hot research point.

  6. The Basic Ply Properties of a Kevlar 49/Epoxy Resin Composite System,

    Science.gov (United States)

    1983-11-01

    Fibre 4 2.3 Composite 4 3 Results 7 3.1 Resin Properties 7 3.2 Composite Properties 9 4 Discussion 14 4.1 Resin System 14 4.2 Composite System 15 5...of the fibre creels before and after fabrication and from the weight of the composite. 3 RESULTS 3.1 Resin Properties TABLE I Resin Tensile Properties

  7. 原位聚合液晶环氧改性环氧树脂的研究%Study on Modifying Epoxy Resin with Liquid Crystalline Epoxy by in-situ Polymerization

    Institute of Scientific and Technical Information of China (English)

    陈立新; 王汝敏; 蓝立文; 郑亚萍

    2001-01-01

    研究了原位聚合PHBHQ对环氧树脂的改性作用。结果表明,随着PHBHQ含量的增加,环氧树脂的冲击强度明显得到提高,而其他性能也有不同程度的改善,并采用SEM分析了PHBHQ/CYD128复合体系的微观结构。%The epoxy resin (CYD-128) modified by in-situ polymerized liquidcrystialline epoxy (PHBHQ) has been discussed. The results show that the epoxy resin impact s trength can be enhanced greatly with the content of PHBHQ increasing and other p roperties are enhanced to varying degrees too. The microstructure of PHBHQ/CYD -128 compound has been observed by SEM.

  8. A Robust Epoxy Resins @ Stearic Acid-Mg(OH)2 Micronanosheet Superhydrophobic Omnipotent Protective Coating for Real-Life Applications.

    Science.gov (United States)

    Si, Yifan; Guo, Zhiguang; Liu, Weimin

    2016-06-29

    Superhydrophobic coating has extremely high application value and practicability. However, some difficult problems such as weak mechanical strength, the need for expensive toxic reagents, and a complex preparation process are all hard to avoid, and these problems have impeded the superhydrophobic coating's real-life application for a long time. Here, we demonstrate one kind of omnipotent epoxy resins @ stearic acid-Mg(OH)2 superhydrophobic coating via a simple antideposition route and one-step superhydrophobization process. The whole preparation process is facile, and expensive toxic reagents needed. This omnipotent coating can be applied on any solid substrate with great waterproof ability, excellent mechanical stability, and chemical durability, which can be stored in a realistic environment for more than 1 month. More significantly, this superhydrophobic coating also has four protective abilities, antifouling, anticorrosion, anti-icing, and flame-retardancy, to cope with a variety of possible extreme natural environments. Therefore, this omnipotent epoxy resins @ stearic acid-Mg(OH)2 superhydrophobic coating not only satisfies real-life need but also has great application potential in many respects.

  9. Changes in the tribological behavior of an epoxy resin by incorporating CuO nanoparticles and PTFE microparticles

    DEFF Research Database (Denmark)

    Larsen, Thomas Ricco Ølholm; Andersen, Tom Løgstrup; Thorning, Bent

    2008-01-01

    Different amounts of CuD nanoparticles are incorporated into both a neat epoxy resin and into an epoxy resin containing PTFE microparticles. The content of CuD is varied in the range of 0-10 vol.% while the PTFE content is fixed at 7.5 vol.%. The dispersion state of added particles is examined...... of thenano-CuO content. However, both parameters are reduced when PTFE is added. Friction and wear data is collected using a custom-made tribotester of the pin-on-disk type. Measurements are performed under dry-sliding conditions against smooth steel counterfaces. When a pressure-velocity (pv) condition of 0.......25 MPa, 6.0 m1s is applied the following is found: without PTFE, the coefficient of friction (p,) is roughly independent of the nano-CuO content. When PTFE is added, an average reduction in p, of 35% is found in the CuD range of 0-0.4 vol.%. At higher CuD concentrations the friction lowering effect...

  10. STUDIES ON APPARENT KINETICS AND RHEOLOGICAL BEHAVIOR OF EPOXY/ACRYLATE IPNS AS VACUUM PRESSURE IMPREGNATION RESINS

    Institute of Scientific and Technical Information of China (English)

    Jing-kuan Duan; Chonung Kim; Ping-kai Jiang

    2009-01-01

    The apparent kinetics and cure behavior of novel interpenetrating polymer networks (IPNs) based on cycloaliphatic epoxy resin (CER) and tri-functional acrylate have been investigated by means of differential scanning calorimetry (DSC) and Fourier transform infrared spectrosccpy (FT-IR). The results of DSC measurements show that the curing reaction of the TMPTMA component is much earlier than that of the CER component, which can lead to the formation of the IPNs. In contrast to neat anhydride-CER system, the anhydride-CER/TMPTMA systems exhibit relatively lower curing temperatures. The activation energy for initiating the reaction of the anhydride-CER system slightly increases, whereas the activation energy for propagating the reaction markedly reduces during the full IPNs formation. The FF-IR spectroscopic changes are interpreted in terms of curing mechanism of CER and TMPTMA components. The extent of reaction is calculated from FT-IR absorption bands, which depends on the reactive group concentration. The experimental results of FT-IR measurements are in good agreements with those of DSC measurements. The theological behavior of anhydride-CER/TMPTMA systems during IPNs formation is studied in this paper. It is confirmed that the introduction of TMPTMA monomer into anhydride-epoxy resin has significant effects on the theological behavior of the system.

  11. Thermal degradation and evolved gas analysis: A polymeric blend of urea formaldehyde (UF and epoxy (DGEBA resin

    Directory of Open Access Journals (Sweden)

    Tansir Ahamad

    2014-12-01

    Full Text Available A polymeric blend has been prepared using urea formaldehyde (UF and epoxy (DGEBA resin in 1:1 mass ratio. The thermal degradation of UF/epoxy resin blend (UFE was investigated by using thermogravimetric analyses (TGA, coupled with FTIR and MS. The results of TGA revealed that the pyrolysis process can be divided into three stages: drying process, fast thermal decomposition and cracking of the sample. There were no solid products except ash content for UFE during combustion at high temperature. The total mass loss during pyrolysis at 775 °C is found to be 97.32%, while 54.14% of the original mass was lost in the second stage between 225 °C and 400 °C. It is observed that the activation energy of the second stage degradation during combustion (6.23 × 10−4 J mol−1 is more than that of pyrolysis (5.89 × 10−4 J mol−1. The emissions of CO2, CO, H2O, HCN, HNCO, and NH3 are identified during thermal degradation of UFE.

  12. Synthesis, characterization and evaluation of reflectivity of nanosized CaTiO3/epoxy resin composites in microwave bands

    Indian Academy of Sciences (India)

    M Murugan; V K Kokate; M S Bapat

    2011-07-01

    Microwave absorbing materials play a major role in electromagnetic interference and compatibility measurements in anechoic chambers. Nanocrystalline calcium titanate (CT) was synthesized by hydrothermal method and further composites of CT/epoxy resin were fabricated as thin solid slabs of four different weight ratios. The composite material was analyzed by X-ray diffraction (XRD) and transmission electron microscopy (TEM), which reveals that CT was observed to be in the monoclinic phase with an average crystallite size of 24 nm. The reflectivity measurement of the composite materials was carried out by the transmission/reflection method using a vector network analyzer R&S: ZVA40, in the X- and Ku-bands. The effective permittivity and permeability of the samples was also computed with the help of measured transmission and reflection coefficients. The results show that CT with equal weight of epoxy resin provides –30 dB at 8.5 GHz in the X-band and –19.5 dB at 18.0 GHz in the Ku-band. Reflectivity was found to be better than –10 dB for 2.2 GHz and 1.9 GHz for X-band and Ku-band, respectively and encourages use of it as potential microwave absorber material.

  13. Large Core Planar 1 x 2 Optical Power Splitter with Acrylate and Epoxy Resin Waveguides on Polydimetylsiloxane Substrate

    Directory of Open Access Journals (Sweden)

    V. Prajzler

    2014-04-01

    Full Text Available Fabrication process of multimode 1x2 optical rectangular planar power splitter suitable for low-cost short distance optical network is presented. The splitters were designed by beam propagation method for standard input/output plastic optical fibre. Materials used for the splitter were: UV acrylate photopolymer polymer or epoxy resin for optical core waveguide layers and Y-groove substrate for the core layer was poly(methyl methacrylate or polydimetylsiloxane made by replication process on poly(methyl methacrylate pattern. The insertion losses of 1x2 splitters with acrylate waveguide layers were around 2.7 dB at 532 nm and 4.1 dB at 650 nm and those for epoxy resin waveguide layer were around 3.7 dB at 850 nm. The 1x2 splitters were tested by signal transmission being connected to the internet network by using optoelectronic switches and we achieved the maximum possible transmission data rate as provided by the computer network.

  14. AFM and XRD characterization of silver nanoparticles films deposited on the surface of DGEBA epoxy resin by ion sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Jose Elisandro de; Machado, Rogerio; Macedo, Marcelo Andrade [Universidade Federal de Sergipe (UFSE), Aracaju, SE (Brazil). Programa de Pos-graduacao em Fisica; Cunha, Frederico Guilherme Carvalho [Universidade Federal de Sergipe (UFSE), Aracaju, SE (Brazil). Programa de Pos-graduacao em Ciencia e Engenharia de Materiais

    2012-07-01

    In this work, silver atoms were deposited by ion sputtering on the surface of diglycidyl ether of bisphenol A (DGEBA) epoxy resin cured at 150 Degree-Sign C for 6 hours in air. The films of DGEBA and its precursors were characterized by Raman spectroscopy to identify the main functional groups and their relationship with the deposited silver atoms. Silver thin films of 5, 10, 15 and 20 nm were deposited on the epoxy resin at room temperature. Both the initial film of DGEBA and the subsequent silver thin film were analyzed by Atomic Force Microscopy (AFM) in the non-contact mode. Silver thin films were also analyzed using X-ray diffraction (XRD) at room temperature. The AFM results showed the formation of silver crystallites on the surface of DGEBA at very low coverage whereas XRD indicated that most of them had their main axis aligned to the normal of the surface. An increase in the coverage led to an increase in the grain size as indicated by AFM. However, XRD results indicated that the crystallite size remained almost constant while the appearance of peaks corresponding to other crystalline orientations suggests the coalescence of the original crystallites and an increase in size of the more dense planes, namely [111]. (author)

  15. AFM and XRD characterization of silver nanoparticles films deposited on the surface of DGEBA epoxy resin by ion sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Jose Elisandro de; Machado, Rogerio; Macedo, Marcelo Andrade; Cunha, Frederico Guilherme Carvalho [Clinica de Medicina Nuclear e Radiologia de Maceio (MedRadiUS), Radiology and Imaging Diagnosis at Universidade Federal de Alagoas (UFAL), Maceio, AL (Brazil)

    2012-07-01

    In this work, silver atoms were deposited by ion sputtering on the surface of diglycidyl ether of bisphenol A (DGEBA) epoxy resin cured at 150 deg C for 6 hours in air. The films of DGEBA and its precursors were characterized by Raman spectroscopy to identify the main functional groups and their relationship with the deposited silver atoms. Silver thin films of 5, 10, 15 and 20 nm were deposited on the epoxy resin at room temperature. Both the initial film of DGEBA and the subsequent silver thin film were analyzed by Atomic Force Microscopy (AFM) in the non-contact mode. Silver thin films were also analyzed using X-ray diffraction (XRD) at room temperature. The AFM results showed the formation of silver crystallites on the surface of DGEBA at very low coverage whereas XRD indicated that most of them had their main axis aligned to the normal of the surface. An increase in the coverage led to an increase in the grain size as indicated by AFM. However, XRD results indicated that the crystallite size remained almost constant while the appearance of peaks corresponding to other crystalline orientations suggests the coalescence of the original crystallites and an increase in size of the more dense planes, namely [111]. (author)

  16. Modification of epoxy resin, silicon and glass surfaces with alkyl- or fluoroalkylsilanes for hydrophobic properties

    Energy Technology Data Exchange (ETDEWEB)

    Marczak, Jacek, E-mail: jacek.marczak@eitplus.pl [Wroclaw Research Centre EIT+ Ltd., 147 Stablowicka St., 54-066 Wrocław (Poland); Kargol, Marta [Wroclaw Research Centre EIT+ Ltd., 147 Stablowicka St., 54-066 Wrocław (Poland); Psarski, Maciej; Celichowski, Grzegorz [Department of Materials Technology and Chemistry, University of Lodz, Pomorska 163, 90-236 Lodz (Poland)

    2016-09-01

    Graphical abstract: - Highlights: • Chemical structure of alkylsilanes and fluoroalkylsilanes can affect the hydrophobic and surface performance of the modified samples. • Wet chemical hydrophobization is relatively simple and inexpensive method to obtain hydrophobic/superhydrophobic coatings. • The samples degradation is not observed and hydrophobic coatings seem to be stable in UV light. - Abstract: Preparation of superhydrophobic materials inspired by nature has attracted a great scientific interest in recent decades. Some of these materials have hierarchical lotus-like structures, i.e. micro- and nano-objects coated by hydrophobic compounds. A major challenge of applying the superhydrophobic surfaces for the self-cleaning coatings preparation is their improved efficiency in varying atmospheric conditions, e.g. UV light. The objective of this research work was to investigate the effect of the different chemical structure and the surface free energy on the hydrophobic and tribological properties of the alkylsilanes and fluoroalkylsilanes deposited on silicon wafers, glass slides and epoxy resin. Tribological and hydrophobic properties of the modified surfaces were correlated with their chemical structures. Chemical structures of the deposited materials were examined by using Fourier transform infrared (FT-IR) spectroscopy and hydrophobic properties were investigated by water contact angle (WCA) and surface free energy (SFE) measurements. The modified surfaces exhibited water contact angles of above 100° for the selected modifiers. It was noticed that the replacement of hydrogen atoms by fluorine atoms in alkyl chain caused an increase in the water contact angle values and a decrease in friction coefficients. The obtained results showed that the carbon chain length of a modifier and its chemical structure can strongly affect the hydrophobic and tribological properties of the modified surfaces. The highest values of WCA, lowest values of SFE and coefficient

  17. Thermal Conductivity of Epoxy Resin Reinforced with Magnesium Oxide Coated Multiwalled Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Fei-Peng Du

    2013-01-01

    Full Text Available Magnesium oxide coated multiwalled carbon nanotubes (MgO@MWNT were fabricated and dispersed into epoxy matrix. The microstructures of MgO@MWNT and epoxy/MgO@MWNT nanocomposites were characterized by TEM and SEM. Electrical resistivity and thermal conductivity of epoxy nanocomposites were investigated with high resistance meter and thermal conductivity meter, respectively. MgO@MWNT has core-shell structure with MgO as shell and nanotube as core, and the thickness of MgO shell is ca. 15 nm. MgO@MWNT has been dispersed well in the epoxy matrix. MgO@MWNT loaded epoxy nanocomposites still retain electrical insulation inspite of the filler content increase. However, thermal conductivity of epoxy was increased with the MgO@MWNT content increasing. When MgO@MWNT content reached 2.0 wt.%, thermal conductivity was increased by 89% compared to neat epoxy, higher than that of unmodified MWNT nanocomposites with the same loading content.

  18. Filled and unfilled temperature-dependent epoxy resin blends for lossy transducer substrates.

    Science.gov (United States)

    Eames, Matthew D C; Hossack, John A

    2009-04-01

    In the context of our ongoing investigation of low-cost 2-dimensional (2-D) arrays, we studied the temperature- dependent acoustic properties of epoxy blends that could serve as an acoustically lossy backing material in compact 2-D array-based devices. This material should be capable of being machined during array manufacture, while also providing adequate signal attenuation to mitigate backing block reverberation artifacts. The acoustic impedance and attenuation of 5 unfilled epoxy blends and 2 filled epoxy blends - tungsten and fiberglass fillers - were analyzed across a 35 degrees C temperature range in 5 degrees C increments. Unfilled epoxy materials possessed an approximately linear variation of impedance and sigmoidal variation of attenuation properties over the range of temperatures of interest. An intermediate epoxy blend was fitted to a quadratic trend line with R(2) values of 0.94 and 0.99 for attenuation and impedance, respectively. It was observed that a fiberglass filler induces a strong quadratic trend in the impedance data with temperature, which results in increased error in the characterization of attenuation and impedance. The tungsten-filled epoxy was not susceptible to such problems because a different method of fabrication was required. At body temperature, the tungsten-filled epoxy could provide a 44 dB attenuation of the round-trip backing block echo in our application, in which the center frequency is 5 MHz and the backing material is 1.1 mm thick. This is an 11 dB increase in attenuation compared with the fiberglass-filled epoxy in the context of our application. This work provides motivation for exploring the use of custom-made tungsten-filled epoxy materials as a substitute PCB-based substrate to provide electrical signal interconnect.

  19. Research Progress in Thermoset Shape Memory Epoxy Resin%热固性环氧树脂形状记忆聚合物的研究进展

    Institute of Scientific and Technical Information of China (English)

    魏堃; 朱光明; 唐玉生; 田光明; 谢建强

    2012-01-01

    The thermoset shape memory epoxy resin was viewed as a hot issue in the field of shape memory polymers(SMP).The latest progress of thermoset shape memory epoxy resin was reviewed and summarized.The characteristics and shape memory properties of all kinds of thermoset shape memory epoxy resin were discussed in detail in the paper.The effects of temperature,radiation and degree of curing on the shape memory properties of thermoset shape memory epoxy resin were also discussed.The mechanical and shape memory properties of thermoset shape memory epoxy based composites were systematically discussed in the paper.At last,some hot issues about themoset shape memory epoxy resin were summed up.%热固性环氧树脂形状记忆聚合物是目前形状记忆聚合物研究领域的热点之一,文中介绍了热固性环氧树脂形状记忆聚合物的最新研究进展,详细探讨了各种热固性环氧树脂形状记忆聚合物的特点与性能,以及温度、辐射、固化程度对环氧树脂形状记忆聚合物性能的影响,并对环氧树脂形状记忆复合材料的性能进行了讨论,最后分析了热固性环氧树脂形状记忆聚合物研究中存在的问题。

  20. Study on the Epoxy Resin Heat Resistance Modified by Polyamide Acid%聚酰胺酸改性环氧树脂耐热性的研究

    Institute of Scientific and Technical Information of China (English)

    周浩然; 孔德忠; 刘达

    2009-01-01

    The epoxy resin heat resistance was prepared with epoxy modified with PAA, and DDS as curing after the pre-reacting and curing. The effects of the amount of PAA, the amount of curing agent, curing condition, reaction time on the heat resistance of epoxy resin were studied. A better formula and appropriate conditions for curing were chosen. The heat resistance of modified epoxy resin was measured with TG in different proportions, pre-reaction time and different curing conditions. Then, the surface morphology and the fracture morphology of the curing epoxy modified were analyzed with SEM. The result has shown that better curing process conditions of modified epoxy resin are as follows: 120 ℃,1 h→150 ℃,1 h→170 ℃,2 h→200 ℃,2 h→250 ℃,2 h,the proportion is 3h. The decomposition temperature of modified epoxy resin is 411 ℃ after the pre-reacting and curing, which is increased by 80 ℃, compared with the decomposition temperature of non-modified epoxy resin. There is no distinct two-phase structure in EP/PAA/DDS system after the pre-reacting and curing, which indicates that the resin has a good compatibility.%用4, 4′-二氨基二苯基砜(DDS)做固化剂,采用聚酰胺酸(PAA)对环氧树脂(EP)进行改性,研究了PAA用量、固化剂用量和反应时间对环氧树脂耐热性的影响,采用TG测定不同配比、预反应时间及不同固化温度下改性EP的耐热性,利用SEM对最佳配比固化后样品的表面和断面形貌进行了分析.结果表明,改性树脂最佳固化工艺条件为:120 ℃,1 h→150 ℃,1 h→170 ℃,2 h→200 ℃,2 h→250 ℃,2 h;改性树脂配比为mEP∶mPAA∶mDDS=1∶0.75∶0.08;预反应时间3 h,改性EP的热分解温度为411 ℃,比未改姓EP提高了近80 ℃以上;EP/PAA/DDS固化后样品无明显的两相结构,树脂的相容性较好.

  1. Inlfuences of Iodonium Salts on the Properties of a Hybrid Composite Resin Containing BisS-GMA and Expanding Monomer Modiifed Epoxy

    Institute of Scientific and Technical Information of China (English)

    LIU Wenjia; FU Jing; WU Xiangnan; MA Yuanyuan; LIU Xiaoqing; LIAO Yunmao; WANG Hang

    2015-01-01

    In order to reduce shrinkage and improve the mechanical properties of dental composite resins, we designed a hybrid resin formulation containing a novel matrix resin, BisS-GMA [bisphenol-S-bis(3-methacrylato-2-hydroxypropyl)ether], and epoxy modiifed by a spiro-orthocarbonate (SOC) expanding monomer. Then, we tested the effects of an iodonium salt, diphenyliodonium hexalfuorphosphate (DPIHFP), on the properties of the hybrid resin with seven different concentrations. The hybrid resin was polymerized by a ternary photo-initiator system. The volumetric shrinkage (VS), degree of conversion (DC) and compressive strength (CS) were assessed using AcuVolTM , FTIR and a universal testing machine, respectively. The VS, DC and CS were improved with increasing DPIHFP concentration, but a high concentration of DPIHFP had a negative inlfuence on the mechanical properties of the hybrid resin and offered no added improvement in the VS and DC. The best performance of a composite resin containing BisS-GMA and SOC-modiifed epoxy was achieved with 2wt%DPIHFP. The results also indicated that the resin containing BisS-GMA was superior to that containing Bis-GMA in terms of VS, DC and CS.

  2. Study Progress on Modified Epoxy Resin for LED Encapsulation%LED封装用改性环氧树脂研究进展

    Institute of Scientific and Technical Information of China (English)

    冯朝波; 侯甫文; 徐耀华; 许京丽

    2011-01-01

    传统的LED环氧树脂封装材料存在脆性大、耐冲击性差、容易老化、透光率低、折射率低等缺陷,限制了其在LED封装产业中的应用,通过环氧树脂改性可弥补其作为LED封装材料的缺陷。本文综述了近年来LED环氧树脂封装材料在高折射率、光稳定、抗黄变、有机硅改性方面的研究进展,并展望了LED改性环氧树脂封装材料的发展前景。%The conventional epoxy resin for LED packaging materials had the disadvantages of brittleness,poor impact resistance,easily aging,low light transmittance,and low refractive index,which limited the application range of LED packaging.However,the modified epoxy resin can make up for its shortcomings.The recent study progress of LED epoxy resin materials in high refractive index,light stabilizers,anti-yellowing,and silicone modified was reviewed,and the development trends of the LED modified epoxy resin packaging materials were prospected.

  3. 日本环氧树脂生产厂商发展概况%GENERAL SITUATION OF SOME EPOXY RESIN MANUFACTURES IN JAPAN

    Institute of Scientific and Technical Information of China (English)

    高良

    2001-01-01

    General situation of main epoxy resin manufactures in Japan,including product variety,production capacity,and development trend,were described in this paper.%着重介绍日本环氧树脂主要生产厂商的发展概况。

  4. Development of liquid-crystalline epoxy resin containing ester mesogen%酯基液晶环氧树脂研究进展

    Institute of Scientific and Technical Information of China (English)

    徐淑权; 李玲; 王晓铭

    2013-01-01

    介绍了酯基液晶环氧树脂的合成方法及其优缺点,介晶基元的长度、取代基以及柔性间隔链对酯基液晶环氧树脂液晶性能的影响,固化剂的选择、固化温度和酯基液晶环氧树脂的化学结构对酯基液晶环氧树脂固化特性的影响,并展望了酯基液晶环氧树脂的发展前景.%The synthesis methods of liquid-crystalline epoxy resin containing ester mesogen and their advantages and disadvantages are introduced in this paper. The influences of the length of the mesogenic unit, substituents and flexible spacer on the performance of the liquid-crystalline epoxy resin containing ester mesogen are analyzed. The effects of curing agent choice, curing temperature and chemical structure of the liquid-crystalline epoxy resin containing ester mesogen on the curing characteristics studied as well. The prospects of liquid-crystalline epoxy resin containing ester mesogen are proposed.

  5. Morphology and properties of amine terminated poly(arylene ether ketone) and poly(arylene ether sulfone) modified epoxy resin systems

    Science.gov (United States)

    Cecere, J. A.; Mcgrath, J. E.; Hedrick, J. L.

    1986-01-01

    Epoxy resin networks cured with DDS were modified by incorporating tough ductile thermoplastics such as the amine terminated polyether sulfones and amine terminated polyether ketones. Both linear copolymers were able to significantly improve the fracture toughness values at the 15 and 30 weight percent concentrations examined. These improvements in fracture toughness were achieved without any significant change in the flexural modulus.

  6. Process for improving mechanical properties of epoxy resins by addition of cobalt ions

    Science.gov (United States)

    Stoakley, D. M.; St.clair, A. K. (Inventor)

    1984-01-01

    A resin product useful as an adhesive, composite or casting resin is described as well as the process used in its preparation to improve its flexural strength mechanical property characteristics. Improved flexural strength is attained with little or no change in density, thermal stability or moisture resistance by chemically incorporating 1.2% to 10.6% by weight Co(3) ions in an epoxidized resin system.

  7. Materials Characterization of High-Temperature Epoxy Resins: SC-79 and SC-15/SC-79 Blend

    Science.gov (United States)

    2011-03-01

    Army composite applications. SC-15 is a toughened commercial vacuum-assisted resin transfer molding ( VARTM ) resin produced by Applied Poleramic Inc...very well in VARTM processes and has good damage resistance in structural and ballistic applications. However, the relatively low glass transition...low-viscosity, two-phase toughened, cycloaliphatic amine–cured commercial VARTM resin system designed to be easy to handle and have a long processing

  8. Toughening Modification Study of Epoxy Resin for GIS%GIS用环氧树脂的增韧改性研究

    Institute of Scientific and Technical Information of China (English)

    曾强; 徐懿; 崔博源; 陈平; 雷清泉

    2015-01-01

    制备了一种聚氨酯型热致性液晶聚合物,采用液晶增韧改性环氧树脂,分析液晶的含量对环氧树脂力学性能和耐热性的影响。在环氧树脂中同时添加液晶和Al2O3制备了三元共混体系,并对共混体系的力学性能和电性能进行分析。结果表明:当液晶与环氧的质量比为3∶100时,复合材料的冲击强度相对于纯环氧树脂体系提高了60%,拉伸强度和弯曲强度也分别提高了80%和87%,而且液晶的加入对环氧的耐热性基本没影响。在室温下,三元体系的介电常数是二元体系介电常数的1.5倍。%A polyurethane-based thermotropic liquid crystalline polymer (TLCP) was prepared. Epoxy resin was modified by the TLCP, and the effect of TLCP content on the mechanical properties and heat resis-tance of the epoxy resin was studied. A ternary blend system was prepared by adding TLCP and Al2O3 to epoxy resin, and the mechanical properties and dielectric properties of the blend system were studied. The results show that when the mass ratio between TLCP and epoxy resin is 3∶100, the impact strength, tensile strength, and bending strength of the modified epoxy resin increase by 60%, 80%, and 87%respectively compared to the pure epoxy resin, and the TLCP has no influence on the heat resistance of the modified epoxy resin. The dielectric constant of the ternary blend system is 1.5 times higher than that of the binary blend system at room temperature.

  9. Rapid embedding methods into epoxy and LR White resins for morphological and immunological analysis of cryofixed biological specimens.

    Science.gov (United States)

    McDonald, Kent L

    2014-02-01

    A variety of specimens including bacteria, ciliates, choanoflagellates (Salpingoeca rosetta), zebrafish (Danio rerio) embryos, nematode worms (Caenorhabditis elegans), and leaves of white clover (Trifolium repens) plants were high pressure frozen, freeze-substituted, infiltrated with either Epon, Epon-Araldite, or LR White resins, and polymerized. Total processing time from freezing to blocks ready to section was about 6 h. For epoxy embedding the specimens were freeze-substituted in 1% osmium tetroxide plus 0.1% uranyl acetate in acetone. For embedding in LR White the freeze-substitution medium was 0.2% uranyl acetate in acetone. Rapid infiltration was achieved by centrifugation through increasing concentrations of resin followed by polymerization at 100°C for 1.5-2 h. The preservation of ultrastructure was comparable to standard freeze substitution and resin embedding methods that take days to complete. On-section immunolabeling results for actin and tubulin molecules were positive with very low background labeling. The LR White methods offer a safer, quicker, and less-expensive alternative to Lowicryl embedding of specimens processed for on-section immunolabeling without traditional aldehyde fixatives.

  10. Strain Rate Sensitivity of Epoxy Resin in Tensile and Shear Loading

    Science.gov (United States)

    Gilat, Amos; Goldberg, Robert K.; Roberts, Gary D.

    2005-01-01

    The mechanical response of E-862 and PR-520 resins is investigated in tensile and shear loadings. At both types of loading the resins are tested at strain rates of about 5x10(exp 5), 2, and 450 to 700 /s. In addition, dynamic shear modulus tests are carried out at various frequencies and temperatures, and tensile stress relaxation tests are conducted at room temperature. The results show that the toughened PR-520 resin can carry higher stresses than the untoughened E-862 resin. Strain rate has a significant effect on the response of both resins. In shear both resins show a ductile response with maximum stress that is increasing with strain rate. In tension a ductile response is observed at low strain rate (approx. 5x10(exp 5) /s), and brittle response is observed at the medium and high strain rates (2, and 700 /s). The hydrostatic component of the stress in the tensile tests causes premature failure in the E-862 resin. Localized deformation develops in the PR-520 resin when loaded in shear. An internal state variable constitutive model is proposed for modeling the response of the resins. The model includes a state variable that accounts for the effect of the hydrostatic component of the stress on the deformation.

  11. 水性环氧树脂涂料研究与应用进展%Research Progress and Application on Waterborne Epoxy Resin Coating

    Institute of Scientific and Technical Information of China (English)

    牛凯辉; 宋伟强; 谢宝粘; 吴龙超

    2015-01-01

    The methods for preparation of waterborne epoxy resin were systematically introduced, including mechanism methods, phase inversion technique, curing agent emulsification method and chemistry modification technique, and all of them were discussed. With epoxy groups, hydroxyl group and other active groups on the molecular chain, epoxy resin could be composited with other resins to improve the comprehensive performance of waterborne epoxy resin coatings. The commonly used methods of modification had polyurethane modification, polyacrylate modification, phosphate modification, silicone modification and nanoparticles modification. The main application fields of waterborne epoxy resin coating were also given. Finally, the development prospects were predicted.%系统地介绍了环氧树脂水性化技术,包括机械法、相反转法、固化剂乳化法及化学改性法,并对各方法进行了评论。环氧树脂分子链上带有环氧基、羟基等活泼基团,可以与其它树脂复合使用,提高水性环氧树脂涂料的综合性能,常用方法有聚氨酯改性、聚丙烯酸酯改性、磷酸酯改性、有机硅改性以及纳米粒子改性。介绍了水性环氧树脂涂料的主要应用领域,并对其发展前景进行了展望。

  12. Improving the toughness of epoxy resin encapsulating materials%环氧树脂灌封材料的增韧研究

    Institute of Scientific and Technical Information of China (English)

    张凯; 范敬辉; 马艳; 黄琨

    2011-01-01

    抗冲击精密电子元器件用灌封材料往往需要具有好的韧性.在综合考虑灌封材料力学性能与灌封工艺性的基础上,采用自制带液晶基团聚酯型环氧树脂对环氧树脂E-51进行了增韧改性研究.结果表明,优化配方的增韧型环氧树脂灌封材料在保持自身较高压缩强度的同时,抗冲击强度提高了4.1倍,且具有良好的灌封工艺性,其在25℃条件下的适用期(凝胶化时间)≥100min.%High toughness is always required for encapsulating materials used for the anti-impact precision electronic components and devices. The effects of addition of a kind of self-synthesized polyester epoxy resin containing liquid crystal groups on improving the toughness of epoxy resin F-51 were studied, while changes in the workability of epoxy resin E-51 were also investigated. The results show that the optimized epoxy resin encapsulating material shows little change in compressive strength but significant increase (by 4.1 times) in impact strength in compassion to pure epoxy resin E-51,and exhibits good workability with the gelation time at room temperature (25 ℃) above 100 minutes.

  13. Bisimide amine cured epoxy /IME/ resins and composites. II - Ten-degree off-axis tensile and shear properties of Celion 6000/IME composites

    Science.gov (United States)

    Scola, D. A.

    1982-01-01

    Bisimide amines (BIAs), which are presently used as curing agents in a state-of-the-art epoxy resin, are oligomeric and polymeric mixtures. A series of composites consisting of the novel BIA-cured epoxy resin reinforced with Celion 6000 graphite fibers were fabricated and evaluated, and the ten-degree, off-axis uniaxial tensile and shear properties of these composites were determined. The use of the intralaminar shear strain-to-failure was used in the calculation of resin shear strain-to-failure. Study results indicate that several of these novel composite systems exhibit shear strain properties that are superior to those of the control composite system of the present experiments, which employed a sulfone curing agent.

  14. Biocatalytic Synthesis of Epoxy Resins from Fatty Acids as a Versatile Route for the Formation of Polymer Thermosets with Tunable Properties.

    Science.gov (United States)

    Torron, Susana; Semlitsch, Stefan; Martinelle, Mats; Johansson, Mats

    2016-12-12

    The work herein presented describes the synthesis and polymerization of series of bio-based epoxy resins prepared through lipase catalyzed transesterification. The epoxy-functional polyester resins with various architectures (linear, tri-branched, and tetra-branched) were synthesized through condensation of fatty acids derived from epoxidized soybean oil and linseed oil with three different hydroxyl cores under bulk conditions. The selectivity of the lipases toward esterification/transesterification reactions allowed the formation of macromers with up to 12 epoxides in the backbone. The high degree of functionality of the resins resulted in polymer thermosets with Tg values ranging from -25 to over 100 °C prepared through cationic polymerization. The determining parameters of the synthesis and the mechanism for the formation of the species were determined through kinetic studies by (1)H NMR, SEC, and molecular modeling studies. The correlation between macromer structure and thermoset properties was studied through real-time FTIR measurements, DSC, and DMA.

  15. Effects of graphene oxides on the cure behaviors of a tetrafunctional epoxy resin

    Directory of Open Access Journals (Sweden)

    2011-09-01

    Full Text Available The influence of graphene oxides (GOs on the cure behavior and thermal stability of a tetrafunctional tetraglycidyl-4,4’-diaminodiphenylmethane cured with 4,4’-diaminodiphenylsulfone was investigated by using dynamic differential scanning calorimetry (DSC and thermogravimetric analysis (TGA. The dynamic DSC results showed that the initial reaction temperature and exothermal peak temperature decreased with the increase of GO contents. Furthermore, the addition of GO increased the enthalpy of epoxy cure reaction. Results from activation energy method showed that activation energies of GO/epoxy nanocomposites greatly decreased with the GO content in the latter stage, indicating that GOs significantly hindered the occurrence of vitrification. The oxygen functionalities, such as hydroxyl and carboxyl groups, on the surface of GOs acted as catalysts and facilitated the curing reaction and the catalytic effect increased with the GO contents. TGA results revealed that the addition of GOs decreased the thermal stability of epoxy.

  16. Effect of titania particles on the microstructure and properties of the epoxy resin coatings on sintered NdFeB permanent magnets

    Science.gov (United States)

    Xu, J. L.; Huang, Z. X.; Luo, J. M.; Zhong, Z. C.

    2014-04-01

    The nanometer titania particles enhanced epoxy resin composite coatings were prepared on the sintered NdFeB permanent magnets by cathodic electrophoretic deposition. The effects of titania particle concentrations on the microstructure and properties of the epoxy coatings were investigated by surface and cross-sectional morphologies observation, surface roughness and microhardness measurement, H2SO4 solution immersion test, neutral salt spray test and magnetic properties measurement. The results showed that the thickness of epoxy coatings with and without the titania particles addition was about 40 μm. The titania particles could be uniformly dispersed and embedded in the epoxy matrix if the titania particles concentration was lower than 40 g/l. With increasing titania particle concentrations, the number of the particles embedded in the epoxy matrix increased and the surface roughness and microhardness of the composite coatings increased. At the same time, the weight loss of the coated samples immersed in H2SO4 solution decreased and the neutral salt spray time of the coated samples prolonged. It could be concluded that the titania particles did not change the thickness of the epoxy coatings and did not deteriorate the magnetic properties of NdFeB substrates, but could greatly improve the microhardness and corrosion resistance of the epoxy coatings.

  17. Insight on mendable resin made by combining Diels-Alder epoxy adducts with DGEBA

    Science.gov (United States)

    Dello Iacono, S.; Martone, A.; Filippone, G.; Acierno, D.; Zarrelli, M.; Giordano, M.; Amendola, E.

    2016-05-01

    Formation of micro-cracks is a critical problem in polymers and polymer composites during their service in structural applications. In this context, materials endowed with self-healing features would lead to the next polymers generation. In the present paper, an epoxy system integrating Diels-Alder epoxy adducts is investigated by thermal and spectroscopic analysis. The direct and retro D-A reaction have been studied by FTIR and specific absorption bands have been identified. Finally, mechanical tests have been performed on the system. The polymer is able to heal fracture and micro-cracks recovering its stiffness after a thermal treatment.

  18. Surface modification of an epoxy resin with polyamines and polydopamine: Adhesion toward electroless deposited copper

    Science.gov (United States)

    Schaubroeck, David; Mader, Lothar; Dubruel, Peter; Vanfleteren, Jan

    2015-10-01

    In this paper the influence of the epoxy roughness, surface modifications and ELD (electroless copper deposition) temperatures on the adhesive strength of the copper is studied. Good adhesion at low roughness values is targeted due to their applicability in high density electronic circuits. Roughened epoxy surfaces are modified with adsorbed polyamines, polydopamine and polyamines grafted to polydopamine. Next the, adhesive strength of ELD copper is determined with peel strength measurements and the interphases are examined with SEM (scanning electron microscopy). Polydopamine and polyamines grafted to polydopamine can lead to increased adhesive strength at lower roughness values compared to the non-modified samples at specific plating temperatures.

  19. Effect of bonding process on the properties of isotropic epoxy resin-bonded Nd-Fe-B magnets

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiuhai; XIONG Weihao

    2009-01-01

    Bonded NdFeB magnets were prepared by compression molding. The effect of preparation technology on their magnetic and mechanical properties was studied through the analysis of density, Br Hcj, (BH)max, bending strength, and compressive strength of the bonded magnets. The results showed that the magnetic properties decreased with increasing binder content, whereas the mechanical properties increased. Brand (BH)max increased with rising pressure, whereas Hcj decreased. For a fixed mass fraction of the binder, the optimal pressure was 620 MPa and the best thermosetting temperature was 160℃. These conditions made the bonded magnets have the optimal mechanical properties. Scanning electron microscopy (SEM) analyses of the fracture surfaces indicated that the epoxy resin bonded magnets exhibited brittle behavior.

  20. Dynamics and mechanism of cavitation erosion on perspex and epoxy resins tested in a rotating disk device

    Science.gov (United States)

    Rao, P. V.; Rao, N. S. L.; Rao, B. C. S.

    1982-01-01

    The cavitation erosion behavior including the initiation, dynamics and mechanism of damage process on perspex and epoxy resin specimens tested in a rotating disk device were discussed with respect to exposure time. The inception of erosion always took place at the location nearest to the center of rotation of the disk. Subsequently, as exposure time increased, erosion initiated at other locations as well. Light optical photographs and scanning electron micrographs clearly indicate that most of the material loss appears to occur form the networks of cracks due to their interaction and pits indicate particle debris. The optical degradation (loss of transmittance) on perspex was observed to be more on the rear side than on the front side.