WorldWideScience

Sample records for advanced polymer composites

  1. Advanced moisture modeling of polymer composites.

    Science.gov (United States)

    2014-04-01

    Long term moisture exposure has been shown to affect the mechanical performance of polymeric composite structures. This reduction : in mechanical performance must be considered during product design in order to ensure long term structure survival. In...

  2. Microgel polymer composite fibres

    OpenAIRE

    Kehren, Dominic

    2014-01-01

    In this thesis some novel ideas and advancements in the field of polymer composite fibres, specifically microgel-based polymer composite fibres have been achieved. The main task was to investigate and understand the electrospinning process of microgels and polymers and the interplay of parameter influences, in order to fabricate reproducible and continuously homogenous composite fibres. The main aim was to fabricate a composite material which combines the special properties of polymer fibres ...

  3. Composite, Polymer-Based Electrolytes for Advanced Batteries

    National Research Council Canada - National Science Library

    Ratner, Mark A

    2001-01-01

    .... Several substantive advances towards new, improved performance electrolyte materials both for low temperature fuel cell applications and for advanced secondary lithium battery materials have been reported...

  4. Nondestructive Evaluation (NDE) of Advanced Fiber Reinforced Polymer Composites

    National Research Council Canada - National Science Library

    Yolken, H

    2001-01-01

    .... The high stiffness-to-weight ratio, low electromagnetic reflectance, and the ability to embed sensors and actuators have made fiber reinforced composites an attractive alternative construction...

  5. Advanced polymers in medicine

    CERN Document Server

    Puoci, Francesco

    2014-01-01

    The book provides an up-to-date overview of the diverse medical applications of advanced polymers. The book opens by presenting important background information on polymer chemistry and physicochemical characterization of polymers. This serves as essential scientific support for the subsequent chapters, each of which is devoted to the applications of polymers in a particular medical specialty. The coverage is broad, encompassing orthopedics, ophthalmology, tissue engineering, surgery, dentistry, oncology, drug delivery, nephrology, wound dressing and healing, and cardiology. The development of polymers that enhance the biocompatibility of blood-contacting medical devices and the incorporation of polymers within biosensors are also addressed. This book is an excellent guide to the recent advances in polymeric biomaterials and bridges the gap between the research literature and standard textbooks on the applications of polymers in medicine.

  6. Erosion Coatings for High-Temperature Polymer Composites: A Collaborative Project With Allison Advanced Development Company

    Science.gov (United States)

    Sutter, James K.

    2000-01-01

    The advantages of replacing metals in aircraft turbine engines with high-temperature polymer matrix composites (PMC's) include weight savings accompanied by strength improvements, reduced part count, and lower manufacturing costs. Successfully integrating high-temperature PMC's into turbine engines requires several long-term characteristics. Resistance to surface erosion is one rarely reported property of PMC's in engine applications because PMC's are generally softer than metals and their erosion resistance suffers. Airflow rates in stationary turbine engine components typically exceed 2.3 kg/sec at elevated temperatures and pressures. In engine applications, as shown in the following photos, the survivability of PMC components is clearly a concern, especially when engine and component life-cycle requirements become longer. Although very few publications regarding the performance of erosion coatings on PMC's are available particularly in high-temperature applications the use of erosion-resistant coatings to significantly reduce wear on metallic substrates is well documented. In this study initiated by the NASA Glenn Research Center at Lewis Field, a low-cost (less than $140/kg) graphite-fiber-reinforced T650 35/PMR 15 sheet-molding compound was investigated with various coatings. This sheet-molding compound has been compression molded into many structurally complicated components, such as shrouds for gas turbine inlet housings and gearboxes. Erosion coatings developed for PMC s in this study consisted of a two-layered system: a bondcoat sprayed onto a cleaned PMC surface, followed by an erosion-resistant, hard topcoat sprayed onto the bondcoat as shown in following photomicrograph. Six erosion coating systems were evaluated for their ability to withstand harsh thermal cycles, erosion resistance (ASTM G76 83 "Standard Practice for Conducting Erosion Tests by Solid Particle Impingement Using Gas Jets") using Al2O3, and adhesion to the graphite fiber polyimide

  7. High Thermal Conductivity Polymer Matrix Composites (PMC) for Advanced Space Radiators

    Science.gov (United States)

    Shin, E. Eugene; Bowman, Cheryl; Beach, Duane

    2007-01-01

    High temperature polymer matrix composites (PMC) reinforced with high thermal conductivity (approx. 1000 W/mK) pitch-based carbon fibers are evaluated for a facesheet/fin structure of large space radiator systems. Significant weight reductions along with improved thermal performance, structural integrity and space durability toward its metallic counterparts were envisioned. Candidate commercial resin systems including Cyanate Esters, BMIs, and polyimide were selected based on thermal capabilities and processability. PMC laminates were designed to match the thermal expansion coefficient of various metal heat pipes or tubes. Large, but thin composite panels were successfully fabricated after optimizing cure conditions. Space durability of PMC with potential degradation mechanisms was assessed by simulated thermal aging tests in high vacuum, 1-3 x 10(exp -6) torr, at three temperatures, 227 C, 277 C, and 316 C for up to one year. Nanocomposites with vapor-grown carbon nano-fibers and exfoliated graphite flakes were attempted to improve thermal conductivity (TC) and microcracking resistance. Good quality nanocomposites were fabricated and evaluated for TC and durability including radiation resistance. TC was measured in both in-plan and thru-the-thickness directions, and the effects of microcracks on TC are also being evaluated. This paper will discuss the systematic experimental approaches, various performance-durability evaluations, and current subcomponent design and fabrication/manufacturing efforts.

  8. Electron beam processing of polymers and composites

    International Nuclear Information System (INIS)

    Singh, R. P.

    1994-01-01

    Electron beam processing has emerged as one of the foremost techniques for surface treatment of materials. Recently polymers and advanced composites are being treated with the electron beams of 1-10 MeV. In polymers the surface improvement is caused by radiation curing, cross linking and grafting. It has made inroads in vital sector of plastic industries in industrially advanced countries. Advanced composites can also be cured at ambient temperatures thus avoiding emission of volatiles during curing. Details of all these aspects of electron beam processing of polymers and composites are given. (author). 9 refs., 1 fig

  9. Precursor polymer compositions comprising polybenzimidazole

    Energy Technology Data Exchange (ETDEWEB)

    Klaehn, John R.; Peterson, Eric S.; Orme, Christopher J.

    2015-07-14

    Stable, high performance polymer compositions including polybenzimidazole (PBI) and a melamine-formaldehyde polymer, such as methylated, poly(melamine-co-formaldehyde), for forming structures such as films, fibers and bulky structures. The polymer compositions may be formed by combining polybenzimidazole with the melamine-formaldehyde polymer to form a precursor. The polybenzimidazole may be reacted and/or intertwined with the melamine-formaldehyde polymer to form the polymer composition. For example, a stable, free-standing film having a thickness of, for example, between about 5 .mu.m and about 30 .mu.m may be formed from the polymer composition. Such films may be used as gas separation membranes and may be submerged into water for extended periods without crazing and cracking. The polymer composition may also be used as a coating on substrates, such as metal and ceramics, or may be used for spinning fibers. Precursors for forming such polymer compositions are also disclosed.

  10. Study of improved resins for advanced supersonic technology composites. Part 1: Heteroaromatic polymers containing ether groups. Part 2: Curing chemistry of aromatic polymers and composite studies

    Science.gov (United States)

    Takekoshi, T.; Hillig, W. B.; Mellinger, G. A.

    1975-01-01

    Fourteen ether-containing, aromatic dianhydrides have been synthesized from N-phenyl-3 or 4-nitrophthalimide and various bisphenols. The process involves nucleophilic displacement of activated nitro groups with bisphenolate ions. Ether-containing dianhydrides were indefinitely stable in the presence of atmospheric moisture. One-step, high temperature solution polymerization of the ether-containing dianhydrides with m-phenylene diamine, 4,4'-oxydianiline and 1, 3-bis(4-aminophenoxy)benzene afforded 42 polyetherimides. The polyetherimides were all soluble in m-cresol except two which were found to be crystalline. The glass transition temperatures of the polyetherimides ranged from 178 to 277 C. Soluble polybenzimidazopyrrolones containing ether groups were also prepared from the same ether-containing dianhydrides and aromatic tetraamines by one-step solution polymerization. Using low molecular weight polyetherimides, various thermoset resin systems were developed and tested as matrices for fiber-reinforced composites. The curing chemistry involving reaction of the phthalonitrile group and the o-diaminophenyl group was found to be generally applicable to crosslinking various aromatic polymers other than polyimides.

  11. Conductive Polymer Composites

    OpenAIRE

    Pierini, Filippo

    2013-01-01

    In recent years, nanotechnologies have led to the production of materials with new and sometimes unexpected qualities through the manipulation of nanoscale components. This research aimed primarily to the study of the correlation between hierarchical structures of hybrid organic-inorganic materials such as conductive polymer composites (CPCs). Using a bottom-up methodology, we could synthesize a wide range of inorganic nanometric materials with a high degree of homogeneity and purity, ...

  12. Application of Composite Polymer Electrolytes

    National Research Council Canada - National Science Library

    Scrosati, Bruno

    2001-01-01

    ...)PEO-based composite polymer electrolytes, by a series of specifically addressed electrochemical tests which included the determination of the conductivity and of the lithium transference number...

  13. Wear of polymers and composites

    CERN Document Server

    Abdelbary, Ahmed

    2015-01-01

    In the field of tribology, the wear behaviour of polymers and composite materials is considered a highly non-linear phenomenon. Wear of Polymers and Composites introduces fundamentals of polymers and composites tribology. The book suggests a new approach to explore the effect of applied load and surface defects on the fatigue wear behaviour of polymers, using a new tribometer and thorough experiments. It discusses effects of surface cracks, under different static and cyclic loading parameters on wear, and presents an intelligent algorithm, in the form of a neural network, to map the relations

  14. Wood and concrete polymer composites

    International Nuclear Information System (INIS)

    Singer, K.

    1974-01-01

    There are several ways to prepare and use wood and concrete polymer composites. The most important improvements in the case of concrete polymer composites are obtained for compressive and tensile strengths. The progress in this field in United States and other countries is discussed in this rview. (M.S.)

  15. Multilayer Electroactive Polymer Composite Material

    Science.gov (United States)

    Ounaies, Zoubeida (Inventor); Park, Cheol (Inventor); Harrison, Joycelyn S. (Inventor); Holloway, Nancy M. (Inventor); Draughon, Gregory K. (Inventor)

    2011-01-01

    An electroactive material comprises multiple layers of electroactive composite with each layer having unique dielectric, electrical and mechanical properties that define an electromechanical operation thereof when affected by an external stimulus. For example, each layer can be (i) a 2-phase composite made from a polymer with polarizable moieties and an effective amount of carbon nanotubes incorporated in the polymer for a predetermined electromechanical operation, or (ii) a 3-phase composite having the elements of the 2-phase composite and further including a third component of micro-sized to nano-sized particles of an electroactive ceramic incorporated in the polymer matrix.

  16. Advanced Polymer Processing Facility

    Energy Technology Data Exchange (ETDEWEB)

    Muenchausen, Ross E. [Los Alamos National Laboratory

    2012-07-25

    Some conclusions of this presentation are: (1) Radiation-assisted nanotechnology applications will continue to grow; (2) The APPF will provide a unique focus for radiolytic processing of nanomaterials in support of DOE-DP, other DOE and advanced manufacturing initiatives; (3) {gamma}, X-ray, e-beam and ion beam processing will increasingly be applied for 'green' manufacturing of nanomaterials and nanocomposites; and (4) Biomedical science and engineering may ultimately be the biggest application area for radiation-assisted nanotechnology development.

  17. Layered plasma polymer composite membranes

    Science.gov (United States)

    Babcock, Walter C.

    1994-01-01

    Layered plasma polymer composite fluid separation membranes are disclosed, which comprise alternating selective and permeable layers for a total of at least 2n layers, where n is .gtoreq.2 and is the number of selective layers.

  18. Graphene-polymer composites

    Science.gov (United States)

    Carotenuto, G.; Romeo, V.; Cannavaro, I.; Roncato, D.; Martorana, B.; Gosso, M.

    2012-09-01

    Graphene is a novel nanostructured material that can be conveniently used as filler for thermoplastic polymers or thermosetting resins, and the resulting nanocomposite material has unique mechanical and chemical/physical properties. Industrial production of graphene/polymer materials requires the availability of a chemical route to produce massive amount of graphene. Natural graphite flakes can be the best starting material for a bulk-production of graphene to be used in the polymeric nanocomposite preparation.

  19. Carbon nanotube-polymer composite actuators

    Science.gov (United States)

    Gennett, Thomas [Denver, CO; Raffaelle, Ryne P [Honeoye Falls, NY; Landi, Brian J [Rochester, NY; Heben, Michael J [Denver, CO

    2008-04-22

    The present invention discloses a carbon nanotube (SWNT)-polymer composite actuator and method to make such actuator. A series of uniform composites was prepared by dispersing purified single wall nanotubes with varying weight percents into a polymer matrix, followed by solution casting. The resulting nanotube-polymer composite was then successfully used to form a nanotube polymer actuator.

  20. Rice Husk Filled Polymer Composites

    Directory of Open Access Journals (Sweden)

    Reza Arjmandi

    2015-01-01

    Full Text Available Natural fibers from agricultural wastes are finding their importance in the polymer industry due to the many advantages such as their light weight, low cost and being environmentally friendly. Rice husk (RH is a natural sheath that forms around rice grains during their growth. As a type of natural fiber obtained from agroindustrial waste, RH can be used as filler in composites materials in various polymer matrices. This review paper is aimed at highlighting previous works of RH filled polymer composites to provide information for applications and further research in this area. Based on the information gathered, application of RH filled composites as alternative materials in building and construction is highly plausible with both light weight and low cost being their main driving forces. However, further investigations on physical and chemical treatment to further improve the interfacial adhesion with polymeric matrix are needed as fiber-polymer interaction is crucial in determining the final composite properties. Better understanding on how the used polymer blends as the matrix and secondary fillers may affect the properties would provide interesting areas to be explored.

  1. Polymer compositions and methods

    Energy Technology Data Exchange (ETDEWEB)

    Allen, Scott D.; Willkomm, Wayne R.

    2018-02-06

    The present invention encompasses polyurethane compositions comprising aliphatic polycarbonate chains. In one aspect, the present invention encompasses polyurethane foams, thermoplastics and elastomers derived from aliphatic polycarbonate polyols and polyisocyanates wherein the polyol chains contain a primary repeating unit having a structure: ##STR00001## In another aspect, the invention provides articles comprising the inventive foam and elastomer compositions as well as methods of making such compositions.

  2. Polymer compositions and methods

    Energy Technology Data Exchange (ETDEWEB)

    Allen, Scott D.; Willkomm, Wayne R.

    2016-09-27

    The present invention encompasses polyurethane compositions comprising aliphatic polycarbonate chains. In one aspect, the present invention encompasses polyurethane foams, thermoplastics and elastomers derived from aliphatic polycarbonate polyols and polyisocyanates wherein the polyol chains contain a primary repeating unit having a structure: ##STR00001## In another aspect, the invention provides articles comprising the inventive foam and elastomer compositions as well as methods of making such compositions.

  3. Shape-Memory Polymer Composites

    Science.gov (United States)

    Madbouly, Samy A.; Lendlein, Andreas

    The development of shape-memory polymer composites (SMPCs) enables high recovery stress levels as well as novel functions such as electrical conductivity, magnetism, and biofunctionality. In this review chapter the substantial enhancement in mechanical properties of shape-memory polymers (SMPs) by incorporating small amounts of stiff fillers will be highlighted exemplarily for clay and polyhedral oligomeric silsesquioxanes (POSS). Three different functions resulting from adding functional fillers to SMP-matrices will be introduced and discussed: magnetic SMPCs with different types of magnetic nanoparticles, conductive SMPCs based on carbon nanotubes (CNTs), carbon black (CB), short carbon fiber (SCF), and biofunctional SMPCs containing hydroxyapatite (HA). Indirect induction of the shape-memory effect (SME) was realized for magnetic and conductive SMPCs either by exposure to an alternating magnetic field or by application of electrical current. Major challenges in design and fundamental understanding of polymer composites are the complexity of the composite structure, and the relationship between structural parameters and properties/functions, which is essential for tailoring SMPCs for specific applications. Therefore the novel functions and enhanced properties of SMPCs will be described considering the micro-/nanostructural parameters, such as dimension, shape, distribution, volume fraction, and alignment of fillers as well as interfacial interaction between the polymer matrix and dispersed fillers. Finally, an outlook is given describing the future challenges of this exciting research field as well as potential applications including automotive, aerospace, sensors, and biomedical applications.

  4. Polymer-composite ball lightning.

    Science.gov (United States)

    Bychkov, V L

    2002-01-15

    Investigations into the state of ball lightning (BL) have been made, and both theory and experiments, related to so-called "polymer-composite" ball lightning, are presented. The properties of such a polymeric BL have been described and are that of a long-lived object capable of storing high energy. Results of experiments, starting with polymeric components in erosive gas discharge experiments, are described and discussed. The model of BL as a highly charged polymer-dielectric structure is described. According to this model BL appears as the result of the aggregation of natural polymers, such as lignin and cellulose, soot, polymeric silica and other natural dust particles. Its ability to glow is explained by the appearance over its perimeter of gas discharges near the highly charged BL surface, and electrical breakdown of some regions on the surface, consisting of polymerized and aggregated threads.

  5. Modelling anisotropic water transport in polymer composite ...

    Indian Academy of Sciences (India)

    and polymer composites were characterized. Parameters for Fickian diffusion and polymer relaxation models were determined by least-square curve fitting to the experimental data. Diffusion parameters of epoxy and vinyl ester resin were used as input during development of finite element (FE) model of polymer composite.

  6. Modelling anisotropic water transport in polymer composite

    Indian Academy of Sciences (India)

    This work reports anisotropic water transport in a polymer composite consisting of an epoxy matrix reinforced with aligned triangular bars made of vinyl ester. By gravimetric experiments, water diffusion in resin and polymer composites were characterized. Parameters for Fickian diffusion and polymer relaxation models were ...

  7. Modelling anisotropic water transport in polymer composite ...

    Indian Academy of Sciences (India)

    Abstract. This work reports anisotropic water transport in a polymer composite consisting of an epoxy matrix reinforced with aligned triangular bars made of vinyl ester. By gravimetric experiments, water diffusion in resin and polymer composites were characterized. Parameters for Fickian diffusion and polymer relaxation ...

  8. Fiber reinforced polymer composites for bridge structures

    Directory of Open Access Journals (Sweden)

    Alexandra CANTORIU

    2013-12-01

    Full Text Available Rapid advances in construction materials technology have led to the emergence of new materials with special properties, aiming at safety, economy and functionality of bridges structures. A class of structural materials which was originally developed many years ago, but recently caught the attention of engineers involved in the construction of bridges is fiber reinforced polymer composites. This paper provides an overview of fiber reinforced polymer composites used in bridge structures including types, properties, applications and future trends. The results of this study have revealed that this class of materials presents outstanding properties such as high specific strength, high fatigue and environmental resistance, lightweight, stiffness, magnetic transparency, highly cost-effective, and quick assembly, but in the same time high initial costs, lack of data on long-term field performance, low fire resistance. Fiber reinforced polymer composites were widely used in construction of different bridge structures such as: deck and tower, I-beams, tendons, cable stands and proved to be materials for future in this field.

  9. Composites incorporated a conductive polymer nanofiber network

    Science.gov (United States)

    Pozzo, Lilo Danielle; Newbloom, Gregory

    2017-04-11

    Methods of forming composites that incorporate networks of conductive polymer nanofibers are provided. Networks of less-than conductive polymers are first formed and then doped with a chemical dopant to provide networks of conductive polymers. The networks of conductive polymers are then incorporated into a matrix in order to improve the conductivity of the matrix. The formed composites are useful as conductive coatings for applications including electromagnetic energy management on exterior surfaces of vehicles.

  10. Asphaltenes-based polymer nano-composites

    Science.gov (United States)

    Bowen, III, Daniel E

    2013-12-17

    Inventive composite materials are provided. The composite is preferably a nano-composite, and comprises an asphaltene, or a mixture of asphaltenes, blended with a polymer. The polymer can be any polymer in need of altered properties, including those selected from the group consisting of epoxies, acrylics, urethanes, silicones, cyanoacrylates, vulcanized rubber, phenol-formaldehyde, melamine-formaldehyde, urea-formaldehyde, imides, esters, cyanate esters, allyl resins.

  11. Holistic High-Fidelity Modeling Strategy for Advanced Composites

    Data.gov (United States)

    National Aeronautics and Space Administration — Engineering demands of current and next generation aerospace vehicles dictate the use of state-of-the-art materials. Advanced Fiber-Reinforced Polymer Composites...

  12. Tribology of natural fiber polymer composites

    CERN Document Server

    Chand, N

    2008-01-01

    Environmental concerns are driving demand for bio-degradable materials such as plant-based natural fiber reinforced polymer composites. These composites are fast replacing conventional materials in many applications, especially in automobiles, where tribology (friction, lubrication and wear) is important. This book covers the availability and processing of natural fiber polymer composites and their structural, thermal, mechanical and, in particular, tribological properties.Chapter 1 discusses sources of natural fibers, their extraction and surface modification. It also reviews the ther

  13. Complex Multifunctional Polymer/Carbon-Nanotube Composites

    Science.gov (United States)

    Patel, Pritesh; Balasubramaniyam, Gobinath; Chen, Jian

    2009-01-01

    A methodology for developing complex multifunctional materials that consist of or contain polymer/carbon-nanotube composites has been conceived. As used here, "multifunctional" signifies having additional and/or enhanced physical properties that polymers or polymer-matrix composites would not ordinarily be expected to have. Such properties include useful amounts of electrical conductivity, increased thermal conductivity, and/or increased strength. In the present methodology, these properties are imparted to a given composite through the choice and processing of its polymeric and CNT constituents.

  14. Mechanics of biological polymer composites

    Science.gov (United States)

    Lomakin, Joseph

    2009-12-01

    Cartilage and cuticle are two natural materials capable of remarkable mechanical performance, especially considering the limitations on composition and processing conditions under which they are constructed. Their impressive properties are postulated to be a consequence of their complex multi-scale organization which has commonly been characterized by biochemical and microscopic methods. The objective of this dissertation is to overcome the limitations of such methods with mechanical analysis techniques generally reserved for the study of synthetic polymers. Methods for transient and dynamic mechanical analysis (DMA) of porcine TMJ disc sections and Tribolium castaneum and Tenebrio molitor elytral (modified forewing) cuticle were developed to characterize the mechanical performance of these biomaterials. The TMJ disc dynamic elastic modulus (E') was determined to be a strong function of disc orientation and pretension ranging from 700+/-240 kPa at (1g pretension) in the mediolateral direction to 73+/-8.5 MPa (150g preload) in the anteroposterior direction. Analogous mechanical testing was used to understand the relationship between composition and mechanical properties of beetle elytral cuticle at variable stages of maturation (tanning). Untanned elytra of both beetle species were ductile with a Young's modulus (E) of 44+/-8 MPa, but became brittle with an E of 2400+/-1100 MPa when fully tanned. Significantly, the E' of the TMJ disc and elytral cuticle exhibited a weak power law increase as a function of oscillation frequency. The exponent of the power law fit ( n) was determined to be a sensitive measure of molecular structure within these biomaterials. With increasing cuticular tanning, more so than with drying, the frequency dependence of cuticle E' diminished, suggesting cuticular cross-linking was an important component of tanning, as postulated by the quinone tanning hypothesis. The natural Black phenotype as well as TcADC iRNA suppressed Tribolium cuticle

  15. Irradiatable polymer composition with improved oxidation resistance

    International Nuclear Information System (INIS)

    Lyons, B.J.

    1977-01-01

    A method is described for the incorporation of a substantially insoluble organic phosphite into a polymer composition such as polyolefin polymers or ethylene copolymers to prevent oxidation of the polymer at elevated temperatures after radiation-induced crosslinking. The crosslinking is readily achieved without affecting the antioxidant properties of the organic phosphite. Particularly suitable organic compounds are derivatives of pentaerythritol, dipentaerythritol, and tripentaerythritol in cooncentrations of 1 to 3% of the mixture to be irradiated

  16. The advanced composition explorer

    International Nuclear Information System (INIS)

    Stone, E.C.; Burlaga, L.F.; Cummings, A.C.; Feldman, W.C.; Frain, W.E.; Geiss, J.; Gloeckler, G.; Gold, R.E.; Hovestadt, D.; Krimigis, S.M.; Mason, G.M.; McComas, D.; Mewaldt, R.A.; Simpson, J.A.; von Rosenvinge, T.T.; Wiedenbeck, M.E.

    1990-01-01

    The Advanced Composition Explorer (ACE) was recently selected as one of two new Explorer-class missions to be developed for launch during the mid-1990's ACE will observe particles of solar, interplanetary, interstellar, and galactic origins, spanning the energy range from that of the solar wind (∼1 keV/nucleon) to galactic cosmic ray energies (several hundred MeV/nucleon). Definitive studies will be made of the abundance of nearly all isotopes from H to Zn (1≤Z≤30), with exploratory isotope studies extending to Zr(Z=40). To accomplish this, the ACE payload includes six high-resolution spectrometers, each designed to provide the optimum charge, mass, or charge-state resolution in its particular energy range, and each having a geometry factor optimized for the expected flux levels, so as to provide a collecting power a factor of 10 to 1000 times greater than previous or planned experiments. The payload also includes several instruments of standard design that will monitor solar wind and magnetic field conditions and energetic H, He, and electron fluxes. We summarize here the scientific objectives, instrumentation, spacecraft, and mission approach that were defined for ACE during the Phase-A study period

  17. RAFT technology for the production of advanced photoresist polymers

    Science.gov (United States)

    Sheehan, Michael T.; Farnham, William B.; Okazaki, Hiroshi; Sounik, James R.; Clark, George

    2008-03-01

    Reversible Addition Fragmentation Chain Transfer (RAFT) technology has been developed for use in producing high yield low polydispersity (PD) polymers for many applications. RAFT technology is being used to produce low PD polymers and to allow control of the polymer architecture. A variety of polymers are being synthesized for use in advanced photoresists using this technique. By varying the RAFT reagent used we can modulate the system reactivity of the RAFT reagent and optimize it for use in acrylate or methacrylate monomer systems (193 and 193i photoresist polymers) or for use in styrenic monomer systems (248 nm photoresist polymers) to achieve PD as low as 1.05. RAFT polymerization technology also allows us to produce block copolymers using a wide variety of monomers. These block copolymers have been shown to be useful in self assembly polymer applications to produce unique and very small feature sizes. The mutual compatibilities of all the components within a single layer 193 photoresist are very important in order to achieve low LWR and low defect count. The advent of immersion imaging demands an additional element of protection at the solid/liquid interface. We have used RAFT technology to produce block copolymers comprising a random "resist" block with composition and size based on conventional dry photoresist materials, and a "low surface energy" block for use in 193i lithography. The relative block lengths and compositions may be varied to tune solution behavior, surface energy, contact angles, and solubility in developer. The use of this technique will be explored to produce polymers used in hydrophobic single layer resists as well as additives compatible with the main photoresist polymer.

  18. High temperature performance of polymer composites

    CERN Document Server

    Keller, Thomas

    2014-01-01

    The authors explain the changes in the thermophysical and thermomechanical properties of polymer composites under elevated temperatures and fire conditions. Using microscale physical and chemical concepts they allow researchers to find reliable solutions to their engineering needs on the macroscale. In a unique combination of experimental results and quantitative models, a framework is developed to realistically predict the behavior of a variety of polymer composite materials over a wide range of thermal and mechanical loads. In addition, the authors treat extreme fire scenarios up to more than 1000°C for two hours, presenting heat-protection methods to improve the fire resistance of composite materials and full-scale structural members, and discuss their performance after fire exposure. Thanks to the microscopic approach, the developed models are valid for a variety of polymer composites and structural members, making this work applicable to a wide audience, including materials scientists, polymer chemist...

  19. Microwave Processed Multifunctional Polymer Matrix Composites Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA has identified polymer matrix composites (PMCs) as a critical need for launch and in-space vehicles, but the significant costs of such materials limits their...

  20. Electromagnetic Characterization of Advanced Composites by Voxel-Based Inverse Methods, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The nondestructive characterization of advanced composites, such as carbon-fiber reinforced polymers (cfrp), by electromagnetic means is well established. What is...

  1. Drilling of polymer-matrix composites

    CERN Document Server

    Krishnaraj, Vijayan; Davim, J Paulo

    2013-01-01

    Polymeric composites are recognised as good candidates for structural components due to their inherent properties. However, they present several kinds of damages while creating holes for assembly. Delamination is considered the most serious damage since it reduces service life of the component. Thrust and delamination can be controlled by proper drill point geometry. Drilling at high speed is also a current requirement of the aerospace industry. This book focus on drilling of polymer matrix composites for aerospace and defence applications. The book presents introduction to machining of polymer composites and discusses drilling as a processing of composites.

  2. Mechanically stiff, electrically conductive composites of polymers and carbon nanotubes

    Science.gov (United States)

    Worsley, Marcus A.; Kucheyev, Sergei O.; Baumann, Theodore F.; Kuntz, Joshua D.; Satcher, Jr., Joe H.; Hamza, Alex V.

    2015-07-21

    Using SWNT-CA as scaffolds to fabricate stiff, highly conductive polymer (PDMS) composites. The SWNT-CA is immersing in a polymer resin to produce a SWNT-CA infiltrated with a polymer resin. The SWNT-CA infiltrated with a polymer resin is cured to produce the stiff and electrically conductive composite of carbon nanotube aerogel and polymer.

  3. Mechanically stiff, electrically conductive composites of polymers and carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Worsley, Marcus A.; Kucheyev, Sergei O.; Baumann, Theodore F.; Kuntz, Joshua D.; Satcher, Jr., Joe H.; Hamza, Alex V.

    2017-10-17

    Using SWNT-CA as scaffolds to fabricate stiff, highly conductive polymer (PDMS) composites. The SWNT-CA is immersing in a polymer resin to produce a SWNT-CA infiltrated with a polymer resin. The SWNT-CA infiltrated with a polymer resin is cured to produce the stiff and electrically conductive composite of carbon nanotube aerogel and polymer.

  4. Ferroelectric Polymer Composite with Enhanced Breakdown Strength

    Science.gov (United States)

    Han, Kuo; Gadinski, Matthew; Wang, Qing

    2013-03-01

    Numerous efforts have been made in the past decades to improve the energy storage capability of dielectric capacitors by incorporating ceramic addictives into polymers. Ferroelectric polymers have been particularly interesting as matrix for dielectric composites because of their highest dielectric permittivity and energy density. However, most polymer composites suffer from significantly reduced breakdown strength, which compromises the potential gain in energy density. In this work, various metallic alkoxide were introduced into the functionalized ferroelectric poly(vinylidene fluoride-co- chlorotrifluoroethylene), P(VDF-CTFE), via covalent bonding. The composite with the optimized composition exhibited the Weibull statistical breakdown strength of 504.8 MV/m, 67.6 % higher than the pristine polymer. The enhanced breakdown strength was mainly ascribed to the cross-linking and the formation of deep traps, which effectively reduced the conduction and further lowered the energy loss. Additionally, the homogeneous dispersion of the inorganic phase and the small contrast in permittivity between the polymer and amorphous oxides also contribute to the improved dielectric strength. The dielectric spectra of the composites have been recorded at varied temperatures and frequencies, which revealed the presence of the interfacial polarization layer in the composites.

  5. Polymer Composites Corrosive Degradation: A Computational Simulation

    Science.gov (United States)

    Chamis, Christos C.; Minnetyan, Levon

    2007-01-01

    A computational simulation of polymer composites corrosive durability is presented. The corrosive environment is assumed to manage the polymer composite degradation on a ply-by-ply basis. The degradation is correlated with a measured pH factor and is represented by voids, temperature and moisture which vary parabolically for voids and linearly for temperature and moisture through the laminate thickness. The simulation is performed by a computational composite mechanics computer code which includes micro, macro, combined stress failure and laminate theories. This accounts for starting the simulation from constitutive material properties and up to the laminate scale which exposes the laminate to the corrosive environment. Results obtained for one laminate indicate that the ply-by-ply degradation degrades the laminate to the last one or the last several plies. Results also demonstrate that the simulation is applicable to other polymer composite systems as well.

  6. Advanced technology composite aircraft structures

    Science.gov (United States)

    Ilcewicz, Larry B.; Walker, Thomas H.

    1991-01-01

    Work performed during the 25th month on NAS1-18889, Advanced Technology Composite Aircraft Structures, is summarized. The main objective of this program is to develop an integrated technology and demonstrate a confidence level that permits the cost- and weight-effective use of advanced composite materials in primary structures of future aircraft with the emphasis on pressurized fuselages. The period from 1-31 May 1991 is covered.

  7. Thermal Protective Coating for High Temperature Polymer Composites

    Science.gov (United States)

    Barron, Andrew R.

    1999-01-01

    The central theme of this research is the application of carboxylate-alumoxane nanoparticles as precursors to thermally protective coatings for high temperature polymer composites. In addition, we will investigate the application of carboxylate-alumoxane nanoparticle as a component to polymer composites. The objective of this research was the high temperature protection of polymer composites via novel chemistry. The significance of this research is the development of a low cost and highly flexible synthetic methodology, with a compatible processing technique, for the fabrication of high temperature polymer composites. We proposed to accomplish this broad goal through the use of a class of ceramic precursor material, alumoxanes. Alumoxanes are nano-particles with a boehmite-like structure and an organic periphery. The technical goals of this program are to prepare and evaluate water soluble carboxylate-alumoxane for the preparation of ceramic coatings on polymer substrates. Our proposed approach is attractive since proof of concept has been demonstrated under the NRA 96-LeRC-1 Technology for Advanced High Temperature Gas Turbine Engines, HITEMP Program. For example, carbon and Kevlar(tm) fibers and matting have been successfully coated with ceramic thermally protective layers.

  8. Polymer composites with plasmonic metal nanoparticles

    Czech Academy of Sciences Publication Activity Database

    Dammer, Ondřej; Vlčková, B.; Podhájecká, Klára; Procházka, M.; Pfleger, Jiří

    2008-01-01

    Roč. 268, č. 1 (2008), s. 91-95 ISSN 1022-1360. [Microsymposium on Advanced Polymer Materials for Photonics and Electronics /47./. Prague, 15.07.2007-19.07.2007] R&D Projects: GA AV ČR IAA4050406 Institutional research plan: CEZ:AV0Z40500505 Keywords : metal nanoparticles * nanocomposites * .pi.-conjugated polymers Subject RIV: CD - Macromolecular Chemistry

  9. Conductive polymer/metal composites for interconnect of flexible devices

    Science.gov (United States)

    Kawakita, Jin; Hashimoto Shinoda, Yasuo; Shuto, Takanori; Chikyow, Toyohiro

    2015-06-01

    An interconnect of flexible and foldable devices based on advanced electronics requires high electrical conductivity, flexibility, adhesiveness on a plastic substrate, and efficient productivity. In this study, we investigated the applicability of a conductive polymer/metal composite to the interconnect of flexible devices. By combining an inkjet process and a photochemical reaction, micropatterns of a polypyrrole/silver composite were formed on flexible plastic substrates with an average linewidth of approximately 70 µm within 10 min. The conductivity of the composite was improved to 6.0 × 102 Ω-1·cm-1. From these results, it is expected that the conducting polymer/metal composite can be applied to the microwiring of flexible electronic devices.

  10. PEO + PVP blended polymer composite

    Indian Academy of Sciences (India)

    Blended polymer films of polyethylene oxide + polyvinyl pyrrolidone (PEO + PVP) containing transition metal (TM) ions like Fe3+, Co2+ and Ni2+ have been synthesized by a solution casting method. For these films, structural, thermal, magnetic and optical properties have been studied. X-ray diffraction results reveal the ...

  11. Atomic Origins of the Self-Healing Function in Cement–Polymer Composites

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Manh Thuong; Wang, Zheming; Rod, Kenton A.; Childers, Matthew I.; Fernandez, Carlos A.; Koech, Phillip K.; Bennett, Wendy D.; Rousseau, Roger J.; Glezakou, Vassiliki-Alexandra

    2018-01-09

    Motivated by recent advances in self-healing cement and epoxy polymer composites, we present a combined ab initio molecular dynamics and sum frequency generation (SFG) spectroscopy study of a calcium-silicate-hydrate/polymer interface. On stable, low-defect surfaces, the polymer only weakly adheres through coordination and hydrogen bonding interactions and can be easily mobilized towards defected surfaces. Conversely, on fractured surfaces, the polymer strongly anchors through ionic Ca-O bonds resulting from the deprotonation of polymer hydroxyl groups. In addition, polymer S-S groups are turned away from the cement/polymer interface, allowing for the self-healing function within the polymer. The overall elasticity and healing properties of these composites stem from a flexible hydrogen bonding network that can readily adapt to surface morphology. The theoretical vibrational signals associated with the proposed cement-polymer interfacial chemistry were confirmed experimentally by SFG spectroscopy.

  12. Advances in mucoadhesion and mucoadhesive polymers.

    Science.gov (United States)

    Khutoryanskiy, Vitaliy V

    2011-06-14

    Mucoadhesion is the ability of materials to adhere to mucosal membranes in the human body and provide a temporary retention. This property has been widely used to develop polymeric dosage forms for buccal, oral, nasal, ocular and vaginal drug delivery. Excellent mucoadhesive properties are typical for hydrophilic polymers possessing charged groups and/or non-ionic functional groups capable of forming hydrogen bonds with mucosal surfaces. This feature article considers recent advances in the study of mucoadhesion and mucoadhesive polymers. It provides an overview on the structure of mucosal membranes, properties of mucus gels and the nature of mucoadhesion. It describes the most common methods to evaluate mucoadhesive properties of various dosage forms and discusses the main classes of mucoadhesives. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Polymer/Layered Silicate Nano composites

    International Nuclear Information System (INIS)

    Bakhit, M.E.E.H.

    2012-01-01

    Polymer–clay nano composites have attracted the attention of many researchers and experimental results are presented in a large number of recent papers and patents because of the outstanding mechanical properties and low gas permeabilities that are achieved in many cases. Polymer-clay nano composites are a new class of mineral-field polymer that contain relatively small amounts (<10%) of nanometer-sized clay particles. Polymer/clay nano composites have their origin in the pioneering research conducted at Toyota Central Research Laboratories and the first historical record goes back to 1987. The matrix was nylon-6 and the filler MMT. Because of its many advantages such as high mechanical properties, good gas barrier, flame retardation, etc. polymer/clay nano composites have been intensely investigated and is currently the subject of many research programs. Nano composite materials are commercially important and several types of products with different shapes and applications including food packaging films and containers, engine parts, dental materials, etc. are now available in markets. A number of synthesis routes have been developed in the recent years to prepare these materials, which include intercalation of polymers or prepolymers from solution, in-situ polymerization, melt intercalation etc. In this study, new nano composite materials were produced from the components of rubber (Nbr, SBR and EPDM) as the polymeric matrix and organically modified quaternary alkylammonium montmorillonite in different contents (3, 5, 7, and 10 phr) as the filler by using an extruder then, the rubber nano composite sheets were irradiated at a dose of 0, 50, 75, 100 and 150 KGy using Electron beam Irradiation technique as a crosslinking agent. These new materials can be characterized by using various analytical techniques including X-ray diffractometer XRD, Thermogravimetric analyzer TGA, scanning electron microscope (SEM), transmission electron microscope (TEM),Fourier transform

  14. New Fabrication Technique of Conductive Polymer / Insulating Polymer Composite Films

    Science.gov (United States)

    Abe, Yayoi; Mathur, Paramatma Chandra; Bhatnagar, Pramod Kumar; Tada, Kazuya; Onoda, Mitsuyoshi

    The electrochemical polymerization of pyrrole on an ITO (indium-tin oxide) coated glass electrode with an insulating film of poly(vinyl alcohol), PVA produces a flexible composite polymer film with electrical, optical and electrochemical properties very similar to polypyrrole (PPy). The rate of electrochemical polymerization depends on the diffusion of the electrolyte across the PVA film to the ITO electrode. Especially, the solvent with hydrophilic nature easily penetrates into the PVA film. By applying this new process, we demonstrate a unique method to form electrically conductive pattern in PVA film. It will be possible to develop electrodes for electrical stimulation of the nervous system using conducting polymer, PPy. Then, by using similar technique we have fabricated poly (3,4-ethylenedioxythiophene), PEDOT/PVA composite films and investigated their electrochemical basic properties.

  15. Self healing in polymers and polymer composites. Concepts, realization and outlook: A review

    Directory of Open Access Journals (Sweden)

    2008-04-01

    Full Text Available Formation of microcracks is a critical problem in polymers and polymer composites during their service in structural applications. Development and coalescence of microcracks would bring about catastrophic failure of the materials and then reduce their lifetimes. Therefore, early sensing, diagnosis and repair of microcracks become necessary for removing the latent perils. In this context, the materials possessing self-healing function are ideal for long-term operation. Self-repairing polymers and polymer composites have attracted increasing research interests. Attempts have been made to develop solutions in this field. The present article reviews state-of-art of the achievements on the topic. According to the ways of healing, the smart materials are classified into two categories: (i intrinsic self-healing ones that are able to heal cracks by the polymers themselves, and (ii extrinsic in which healing agent has to be pre-embedded. The advances in this field show that selection and optimization of proper repair mechanisms are prerequisites for high healing efficiency. It is a challenging job to either invent new polymers with inherent crack repair capability or integrate existing materials with novel healing system.

  16. Electron beam curing of polymer matrix composites

    International Nuclear Information System (INIS)

    Janke, C.J.; Wheeler, D.; Saunders, C.

    1998-01-01

    The purpose of the CRADA was to conduct research and development activities to better understand and utilize the electron beam PMC curing technology. This technology will be used to replace or supplement existing PMC thermal curing processes in Department of Energy (DOE) Defense Programs (DP) projects and American aircraft and aerospace industries. This effort involved Lockheed Martin Energy Systems, Inc./Lockheed Martin Energy Research Corp. (Contractor), Sandia National Laboratories, and ten industrial Participants including four major aircraft and aerospace companies, three advanced materials companies, and three electron beam processing organizations. The technical objective of the CRADA was to synthesize and/or modify high performance, electron beam curable materials that meet specific end-use application requirements. There were six tasks in this CRADA including: Electron beam materials development; Electron beam database development; Economic analysis; Low-cost Electron Beam tooling development; Electron beam curing systems integration; and Demonstration articles/prototype structures development. The contractor managed, participated and integrated all the tasks, and optimized the project efforts through the coordination, exchange, and dissemination of information to the project participants. Members of the Contractor team were also the principal inventors on several electron beam related patents and a 1997 R and D 100 Award winner on Electron-Beam-Curable Cationic Epoxy Resins. The CRADA achieved a major breakthrough for the composites industry by having successfully developed high-performance electron beam curable cationic epoxy resins for use in composites, adhesives, tooling compounds, potting compounds, syntactic foams, etc. UCB Chemicals, the world's largest supplier of radiation-curable polymers, has acquired a license to produce and sell these resins worldwide

  17. Method of making metal-polymer composite catalysts

    Science.gov (United States)

    Zelena, Piotr [Los Alamos, NM; Bashyam, Rajesh [Los Alamos, NM

    2009-06-23

    A metal-polymer-carbon composite catalyst for use as a cathode electrocatalyst in fuel cells. The catalyst includes a heteroatomic polymer; a transition metal linked to the heteroatomic polymer by one of nitrogen, sulfur, and phosphorus, and a recast ionomer dispersed throughout the heteroatomic polymer-carbon composite. The method includes forming a heteroatomic polymer-carbon composite and loading the transition metal onto the composite. The invention also provides a method of making a membrane electrode assembly for a fuel cell that includes the metal-polymer-carbon composite catalyst.

  18. Mechanical properties of glass polymer multilayer composite

    Indian Academy of Sciences (India)

    Unknown

    Mechanical properties of glass polymer multilayer composite. A SEAL, N R BOSE, S K DALUI, A K MUKHOPADHYAY*, K K PHANI and. H S MAITI. Central Glass and Ceramic Research Institute, Kolkata 700 032, India. Abstract. The preliminary experimental studies on the comparative behaviour of the deformation ...

  19. Diamond structures grown from polymer composite nanofibers

    Czech Academy of Sciences Publication Activity Database

    Potocký, Štěpán; Kromka, Alexander; Babchenko, Oleg; Rezek, Bohuslav; Martinová, L.; Pokorný, P.

    2013-01-01

    Roč. 5, č. 6 (2013), s. 519-521 ISSN 2164-6627 R&D Projects: GA ČR GAP108/12/0910; GA ČR GAP205/12/0908 Institutional support: RVO:68378271 Keywords : chemical vapour deposition * composite polymer * nanocrystalline diamond * nanofiber sheet * SEM Subject RIV: BM - Solid Matter Physics ; Magnetism

  20. Piezoresistive polymer composites for cantilever readout

    DEFF Research Database (Denmark)

    Lillemose, Michael

    concentrations. No signicant piezoresistive eect was observed for the silver nanoparticle doped composites. Thin lm structures of the intrinsically conductive polymer, polyaniline, have been fabricated and a negative piezoresistive eect was observed. Thin gold lms were investigated, with the aim of measuring...

  1. Composite Polymer-Garnet Solid State Electrolytes

    Science.gov (United States)

    Villa, Andres; Oduncu, Muhammed R.; Scofield, Gregory D.; Marinero, Ernesto E.; Forbey, Scott

    Solid-state electrolytes provide a potential solution to the safety and reliability issues of Li-ion batteries. We have synthesized cubic-phase Li7-xLa3Zr2-xBixO12 compounds utilizing inexpensive, scalable Sol-gel synthesis and obtained ionic conductivities 1.2 x 10-4 S/cm at RT in not-fully densified pellets. In this work we report on the fabrication of composite polymer-garnet ceramic particle electrolytes to produce flexible membranes that can be integrated with standard battery electrodes without the need for a separator. As a first step we incorporated the ceramic particles into polyethylene oxide polymers (PEO) to form flexible membranes. Early results are encouraging yielding ionic conductivity values 1.0 x 10-5 S/cm at RT. To increment the conductivity in the membranes, we are optimizing amongst other: the ceramic particle size distribution and weight load, the polymer molecular weight and chemical composition and the solvated Li-salt composition and content. Unhindered ion transport across interfaces between the composites and the battery electrode materials is paramount for battery performance. To this end, we are investigating the effect of interface morphology, its atomic composition and exploring novel electrode structures that facilitate ionic transport.

  2. Chemical microsensors based on polymer fiber composites

    Science.gov (United States)

    Kessick, Royal F.; Levit, Natalia; Tepper, Gary C.

    2005-05-01

    There is an urgent need for new chemical sensors for defense and security applications. In particular, sensors are required that can provide higher sensitivity and faster response in the field than existing baseline technologies. We have been developing a new solid-state chemical sensor technology based on microscale polymer composite fiber arrays. The fibers consist of an insulating polymer doped with conducting particles and are electrospun directly onto the surface of an interdigitated microelectrode. The concentration of the conducting particles within the fiber is controlled and is near the percolation threshold. Thus, the electrical resistance of the polymer fiber composite is very sensitive to volumetric changes produced in the polymer by vapor absorption. Preliminary results are presented on the fabrication and testing of the new microsensor. The objective is to take advantage of the very high surface to volume ratio, low thermal mass and linear geometry of the composite fibers to produce sensors exhibiting an extremely high vapor sensitivity and rapid response. The simplicity and low cost of a resistance-based chemical microsensor makes this sensing approach an attractive alternative to devices requiring RF electronics or time-of-flight analysis. Potential applications of this technology include battlespace awareness, homeland security, environmental surveillance, medical diagnostics and food process monitoring.

  3. Characterizing SWCNT Dispersion in Polymer Composites

    Science.gov (United States)

    Lillehei, Peter T.; Kim, Jae-Woo; Gibbons, Luke; Park, Cheol

    2007-01-01

    The new wave of single wall carbon nanotube (SWCNT) infused composites will yield structurally sound multifunctional nanomaterials. The SWCNT network requires thorough dispersion within the polymer matrix in order to maximize the benefits of the nanomaterial. However, before any nanomaterials can be used in aerospace applications a means of quality assurance and quality control must be certified. Quality control certification requires a means of quantification, however, the measurement protocol mandates a method of seeing the dispersion first. We describe here the new tools that we have developed and implemented to first be able to see carbon nanotubes in polymers and second to measure or quantify the dispersion of the nanotubes.

  4. Polymer compositions, polymer films and methods and precursors for forming same

    Science.gov (United States)

    Klaehn, John R; Peterson, Eric S; Orme, Christopher J

    2013-09-24

    Stable, high performance polymer compositions including polybenzimidazole (PBI) and a melamine-formaldehyde polymer, such as methylated, poly(melamine-co-formaldehyde), for forming structures such as films, fibers and bulky structures. The polymer compositions may be formed by combining polybenzimidazole with the melamine-formaldehyde polymer to form a precursor. The polybenzimidazole may be reacted and/or intertwined with the melamine-formaldehyde polymer to form the polymer composition. For example, a stable, free-standing film having a thickness of, for example, between about 5 .mu.m and about 30 .mu.m may be formed from the polymer composition. Such films may be used as gas separation membranes and may be submerged into water for extended periods without crazing and cracking. The polymer composition may also be used as a coating on substrates, such as metal and ceramics, or may be used for spinning fibers. Precursors for forming such polymer compositions are also disclosed.

  5. Mechanical Properties of Polymer Nano-composites

    Science.gov (United States)

    Srivastava, Iti

    Thermoset polymer composites are increasingly important in high-performance engineering industries due to their light-weight and high specific strength, finding cutting-edge applications such as aircraft fuselage material and automobile parts. Epoxy is the most widely employed thermoset polymer, but is brittle due to extensive cross-linking and notch sensitivity, necessitating mechanical property studies especially fracture toughness and fatigue resistance, to ameliorate the low crack resistance. Towards this end, various nano and micro fillers have been used with epoxy to form composite materials. Particularly for nano-fillers, the 1-100 nm scale dimensions lead to fascinating mechanical properties, oftentimes proving superior to the epoxy matrix. The chemical nature, topology, mechanical properties and geometry of the nano-fillers have a profound influence on nano-composite behavior and hence are studied in the context of enhancing properties and understanding reinforcement mechanisms in polymer matrix nano-composites. Using carbon nanotubes (CNTs) as polymer filler, uniquely results in both increased stiffness as well as toughness, leading to extensive research on their applications. Though CNTs-polymer nano-composites offer better mechanical properties, at high stress amplitude their fatigue resistance is lost. In this work covalent functionalization of CNTs has been found to have a profound impact on mechanical properties of the CNT-epoxy nano-composite. Amine treated CNTs were found to give rise to effective fatigue resistance throughout the whole range of stress intensity factor, in addition to significantly enhancing fracture toughness, ductility, Young's modulus and average hardness of the nano-composite by factors of 57%, 60%, 30% and 45% respectively over the matrix as a result of diminished localized cross-linking. Graphene, a one-atom-thick sheet of atoms is a carbon allotrope, which has garnered significant attention of the scientific community and is

  6. Smooth Nanowire/Polymer Composite Transparent Electrodes

    KAUST Repository

    Gaynor, Whitney

    2011-04-29

    Smooth composite transparent electrodes are fabricated via lamination of silver nanowires into the polymer poly-(4,3-ethylene dioxythiophene): poly(styrene-sulfonate) (PEDOT:PSS). The surface roughness is dramatically reduced compared to bare nanowires. High-efficiency P3HT:PCBM organic photovoltaic cells can be fabricated using these composites, reproducing the performance of cells on indium tin oxide (ITO) on glass and improving the performance of cells on ITO on plastic. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Microwave Measurements of Ferrite Polymer Composite Materials

    Directory of Open Access Journals (Sweden)

    Rastislav Dosoudil

    2004-01-01

    Full Text Available The article focuses on the microwave measurements performed on the nickel-zinc sintered ferrite with the chemical formula Ni0.3Zn0.7Fe2O4 produced by the ceramic technique and composite materials based on this ferrite and a non-magnetic polymer (polyvinyl chloride matrix. The prepared composite samples had the same particle size distribution 0-250um but different ferrite particle concentrations between 23 vol% and 80 vol%. The apparatus for measurement of the signal proportional to the absolute value of scattering parameter S11 (reflexion coefficient is described and the dependence of measured reflected signal on a bias magnetic field has been studied. By means of experiments, the resonances to be connected with the geometry of microwave experimental set-up were distinguished from ferromagnetic resonance arising in ferrite particles of composite structure. The role of local interaction fields of ferrite particles in composite material has been discussed.

  8. Durable polymer-aerogel based superhydrophobic coatings, a composite material

    Science.gov (United States)

    Kissel, David J; Brinker, Charles Jeffrey

    2014-03-04

    Provided are polymer-aerogel composite coatings, devices and articles including polymer-aerogel composite coatings, and methods for preparing the polymer-aerogel composite. The exemplary article can include a surface, wherein the surface includes at least one region and a polymer-aerogel composite coating disposed over the at least one region, wherein the polymer-aerogel composite coating has a water contact angle of at least about 140.degree. and a contact angle hysteresis of less than about 1.degree.. The polymer-aerogel composite coating can include a polymer and an ultra high water content catalyzed polysilicate aerogel, the polysilicate aerogel including a three dimensional network of silica particles having surface functional groups derivatized with a silylating agent and a plurality of pores.

  9. Durable polymer-aerogel based superhydrophobic coatings: a composite material

    Science.gov (United States)

    Kissel, David J.; Brinker, Charles Jeffrey

    2016-02-02

    Provided are polymer-aerogel composite coatings, devices and articles including polymer-aerogel composite coatings, and methods for preparing the polymer-aerogel composite. The exemplary article can include a surface, wherein the surface includes at least one region and a polymer-aerogel composite coating disposed over the at least one region, wherein the polymer-aerogel composite coating has a water contact angle of at least about 140.degree. and a contact angle hysteresis of less than about 1.degree.. The polymer-aerogel composite coating can include a polymer and an ultra high water content catalyzed polysilicate aerogel, the polysilicate aerogel including a three dimensional network of silica particles having surface functional groups derivatized with a silylating agent and a plurality of pores.

  10. Phase stability and dynamics of entangled polymer-nanoparticle composites.

    KAUST Repository

    Mangal, Rahul

    2015-06-05

    Nanoparticle-polymer composites, or polymer-nanoparticle composites (PNCs), exhibit unusual mechanical and dynamical features when the particle size approaches the random coil dimensions of the host polymer. Here, we harness favourable enthalpic interactions between particle-tethered and free, host polymer chains to create model PNCs, in which spherical nanoparticles are uniformly dispersed in high molecular weight entangled polymers. Investigation of the mechanical properties of these model PNCs reveals that the nanoparticles have profound effects on the host polymer motions on all timescales. On short timescales, nanoparticles slow-down local dynamics of the host polymer segments and lower the glass transition temperature. On intermediate timescales, where polymer chain motion is typically constrained by entanglements with surrounding molecules, nanoparticles provide additional constraints, which lead to an early onset of entangled polymer dynamics. Finally, on long timescales, nanoparticles produce an apparent speeding up of relaxation of their polymer host.

  11. Modified glass fibre reinforced polymer composites

    Science.gov (United States)

    Cao, Yumei

    A high ratio of strength to density and relatively low-cost are some of the significant features of glass fibre reinforced polymer composites (GFRPCs) that made them one of the most rapidly developed materials in recent years. They are widely used as the material of construction in the areas of aerospace, marine and everyday life, such as airplane, helicopter, boat, canoe, fishing rod, racket, etc. Traditionally, researchers tried to raise the mechanical properties and keep a high strength/weight ratio using all or some of the following methods: increasing the volume fraction of the fibre; using different polymeric matrix material; or changing the curing conditions. In recent years, some new techniques and processing methods were developed to further improve the mechanical properties of glass fibre (GF) reinforced polymer composite. For example, by modifying the surface condition of the GF, both the interface strength between the GF and the polymer matrix and the shear strength of the final composite can be significantly increased. Also, by prestressing the fibre during the curing process of the composite, the tensile, flexural and the impact properties of the composite can be greatly improved. In this research project, a new method of preparing GFRPCs, which combined several traditional and modern techniques together, was developed. This new method includes modification of the surface of the GF with silica particles, application of different levels of prestressing on the GF during the curing process, and the change of the fibre volume fraction and curing conditions in different sets of experiments. The results of the new processing were tested by the three-point bend test, the short beam shear test and the impact test to determine the new set of properties so formed in the composite material. Scanning electronic microscopy (SEM) was used to study the fracture surface of the new materials after the mechanical tests were performed. By taking advantages of the

  12. Magnetic polymer composite artificial bacterial flagella

    International Nuclear Information System (INIS)

    Peyer, K E; Siringil, E; Nelson, B J; Zhang, L

    2014-01-01

    Artificial bacterial flagella (ABFs) are magnetically actuated swimming microrobots inspired by Escherichia coli bacteria, which use a helical tail for propulsion. The ABFs presented are fabricated from a magnetic polymer composite (MPC) containing iron-oxide nanoparticles embedded in an SU-8 polymer that is shaped into a helix by direct laser writing. The paper discusses the swim performance of MPC ABFs fabricated with varying helicity angles. The locomotion model presented contains the fluidic drag of the microrobot, which is calculated based on the resistive force theory. The robot’s magnetization is approximated by an analytical model for a soft-magnetic ellipsoid. The helicity angle influences the fluidic and magnetic properties of the robot, and it is shown that weakly magnetized robots prefer a small helicity angle to achieve corkscrew-type motion. (paper)

  13. Characterization of Hybrid CNT Polymer Matrix Composites

    Science.gov (United States)

    Grimsley, Brian W.; Cano, Roberto J.; Kinney, Megan C.; Pressley, James; Sauti, Godfrey; Czabaj, Michael W.; Kim, Jae-Woo; Siochi, Emilie J.

    2015-01-01

    Carbon nanotubes (CNTs) have been studied extensively since their discovery and demonstrated at the nanoscale superior mechanical, electrical and thermal properties in comparison to micro and macro scale properties of conventional engineering materials. This combination of properties suggests their potential to enhance multi-functionality of composites in regions of primary structures on aerospace vehicles where lightweight materials with improved thermal and electrical conductivity are desirable. In this study, hybrid multifunctional polymer matrix composites were fabricated by interleaving layers of CNT sheets into Hexcel® IM7/8552 prepreg, a well-characterized toughened epoxy carbon fiber reinforced polymer (CFRP) composite. The resin content of these interleaved CNT sheets, as well as ply stacking location were varied to determine the effects on the electrical, thermal, and mechanical performance of the composites. The direct-current electrical conductivity of the hybrid CNT composites was characterized by in-line and Montgomery four-probe methods. For [0](sub 20) laminates containing a single layer of CNT sheet between each ply of IM7/8552, in-plane electrical conductivity of the hybrid laminate increased significantly, while in-plane thermal conductivity increased only slightly in comparison to the control IM7/8552 laminates. Photo-microscopy and short beam shear (SBS) strength tests were used to characterize the consolidation quality of the fabricated laminates. Hybrid panels fabricated without any pretreatment of the CNT sheets resulted in a SBS strength reduction of 70 percent. Aligning the tubes and pre-infusing the CNT sheets with resin significantly improved the SBS strength of the hybrid composite To determine the cause of this performance reduction, Mode I and Mode II fracture toughness of the CNT sheet to CFRP interface was characterized by double cantilever beam (DCB) and end notch flexure (ENF) testing, respectively. Results are compared to the

  14. Polymers as advanced materials for desiccant applications

    Energy Technology Data Exchange (ETDEWEB)

    Czanderna, A.W.

    1990-12-01

    This research is concerned with solid materials used as desiccants for desiccant cooling systems (DCSs) that process water vapor in an atmosphere to produce cooling. Background information includes an introduction to DCSs and the role of the desiccant as a system component. The water vapor sorption performance criteria used for screening the modified polymers prepared include the water sorption capacity from 5% to 80% relative humidity (R.H.), isotherm shape, and rate of adsorption and desorption. Measurements are presented for the sorption performance of modified polymeric advanced desiccant materials with the quartz crystal microbalance. Isotherms of polystyrene sulfonic acid (PSSA) taken over a 5-month period show that the material has a dramatic loss in capacity and that the isotherm shape is time dependent. The adsorption and desorption kinetics for PSSA and all the ionic salts of it studied are easily fast enough for commercial DCS applications with a wheel rotation speed of 6 min per revolution. Future activities for the project are addressed, and a 5-year summary of the project is included as Appendix A. 34 refs., 20 figs., 3 tabs.

  15. Hyperbranched polymers: advances from synthesis to applications.

    Science.gov (United States)

    Zheng, Yaochen; Li, Sipei; Weng, Zhulin; Gao, Chao

    2015-06-21

    Hyperbranched polymers (HPs) are highly branched three-dimensional (3D) macromolecules. Their globular and dendritic architectures endow them with unique structures and properties such as abundant functional groups, intramolecular cavities, low viscosity, and high solubility. HPs can be facilely synthesized via a one-pot polymerization of traditional small molecular monomers or emerging macromonomers. The great development in synthetic strategies, from click polymerization (i.e., copper-catalyzed azide-alkyne cycloaddition, metal-free azide-alkyne cycloaddition, strain-promoted azide-alkyne cycloaddition, thiol-ene/yne addition, Diels-Alder cycloaddition, Menschutkin reaction, and aza-Michael addition) to recently reported multicomponent reactions, gives rise to diverse HPs with desirable functional/hetero-functional groups and topologies such as segmented or sequential ones. Benefiting from tailorable structures and correspondingly special properties, the achieved HPs have been widely applied in various fields such as light-emitting materials, nanoscience and technology, supramolecular chemistry, biomaterials, hybrid materials and composites, coatings, adhesives, and modifiers. In this review, we mainly focus on the progress in the structural control, synthesis, functionalization, and potential applications of both conventional and segmented HPs reported over the last decade.

  16. Nanotube/Polymer Composites: Materials Selection and Process Design

    National Research Council Canada - National Science Library

    Winey, Karen

    2004-01-01

    ...) define processing methods most appropriate for the materials identified. Our study of SWNT-polymer composites focuses on thermoplastics, because these materials can be readily drawn into fibers...

  17. Constitutive Behavior and Damage Characterization of High Temperature Polymer Composites

    National Research Council Canada - National Science Library

    Daniel, Isaac

    2001-01-01

    The objective of this investigation was to characterize the constitutive behavior, physical aging, damage mechanisms and damage development in high temperature polymer matrix composites under various...

  18. Advanced composites take a powder

    Energy Technology Data Exchange (ETDEWEB)

    Holty, D.W. (Custom Composite Materials, Inc., Atlanta, GA (United States))

    1993-06-01

    To a professional chemist with more than 25 years of industrial experience, the world of advanced composites is a fascinating new venue. Here resins and fibers come together in a completely synergistic partnership, achieving marvels of strength and light weight that make advanced composite materials virtually the only solution for challenging applications. In the late 1980s, Professor John Muzzy of the Georgia Institute of Technology, was intrigued by the physical properties of thermoplastics, and he developed a new way to bring the thermoplastic resins together with high-performance fibers. As part of the work Muzzy did with Lockheed and NASA he demonstrated that electrostatic powder coating was an attractive new method for combining thermoplastic resins with reinforcing fibers. Presentation of this work by Lockheed at a government-industry conference led to a new project for Muzzy, sponsored by NASA Langley. Powder prepregging proved to be the attractive alternative that NASA was looking for. While working on powder prepregging with LaRC-TPI, Muzzy and his colleagues developed methods for exposing all of the fibers to the powder to improve the distribution of the resin on the tow, a continuous bundle of filaments. Optimal resin distribution was achieved by spreading the moving tow. A very flexible towpreg was produced by maintaining the spread tow through the powder coating chamber and into the oven, where the resin particles were fused to the individual filaments. Muzzy's invention has enabled Custom Composite Materials, Inc. to offer resin/fiber combinations based on thermoplastic resins such as nylon and polypropylene. Beyond the expected advantages over epoxy thermoset systems, they are beginning to exploit a fundamental property of thermoplastic resins: viscoelasticity, which can be defined as the resistance to flow as a function of applied stress. Thermoplastics have a much higher viscoelasticity than thermosets.

  19. Advanced functional polymers for regenerative and therapeutic dentistry.

    Science.gov (United States)

    Lai, W-F; Oka, K; Jung, H-S

    2015-07-01

    Use of ceramics and polymers continues to dominate clinical procedures in modern dentistry. Polymers have provided the basis for adhesives, tissue void fillers, and artificial replacements for whole teeth. They have been remarkably effective in the clinic at restoration of major dental functions after damage or loss of teeth. With the rapid development of polymer science, dental materials science has significantly lagged behind in harnessing these advanced polymer products. What they offer is new and unique properties superior to traditional polymers and crucially a range of properties that more closely match natural biomaterials. Therefore, we should pursue more vigorously the benefits of advanced polymers in dentistry. In this review, we highlight how the latest generation of advanced polymers will enhance the application of materials in the dental clinic using numerous promising examples. Polymers have a broad range of applications in modern dentistry. Some major applications are to construct frameworks that mimic the precise structure of tissues, to restore tooth organ function, and to deliver bioactive agents to influence cell behavior from the inside. The future of polymers in dentistry must include all these new enhancements to increase biological and clinical effectiveness beyond what can be achieved with traditional biomaterials. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. A review of electrohydrodynamic casting energy conversion polymer composites

    Directory of Open Access Journals (Sweden)

    Yong X. Gan

    2018-03-01

    Full Text Available This paper provides a brief review on manufacturing polymer composite materials through the nontraditional electrohydrodynamic (EHD casting approach. First, the EHD technology will be introduced. Then, typical functional polymer composite materials including thermoelectric and photoelectric energy conversion polymers and their composites will be presented. Specifically, how to make composite materials containing functional nanoparticles will be discussed. Converting polymeric fibers into partially carbonized fiber composites will also be shown. The latest research results of polymeric composite materials with energy conversion and sensing functions will be given.

  1. Accelerated Aging of Polymer Composite Bridge Materials

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Nancy Margaret; Blackwood, Larry Gene; Torres, Lucinda Laine; Rodriguez, Julio Gallardo; Yoder, Timothy Scott

    1999-03-01

    Accelerated aging research on samples of composite material and candidate ultraviolet (UV) protective coatings is determining the effects of six environmental factors on material durability. Candidate fastener materials are being evaluated to determine corrosion rates and crevice corrosion effects at load-bearing joints. This work supports field testing of a 30-ft long, 18-ft wide polymer matrix composite (PMC) bridge at the Idaho National Engineering and Environmental Laboratory (INEEL). Durability results and sensor data from tests with live loads provide information required for determining the cost/benefit measures to use in life-cycle planning, determining a maintenance strategy, establishing applicable inspection techniques, and establishing guidelines, standards, and acceptance criteria for PMC bridges for use in the transportation infrastructure.

  2. Inorganic-whisker-reinforced polymer composites synthesis, properties and applications

    CERN Document Server

    Sun, Qiuju

    2015-01-01

    Inorganic-Whisker-Reinforced Polymer Composites: Synthesis, Properties and Applications gives a comprehensive presentation of inorganic microcrystalline fibers, or whiskers, a polymer composite filler. It covers whisker synthesis, surface modification, applications for reinforcing polymer-matrix composites, and analysis of resulting filled polymer composites. It focuses on calcium carbonate whiskers as a primary case study, introducing surface treatment methods for calcium carbonate whiskers and factors that influence them. Along with calcium carbonate, the book discusses potassium titanate and aluminum borate whiskers, which also comprise the new generation of inorganic whiskers. According to research results, composites filled by inorganic whiskers show improved strength, wear-resistance, thermal conductivity, and antistatic properties. It explains the importance of modifying polymer materials for use with inorganic whiskers and describes preparation and evaluation methods of polymers filled with inorganic ...

  3. Advanced luminescent materials based on organoboron polymers.

    Science.gov (United States)

    Tanaka, Kazuo; Chujo, Yoshiki

    2012-08-14

    Our work on the characteristics of organoboron-containing polymers is reviewed. The electronic interaction and correlation involving organoboron complexes are responsible for the optical and electric properties of the polymers. To understand the origins of these properties and apply them to the next generation of new materials, we have gathered not only fundamental knowledge on the electronic states and behaviors of each organoboron complex in the polymers but also on the functions of the polymers in devices. In this article, we introduce our findings obtained from a series of studies on polymers involving cyclodiborazane, quinolate, diketonate, dipyrromethene, pyrazabole, and carborane complexes. In particular, there is a focus on results from recent work. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Inkjet printed superparamagnetic polymer composite hemispheres with programmed magnetic anisotropy

    Science.gov (United States)

    Ergeneman, Olgaç; Peters, Christian; Gullo, Maurizio R.; Jacot-Descombes, Loïc; Gervasoni, Simone; Özkale, Berna; Fatio, Philipe; Cadarso, Victor J.; Mastrangeli, Massimo; Pané, Salvador; Brugger, Jürgen; Hierold, Christofer; Nelson, Bradley J.

    2014-08-01

    We present the fabrication and characterization of large arrays of inkjet-printed superparamagnetic polymer composite (SPMPC) hemispherical microstructures. SPMPCs are appealing for applications in microsystems and nanorobotics due to the added functionality of polymers and the significant magnetic attributes of embedded nanostructures. SPMPC-based microarchitectures can be used to perform different functions wirelessly in various media (e.g. water, solvents) using external magnetic fields: handling and assembling small objects, delivering drugs or biomass, or sensing specific physical or chemical changes. In this work superparamagnetic magnetite nanoparticles are dispersed in SU-8 to form magnetic hemispheres. Magnetically anisotropic hemispheres as well as standard SPMPC hemispheres are fabricated. Magnetic anisotropy is programmed by applying a magnetic field during curing. The distribution of nanoparticles inside the polymer matrix and magnetic characteristics of the SPMPC are investigated. Magnetic manipulation of hemispheres is demonstrated at liquid-liquid interfaces. Different assembly strategies to form lines or geometric shapes from hemispheres as well as their independent dynamic control are demonstrated. Finally, a two-interface assembly strategy is demonstrated to assemble hemispheres into complete spheres for advanced self-assembly tasks.We present the fabrication and characterization of large arrays of inkjet-printed superparamagnetic polymer composite (SPMPC) hemispherical microstructures. SPMPCs are appealing for applications in microsystems and nanorobotics due to the added functionality of polymers and the significant magnetic attributes of embedded nanostructures. SPMPC-based microarchitectures can be used to perform different functions wirelessly in various media (e.g. water, solvents) using external magnetic fields: handling and assembling small objects, delivering drugs or biomass, or sensing specific physical or chemical changes. In this

  5. Mechanical Evaluation of Polymer Composite Hip Protectors

    Directory of Open Access Journals (Sweden)

    Jose Daniel Diniz Melo

    2010-01-01

    Full Text Available Hip fractures often result in serious health implications, particularly in the geriatric population, and have been related to long-term morbidity and death. In most cases, these fractures are caused by impact loads in the area of the greater trochanter, which are produced in a fall. This work is aimed at developing hip protectors using composite materials and evaluating their effectiveness in preventing hip fractures under high impact energy (120 J. The hip protectors were developed with an inner layer of energy absorbing soft material and an outer rigid shell of fiberglass-reinforced polymer composite. According to the experimental results, all tested configurations proved to be effective at reducing the impact load to below the average fracture threshold of proximal femur. Furthermore, an addition of Ethylene Vinyl Acetate (EVA to the impacted area of the composite shell proved to be beneficial to increase impact strength of the hip protectors. Thus, composite hip protectors proved to be a viable alternative for a mechanically efficient and cost-effective solution to prevent hip fractures.

  6. Recent Advances in Antimicrobial Polymers: A Mini-Review

    Directory of Open Access Journals (Sweden)

    Keng-Shiang Huang

    2016-09-01

    Full Text Available Human safety and well-being is threatened by microbes causing numerous infectious diseases resulting in a large number of deaths every year. Despite substantial progress in antimicrobial drugs, many infectious diseases remain difficult to treat. Antimicrobial polymers offer a promising antimicrobial strategy for fighting pathogens and have received considerable attention in both academic and industrial research. This mini-review presents the advances made in antimicrobial polymers since 2013. Antimicrobial mechanisms exhibiting either passive or active action and polymer material types containing bound or leaching antimicrobials are introduced. This article also addresses the applications of these antimicrobial polymers in the medical, food, and textile industries.

  7. Advanced Functional Polymers for Increasing the Stability of Organic Photovoltaics

    DEFF Research Database (Denmark)

    Bundgaard, Eva; Helgesen, Martin; Carlé, Jon Eggert

    2013-01-01

    The development of new advanced polymers for improving the stability of OPV is reviewed. Two main degradation pathways for the OPV active layer are identified: photochemically initiated reactions primarily starting in the side chains and morphological changes that degrade the important...... nanostructure. Chemical units can be introduced that impart an increased stability. Similarly, the morphological degradation of the optimal nanostructure can be reduced. Active polymers and blends with acceptor material are used to create nanoparticle links with controlled size. Most of these advanced polymers...

  8. Advanced field theoretic simulations of polymer nanocomposites

    Science.gov (United States)

    Koski, Jason

    Polymers nanocomposites (PNCs) have emerged as a promising class of materials that can exhibit enhanced mechanical, optical, and electrical properties over polymers or nanoparticles alone. The outstanding issue is that the parameter space associated with PNCs is vast and a global framework for what parameters and processing conditions determine the resulting structure is lacking. Polymer field theory has been established as the primary tool in understanding inhomogeneous polymer systems. Here, we extend the polymer field theory framework to efficiently model PNCs, which we refer to as polymer nanocomposite field theory (PNC-FT). The utility of the PNC-FT method is the ability to efficiently study the thermodynamics and vast parameter space associated with PNCs. The PNC-FT method is developed to efficiently model a wide array of systems: nanospheres, nanorods, grafted nanoparticles with simple (homopolymer) and complex (diblock, mixed, and Janus) grafting architectures. Moreover, a numerical dynamic mean-field theory (DMFT) is presented as an additional tool to capture non-equilibrium behavior in PNC systems. The PNC-FT framework is validated through comparisons with Monte Carlo simulations and by demonstrations of the ability to capture particle correlations, a feature that is not captured in the conventional polymer field theory framework. The PNC-FT method is used to study: the ideal domain spacing of lamellar forming block copolymer nanocomposites, the segregation of homopolymers and nanoparticles to tilt grain boundaries in block copolymer thin films, complex grafted nanoparticles acting as surfactants in a homopolymer blend, and grafted gold nanorods in polymer thin films. The grafted gold nanorod study is done in direct collaboration with experimentalists where we provide an additional systematic study that demonstrates the advantages and disadvantages of: a previously developed hybrid particle-field theory (HPFT), PNC-FT, and DMFT. In investigating this wide

  9. Recent Advances in Glycerol Polymers: Chemistry and Biomedical Applications

    Science.gov (United States)

    Zhang, Heng

    2015-01-01

    Glycerol polymers are attracting increased attention due to the diversity of polymer compositions and architectures available. This article provides a brief chronological review on the current status of these polymers along with representative examples of their use for biomedical applications. First, we describe the underlying chemistry of glycerol, which provides access to a range of monomers for subsequent polymerizations. We then review the various synthetic methodologies to prepare glycerol-based polymers including polyethers, polycarbonates, polyesters, and so forth. Next, we describe several biomedical applications where glycerol polymers are being investigated including carriers for drug delivery, sealants or coatings for tissue repair, and agents possessing antibacterial activity. Fourth, we describe the growing market opportunity for the use of polymers in medicine. Finally we conclude and summarize the findings, as well as discuss potential opportunities for continued research efforts. PMID:25308354

  10. Recent advances in glycerol polymers: chemistry and biomedical applications.

    Science.gov (United States)

    Zhang, Heng; Grinstaff, Mark W

    2014-11-01

    Glycerol polymers are attracting increased attention due to the diversity of polymer compositions and architectures available. This article provides a brief chronological review on the current status of these polymers along with representative examples of their use for biomedical applications. First, the underlying chemistry of glycerol that provides access to a range of monomers for subsequent polymerizations is described. Then, the various synthetic methodologies to prepare glycerol-based polymers including polyethers, polycarbonates, polyesters, and so forth are reviewed. Next, several biomedical applications where glycerol polymers are being investigated including carriers for drug delivery, sealants or coatings for tissue repair, and agents possessing antibacterial activity are described. Fourth, the growing market opportunity for the use of polymers in medicine is described. Finally, the findings are concluded and summarized, as well as the potential opportunities for continued research efforts are discussed. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Mechanical properties of natural fibre reinforced polymer composites

    Indian Academy of Sciences (India)

    Wintec

    green composites involving Hibiscus sabdariffa fibre as a reinforcing material in urea–formaldehyde (UF) resin based polymer ... mixed Hibiscus sabdariffa fibre reinforced polymer composites such as tensile, compressive and wear proper- ties were ... in natural fibres and its applications in various fields. Natural fibres are ...

  12. Viscoelastic properties of polymer composites during processing

    Science.gov (United States)

    O'Brien, Daniel James

    Residual stresses that are induced during processing of polymer matrix composites lead to warpage of structural parts and can produce microcracks and other forms of damage. Process models that track the development of residual stresses in composites during processing have received growing attention in recent years. An accurate and easy to implement simulation will help lower the manufacturing cost by enabling engineers to predict and prevent the warpage in parts due to residual stress. The critical feature of a process model is the development of an accurate material model to predict mechanical properties throughout the entire manufacturing cycle. Material models are very complex since the matrix changes from a fluid to a viscoelastic solid at the end of cure. In this work several aspects of the curing, viscoelastic, and cure shrinkage behavior of an aerospace grade epoxy resin were characterized and modeled for the purpose of composites process modeling. Measurement of matrix viscoelastic properties during cure was accomplished through two experimental approaches, each suited to a particular range of cure states. To investigate the material behavior during later stages of cure after gelation, small beam specimens were tested in three-point bending. During early stages of curing, samples were examined by shearing the material between parallel plates in a rheometer. Specimens for each configuration were manufactured at several cure states and tested at a range of temperatures. These data were used to develop a material model to predict the relaxation modulus of the matrix at any time during cure. Additionally, moire interferometry was successfully applied to the measurement of the viscoelastic Poisson's ratio of the matrix through its entire glassy-to-rubbery transition. The matrix viscoelastic material models were then used to predict composite viscoelastic properties and correlated with experimental results. In addition, the viscoelastic shrinkage behavior of the

  13. Polymer-SnO2 composite membranes

    DEFF Research Database (Denmark)

    Nørgaard, Casper Frydendal; Skou, Eivind Morten

    When designing sulfonic acid based ionomers, high ion exchange capacity (IEC) comes at the expense of the mechanical properties. With too high IEC, the membrane will excessively swell or even dissolve in water. Therefore a suitable compromise must be found between high charge carrier concentration...... and adequate mechanical properties. It has been demonstrated that this compromise can be found at higher IEC when the mechanical properties are improved by increasing crystallinity, increasing molecular weight, crosslinking or reinforcement of the membrane by dispersion of interacting particles therein....... This work utilizes the latter approach and makes use of particles of tin dioxide (SnO2). Polymer-SnO2 composite membranes were successfully prepared using an ion-exchange method. SnO2 was incorporated into membranes by ion-exchange in solutions of SnCl2 ∙ 2 H2O in methanol, followed by oxidation to SnO2...

  14. Processing and characterization of ceramic superconductor/polymer composites

    International Nuclear Information System (INIS)

    Kander, R.G.; Namboodri, S.L.

    1993-01-01

    One way to more easily process a brittle high-temperature ceramic superconductor into a useful structure is to combine it with a polymer to form a composite material. Processing of polymer-based composites into complex shapes is well established and relatively easy when compared with traditional ceramic processing unit operations. In addition, incorporating a ceramic superconductor into a polymer matrix can improve mechanical performance as compared with a monolithic ceramic. Finally, because ceramic superconductors are susceptible to attack by moisture, a polymer-based composite structure can also provide protection from deleterious environmental effects. This paper focuses on the processing and subsequent characterization of ceramic superconductor/polymer composites designed primarily for electromagnetic shielding and diamagnetic applications. YBa 2 Cu 3 O 7-x [YBCO] ceramic superconductor is combined with poly(methyl methacrylate) [PMMA] to form novel composite structures. Composite structures have been molded with both a discontinuous superconducting phase (i.e., ceramic particulate reinforced polymers) and with a continuous superconducting phase (i.e., polymer infiltrated porous ceramics). Characterization of these composite structures includes the determination of diamagnetic strength, electromagnetic shielding effectiveness, mechanical performance, and environmental resistance. The goal of this program is to produce a composite structure with increased mechanical integrity and environmental resistance at liquid nitrogen temperatures without compromising the electromagnetic shielding and diamagnetic properties of the superconducting phase. Composites structures of this type are potentially useful in numerous magnetic applications including electromagnetic shielding, magnetic sensors, energy storage, magnetic levitation, and motor windings

  15. Effects of reprocessing on nanoalumina polymer composites

    Science.gov (United States)

    Huang, Chunchia

    The life cycle of reprocessed polymer nanocomposites is a critical factor associated with their growing use, but the limited work on reprocessing of nanocomposites has focused solely on the effects of organoclays. This research investigated of the structure and property changes during reprocessing of polypropylene (PP) and polycarbonate (PC) nanocomposites with 3 wt. % nanoalumina. Neat PP and PC were used as controls. Reprocessing of the neat polymers and nanocomposites produced no indication of oxidation (in FTIR), no changes in the glass transition temperature of PC and the melting temperatures of PP, and no changes in thermal stability (as measured using thermogravimetric analysis). Significant decreases, however, occurred in the melt viscosity of the materials. The introduction of nanoalumina during twin screw extrusion also produced a significant decrease in the viscosity and a 10°C decrease in the glass transition temperature of the PC nanocomposite. Color changes did not correspond to the chain scission in PP and PC; neat PP and PP composite yellowed, neat PC turned brown, and the PC nanocomposite did not change color. Dispersion of the nanoalumina in both PP and PC improved with repeated reprocessing, the crystallinity in the PP/nanoalumina composites remained constant. The Young's moduli of both the PP and PP/A12O3 nanocomposite were similar, whereas the Young's modulus values of the PC/A1 2O3 nanocomposite was slighted lower than that of the neat PC. In contrast, the elongations at break of the PP/A12O3 and PC/A12O3 nanocomposites were, respectively, 50% and 16% of the values measured for the neat resins. All modulus and elongation at break values, however, remained constant over five reprocessing cycles. This behavior suggests that the major degradation mechanism during reprocessing of neat PP and PP nanocomposites was thermal-mechanical polymer chain scission and that the nanoalumina enhanced this degradation in the PC/nanoalumina. This additional

  16. Multilayer Electroactive Polymer Composite Material Comprising Carbon Nanotubes

    Science.gov (United States)

    Ounaies, Zoubeida (Inventor); Park, Cheol (Inventor); Harrison, Joycelyn S. (Inventor); Holloway, Nancy M. (Inventor); Draughon, Gregory K. (Inventor)

    2009-01-01

    An electroactive material comprises multiple layers of electroactive composite with each layer having unique dielectric, electrical and mechanical properties that define an electromechanical operation thereof when affected by an external stimulus. For example, each layer can be (i) a 2-phase composite made from a polymer with polarizable moieties and an effective amount of carbon nanotubes incorporated in the polymer for a predetermined electromechanical operation, or (ii) a 3-phase composite having the elements of the 2-phase composite and further including a third component of micro-sized to nano-sized particles of an electroactive ceramic incorporated in the polymer matrix.

  17. Recent Advances in Conjugated Polymers for Light Emitting Devices

    Science.gov (United States)

    AlSalhi, Mohamad Saleh; Alam, Javed; Dass, Lawrence Arockiasamy; Raja, Mohan

    2011-01-01

    A recent advance in the field of light emitting polymers has been the discovery of electroluminescent conjugated polymers, that is, kind of fluorescent polymers that emit light when excited by the flow of an electric current. These new generation fluorescent materials may now challenge the domination by inorganic semiconductor materials of the commercial market in light-emitting devices such as light-emitting diodes (LED) and polymer laser devices. This review provides information on unique properties of conjugated polymers and how they have been optimized to generate these properties. The review is organized in three sections focusing on the major advances in light emitting materials, recent literature survey and understanding the desirable properties as well as modern solid state lighting and displays. Recently, developed conjugated polymers are also functioning as roll-up displays for computers and mobile phones, flexible solar panels for power portable equipment as well as organic light emitting diodes in displays, in which television screens, luminous traffic, information signs, and light-emitting wallpaper in homes are also expected to broaden the use of conjugated polymers as light emitting polymers. The purpose of this review paper is to examine conjugated polymers in light emitting diodes (LEDs) in addition to organic solid state laser. Furthermore, since conjugated polymers have been approved as light-emitting organic materials similar to inorganic semiconductors, it is clear to motivate these organic light-emitting devices (OLEDs) and organic lasers for modern lighting in terms of energy saving ability. In addition, future aspects of conjugated polymers in LEDs were also highlighted in this review. PMID:21673938

  18. Fabrication of composite microstructures by capillarity-driven wetting of aligned carbon nanotubes with polymers

    Energy Technology Data Exchange (ETDEWEB)

    GarcIa, E J [Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Hart, A J [Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Wardle, B L [Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Slocum, A H [Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2007-04-25

    The interaction, or wetting, of long aligned carbon nanotube (CNT) forests with off-the-shelf (no solvent added) commercial thermoset polymers is investigated experimentally. A technique for creating vertically aligned CNT composite microstructures of various shapes is presented. The effective wetting of the forests, as evidenced by a lack of voids, by three polymers with widely varying viscosities supports the feasibility of using CNT forests in large-scale hybrid advanced composite architectures. Among various routes identified for the polymer to penetrate the forest, capillarity-driven wetting along the CNT axis is the preferred route. Aligned CNT microstructures are useful in many applications including test structures for direct mechanical and multifunctional property characterization of the aligned CNT-polymer composite materials.

  19. Center for Advanced Electrical and Structural Polymers

    Science.gov (United States)

    1993-10-15

    Bristowe (MIT) Dr. Feng Gao (WSU) Dr. Raymon Albalak (MIT) Dr. B.R. McKellar (WSU) Dr. Maria Goncalves (MIT) SDr. Weipang Zhang (MIT) Dr. Gia Kim (MIT... Machado ) "Improved Mass Transport in3 Rechargeable Electrodes Employing Conducting Polymer Blends". 15. MRS Proceedings, Volume 171, Materials

  20. Large Dielectric Constant Enhancement in MXene Percolative Polymer Composites

    KAUST Repository

    Tu, Shao Bo

    2018-04-06

    near the percolation limit of about 15.0 wt % MXene loading, which surpasses all previously reported composites made of carbon-based fillers in the same polymer. With up to 10 wt % MXene loading, the dielectric loss of the MXene/P(VDF-TrFE-CFE) composite indicates only an approximately 5-fold increase (from 0.06 to 0.35), while the dielectric constant increased by 25 times over the same composition range. Furthermore, the ratio of permittivity to loss factor of the MXene-polymer composite is superior to that of all previously reported fillers in this same polymer. The dielectric constant enhancement effect is demonstrated to exist in other polymers as well when loaded with MXene. We show that the dielectric constant enhancement is largely due to the charge accumulation caused by the formation of microscopic dipoles at the surfaces between the MXene sheets and the polymer matrix under an external applied electric field.

  1. Standardization of Tests for Advanced Composites

    OpenAIRE

    石川, 隆司; ISHIKAWA, Takashi; 野口, 義男; NOGUCHI, Yoshio; 濱口, 泰正; HAMAGUCHI, Yasumasa

    2003-01-01

    Advanced composites are essentially the only feasible materials for the construction of newly developed aerospace vehicle. However, the path to be followed for the validation, evaluation and certification of composite aircraft structures is quite different from that of traditional metallic aircraft structures, and the importance of a composites database is now well recognized. A key issue in constructing a fully descriptive composites database is to establish standard composite test methods, ...

  2. Polymer composites on the aryl alicyclic polyimide base with another polymers

    International Nuclear Information System (INIS)

    Zhubanov, B.; Kudajkulova, S.; Musapirova, Z.

    2003-01-01

    Optimal conditions for synthesis of polymer composites on the base of aryl alicyclic polyimide (PI) with thermo stable polymers - polycarbonate (PC) and polysulfone (PS) - were selected. It was found 2 ways for obtain polymer-polymer composites: 1) mechanical mixing in m-cresol the polymers at different ratio of PI/PC and PI/PS equal to 90/10, 80/20,70/30; 2) reaction mixing of solution of PC or PS in m-cresol with monomers for syntheses of polyimide - tree cyclo decen tetra carbonic acid and oxydianiline. Physico-chemical properties and structure of the composites were studied by methods of UR-, X-ray-spectroscopy, optical microscopy and viscosimeter. X-ray phase spectroscopy possess to determine structure of polymers and their changes, phase transformations and conformation of macromolecules under different kinds of influence. It was shown that new modern materials with nano structure can be synthesised by suggested method

  3. Polymeric drugs: Advances in the development of pharmacologically active polymers

    Science.gov (United States)

    Li, Jing; Yu, Fei; Chen, Yi; Oupický, David

    2015-01-01

    Synthetic polymers play a critical role in pharmaceutical discovery and development. Current research and applications of pharmaceutical polymers are mainly focused on their functions as excipients and inert carriers of other pharmacologically active agents. This review article surveys recent advances in alternative pharmaceutical use of polymers as pharmacologically active agents known as polymeric drugs. Emphasis is placed on the benefits of polymeric drugs that are associated with their macromolecular character and their ability to explore biologically relevant multivalency processes. We discuss the main therapeutic uses of polymeric drugs as sequestrants, antimicrobials, antivirals, and anticancer and anti-inflammatory agents. PMID:26410809

  4. Polyethylene Modification as Biodegradable Composite Polymer for Packing Materials

    International Nuclear Information System (INIS)

    Deswita; Aloma KK; Sudirman; Indra Gunawan

    2008-01-01

    The synthesis of biodegradable polymer using blending method has been done. The aim of this research is to synthesize kinds of biodegradable composite polymer materials which could be applied in many kinds of requirements such as environmental friendly packaging and degradable. In this paper, the synthetic of biodegradable composite polymer was performed by adding biodegradable filler to the synthetic polymer using blending method. In this experiment Low Linier Density Polyethylene (LLDPE), High Density Polyethylene (HDPE) and filler of tapioca were used. The variation of tapioca meal composition were 50 in weight percent, 55 in weight percent, 60 in weight percent, 65 in weight percent, 70 in weight percent and 75 in weight percent. The characterization was done by means of thermal test, microstructure test, biodegradable and mechanical test. The result showed that the mechanical properties of the materials decreased with increasing composition of tapioca but did not show significant change to the polymer composite materials. For burrying time inside the ground of 8 weeks, all specimens based on polymer LLDPE for all composition of tapioca filler were degraded inside the ground, where as for all specimens based on polymer HDPE with all composition of tapioca filler did not show any degradation. (author)

  5. Self Healing Fibre-reinforced Polymer Composites: an Overview

    Science.gov (United States)

    Bond, Ian P.; Trask, Richard S.; Williams, Hugo R.; Williams, Gareth J.

    Lightweight, high-strength, high-stiffness fibre-reinforced polymer composite materials are leading contenders as component materials to improve the efficiency and sustainability of many forms of transport. For example, their widespread use is critical to the success of advanced engineering applications, such as the Boeing 787 and Airbus A380. Such materials typically comprise complex architectures of fine fibrous reinforcement e.g. carbon or glass, dispersed within a bulk polymer matrix, e.g. epoxy. This can provide exceptionally strong, stiff, and lightweight materials which are inherently anisotropic, as the fibres are usually arranged at a multitude of predetermined angles within discrete stacked 2D layers. The direction orthogonal to the 2D layers is usually without reinforcement to avoid compromising in-plane performance, which results in a vulnerability to damage in the polymer matrix caused by out-of-plane loading, i.e. impact. Their inability to plastically deform leaves only energy absorption via damage creation. This damage often manifests itself internally within the material as intra-ply matrix cracks and inter-ply delaminations, and can thus be difficult to detect visually. Since relatively minor damage can lead to a significant reduction in strength, stiffness and stability, there has been some reticence by designers for their use in safety critical applications, and the adoption of a `no growth' approach (i.e. damage propagation from a defect constitutes failure) is now the mindset of the composites industry. This has led to excessively heavy components, shackling of innovative design, and a need for frequent inspection during service (Richardson 1996; Abrate 1998).

  6. Polymer blend compositions and methods of preparation

    Science.gov (United States)

    Naskar, Amit K.

    2016-09-27

    A polymer blend material comprising: (i) a first polymer containing hydrogen bond donating groups having at least one hydrogen atom bound to a heteroatom selected from oxygen, nitrogen, and sulfur, or an anionic version of said first polymer wherein at least a portion of hydrogen atoms bound to a heteroatom is absent and replaced with at least one electron pair; (ii) a second polymer containing hydrogen bond accepting groups selected from nitrile, halogen, and ether functional groups; and (iii) at least one modifying agent selected from carbon particles, ether-containing polymers, and Lewis acid compounds; wherein, if said second polymer contains ether functional groups, then said at least one modifying agent is selected from carbon particles and Lewis acid compounds. Methods for producing the polymer blend, molded forms thereof, and articles thereof, are also described.

  7. Computational modeling of biodegradable starch based polymer composites

    Science.gov (United States)

    Joshi, Sachin Sudhakar

    2007-12-01

    Purpose. The goal of this study is to improve the favorable molecular interactions between starch and PPC by addition of grafting monomers MA and ROM as compatibilizers, which would advance the mechanical properties of starch/PPC composites. Methodology. DFT and semi-empirical methods based calculations were performed on three systems: (a) starch/PPC, (b) starch/PPC-MA, and (c) starch-ROM/PPC. Theoretical computations involved the determination of optimal geometries, binding-energies and vibrational frequencies of the blended polymers. Findings. Calculations performed on five starch/PPC composites revealed hydrogen bond formation as the driving force behind stable composite formation, also confirmed by the negative relative energies of the composites indicating the existence of binding forces between the constituent co-polymers. The interaction between starch and PPC is also confirmed by the computed decrease in stretching CO and OH group frequencies participating in hydrogen bond formation, which agree qualitatively with the experimental values. A three-step mechanism of grafting MA on PPC was proposed to improve the compatibility of PPC with starch. Nine types of 'blends' produced by covalent bond formation between starch and MA-grafted PPC were found to be energetically stable, with blends involving MA grafted at the 'B' and 'C' positions of PPC indicating a binding-energy increase of 6.8 and 6.2 kcal/mol, respectively, as compared to the non-grafted starch/PPC composites. A similar increase in binding-energies was also observed for three types of 'composites' formed by hydrogen bond formation between starch and MA-grafted PPC. Next, grafting of ROM on starch and subsequent blend formation with PPC was studied. All four types of blends formed by the reaction of ROM-grafted starch with PPC were found to be more energetically stable as compared to the starch/PPC composite and starch/PPC-MA composites and blends. A blend of PPC and ROM grafted at the '

  8. Solid polymer electrolyte composite membrane comprising laser micromachined porous support

    Science.gov (United States)

    Liu, Han [Waltham, MA; LaConti, Anthony B [Lynnfield, MA; Mittelsteadt, Cortney K [Natick, MA; McCallum, Thomas J [Ashland, MA

    2011-01-11

    A solid polymer electrolyte composite membrane and method of manufacturing the same. According to one embodiment, the composite membrane comprises a rigid, non-electrically-conducting support, the support preferably being a sheet of polyimide having a thickness of about 7.5 to 15 microns. The support has a plurality of cylindrical pores extending perpendicularly between opposing top and bottom surfaces of the support. The pores, which preferably have a diameter of about 5 microns, are made by laser micromachining and preferably are arranged in a defined pattern, for example, with fewer pores located in areas of high membrane stress and more pores located in areas of low membrane stress. The pores are filled with a first solid polymer electrolyte, such as a perfluorosulfonic acid (PFSA) polymer. A second solid polymer electrolyte, which may be the same as or different than the first solid polymer electrolyte, may be deposited over the top and/or bottom of the first solid polymer electrolyte.

  9. Ceramic matrix composites -- Advanced high-temperature structural materials

    International Nuclear Information System (INIS)

    Lowden, R.A.; Ferber, M.K.; DiPietro, S.G.

    1995-01-01

    This symposium on Ceramic Matrix Composites: Advanced High-Temperature Structural Materials was held at the 1994 MRS Fall Meeting in Boston, Massachusetts on November 28--December 2. The symposium was sponsored by the Department of Energy's Office of Industrial Technology's Continuous Fiber Ceramic Composites Program, the Air Force Office of Scientific Research, and NASA Lewis Research Center. Among the competing materials for advanced, high-temperature applications, ceramic matrix composites are leading candidates. The symposium was organized such that papers concerning constituents--fibers and matrices--were presented first, followed by composite processing, modeling of mechanical behavior, and thermomechanical testing. More stable reinforcements are necessary to enhance the performance and life of fiber-reinforced ceramic composites, and to ensure final acceptance of these materials for high-temperature applications. Encouraging results in the areas of polymer-derived SiC fibers and single crystal oxide filaments were given, suggesting composites with improved thermomechanical properties and stability will be realized in the near future. The significance of the fiber-matrix interface in the design and performance of these materials is evident. Numerous mechanical models to relate interface properties to composite behavior, and interpret test methods and data, were enthusiastically discussed. One issue of great concern for any advanced material for use in extreme environments is stability. This theme arose frequently throughout the symposium and was the topic of focus on the final day. Fifty nine papers have been processed separately for inclusion on the data base

  10. Advances in radiation chemistry of polymers. Proceedings of a technical meeting

    International Nuclear Information System (INIS)

    2004-11-01

    The meeting on radiation effects on polymers was held at the Radiation Laboratory at the University of Notre Dame to review and discuss advances in the radiation processing of polymers. The trends in the basic research, research and development, and industrial applications were reported. The scope of more applied uses of irradiation involving polymers ranged from discussions of the curing of materials for dental applications, to the effects on polyolefins, the most broadly used class of polymers prevalent in industrial radiation processing, and to emerging interests in hydrogels, carbon fiber composites, heterogeneous mixtures based on material by-products (scrap plastic and wood fragments), grafted materials and materials for electronic uses. In addition, the emerging interests in the use of recently developed high power x ray systems for industrial use were presented. The document contains 12 individual papers, each of them was indexed and abstracted separately

  11. Carbon nanotube buckypaper reinforced polymer composites: a review

    Directory of Open Access Journals (Sweden)

    Bruno Ribeiro

    2017-09-01

    Full Text Available Abstract This review provides valuable information about the general characteristics, processing conditions and physical properties of carbon nanotube buckypaper (BP and its polymer composites. Vacuum filtration is the most common technique used for manufacturing BP, since the carbon nanotubes are dispersed in aqueous solution with the aid of surfactant. Previous works have reported that mechanical properties of BP prepared by vacuum filtration technique are relatively weak. On the other hand, the incorporation of polymer materials in those nanostructures revealed a significant improvement in their mechanical behavior, since the impregnation between matrix and BP is optimized. Electrical conductivity of BP/polymer composites can reach values as high as 2000 S/m, which are several orders of magnitude greater than traditional CNT/polymer composites. Also, BP can improve remarkably the thermal stability of polymer matrices, opening new perspectives to use this material in fire retardant applications.

  12. Natural fiber-reinforced polymer composites

    International Nuclear Information System (INIS)

    Taj, S.; Khan, S.; Munawar, M.A.

    2007-01-01

    Natural fibers have been used to reinforce materials for over 3,000 years. More recently they have been employed in combination with plastics. Many types of natural fi fibers have been investigated for use in plastics including Flax, hemp, jute, straw, wood fiber, rice husks, wheat, barley, oats, rye, cane (sugar and bamboo), grass reeds, kenaf, ramie, oil palm empty fruit bunch, sisal, coir, water hyacinth, pennywort, kapok, paper-mulberry, raphia, banana fiber, pineapple leaf fiber and papyrus. Natural fibers have the advantage that they are renewable resources and have marketing appeal. The Asian markets have been using natural fibers for many years e.g., jute is a common reinforcement in India. Natural fibers are increasingly used in automotive and packaging materials. Pakistan is an agricultural country and it is the main stay of Pakistan's economy. Thousands of tons of different crops are produced but most of their wastes do not have any useful utilization. Agricultural wastes include wheat husk, rice husk, and their straw, hemp fiber and shells of various dry fruits. These agricultural wastes can be used to prepare fiber reinforced polymer composites for commercial use. This report examines the different types of fibers available and the current status of research. Many references to the latest work on properties, processing and application have been cited in this review. (author)

  13. Polymer Matrix Composite Materials for Lightning Strike Mitigation, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — In this phase I SBIR program, a team led by Advanced Ceramics Research Inc. (ACR) propose a novel, low-cost manufacturing process for multi-functional polymer...

  14. Self-healing polymers and composites based on thermal activation

    Science.gov (United States)

    Wang, Ying; Bolanos, Ed; Wudl, Fred; Hahn, Thomas; Kwok, Nathan

    2007-04-01

    Structural polymer composites are susceptible to premature failure in the form of microcracks in the matrix. Although benign initially when they form, these matrix cracks tend to coalesce and lead in service to critical damage modes such as ply delamination. The matrix cracks are difficult to detect and almost impossible to repair because they form inside the composite laminate. Therefore, polymers with self-healing capability would provide a promising potential to minimize maintenance costs while extending the service lifetime of composite structures. In this paper we report on a group of polymers and their composites which exhibit mendable property upon heating. The failure and healing mechanisms of the polymers involve Diels-Alder (DA) and retro-Diels-Alder (RDA) reactions on the polymer back-bone chain, which are thermally reversible reactions requiring no catalyst. The polymers exhibited good healing property in bulk form. Composite panels were prepared by sandwiching the monomers between carbon fiber fabric layers and cured in autoclave. Microcracks were induced on the resin-rich surface of composite with Instron machine at room temperature by holding at 1% strain for 1 min. The healing ability of the composite was also demonstrated by the disappearance of microcracks after heating. In addition to the self-healing ability, the polymers and composites also exhibited shape memory property. These unique properties may provide the material multi-functional applications. Resistance heating of traditional composites and its applicability in self-healing composites is also studied to lay groundwork for a fully integrated self-healing composite.

  15. Flows in polymers, reinforced polymers and composites a multi-scale approach

    CERN Document Server

    Binetruy, Christophe; Keunings, Roland

    2015-01-01

    This book gives a detailed and practical introduction to complex flows of polymers and reinforced polymers as well as the flow of simple fluids in complex microstructures. Over the last decades, an increasing number of functional and structural parts, made so far with metals, has been progressively reengineered by replacing metallic materials by polymers, reinforced polymers and composites. The motivation for this substitution may be the weight reduction, the simpler, cheaper or faster forming process, or the ability to exploit additional functionalities. The present Brief surveys modern developments related to the multi-scale modeling and simulation of polymers, reinforced polymers, that involve a flowing microstructure and continuous fiber-reinforced composites, wherein the fluid flows inside a nearly stationary multi-scale microstructure. These developments concern both multi-scale modeling, defining bridges between the micro and macro scales - with special emphasis on the mesoscopic scale at which kinetic...

  16. Recent Advances in Wide-Bandgap Photovoltaic Polymers.

    Science.gov (United States)

    Cai, Yunhao; Huo, Lijun; Sun, Yanming

    2017-06-01

    The past decade has witnessed significant advances in the field of organic solar cells (OSCs). Ongoing improvements in the power conversion efficiency of OSCs have been achieved, which were mainly attributed to the design and synthesis of novel conjugated polymers with different architectures and functional moieties. Among various conjugated polymers, the development of wide-bandgap (WBG) polymers has received less attention than that of low-bandgap and medium-bandgap polymers. Here, we briefly summarize recent advances in WBG polymers and their applications in organic photovoltaic (PV) devices, such as tandem, ternary, and non-fullerene solar cells. Addtionally, we also dissuss the application of high open-circuit voltage tandem solar cells in PV-driven electrochemical water dissociation. We mainly focus on the molecular design strategies, the structure-property correlations, and the photovoltaic performance of these WBG polymers. Finally, we extract empirical regularities and provide invigorating perspectives on the future development of WBG photovoltaic materials. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Corrosive effect of environmental change on selected properties of polymer composites

    Science.gov (United States)

    Markovičová, L.; Zatkalíková, V.

    2017-11-01

    The development of composite materials and the related design and manufacturing technologies is one of the most important advances in the history of materials. Composites are multifunctional materials having unprecedented mechanical and physical properties that can be tailored to meet the requirements of a particular application. Ageing is also important and it is defined as the process of deterioration of engineering materials resulting from the combined effects of atmospheric radiation, heat, oxygen, water, micro-organisms and other atmospheric factors. The present article deals with monitoring the changes in the mechanical properties of composites with polymer matrix. The composite was formed from the PA matrix and glass fibers (GF). The composite contains 10, 20 and 30 % of glass fibers. The mechanical properties were evaluated on samples of the composite before and after UV radiation on the sample. Light microscopy was evaluated distribution of glass fibers in the polymer matrix and the presence of cracks caused by UV radiation.

  18. Fiberglass reinforced polymer composite bridge deck construction in Illinois

    Science.gov (United States)

    2002-09-01

    An experiment was conducted using a fiber reinforced polymer composite material for the bridge deck of a low volume bridge. The test location was on South Fayette Street over the Town Brook in Jacksonville, Illinois. This project included removal of ...

  19. Investigating accidents involving aircraft manufactured from polymer composite materials

    OpenAIRE

    Dunn, Leigh

    2013-01-01

    This thesis looks into the examination of polymer composite wreckage from the perspective of the aircraft accident investigator. It develops an understanding of the process of wreckage examination as well as identifying the potential for visual and macroscopic interpretation of polymer composite aircraft wreckage. The in-field examination of aircraft wreckage, and subsequent interpretations of material failures, can be a significant part of an aircraft accident investigation. ...

  20. Thermally stimulated discharge conductivity in polymer composite ...

    Indian Academy of Sciences (India)

    Unknown

    Klason Carl and Kubat Josef 1975 J. Appl. Polym. Sci. 19 831. Ramadin Y, Ahmed M, Jawad S A and Zihlif A 1993 J. Polym. Mater. 10 251. Sangawar V S 1996 D.C. electrical conductivity study of poly- styrene and polymethyl methacrylate iodine doped thermo- electrets, Ph.D. Thesis, Amravati University, Amravati.

  1. Analysis of organometallics dispersed polymer composite irradiated ...

    Indian Academy of Sciences (India)

    about by ion beam in polymers underline that the physical modifications are limited to a few basic processes: gas evolution, cross linking and degradation. The chemical changes are more dramatic in polymers because of the macromolecular structure of these materials. The kind of changes, which predominate, depends on ...

  2. Tethered Nanoparticle–Polymer Composites: Phase Stability and Curvature

    KAUST Repository

    Srivastava, Samanvaya

    2012-04-17

    Phase behavior of poly(ethylene glycol) (PEG) tethered silica nanoparticles dispersed in PEG hosts is investigated using small-angle X-ray scattering. Phase separation in dispersions of densely grafted nanoparticles is found to display strikingly different small-angle X-ray scattering signatures in comparison to phase-separated composites comprised of bare or sparsely grafted nanoparticles. A general diagram for the dispersion state and phase stability of polymer tethered nanoparticle-polymer composites incorporating results from this as well as various other contemporary studies is presented. We show that in the range of moderate to high grafting densities the dispersion state of nanoparticles in composites is largely insensitive to the grafting density of the tethered chains and chemistry of the polymer host. Instead, the ratio of the particle diameter to the size of the tethered chain and the ratio of the molecular weights of the host and tethered polymer chains (P/N) are shown to play a dominant role. Additionally, we find that well-functionalized nanoparticles form stable dispersions in their polymer host beyond the P/N limit that demarcates the wetting/dewetting transition in polymer brushes on flat substrates interacting with polymer melts. A general strategy for achieving uniform nanoparticle dispersion in polymers is proposed. © 2012 American Chemical Society.

  3. 3D Printing of Biocompatible Supramolecular Polymers and their Composites.

    Science.gov (United States)

    Hart, Lewis R; Li, Siwei; Sturgess, Craig; Wildman, Ricky; Jones, Julian R; Hayes, Wayne

    2016-02-10

    A series of polymers capable of self-assembling into infinite networks via supramolecular interactions have been designed, synthesized, and characterized for use in 3D printing applications. The biocompatible polymers and their composites with silica nanoparticles were successfully utilized to deposit both simple cubic structures, as well as a more complex twisted pyramidal feature. The polymers were found to be not toxic to a chondrogenic cell line, according to ISO 10993-5 and 10993-12 standard tests and the cells attached to the supramolecular polymers as demonstrated by confocal microscopy. Silica nanoparticles were then dispersed within the polymer matrix, yielding a composite material which was optimized for inkjet printing. The hybrid material showed promise in preliminary tests to facilitate the 3D deposition of a more complex structure.

  4. The application of radiothermoluminescence method to the analysis of polymers and polymer composites

    International Nuclear Information System (INIS)

    Nikol'skii, V.G.

    1982-01-01

    The basic results concerning the examination of copolymers, cross-linked polymers and polyblends structure, obtained by means of radiothermoluminescence method, are reviewed. The main emphasis is on the glow curve shape analysis that allows: a) to determine quantitatively the random copolymer composition; b) to reveal the existence of blocks in macromolecules; c) to examine the grafted copolymer distribution in polymer matrix; d) to estimate the degree of cross-linking both for individual polymers and heterogeneous polyblends; e) to study the mutual solubility of polymers. (author)

  5. Metallized Nanotube Polymer Composite (MNPC) and Methods for Making Same

    Science.gov (United States)

    Park, Cheol (Inventor); Harrison, Joycelyn S. (Inventor); Nazem, Negin (Inventor); Taylor, Larry (Inventor); Kang, Jin Ho (Inventor); Kim, Jae-Woo (Inventor); Sauti, Godfrey (Inventor); Lillehei, Peter T. (Inventor); Lowther, Sharon E. (Inventor)

    2017-01-01

    A novel method to develop highly conductive functional materials which can effectively shield various electromagnetic effects (EMEs) and harmful radiations. Metallized nanotube polymer composites (MNPC) are composed of a lightweight polymer matrix, superstrong nanotubes (NT), and functional nanoparticle inclusions. MNPC is prepared by supercritical fluid infusion of various metal precursors (Au, Pt, Fe, and Ni salts), incorporated simultaneously or sequentially, into a solid NT-polymer composite followed by thermal reduction. The infused metal precursor tends to diffuse toward the nanotube surface preferentially as well as the surfaces of the NT-polymer matrix, and is reduced to form nanometer-scale metal particles or metal coatings. The conductivity of the MNPC increases with the metallization, which provides better shielding capabilities against various EMEs and radiations by reflecting and absorbing EM waves more efficiently. Furthermore, the supercritical fluid infusion process aids to improve the toughness of the composite films significantly regardless of the existence of metal.

  6. Multifunctional Composites Obtained by Incorporating Nanocrystals into Decorated PVK Polymers

    Directory of Open Access Journals (Sweden)

    Haizhu Sun

    2007-01-01

    Full Text Available Poly(vinylcarbazole (PVK was decorated with surfactant group to achieve amphiphilic polymer with luminescent property. The composition and properties of the polymers were systematically investigated using FTIR, EA, TGA, UV-Vis, and PL characterizations. Different CdTe nanocrystals (NCs prepared in aqueous medium were directly transferred to organic phase using the PVK-based polymers. The quantum yield of NCs in the composites had been improved by 50% compared with their parent aqueous solution due to the short distance from carbazole moieties to NCs, which facilitated the Förster resonant energy transfer (FRET between them. Moreover, efficient electron transfer at the interface of NCs and polymers had been confirmed which also indicated the application in photovoltaic cell for such composites.

  7. 25th Anniversary Article: Polymer-Particle Composites: Phase Stability and Applications in Electrochemical Energy Storage

    KAUST Repository

    Srivastava, Samanvaya

    2013-12-09

    Polymer-particle composites are used in virtually every field of technology. When the particles approach nanometer dimensions, large interfacial regions are created. In favorable situations, the spatial distribution of these interfaces can be controlled to create new hybrid materials with physical and transport properties inaccessible in their constituents or poorly prepared mixtures. This review surveys progress in the last decade in understanding phase behavior, structure, and properties of nanoparticle-polymer composites. The review takes a decidedly polymers perspective and explores how physical and chemical approaches may be employed to create hybrids with controlled distribution of particles. Applications are studied in two contexts of contemporary interest: battery electrolytes and electrodes. In the former, the role of dispersed and aggregated particles on ion-transport is considered. In the latter, the polymer is employed in such small quantities that it has been historically given titles such as binder and carbon precursor that underscore its perceived secondary role. Considering the myriad functions the binder plays in an electrode, it is surprising that highly filled composites have not received more attention. Opportunities in this and related areas are highlighted where recent advances in synthesis and polymer science are inspiring new approaches, and where newcomers to the field could make important contributions. Polymer-particle composites are used in virtually every field of technology. When the particles approach nanometer dimensions, large interfacial regions are created that can be exploited for applications. The fundamental approaches and bottom-up synthesis strategies for understanding and controlling nanoparticle dispersion in polymers are reviewed. Applications of these approaches for creating polymer-particle composite electrolytes and electrodes for energy storage are also considered. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. 2014 Global Conference on Polymer and Composite Materials (PCM 2014)

    Science.gov (United States)

    2014-08-01

    The 2014 Global Conference on Polymer and Composite Materials (PCM 2014) sponsored by Ningbo Adhesives and Products Industry Association, Shanghai Bonding Technology Association, Zhejiang Bonding Technology Association, Wuhan Bonding Technology Association, Hebei Bonding and Coatings Association and Polyurethane Industry Association was held from May 27 to May 29 2014 in Ningbo, China. The technical program consisted of 8 international keynote speakers, oral presentations, and a poster session. The conference also included an industrial exhibition where more than 50 companies displayed in their booths their most recent advanced products and services. The present issue of IOP Conference Series: Materials Science and Engineering (MSE) records the proceedings of PCM 2014 and contains 37 specially selected manuscripts submitted to PCM2014 conference. The electronic submission and handling of manuscripts via the conference website, including the selection of reviewers and evaluation of manuscripts, were identical to the procedures applied to manuscripts submitted as regular contributions for publication. The organization of this conference and the preparation of proceedings volumes would have been impossible without the tremendous efforts and dedication of many individuals, especially from Ms. Yin Pan, who oversaw the organization of the conference and the program; and a large team of reviewers with their timely submission of quality reports. We express our sincere thanks to all authors and presenters for their contributions. We also thank very much our sponsors for their generous support. The 2015 Global Conference on Polymer and Composite Materials (PCM2015) will be held in Beijing, China on May 16-18, 2015. Beijing, the capital of the People's Republic of China and one of the most populous cities in the world, will welcome to all participants for a renewed and vibrant conference. Prof. Dr. Esteban Broitman Linköping University, Sweden Editor in Chief — PCM2014

  9. Carbon nanotube polymer composition and devices

    Science.gov (United States)

    Liu, Gao [Oakland, CA; Johnson, Stephen [Richmond, CA; Kerr, John B [Oakland, CA; Minor, Andrew M [El Cerrito, CA; Mao, Samuel S [Castro Valley, CA

    2011-06-14

    A thin film device and compound having an anode, a cathode, and at least one light emitting layer between the anode and cathode, the at least one light emitting layer having at least one carbon nanotube and a conductive polymer.

  10. Multifunctional Hybrid Carbon Nanotube/Carbon Fiber Polymer Composites

    Science.gov (United States)

    Kang, Jin Ho; Cano, Roberto J.; Ratcliffe, James G.; Luong, Hoa; Grimsley, Brian W.; Siochi, Emilie J.

    2016-01-01

    For aircraft primary structures, carbon fiber reinforced polymer (CFRP) composites possess many advantages over conventional aluminum alloys due to their light weight, higher strengthand stiffness-to-weight ratio, and low life-cycle maintenance costs. However, the relatively low electrical and thermal conductivities of CFRP composites fail to provide structural safety in certain operational conditions such as lightning strikes. Despite several attempts to solve these issues with the addition of carbon nanotubes (CNT) into polymer matrices, and/or by interleaving CNT sheets between conventional carbon fiber (CF) composite layers, there are still interfacial problems that exist between CNTs (or CF) and the resin. In this study, hybrid CNT/CF polymer composites were fabricated by interleaving layers of CNT sheets with Hexcel® IM7/8852 prepreg. Resin concentrations from 1 wt% to 50 wt% were used to infuse the CNT sheets prior to composite fabrication. The interlaminar properties of the resulting hybrid composites were characterized by mode I and II fracture toughness testing (double cantilever beam and end-notched flexure test). Fractographical analysis was performed to study the effect of resin concentration. In addition, multi-directional physical properties like thermal conductivity of the orthotropic hybrid polymer composite were evaluated. Interleaving CNT sheets significantly improved the in-plane (axial and perpendicular direction of CF alignment) thermal conductivity of the hybrid composite laminates by 50 - 400%.

  11. Preparation and characterization of polymer composites based on ...

    Indian Academy of Sciences (India)

    Polymer composites based on charge-transfer complex of phenothiazine and iodine with polystyrene have been prepared in different weight ratios and characterized by FTIR, XRD, mechanical, microstructure and electrical properties (d.c. as well as a.c.). These composites show semiconducting behaviour as the ...

  12. Preparation and characterization of polymer composites based on ...

    Indian Academy of Sciences (India)

    Unknown

    2003-11-29

    Nov 29, 2003 ... Abstract. Polymer composites based on charge-transfer complex of phenothiazine and iodine with polystyrene have been prepared in different weight ratios and characterized by FTIR, XRD, mechanical, microstructure and electrical properties (d.c. as well as a.c.). These composites show semiconducting ...

  13. Bio-applications of ionic polymer metal composite transducers

    International Nuclear Information System (INIS)

    Aw, K C; McDaid, A J

    2014-01-01

    Traditional robotic actuators have advanced performance which in some aspects can surpass that of humans, however they are lacking when it comes to developing devices which are capable of operating together with humans. Bio-inspired transducers, for example ionic polymer metal composites (IPMC), which have similar properties to human tissue and muscle, demonstrate much future promise as candidates for replacing traditional robotic actuators in medical robotics applications. This paper outlines four biomedical robotics applications, an IPMC stepper motor, an assistive glove exoskeleton/prosthetic hand, a surgical robotic tool and a micromanipulation system. These applications have been developed using mechanical design/modelling techniques with IPMC ‘artificial muscle’ as the actuation system. The systems are designed by first simulating the performance using an IPMC model and dynamic models of the mechanical system; the appropriate advanced adaptive control schemes are then implemented to ensure that the IPMCs operate in the correct manner, robustly over time. This paper serves as an overview of the applications and concludes with some discussion on the future challenges of developing real-world IPMC applications

  14. Standard Guide for Testing Polymer Matrix Composite Materials

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 This guide summarizes the application of ASTM standard test methods (and other supporting standards) to continuous-fiber reinforced polymer matrix composite materials. The most commonly used or most applicable ASTM standards are included, emphasizing use of standards of Committee D30 on Composite Materials. 1.2 This guide does not cover all possible standards that could apply to polymer matrix composites and restricts discussion to the documented scope. Commonly used but non-standard industry extensions of test method scopes, such as application of static test methods to fatigue testing, are not discussed. A more complete summary of general composite testing standards, including non-ASTM test methods, is included in the Composite Materials Handbook (MIL-HDBK-17). Additional specific recommendations for testing textile (fabric, braided) composites are contained in Guide D6856. 1.3 This guide does not specify a system of measurement; the systems specified within each of the referenced standards shall appl...

  15. Bisphenyl-Polymer/Carbon-Fiber-Reinforced Composite Compared to Titanium Alloy Bone Implant.

    Science.gov (United States)

    Petersen, Richard C

    2011-05-03

    Aerospace/aeronautical thermoset bisphenyl-polymer/carbon-fiber-reinforced composites are considered as new advanced materials to replace metal bone implants. In addition to well-recognized nonpolar chemistry with related bisphenol-polymer estrogenic factors, carbon-fiber-reinforced composites can offer densities and electrical conductivity/resistivity properties close to bone with strengths much higher than metals on a per-weight basis. In vivo bone-marrow tests with Sprague-Dawley rats revealed far-reaching significant osseoconductivity increases from bisphenyl-polymer/carbon-fiber composites when compared to state-of-the-art titanium-6-4 alloy controls. Midtibial percent bone area measured from the implant surface increased when comparing the titanium alloy to the polymer composite from 10.5% to 41.6% at 0.8 mm, P < 10 -4 , and 19.3% to 77.7% at 0.1 mm, P < 10 -8 . Carbon-fiber fragments planned to occur in the test designs, instead of producing an inflammation, stimulated bone formation and increased bone integration to the implant. In addition, low-thermal polymer processing allows incorporation of minerals and pharmaceuticals for future major tissue-engineering potential.

  16. Bisphenyl-Polymer/Carbon-Fiber-Reinforced Composite Compared to Titanium Alloy Bone Implant

    Directory of Open Access Journals (Sweden)

    Richard C. Petersen

    2011-01-01

    Full Text Available Aerospace/aeronautical thermoset bisphenyl-polymer/carbon-fiber-reinforced composites are considered as new advanced materials to replace metal bone implants. In addition to well-recognized nonpolar chemistry with related bisphenol-polymer estrogenic factors, carbon-fiber-reinforced composites can offer densities and electrical conductivity/resistivity properties close to bone with strengths much higher than metals on a per-weight basis. In vivo bone-marrow tests with Sprague-Dawley rats revealed far-reaching significant osseoconductivity increases from bisphenyl-polymer/carbon-fiber composites when compared to state-of-the-art titanium-6-4 alloy controls. Midtibial percent bone area measured from the implant surface increased when comparing the titanium alloy to the polymer composite from 10.5% to 41.6% at 0.8 mm, P<10−4, and 19.3% to 77.7% at 0.1 mm, P<10−8. Carbon-fiber fragments planned to occur in the test designs, instead of producing an inflammation, stimulated bone formation and increased bone integration to the implant. In addition, low-thermal polymer processing allows incorporation of minerals and pharmaceuticals for future major tissue-engineering potential.

  17. Compositions, methods, and systems comprising fluorous-soluble polymers

    Science.gov (United States)

    Swager, Timothy M.; Lim, Jeewoo; Takeda, Yohei

    2015-10-13

    The present invention generally relates to compositions, methods, and systems comprising polymers that are fluorous-soluble and/or organize at interfaces between a fluorous phase and a non-fluorous phase. In some embodiments, emulsions or films are provided comprising a polymer. The polymers, emulsions, and films can be used in many applications, including for determining, treating, and/or imaging a condition and/or disease in a subject. The polymer may also be incorporated into various optoelectronic device such as photovoltaic cells, organic light-emitting diodes, organic field effect transistors, or the like. In some embodiments, the polymers comprise pi-conjugated backbones, and in some cases, are highly emissive.

  18. Preparation of wood-polymer composites using radiation

    International Nuclear Information System (INIS)

    Ajji, Z.

    2003-11-01

    Wood-polymer composites (WPC) have been prepared of pinewood with different monomers using Gamma radiation: acrylamide, butyl acrylate, butyl methacrylate, styrene, acrylonitrile, and polyester. The polymer loading was determined as a function of monomer concentration and absorbed dose. The data show that polymer loading increases by increasing the monomer concentration. In two cases, BMA and polyester, the polymer loading decreases at high concentrations. This can be explained by the increase of the viscosity. Thus the diffusion of the compound into bulk would be slower. The absorbed dose seems to play a positive role in enhancing the polymer loading by increasing the dose. The mechanical properties, tensile and compression strength, have been improved in the most cases for all monomer concentrations or absorbed doses. Using polyester there was no improvement in the mechanical properties, and using acrylamide the improvement was at high monomer concentration.(author)

  19. Structural studies of thermally stable, combustion-resistant polymer composites

    OpenAIRE

    Smith, G.N.; Hallett, J.E.; Joseph, P.; Tretsiakova-McNally, S.; Zhang, T.; Blum, F.D.; Eastoe, J.

    2017-01-01

    Composites of the industrially important polymer, poly(methyl methacrylate) (PMMA), were prepared by free-radical polymerization of MMA with varying amounts (1–30 wt. %) of sodium dioctylsulfosuccinate (Aerosol OT or AOT) surfactant added to the reaction mixture. The composites with AOT incorporated show enhanced resistance to thermal degradation compared to pure PMMA homopolymer, and micro-cone combustion calorimetry measurements also show that the composites are combustion-resistant. The ph...

  20. Nano-structured polymer composites and process for preparing same

    Science.gov (United States)

    Hillmyer, Marc; Chen, Liang

    2013-04-16

    A process for preparing a polymer composite that includes reacting (a) a multi-functional monomer and (b) a block copolymer comprising (i) a first block and (ii) a second block that includes a functional group capable of reacting with the multi-functional monomer, to form a crosslinked, nano-structured, bi-continuous composite. The composite includes a continuous matrix phase and a second continuous phase comprising the first block of the block copolymer.

  1. Conductive polymer composites with carbonic fillers: Shear induced electrical behaviour

    Czech Academy of Sciences Publication Activity Database

    Starý, Zdeněk; Krückel, J.

    2018-01-01

    Roč. 139, 14 March (2018), s. 52-59 ISSN 0032-3861 R&D Projects: GA ČR(CZ) GA17-05654S; GA MŠk(CZ) LO1507 Institutional support: RVO:61389013 Keywords : polymer-matrix composites * carbon fibres * electrical properties Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 3.684, year: 2016

  2. Uranium-containing plastisol compositions and polymers based on them

    International Nuclear Information System (INIS)

    Katkova, M.A.; Leonov, M.R.; Severina, T.V.; Selivestrov, V.N.; Kozina, I.Z.

    1992-01-01

    Uranium-containing polyvinylchloride plastisol compositions are prepared, from which flexible polymer dielectric films with uranium trioxide content up to 80 % are produced. It is shown that uranium trioxide is an active filler of PVC plastisols, the influence of which on the properties of the polymers produced is diverse and complex. Thus, extreme dependence of strength characteristics of uranium-containing polymers on filling degree is ascertained. Introduction of uranium oxide increases considerably the rate of thermal decomposition and changes sharply absorption characteristics of X radiation

  3. Polymer-Nanoparticle Composites: From Synthesis to Modern Applications

    Directory of Open Access Journals (Sweden)

    Thomas Hanemann

    2010-05-01

    Full Text Available The addition of inorganic spherical nanoparticles to polymers allows the modification of the polymers physical properties as well as the implementation of new features in the polymer matrix. This review article covers considerations on special features of inorganic nanoparticles, the most important synthesis methods for ceramic nanoparticles and nanocomposites, nanoparticle surface modification, and composite formation, including drawbacks. Classical nanocomposite properties, as thermomechanical, dielectric, conductive, magnetic, as well as optical properties, will be summarized. Finally, typical existing and potential applications will be shown with the focus on new and innovative applications, like in energy storage systems.

  4. Compositions for directed alignment of conjugated polymers

    Science.gov (United States)

    Kim, Jinsang; Kim, Bong-Gi; Jeong, Eun Jeong

    2016-04-19

    Conjugated polymers (CPs) achieve directed alignment along an applied flow field and a dichroic ratio of as high as 16.67 in emission from well-aligned thin films and fully realized anisotropic optoelectronic properties of CPs in field-effect transistor (FET).

  5. Light weight polymer matrix composite material

    Science.gov (United States)

    Bowles, Kenneth J. (Inventor); Lowell, Carl E. (Inventor)

    1991-01-01

    A graphite fiber reinforced polymer matrix is layed up, cured, and thermally aged at about 750.degree. F. in the presence of an inert gas. The heat treatment improves the structural integrity and alters the electrical conductivity of the materials. In the preferred embodiment PMR-15 polyimides and Celion-6000 graphite fibers are used.

  6. Electrospinning of polymer-aerogel composite fibres

    DEFF Research Database (Denmark)

    Christiansen, Lasse; Fojan, Peter

    En poster om produktion af polymer-aerogel kompositfibre ved hjælp af elektrospinning. Fiberne er produceret fra en opløsning af aerogel og polyethylene oxide i vand, som er elektrospundet gennem en enkeltnålsprocess....

  7. Fabrication of an Electrically-Resistive, Varistor-Polymer Composite

    Directory of Open Access Journals (Sweden)

    Sanaz A. Mohammadi

    2012-11-01

    Full Text Available This study focuses on the fabrication and electrical characterization of a polymer composite based on nano-sized varistor powder. The polymer composite was fabricated by the melt-blending method. The developed nano-composite was characterized by X-ray diffraction (XRD, transmission electron microscopy (TEM, field emission scanning electron microscopy (FeSEM, and energy-dispersive X-ray spectroscopy (EDAX. The XRD pattern revealed the crystallinity of the composite. The XRD study also showed the presence of secondary phases due to the substitution of zinc by other cations, such as bismuth and manganese. The TEM picture of the sample revealed the distribution of the spherical, nano-sized, filler particles throughout the matrix, which were in the 10–50 nm range with an average of approximately 11 nm. The presence of a bismuth-rich phase and a ZnO matrix phase in the ZnO-based varistor powder was confirmed by FeSEM images and EDX spectra. From the current-voltage curves, the non-linear coefficient of the varistor polymer composite with 70 wt% of nano filler was 3.57, and its electrical resistivity after the onset point was 861 KΩ. The non-linear coefficient was 1.11 in the sample with 100 wt% polymer content. Thus, it was concluded that the composites established a better electrical non-linearity at higher filler amounts due to the nano-metric structure and closer particle linkages.

  8. Polymer/inorganic nanocomposites with tailored hierarchical structure as advanced dielectric materials

    Energy Technology Data Exchange (ETDEWEB)

    Manias, Evangelos [Pennsylvania State University; Randall, Clive [Pennsylvania State University; Tomer, Vivek [Pennsylvania State University; Polyzos, Georgios [ORNL

    2012-01-01

    Most advances and commercial successes of polymer/inorganic nanocomposites rely only on the dispersion of nanoparticles in a polymer matrix. Such approaches leave untapped opportunities where performance can be improved by controlling the larger length-scale structures. Here, we review selected examples where the hierarchical structure (from millimeter to nanometer) is tailored to control the transport properties of the materials, giving rise to marked property enhancements, relevant to dielectric materials for power capacitors. These examples address composite structures that are self-assembled, both at the nm and the micron scales, and, thus, can be produced using standard industrial practices. Specifically, polyethylene (PE) blends or poly(vinylidene fluoride) (PVDF) copolymers are reinforced with nanofillers; these composites are designed with high filler orientation, which yielded marked improvements in electric-field breakdown strength and, consequently, large improvements in their recoverable energy densities.

  9. Method for producing nanowire-polymer composite electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Pei, Qibing; Yu, Zhibin

    2017-11-21

    A method for producing flexible, nanoparticle-polymer composite electrodes is described. Conductive nanoparticles, preferably metal nanowires or nanotubes, are deposited on a smooth surface of a platform to produce a porous conductive layer. A second application of conductive nanoparticles or a mixture of nanoparticles can also be deposited to form a porous conductive layer. The conductive layer is then coated with at least one coating of monomers that is polymerized to form a conductive layer-polymer composite film. Optionally, a protective coating can be applied to the top of the composite film. In one embodiment, the monomer coating includes light transducing particles to reduce the total internal reflection of light through the composite film or pigments that absorb light at one wavelength and re-emit light at a longer wavelength. The resulting composite film has an active side that is smooth with surface height variations of 100 nm or less.

  10. Large energy absorption in Ni-Mn-Ga/polymer composites

    International Nuclear Information System (INIS)

    Feuchtwanger, Jorge; Richard, Marc L.; Tang, Yun J.; Berkowitz, Ami E.; O'Handley, Robert C.; Allen, Samuel M.

    2005-01-01

    Ferromagnetic shape memory alloys can respond to a magnetic field or applied stress by the motion of twin boundaries and hence they show large hysteresis or energy loss. Ni-Mn-Ga particles made by spark erosion have been dispersed and oriented in a polymer matrix to form pseudo 3:1 composites which are studied under applied stress. Loss ratios have been determined from the stress-strain data. The loss ratios of the composites range from 63% to 67% compared to only about 17% for the pure, unfilled polymer samples

  11. Nanophosphor composite scintillators comprising a polymer matrix

    Science.gov (United States)

    Muenchausen, Ross Edward; Mckigney, Edward Allen; Gilbertson, Robert David

    2010-11-16

    An improved nanophosphor composite comprises surface modified nanophosphor particles in a solid matrix. The nanophosphor particle surface is modified with an organic ligand, or by covalently bonding a polymeric or polymeric precursor material. The surface modified nanophosphor particle is essentially charge neutral, thereby preventing agglomeration of the nanophosphor particles during formation of the composite material. The improved nanophosphor composite may be used in any conventional scintillator application, including in a radiation detector.

  12. RETROFITTING OF REINFORCED CONCRETE BEAMS USING FIBRE REINFORCED POLYMER (FRP COMPOSITES - A REVIEW

    Directory of Open Access Journals (Sweden)

    Namasivayam Aravind

    2013-01-01

    Full Text Available Rehabilitation and strengthening of old structures using advanced materials is a contemporary research in the field of Structural Engineering. During past two decades, much research has been carried out on shear and flexural strengthening of reinforced concrete beams using different types of fibre reinforced polymers and adhesives. Strengthening of old structures is necessary to obtain an expected life span. Life span of Reinforced Concrete (RC structures may be reduced due to many reasons, such as deterioration of concrete and development of surface cracks due to ingress of chemical agents, improper design and unexpected external lateral loads such as wind or seismic forces acting on a structure, which are also the reasons for failure of structural members. The superior properties of polymer composite materials like high corrosion resistance, high strength, high stiffness, excellent fatigue performance and good resistance to chemical attack etc., has motivated the researchers and practicing engineers to use the polymer composites in the field of rehabilitation of structures. This paper reviews fourteen articles on rehabilitation of reinforced concrete (RC beams. The paper reviews the different properties of Glass Fibre Reinforced Polymer (GFRP and Carbon Fibre Reinforced Polymer (CFRP composites and adhesives, influence of dimensions of beams and loading rate causing failure. The paper proposes an enhanced retrofitting technique for flexural members and to develop a new mathematical model.

  13. RETROFITTING OF REINFORCED CONCRETE BEAMS USING FIBRE REINFORCED POLYMER (FRP COMPOSITES – A REVIEW

    Directory of Open Access Journals (Sweden)

    Namasivayam Aravind

    2013-06-01

    Full Text Available Rehabilitation and strengthening of old structures using advanced materials is a contemporary research in the field of Structural Engineering. During past two decades, much research has been carried out on shear and flexural strengthening of reinforced concrete beams using different types of fibre reinforced polymers and adhesives. Strengthening of old structures is necessary to obtain an expected life span. Life span of Reinforced Concrete (RC structures may be reduced due to many reasons, such as deterioration of concrete and development of surface cracks due to ingress of chemical agents, improper design and unexpected external lateral loads such as wind or seismic forces acting on a structure, which are also the reasons for failure of structural members. The superior properties of polymer composite materials like high corrosion resistance, high strength, high stiffness, excellent fatigue performance and good resistance to chemical attack etc., has motivated the researchers and practicing engineers to use the polymer composites in the field of rehabilitation of structures. This paper reviews fourteen articles on rehabilitation of reinforced concrete (RC beams. The paper reviews the different properties of Glass Fibre Reinforced Polymer (GFRP and Carbon Fibre Reinforced Polymer (CFRP composites and adhesives, influence of dimensions of beams and loading rate causing failure. The paper proposes an enhanced retrofitting technique for flexural members and to develop a new mathematical model.

  14. Enzyme-polymer composites with high biocatalytic activity and stability

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jungbae; Kosto, Timothy J.; Manimala, Joseph C.; Nauman, E B.; Dordick, Jonathan S.

    2004-08-22

    We have applied vacuum-spraying and electrospinning to incorporate an enzyme into a polymer matrix, creating a novel and highly active biocatalytic composite. As a unique technical approach, enzymes were co-dissolved in toluene with polymers, and the solvent was then rapidly removed by injecting the mixture into a vacuum chamber or by electrospinning. Subsequent crosslinking of the enzyme with glutaraldehyde resulted in stable entrapped enzyme within the polymeric matrices. For example, an amorphous composite of alpha-chymotrypsin and polyethylene showed no significant loss of enzymatic activity in aqueous buffer for one month. Nanofibers of alpha-chymotrypsin and polystyrene also showed no decrease in activity for more than two weeks. The normalized activity of amorphous composite in organic solvents was 3-13 times higher than that of native alpha-chymotrypsin. The activity of nanofibers was 5-7 times higher than that of amorphous composite in aqueous buffer solution. The composites of alpha-chymotrypsin and polymers demonstrate the feasibility of obtaining a wide variety of active and stable biocatalytic materials with many combinations of enzymes and polymers.

  15. Solid polymer electrolyte composite membrane comprising plasma etched porous support

    Science.gov (United States)

    Liu, Han; LaConti, Anthony B.

    2010-10-05

    A solid polymer electrolyte composite membrane and method of manufacturing the same. According to one embodiment, the composite membrane comprises a rigid, non-electrically-conducting support, the support preferably being a sheet of polyimide having a thickness of about 7.5 to 15 microns. The support has a plurality of cylindrical pores extending perpendicularly between opposing top and bottom surfaces of the support. The pores, which preferably have a diameter of about 0.1 to 5 microns, are made by plasma etching and preferably are arranged in a defined pattern, for example, with fewer pores located in areas of high membrane stress and more pores located in areas of low membrane stress. The pores are filled with a first solid polymer electrolyte, such as a perfluorosulfonic acid (PFSA) polymer. A second solid polymer electrolyte, which may be the same as or different than the first solid polymer electrolyte, may be deposited over the top and/or bottom of the first solid polymer electrolyte.

  16. Polymer nanocomposites for high-temperature composite repair

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, Xia [Iowa State Univ., Ames, IA (United States)

    2008-01-01

    A novel repair agent for resin-injection repair of advanced high temperature composites was developed and characterized. The repair agent was based on bisphenol E cyanate ester (BECy) and reinforced with alumina nanoparticles. To ensure good dispersion and compatibility with the BECy matrix in nanocomposites, the alumina nanoparticles were functionalized with silanes. The BECy nanocomposites, containing bare and functionalized alumina nanoparticles, were prepared and evaluated for their thermal, mechanical, rheological, and viscoelastic properties. The monomer of BECy has an extremely low viscosity at ambient temperature, which is good for processability. The cured BECy polymer is a highly cross-linked network with excellent thermal mechanical properties, with a high glass transition temperature (Tg) of 270 C and decomposition temperature above 350 C. The incorporation of alumina nanoparticles enhances the mechanical and rheological properties of the BECy nanocomposites. Additionally, the alumina nanoparticles are shown to catalyze the cure of BECy. Characterization of the nanocomposites included dynamic mechanical analysis, differential scanning calorimetry, thermogravimetric analysis, rheological and rheokinetic evaluation, and transmission electron microscopy. The experimental results show that the BECy nanocomposite is a good candidate as repair agent for resin-injection repair applications.

  17. Characterization of chitosan composites with synthetic polymers and inorganic additives.

    Science.gov (United States)

    Lewandowska, Katarzyna

    2015-11-01

    In the present study, the results from thermogravimetric analysis (TGA), contact angle measurements, tensile tests, scanning electron microscopy (SEM) and atomic force microscopy (AFM) of polymer composites containing chitosan (Ch) and montmorillonite (MMT) with and without poly(vinyl alcohol) (PVA) are presented. Measurements of the contact angles for diiodomethane (D) and glycerol (G) on the surfaces of chitosan films, Ch/MMT and Ch/PVA/MMT, were made and surface free energies were calculated. It was found that the wettability of the chitosan/MMT or Ch/PVA/MMT composite films decreased relative to the wettability of chitosan. The microstructure of unmodified polymers and their composites, as observed by SEM and AFM, showed particles that are relatively well dispersed in the polymer matrix. The TGA thermograms and mass loss percentages at different decomposition temperatures showed that the thermal stability of the binary composite slightly decreases upon the addition of PVA. The film mechanical properties such as tensile strength, Young's modulus and tensile strain at break depend on the composition and varied non-uniformly. Both composites possessed a tensile strength and Young's modulus of 27.6-94.3MPa and 1.5-3.5GPa, respectively. The addition of PVA to the composite led to a reduction in tensile strength by approximately 40%. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Analysis Models for Polymer Composites Across Different Length Scales

    Science.gov (United States)

    Camanho, Pedro P.; Arteiro, Albertino

    This chapter presents the analysis models, developed at different length scales, for the prediction of inelastic deformation and fracture of polymer composite materials reinforced by unidirectional fibers. Three different length scales are covered. Micro-mechanical models are used to understand in detail the effects of the constituents on the response of the composite material, and to support the development of analysis models based on homogenized representations of composite materials. Meso-mechanical models are used to predict the strength of composite structural components under general loading conditions. Finally, macro-mechanical models based on Finite Fracture Mechanics, which enable fast strength predictions of simple structural details, are discussed.

  19. Advanced Ceramics from Preceramic Polymers Modified at the Nano-Scale: A Review

    Science.gov (United States)

    Bernardo, Enrico; Fiocco, Laura; Parcianello, Giulio; Storti, Enrico; Colombo, Paolo

    2014-01-01

    Preceramic polymers, i.e., polymers that are converted into ceramics upon heat treatment, have been successfully used for almost 40 years to give advanced ceramics, especially belonging to the ternary SiCO and SiCN systems or to the quaternary SiBCN system. One of their main advantages is the possibility of combining the shaping and synthesis of ceramics: components can be shaped at the precursor stage by conventional plastic-forming techniques, such as spinning, blowing, injection molding, warm pressing and resin transfer molding, and then converted into ceramics by treatments typically above 800 °C. The extension of the approach to a wider range of ceramic compositions and applications, both structural and thermo-structural (refractory components, thermal barrier coatings) or functional (bioactive ceramics, luminescent materials), mainly relies on modifications of the polymers at the nano-scale, i.e., on the introduction of nano-sized fillers and/or chemical additives, leading to nano-structured ceramic components upon thermal conversion. Fillers and additives may react with the main ceramic residue of the polymer, leading to ceramics of significant engineering interest (such as silicates and SiAlONs), or cause the formation of secondary phases, significantly affecting the functionalities of the polymer-derived matrix. PMID:28788548

  20. Advanced Ceramics from Preceramic Polymers Modified at the Nano-Scale: A Review

    Directory of Open Access Journals (Sweden)

    Enrico Bernardo

    2014-03-01

    Full Text Available Preceramic polymers, i.e., polymers that are converted into ceramics upon heat treatment, have been successfully used for almost 40 years to give advanced ceramics, especially belonging to the ternary SiCO and SiCN systems or to the quaternary SiBCN system. One of their main advantages is the possibility of combining the shaping and synthesis of ceramics: components can be shaped at the precursor stage by conventional plastic-forming techniques, such as spinning, blowing, injection molding, warm pressing and resin transfer molding, and then converted into ceramics by treatments typically above 800 °C. The extension of the approach to a wider range of ceramic compositions and applications, both structural and thermo-structural (refractory components, thermal barrier coatings or functional (bioactive ceramics, luminescent materials, mainly relies on modifications of the polymers at the nano-scale, i.e., on the introduction of nano-sized fillers and/or chemical additives, leading to nano-structured ceramic components upon thermal conversion. Fillers and additives may react with the main ceramic residue of the polymer, leading to ceramics of significant engineering interest (such as silicates and SiAlONs, or cause the formation of secondary phases, significantly affecting the functionalities of the polymer-derived matrix.

  1. Advanced Ceramics from Preceramic Polymers Modified at the Nano-Scale: A Review.

    Science.gov (United States)

    Bernardo, Enrico; Fiocco, Laura; Parcianello, Giulio; Storti, Enrico; Colombo, Paolo

    2014-03-06

    Preceramic polymers, i.e. , polymers that are converted into ceramics upon heat treatment, have been successfully used for almost 40 years to give advanced ceramics, especially belonging to the ternary SiCO and SiCN systems or to the quaternary SiBCN system. One of their main advantages is the possibility of combining the shaping and synthesis of ceramics: components can be shaped at the precursor stage by conventional plastic-forming techniques, such as spinning, blowing, injection molding, warm pressing and resin transfer molding, and then converted into ceramics by treatments typically above 800 °C. The extension of the approach to a wider range of ceramic compositions and applications, both structural and thermo-structural (refractory components, thermal barrier coatings) or functional (bioactive ceramics, luminescent materials), mainly relies on modifications of the polymers at the nano-scale, i.e. , on the introduction of nano-sized fillers and/or chemical additives, leading to nano-structured ceramic components upon thermal conversion. Fillers and additives may react with the main ceramic residue of the polymer, leading to ceramics of significant engineering interest (such as silicates and SiAlONs), or cause the formation of secondary phases, significantly affecting the functionalities of the polymer-derived matrix.

  2. Nanocellulose based polymer composite for acoustical materials

    Science.gov (United States)

    Farid, Mohammad; Purniawan, Agung; Susanti, Diah; Priyono, Slamet; Ardhyananta, Hosta; Rahmasita, Mutia E.

    2018-04-01

    Natural fibers are biodegradable materials that are innovatively and widely used for composite reinforcement in automotive components. Nanocellulose derived from natural fibers oil palm empty bunches have properties that are remarkable for use as a composite reinforcement. However, there have not been many investigations related to the use of nanocellulose-based composites for wideband sound absorption materials. The specimens of nanocellulose-based polyester composite were prepared using a spray method. An impedance tube method was used to measure the sound absorption coefficient of this composite material. To reveal the characteristics of the nanocellulose-based polyester composite material, SEM (scanning electron microscope), TEM (Transmission Electron Microscope), FTIR (Fourier Transform Infra Red), TGA (Thermogravimetric Analysis), and density tests were performed. Sound absorption test results showed the average value of sound absorption coefficient of 0.36 to 0,46 for frequency between 500 and 4000 Hz indicating that this nanocellulose-based polyester composite materials had a tendency to wideband sound absorption materials and potentially used as automotive interior materials.

  3. Properties of Polymer Composites Used in High-Voltage Applications

    Directory of Open Access Journals (Sweden)

    Ilona Pleşa

    2016-04-01

    Full Text Available The present review article represents a comprehensive study on polymer micro/nanocomposites that are used in high-voltage applications. Particular focus is on the structure-property relationship of composite materials used in power engineering, by exploiting fundamental theory as well as numerical/analytical models and the influence of material design on electrical, mechanical and thermal properties. In addition to describing the scientific development of micro/nanocomposites electrical features desired in power engineering, the study is mainly focused on the electrical properties of insulating materials, particularly cross-linked polyethylene (XLPE and epoxy resins, unfilled and filled with different types of filler. Polymer micro/nanocomposites based on XLPE and epoxy resins are usually used as insulating systems for high-voltage applications, such as: cables, generators, motors, cast resin dry-type transformers, etc. Furthermore, this paper includes ample discussions regarding the advantages and disadvantages resulting in the electrical, mechanical and thermal properties by the addition of micro- and nanofillers into the base polymer. The study goals are to determine the impact of filler size, type and distribution of the particles into the polymer matrix on the electrical, mechanical and thermal properties of the polymer micro/nanocomposites compared to the neat polymer and traditionally materials used as insulation systems in high-voltage engineering. Properties such as electrical conductivity, relative permittivity, dielectric losses, partial discharges, erosion resistance, space charge behavior, electric breakdown, tracking and electrical tree resistance, thermal conductivity, tensile strength and modulus, elongation at break of micro- and nanocomposites based on epoxy resin and XLPE are analyzed. Finally, it was concluded that the use of polymer micro/nanocomposites in electrical engineering is very promising and further research work

  4. Gamma and electron beam curing of polymers and composites

    International Nuclear Information System (INIS)

    Saunders, C.B.; Dickson, L.W.; Singh, A.

    1987-01-01

    Radiation polymerization has helped us understand polymer chemistry, and is also playing an increasing role in the field of practical applications. Radiation curing has a present market share of about 5% of the total market for curing of polymers and composites and the annual growth rate of the radiation curing market is ≥20% per year. Advantages of radiation curing over thermal or chemical curing methods include: improved control of the curing rate, reduced curing times, curing at ambient temperatures, curing without the need for chemical initiators, and complete (100%) curing with minimal toxic chemical emissions. Radiation treatment may also be used to effect crosslinking and grafting of polymer and composite materials. The major advantage in these cases is the ability to process products in their final shape. Cable insulation, automotive and aircraft components, and improved construction materials are some of the current and near-future industrial applications of radiation curing and crosslinking. 19 refs

  5. Effects of mechanical properties of polymer on ceramic-polymer composite thick films fabricated by aerosol deposition

    OpenAIRE

    Kwon, Oh-Yun; Na, Hyun-Jun; Kim, Hyung-Jun; Lee, Dong-Won; Nam, Song-Min

    2012-01-01

    Two types of ceramic-polymer composite thick films were deposited on Cu substrates by an aerosol deposition process, and their properties were investigated to fabricate optimized ceramic-based polymer composite thick films for application onto integrated substrates with the advantage of plasticity. When polymers with different mechanical properties, such as polyimide (PI) and poly(methyl methacrylate) (PMMA), are used as starting powders together with α-Al2O3 powder, two types of composite fi...

  6. Solution electrospinning of particle-polymer composite fibres

    DEFF Research Database (Denmark)

    Christiansen, Lasse; Fojan, Peter

    2016-01-01

    into scaffolds. The formation of a particle/polymer composite results in improved mechanical stability, without compromising the porosity. In the presented study, aerogel and poly(ethylene oxide) are mixed into a solution, and spun to thin fibres. Thereby a porous membrane, on the micro- and nano...

  7. Polymer--calcium phosphate cement composites for bone substitutes.

    Science.gov (United States)

    Mickiewicz, Rafal A; Mayes, Anne M; Knaack, David

    2002-09-15

    The use of self-setting calcium phosphate cements (CPCs) as bioresorbable bone-replacement implant materials presently is limited to non-load-bearing applications because of their low compressive strength relative to natural bone. The present study investigated the possibility of strengthening a commercially available CPC, alpha-BSM, by incorporating various water-soluble polymers into the cement paste during setting. Several polyelectrolytes, poly(ethylene oxide), and the protein bovine serum albumin (BSA) were added in solution to the cement paste to create calcium phosphate-polymer composites. Composites formulated with the polycations poly(ethylenimine) and poly(allylamine hydrochloride) exhibited compressive strengths up to six times greater than that of pure alpha-BSM material, with a maximum value reached at intermediate polymer content and for the highest molecular weight studied. Composites containing BSA developed compressive strengths twice that of the original cement at protein concentrations of 13-25% by weight. In each case, XRD studies correlate the improvement in compressive strength with reduced crystallite dimensions, as evidenced by a broadening of the (0,0,2) reflection. This suggests that polycation or BSA adsorption inhibits crystal growth and possibly leads to a larger crystal aspect ratio. SEM results indicate a denser, more interdigitated microstructure. The increased strength was attributed to the polymer's capacity to bridge between multiple crystallites (thus forming a more cohesive composite) and to absorb energy through plastic flow. Copyright 2002 Wiley Periodicals, Inc.

  8. Effects Of Solvent Composition And Polymer Concentration On Poly ...

    African Journals Online (AJOL)

    Its solution in Phenol: 1,2-dichlorobenzene solvent mixtures of 35%: 65%, 50%: 50%, 65%: 35% by weight was degraded at 143± 2oC. The effects of solvent composition and polymer concentration on poly (ethylene terephthalate) degradation in solution were investigated by dilute solution viscometric method using 0.460, ...

  9. Polymer-based composites for RFI/EMI/ applications

    Science.gov (United States)

    Williams, Neil; Varadan, Vijay K.; Varadan, Vasundara V.

    1990-10-01

    A conductive polymer composite of 2.4 mm thickness has been measured at a frequency range of 100 MHz to 18 GHz. This sample was measured for its EMI and EMC characteristics for use in electromagnetic shielding applications. It was shown that this thin sample achieved high transmission loss over a broad frequency range.

  10. Tribological performance of polymer composites used in electrical ...

    Indian Academy of Sciences (India)

    GFR) polymer composite. Wear test was carried out at 10, 20 and 30 N applied load values and 0·5 m/s sliding speed and at ambient temperature and humidity. Different combinations of rubbing surfaces were examined and friction coefficient and ...

  11. Mechanical properties of natural fibre reinforced polymer composites

    Indian Academy of Sciences (India)

    In the present communication, a study on the synthesis and mechanical properties of new series of green composites involving Hibiscus sabdariffa fibre as a reinforcing material in urea–formaldehyde (UF) resin based polymer matrix has been reported. Static mechanical properties of randomly oriented intimately mixed ...

  12. Tribological performance of polymer composites used in electrical ...

    Indian Academy of Sciences (India)

    Sliding wear performance of 20% mica-filled polyamide 6 (PA6 + 20% mica) and 20% short glass fibrereinforced polysulphone (PSU + 20 GFR) polymer composites used in electrical applications were investigated using a pin-on-disc wear test apparatus. Two different disc materials were used in this study. These are AISI ...

  13. Mechanics of Carbon Nanotubes and their Polymer Composites

    Science.gov (United States)

    Wei, Chenyu; Cho, K. J.; Srivastava, Deepak; Tang, Harry (Technical Monitor)

    2002-01-01

    Contents include the folloving: carbon nanotube (CNT): structures, application of carbon nanotubes, simulation method, Elastic properties of carbon nanotubes, yield strain of CNT, yielding under tensile stress, yielding: strain-rate and temperature dependence, yield strain under tension, yielding at realistic conditions, nano fibers, polymer CNT composite, force field, density dependency on temperature, diffusion coefficients, young modulus, and conclusions.

  14. Tribological performance of polymer composites used in electrical ...

    Indian Academy of Sciences (India)

    These are AISI 316 L stainless steel and 30% glass fibre-reinforced polyphenylenesulphide (PPS + 30%GFR) polymer composite. Wear test was carried out at 10, 20 and 30 N applied load values and 0.5 m/s sliding speed and at ambient temperature and humidity. Different combinations of rubbing surfaces were examined ...

  15. Machining of Machine Elements Made of Polymer Composite Materials

    Science.gov (United States)

    Baurova, N. I.; Makarov, K. A.

    2017-12-01

    The machining of the machine elements that are made of polymer composite materials (PCMs) or are repaired using them is considered. Turning, milling, and drilling are shown to be most widely used among all methods of cutting PCMs. Cutting conditions for the machining of PCMs are presented. The factors that most strongly affect the roughness parameters and the accuracy of cutting PCMs are considered.

  16. All-solid state flexible supercapacitors based on graphene/polymer composites

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Won; Choi, Bong Gill, E-mail: bgchoi@kangwon.ac.kr

    2015-06-01

    Recent advances in lightweight, flexible, and wearable electronic equipment has led to advancements in the development of sufficiently compact and flexible energy storage. A challenge remains to integrate the storage elements as closely as possible within a fully flexible device. Here, we demonstrate the fabrication of all-solid state flexible supercapacitors with the integration of two electrodes that consist of graphene/polymer composites. Robust conductive free-standing thin graphene/polymer composite electrodes were prepared through a simple “physical grinding” process. As-prepared composite electrodes store energy up to a reversible gravimetric capacitance of 90.6 F/g, at a constant current density of 0.5 A/g while also delivering long-term durability (90% retention) for excess of five-thousands of cycles. Notably, the enhancement of mechanical properties of supercapacitors enables them to maintain their electrochemical performance even when twisted or folded. This straightforward approach to the fabrication of fully flexible supercapacitors provides new design opportunities within wearable electronics and electrochemical applications. - Highlights: • All solid-sate supercapacitors were fabricated using graphene/polymer composite electrodes. • Supercapacitor devices show an excellent mechanical flexibility. • High electrochemical performances were demonstrated.

  17. Extrudable polymer-polymer composites based on ultra-high molecular weight polyethylene

    Science.gov (United States)

    Panin, S. V.; Kornienko, L. A.; Alexenko, V. O.; Buslovich, D. G.; Dontsov, Yu. V.

    2017-12-01

    Mechanical and tribotechnical characteristics of polymer-polymeric composites of UHMWPE are studied with the aim of developing extrudable, wear-resistant, self-lubricant polymer mixtures for Additive Manufacturing (AM). The motivation of the study is their further application as feedstocks for 3D printing. Blends of UHMWPE with graft- and block copolymers of low-density polyethylene (HDPE-g-VTMS, HDPE-g-SMA, HDPE-b-EVA), polypropylene (PP), block copolymers of polypropylene and polyamide with linear low density polyethylene (PP-b-LLDPE, PA-b-LLDPE), as well as cross-linked polyethylene (PEX-b), are examined. The choice of compatible polymer components for an ultra- high molecular weight matrix for increasing processability (extrudability) is motivated by the search for commercially available and efficient additives aimed at developing wear-resistant extrudable polymer composites for additive manufacturing. The extrudability, mechanical properties and wear resistance of UHMWPE-based polymer-polymeric composites under sliding friction with different velocities and loads are studied.

  18. Polymer derived ceramic composites as environmental barrier coatings on steel

    Science.gov (United States)

    Torrey, Jessica D.

    Polymer derived ceramics have shown promise as a novel way to process low-dimensional ceramics such as fibers and coatings. They offer advantages over traditional ceramic processing routes including lower pyrolysis temperatures and the ability to employ polymeric processing techniques. The main drawback to preceramic polymers is that they undergo a shrinkage during pyrolysis that can be greater than 50-volume%. One way to overcome this shrinkage is to add filler particles, usually elemental or binary metals, which will expand upon reaction with the pyrolysis atmosphere, thereby compensating for the shrinkage of the polymer. The aim of this study is to develop a polymer derived ceramic composite coating on steel as a barrier to oxidation and carburization, while concurrently gaining insight as to the fundamental mechanisms for compositional and microstructural evolution within the system. A systematic approach to selecting the preceramic polymer and expansion agents was taken. Six commercially available poly(silsesquioxane) polymers and a polysiloxane were studied. Several metals and an intermetallic were considered as potential expansion agents. The most desirable polymer/expansion agent combination was achieved with poly(hydridomethylsiloxane) as the matrix and titanium disilicide as the filler. Processing parameters have been optimized and a relationship derived to predict final coating thickness based on slurry viscosity and dip coating withdrawal speed. Microstructural analysis reveals an amorphous composite coating of oxidized filler particles in a silica matrix. A diffusion layer is visible at the coating-steel interface, indicating good bonding. The optimized coatings are ˜18mum thick, have some residual porosity and a density of 2.57g/cm3. A systematic study of the phase transformations and microstructural changes in the coating and its components during pyrolysis in air is also presented. The system evolves from a polymer filled with a binary metal at

  19. Ultrasonic characterization of silicate glasses, polymer composites and hydrogels

    Science.gov (United States)

    Lee, Wan Jae

    In many applications of material designing and engineering, high-frequency linear viscoelastic properties of materials are essential. Traditionally, the high-frequency properties are estimated through the time-temperature superposition (WLF equation) of low-frequency data, which are questionable because the existence of multi-phase in elastomer compounds. Moreover, no reliable data at high frequencies over MHz have been available thus far. Ultrasound testing is cost-effective for measuring high-frequency properties. Although both ultrasonic longitudinal and shear properties are necessary in order to fully characterize high-frequency mechanical properties of materials, longitudinal properties will be extensively explored in this thesis. Ultrasonic pulse echo method measures longitudinal properties. A precision ultrasonic measurement system has been developed in our laboratory, which allows us to monitor the in-situ bulk and/or surface properties of silicate glasses, polymer composites and even hydrogels. The system consists of a pulse-echo unit and an impedance measurement unit. A pulse echo unit is explored mainly. First, a systematic procedure was developed to obtain precise water wavespeed value. A calibration curve of water wavespeed as a function of temperature has been established, and water wavespeed at 23°C serves as a yardstick to tell whether or not a setup is properly aligned. Second, a sound protocol in calculating attenuation coefficient and beam divergence effects was explored using three kinds of silicate glass of different thicknesses. Then the system was applied to four composite slabs, two slabs for each type of fiberglass reinforced plastics, phenolic and polyester manufactured under different processing conditions: one was made by the normal procedures and the other with deliberate flaws such as voids, tapes and/or prepared at improper operation temperature and pressure. The experiment was conducted under the double blind test protocol. After

  20. Radiation Processing of Advanced Composite Materials

    International Nuclear Information System (INIS)

    Kang, Phil Hyun; Jeun, Joonpyo; Nho, Young Chang

    2008-01-01

    Advanced composites, such as carbon-fiber-reinforced plastics, are being used widely for many applications. Carbon fiber/epoxies composites have attracted special attention from the aircraft, aerospace, marine engineering, sporting goods and transportation industries, because they have useful mechanical properties including high strength-to-weight and stiffness-to-weight ratios, a corrosion resistant, impact and damage tolerance characteristics and wear properties. Thermal curing has been the dominant industrial process for advanced composites until now, however, a radiation curing process using UV, microwave x-ray, electron-beam(E-beam) and γ-ray has emerged as a better alternative in recent years. These processes are compatible with the manufacturing of composites using traditional fabrication methods including a filament/tape winding, pultrusion, resin transfer moulding and hand lay-up. In this study, E-beam curable carbon fiber/epoxy composites were manufactured, and their mechanical properties were investigated. Two epoxy resins (bisphenol-A, bisphenol-F) containing photo-initiators (tri aryl sulfonium hexafluorophosphate, tri aryl sulfonium hexafluoroantimonate) were used as a matrix and a 4H-satin carbon woven fabric was used as a reinforcement. And then an electron beam irradiated the composites up to 200 kGy in a vacuum and an inert atmosphere. The cure cycle was optimized and the properties of composites were evaluated and analyzed via a differential scanning calorimetry, scanning electron microscopy, sol-gel extractions, FT-NIR, universal test machine, and an impact tester. The gel content, glass transition temperature and mechanical strength of the irradiated composites were increased with an increasing radiation dose

  1. Porous polymer networks and ion-exchange media and metal-polymer composites made therefrom

    Science.gov (United States)

    Kanatzidis, Mercouri G.; Katsoulidis, Alexandros

    2016-10-18

    Porous polymeric networks and composite materials comprising metal nanoparticles distributed in the polymeric networks are provided. Also provided are methods for using the polymeric networks and the composite materials in liquid- and vapor-phase waste remediation applications. The porous polymeric networks, are highly porous, three-dimensional structures characterized by high surface areas. The polymeric networks comprise polymers polymerized from aldehydes and phenolic molecules.

  2. Properties of Plant Fiber Yarn Polymer Composites

    DEFF Research Database (Denmark)

    Madsen, Bo

    2004-01-01

    . The thesis presents experimental investigations and modelling of the properties of aligned plant fibre composites based on textile hemp yarn and thermoplastic matrices. The textile hemp yarn has been characterised. It is high in cellulose and with fibres well separated from each other; i.e. only few fibres...... are situated in bundles. The twisting angle is low; i.e. about 15 o for the outermost fibres in the yarn. The moisture sorption capacity of the yarn fibres is much lower than that of raw hemp fibres. Stiffness and strength of the fibres as calculated from composite data are in the ranges 50-65 GPa and 530......-650 MPa respectively. These properties show that textile hemp yarn is well suited as composite reinforcement. The relationship between fibre volume fraction and porosity has been studied. A model has been developed that predicts porosity from experimentally determined parameters such as fibre lumen...

  3. Electrochemical properties of polypyrrole/polyfuran polymer composite electrode

    International Nuclear Information System (INIS)

    Cha, Seong Keuck

    1998-01-01

    Poly pyrrole polymer(ppy) has an excellent electrical conductivity and can be easily polymerized on anode to give various morphology according to doped anion on electroactive sites. To improve the properties of brittleness, ageing and hydrophobicity, poly furan polymer(pfu) having a high initiation potential was anodically implanted in this porous ppy film matrix to get the Pt/ppy/pfu(x)type of polymer campsite electrode. Cyclic voltammetry and electrochemical impedance methods were used to these electrode, where PF 6 - , BF 4 - , and ClO 4 - ions were employed as dopants. The composition of the pfu(x) at the electrode was changed from 0 to 1.10, but the range was useful only at 0.1 to 0.2 as the redox electrode. The polymer composite electrode doped with PF 6 - was better in charge transfer resistance by a factor of 40 times and in double layer capacitance by a factor of 20 times than others. The charge transfer in the polymer film of the electrode was influenced on frequency change and equivalent circuit of this electrode had Warburg impedance including mass transfer

  4. Composite Polymer Electrolytes: Nanoparticles Affect Structure and Properties

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2016-11-01

    Full Text Available Composite polymer electrolytes (CPEs can significantly improve the performance in electrochemical devices such as lithium-ion batteries. This review summarizes property/performance relationships in the case where nanoparticles are introduced to polymer electrolytes. It is the aim of this review to provide a knowledge network that elucidates the role of nano-additives in the CPEs. Central to the discussion is the impact on the CPE performance of properties such as crystalline/amorphous structure, dielectric behavior, and interactions within the CPE. The amorphous domains of semi-crystalline polymer facilitate the ion transport, while an enhanced mobility of polymer chains contributes to high ionic conductivity. Dielectric properties reflect the relaxation behavior of polymer chains as an important factor in ion conduction. Further, the dielectric constant (ε determines the capability of the polymer to dissolve salt. The atom/ion/nanoparticle interactions within CPEs suggest ways to enhance the CPE conductivity by generating more free lithium ions. Certain properties can be improved simultaneously by nanoparticle addition in order to optimize the overall performance of the electrolyte. The effects of nano-additives on thermal and mechanical properties of CPEs are also presented in order to evaluate the electrolyte competence for lithium-ion battery applications.

  5. Sensing and Energy Harvesting Novel Polymer Composites

    NARCIS (Netherlands)

    Zwaag, S. van der; Ende, D.A. van der; Groen, W.A.

    2014-01-01

    This chapter describes the development and properties of novel functional composite materials consisting of aligned piezo-ceramic particles or fibers in a polymeric matrix, which can be fully integrated in thermoset or thermoplastic products. The materials have a low potential for applications

  6. Characterization of piezoelectric polymer composites for MEMS ...

    Indian Academy of Sciences (India)

    Abstract. Composite piezoelectric ceramics are important materials for transducer applications in medical diag- nostic devices and MEMS devices. In micrometer scale the material properties of piezopolymers or piezoceramics do not coincide with that of bulk materials. The present work is aimed at simulating the material ...

  7. Additive Manufacturing of Ultem Polymers and Composites

    Science.gov (United States)

    Chuang, Kathy C.; Grady, Joseph E.; Draper, Robert D.; Shin, Euy-Sik E.; Patterson, Clark; Santelle, Thomas D.

    2015-01-01

    The objective of this project was to conduct additive manufacturing to produce aircraft engine components by Fused Deposition Modeling (FDM), using commercially available polyetherimdes Ultem 9085 and experimental Ultem 1000 filled with 10 chopped carbon fiber. A property comparison between FDM-printed and injection molded coupons for Ultem 9085, Ultem 1000 resin and the fiber-filled composite Ultem 1000 was carried out. Furthermore, an acoustic liner was printed from Ultem 9085 simulating conventional honeycomb structured liners and tested in a wind tunnel. Composite compressor inlet guide vanes were also printed using fiber-filled Ultem 1000 filaments and tested in a cascade rig. The fiber-filled Ultem 1000 filaments and composite vanes were characterized by scanning electron microscope (SEM) and acid digestion to determine the porosity of FDM-printed articles which ranged from 25-31. Coupons of Ultem 9085, experimental Ultem 1000 composites and XH6050 resin were tested at room temperature and 400F to evaluate their corresponding mechanical properties.

  8. Ice-Templated Assembly Strategy to Construct 3D Boron Nitride Nanosheet Networks in Polymer Composites for Thermal Conductivity Improvement.

    Science.gov (United States)

    Zeng, Xiaoliang; Yao, Yimin; Gong, Zhengyu; Wang, Fangfang; Sun, Rong; Xu, Jianbin; Wong, Ching-Ping

    2015-12-01

    Owing to the growing heat removal issue of modern electronic devices, polymer composites with high thermal conductivity have drawn much attention in the past few years. However, a traditional method to enhance the thermal conductivity of the polymers by addition of inorganic fillers usually creates composite with not only limited thermal conductivity but also other detrimental effects due to large amount of fillers required. Here, novel polymer composites are reported by first constructing 3D boron nitride nanosheets (3D-BNNS) network using ice-templated approach and then infiltrating them with epoxy matrix. The obtained polymer composites exhibit a high thermal conductivity (2.85 W m(-1) K(-1)), a low thermal expansion coefficient (24-32 ppm K(-1)), and an increased glass transition temperature (T(g)) at relatively low BNNSs loading (9.29 vol%). These results demonstrate that this approach opens a new avenue for design and preparation of polymer composites with high thermal conductivity. The polymer composites are potentially useful in advanced electronic packaging techniques, namely, thermal interface materials, underfill materials, molding compounds, and organic substrates. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Magnetoelectric polymer-based composites fundamentals and applications

    CERN Document Server

    Martins, Pedro

    2017-01-01

    The first book on this topic provides a comprehensive and well-structured overview of the fundamentals, synthesis and emerging applications of magnetoelectric polymer materials. Following an introduction to the basic aspects of polymer based magnetoelectric materials and recent developments, subsequent chapters discuss the various types as well as their synthesis and characterization. There then follows a review of the latest applications, such as memories, sensors and actuators. The book concludes with a look at future technological advances. An essential reference for entrants to the field as well as for experienced researchers.

  10. Nanomodified polymer composites: Thermophysical and physico-mechanical properties

    Science.gov (United States)

    Shchegolkov, Alexander; Shchegolkov, Alexey; Dyachkova, Tatyana; Borovskikh, Pavel

    2017-11-01

    The paper presents the results of investigation of thermophysical and physicomechanical properties of polymer-based composites modified with paraffin and carbon nanotubes (CNTs) mixture. Thermal conductivity of composites based on polyethylene, fluoroplastic, polyvinyl chloride (PVC) is 0.48, 0.42 and 0.36 W/(m.°C), respectively, compared to thermal conductivity of pure paraffin - 0.25 W/(m.°C). It has been revealed that for materials heat capacity the polymer matrix determines the position of the maximum point on temperature dependence having extreme nature. Temperature changes in composites volume do not exceed 3% from the initial state to the phase transition, that allows them to be used in a combination with other materials.

  11. Improvement of acoustical characteristics : wideband bamboo based polymer composite

    Science.gov (United States)

    Farid, M.; Purniawan, A.; Rasyida, A.; Ramadhani, M.; Komariyah, S.

    2017-07-01

    Environmental friendly and comfortable materials are desirable for applications in the automobile interior. The objective of this research was to examine and develop bamboo based polymer composites applied to the sound absorption materials of automobile door panels. Morphological analysis of the polyurethane/bamboo powder composite materials was carried out using scanning electron microscope to reveal the microscopic material behavior and followed by the FTIR and TGA testing. The finding demonstrated that this acoustical polymer composite materials provided a potential wideband sound absorption material. The range of frequency can be controlled between 500 and 4000 Hz with an average of sound absorption coefficient around 0.411 and it met to the door panels criteria.

  12. Thermoresistive mechanisms of carbon nanotube/polymer composites

    Science.gov (United States)

    Cen-Puc, M.; Oliva-Avilés, A. I.; Avilés, F.

    2018-01-01

    The mechanisms governing thermoresistivity of carbon nanotube (CNT)/polymer composites are theoretically and experimentally investigated. Two modeling approaches are proposed to this aim considering a broad range of CNT concentrations (0.5-50 wt%). In the first model, thermal expansion of the polymer composite is predicted using a finite element model; the resulting CNT-to-CNT separation distance feeds a classical tunneling model to predict the dependence of the electrical resistance with temperature. The second approach uses the general effective medium considering the dilution of the CNT volume fraction due to the thermal expansion of the polymer. Both models predict that the electrical resistance increases with increased temperature (i.e. a positive temperature coefficient of resistance, TCR) for all investigated CNT concentrations, with higher TCRs for lower CNT concentrations. Comparison between modeling outcomes and experimental data suggests that polymer thermal expansion (and tunneling) play a dominant role for low CNT concentrations (≤ 10 wt%) heated above room temperature. On the other hand, for composites at high CNT concentrations (50 wt%) or for freezing temperatures (-110 °C), a negative TCR was experimentally obtained, suggesting that for those conditions the CNT intrinsic thermoresistivity and the electronic conduction between CNTs by thermal activation may play a paramount role.

  13. RF electromagnetic wave absorbing properties of ferrite polymer composite materials

    International Nuclear Information System (INIS)

    Dosoudil, Rastislav; Usakova, Marianna; Franek, Jaroslav; Slama, Jozef; Olah, Vladimir

    2006-01-01

    The frequency dispersion of complex initial (relative) permeability (μ * =μ ' -jμ ' ') and the electromagnetic wave absorbing properties of composite materials based on NiZn sintered ferrite and a polyvinylchloride (PVC) polymer matrix have been studied in frequency range from 1MHz to 1GHz. The complex permeability of the composites was found to increase as the ferrite content increased, and was characterized by frequency dispersion localized above 50MHz. The variation of return loss (RL) of single-layer RF absorbers using the prepared composite materials has been investigated as a function of frequency, ferrite content and the thickness of the absorbers

  14. Advanced composite elevator for Boeing 727 aircraft

    Science.gov (United States)

    1979-01-01

    Detail design activities are reported for a program to develop an advanced composites elevator for the Boeing 727 commercial transport. Design activities include discussion of the full scale ground test and flight test activities, the ancillary test programs, sustaining efforts, weight status, and the production status. Prior to flight testing of the advanced composites elevator, ground, flight flutter, and stability and control test plans were reviewed and approved by the FAA. Both the ground test and the flight test were conducted according to the approved plan, and were witnessed by the FAA. Three and one half shipsets have now been fabricated without any significant difficulty being encountered. Two elevator system shipsets were weighed, and results validated the 26% predicted weight reduction. The program is on schedule.

  15. Tridimensional ionic polymer metal composites: optimization of the manufacturing techniques

    International Nuclear Information System (INIS)

    Bonomo, C; Brunetto, P; Fortuna, L; Graziani, S; Bottino, M; Di Pasquale, G; Pollicino, A

    2010-01-01

    Ionic polymer metal composites (IPMCs) belong to electroactive polymers (EAPs) and have been suggested for various applications due to their light weight and to the fact that they react mechanically when stimulated by an electrical signal and vice versa. Thick IPMCs (3D-IPMCs) have been fabricated by hot pressing several Nafion ® 117 films. Additional post-processes (more cycles of Pt electroless plating and dispersing agents) have been applied to improve the 3D-IPMC performance. The electromechanical response of 3D-IPMCs has been examined by applying electrical signals and measuring the displacement and blocking force produced

  16. Advanced powder metallurgy aluminum alloys and composites

    Science.gov (United States)

    Lisagor, W. B.; Stein, B. A.

    1982-01-01

    The differences between powder and ingot metallurgy processing of aluminum alloys are outlined. The potential payoff in the use of advanced powder metallurgy (PM) aluminum alloys in future transport aircraft is indicated. The national program to bring this technology to commercial fruition and the NASA Langley Research Center role in this program are briefly outlined. Some initial results of research in 2000-series PM alloys and composites that highlight the property improvements possible are given.

  17. Dispersion and alignment of carbon nanotubes in polymer based composites

    Science.gov (United States)

    Camponeschi, Erin Lynn

    This research is intended to create usable carbon nanotube polymer based composites for structural applications by effectively aligning and dispersing the carbon nanotubes in a polymer matrix. The motivation for this research is to create very lightweight, high strength materials that will surpass their predecessors: carbon fibers. The final product then can be used in applications across the industries. This research determined the effect of three different surface-active agents and two different aligning methods on the structural features and mechanical properties of the polymer-based composite. The three types of surface-active agents used in this research are a surfactant and two different block copolymers. From this research, it will be determined how different surface-active agents adequately disperse the carbon nanotube, and the effects the dispersing agent have on a final dispersed product. In addition, the dispersing agent effects on the alignment of the carbon nanotubes and the final product can be compared. The two alignment techniques used in this research were alignment via shear flow and tethering iron oxide particles to the carbon nanotubes to induce alignment in a magnetic field. The method of shear aligning carbon nanotubes is very simplistic in theory, but actual application becomes much more challenging. This research illustrates the effects on shear alignment in a viscous polymer flow and then applies those theories to polymers. This work then compares the different alignment techniques to determine the overall increase of properties and the effective carbon nanotube alignment. This research provides a framework for the creation of dispersed and aligned composites that can be expanded upon and improved to further develop the carbon nanotubes as possible replacement fillers for composite materials.

  18. Space environmental effects on LDEF low Earth orbit exposed graphite reinforced polymer matrix composites

    International Nuclear Information System (INIS)

    George, P.

    1992-01-01

    The Long Duration Exposure Facility (LDEF) was deployed on April 7, 1984 in low earth orbit (LEO) at an altitude of 482 kilometers. On board experiments experienced the harsh LEO environment including atomic oxygen (AO), ultraviolet radiation (UV), and thermal cycling. During the 5.8 year mission, the LDEF orbit decayed to 340 kilometers where significantly higher AO concentrations exist. One experiment on board LDEF was M0003, Space Effects on Spacecraft Materials. As a subset of M0003 nearly 500 samples of polymer, metal, and glass matrix composites were flown as the Advanced Composites Experiment M0003-10. The Advanced Composites Experiment is a joint effort between government and industry with the Aerospace Corporation serving as the experiment integrator. A portion of the graphite reinforced polymer matrix composites were furnished by the Boeing Defense and Space Group, Seattle, Washington. Test results and discussions for the Boeing portion of M0003-10 are presented. Experiment and specimen location on the LDEF are presented along with a quantitative summary of the pertinent exposure conditions. Matrix materials selected for the test were epoxy, polysulfone, and polyimide. These composite materials were selected due to their suitability for high performance structural capability in spacecraft applications. Graphite reinforced polymer matrix composites offer higher strength to weight ratios along with excellent dimensional stability. The Boeing space exposed and corresponding ground control composite specimens were subjected to post flight mechanical, chemical, and physical testing in order to determine any changes in critical properties and performance characteristics. Among the more significant findings are the erosive effect of atomic oxygen on leading edge exposed specimens and microcracking in non-unidirectionally reinforced flight specimens

  19. VARTM Processing of High Temperature Polymer Matrix Composites

    National Research Council Canada - National Science Library

    Criss, Jr, Jim M

    2008-01-01

    The overall technical objective of the Phase 1 effort was to extend and advance the state the-art in high temperature composite fabrication techniques by developing a High Tempera Vacuum Assisted Resin Transfer Molding (VARTM...

  20. Nanostructures on spin-coated polymer films controlled by solvent composition and polymer molecular weight

    Energy Technology Data Exchange (ETDEWEB)

    Dario, Aline F.; Macia, Henrique B.; Petri, Denise F.S., E-mail: dfsp@iq.usp.br

    2012-12-01

    In this study we systematically investigated how the solvent composition used for polymer dissolution affects the porous structures of spin-coated polymers films. Cellulose acetate butyrate (CAB) and poly(methyl methacrylate) with low (PMMA-L) and high (PMMA-H) molecular weights were dissolved in mixtures of acetone (AC) and ethyl acetate (EA) at constant polymer concentration of 10 g/L The films were spin-coated at a relative air humidity of 55 {+-} 5%, their thickness and index of refraction were determined by means of ellipsometry and their morphology was analyzed by atomic force microscopy. The dimensions and frequency of nanocavities on polymer films increased with the acetone content ({phi}{sub AC}) in the solvent mixture and decreased with increasing polymer molecular weight. Consequently, as the void content increased in the films, their apparent thicknesses increased and their indices of refraction decreased, creating low-cost anti-reflection surface. The void depth was larger for PMMA-L than for CAB. This effect was attributed to different activities of EA and AC in CAB or PMMA-L solution, the larger mobility of chains and the lower polarity of PMMA-L in comparison to CAB. - Highlights: Black-Right-Pointing-Pointer Nanostructures in spin-coated polymer films depend on the solvent vapor pressure. Black-Right-Pointing-Pointer Anti-reflection polymer films are produced at high solvent vapor pressure. Black-Right-Pointing-Pointer Only shallow cavities are obtained in films of polymers with high molecular weight.

  1. Smart conducting polymer composites having zero temperature coefficient of resistance

    Science.gov (United States)

    Chu, Kunmo; Lee, Sung-Chul; Lee, Sangeui; Kim, Dongearn; Moon, Changyoul; Park, Sung-Hoon

    2014-12-01

    Zero temperature coefficient of resistance (TCR) is essential for the precise control of temperature in heating element and sensor applications. Many studies have focused on developing zero-TCR systems with inorganic compounds; however, very few have dealt with developing zero-TCR systems with polymeric materials. Composite systems with a polymer matrix and a conducting filler show either a negative (NTC) or a positive temperature coefficient (PTC) of resistance, depending on several factors, e.g., the polymer nature and the filler shape. In this study, we developed a hybrid conducting zero-TCR composite having self-heating properties for thermal stability and reliable temperature control. The bi-layer composites consisted of a carbon nanotube (CNT)-based layer having an NTC of resistance and a carbon black (CB)-based layer having a PTC of resistance which was in direct contact with electrodes to stabilize the electrical resistance change during electric Joule heating. The composite showed nearly constant resistance values with less than 2% deviation of the normalized resistance until 200 °C. The CB layer worked both as a buffer and as a distributor layer against the current flow from an applied voltage. This behavior, which was confirmed both experimentally and theoretically, has been rarely reported for polymer-based composite systems.Zero temperature coefficient of resistance (TCR) is essential for the precise control of temperature in heating element and sensor applications. Many studies have focused on developing zero-TCR systems with inorganic compounds; however, very few have dealt with developing zero-TCR systems with polymeric materials. Composite systems with a polymer matrix and a conducting filler show either a negative (NTC) or a positive temperature coefficient (PTC) of resistance, depending on several factors, e.g., the polymer nature and the filler shape. In this study, we developed a hybrid conducting zero-TCR composite having self

  2. Self-healing polymer cement composites for geothermal wellbore applications

    Science.gov (United States)

    Rod, K. A.; Fernandez, C.; Childers, I.; Koech, P.; Um, W.; Roosendaal, T.; Nguyen, M.; Huerta, N. J.; Chun, J.; Glezakou, V. A.

    2017-12-01

    Cement is vital for controlling leaks from wellbores employed in oil, gas, and geothermal operations by sealing the annulus between the wellbore casing and geologic formation. Wellbore cement failure due to physical and chemical stresses is common and can result in significant environmental consequences and ultimately significant financial costs due to remediation efforts. To date numerous alternative cement blends have been proposed for the oil and gas industry. Most of these possess poor mechanical properties, or are not designed to work in high temperature environments. This research investigates novel polymer-cement composites which could function at most geothermal temperatures. Thermal stability and mechanical strength of the polymer is attributed to the formation of a number of chemical interactions between the polymer and cement matrix including covalent bonds, hydrogen bonding, and van der Waals interactions. It has been demonstrated that the bonding between cement and casing is more predictable when polymer is added to cement and can even improve healing of adhesion break when subjected to stresses such as thermal shock. Fractures have also been healed, effectively reducing permeability with fractures up to 0.3-0.5mm apertures, which is two orders of magnitude larger than typical wellbore fractures. Additionally, tomography analysis was used to determine internal structure of the cement polymer composite and imaging reveals that polymers fill fractures in the cement and between the cement and casing. By plugging fractures that occur in wellbore cement, reducing permeability of fractures, both environmental safety and economics of subsurface operations will be improved for geothermal energy and oil and gas production.

  3. Polymer matrix composites research: A survey of federally sponsored programs

    Energy Technology Data Exchange (ETDEWEB)

    1990-06-01

    This report identifies research conducted by agencies of the federal government other than the Department of Energy (DOE) in the area of advanced polymer matrix composites (PMCs). DOE commissioned the report to avoid duplicating other agencies' efforts in planning its own research program for PMCs. PMC materials consist of high-strength, short or continuous fibers fused together by an organic matrix. Compared to traditional structural metals, PMCs provide greater strength and stiffness, reduced weight and increased heat resistance. The key contributors to PMC research identified by the survey are the Department of Defense (DOD), the National Aeronautics and Space Administration (NASA), the National Science Foundation (NSF), and the Department of Transportation (DOT). The survey identified a total of 778 projects. More than half of the total projects identified emphasize materials research with a goal toward developing materials with improved performance. Although an almost equal number of identified materials projects focus on thermosets and thermoplastics receive more attention because of their increased impact resistance and their easy formability and re-formability. Slightly more than one third of projects identified target structures research. Only 15 percent of the projects identified focus on manufacturing techniques, despite the need for efficient, economical methods manufacturing products constructed of PMCs--techniques required for PMCs to gain widespread acceptance. Three issues to be addressed concerning PMCs research are economy of use, improvements in processing, and education and training. Five target technologies have been identified that could benefit greatly from increased use of PMCs: aircraft fuselages, automobile frames, high-speed machinery, electronic packaging, and construction.

  4. Thermosetting Polymer-Matrix Composites for Strucutral Repair Applications

    Energy Technology Data Exchange (ETDEWEB)

    Goertzen, William Kirby [Iowa State Univ., Ames, IA (United States)

    2007-12-01

    Several classes of thermosetting polymer matrix composites were evaluated for use in structural repair applications. Initial work involved the characterization and evaluation of woven carbon fiber/epoxy matrix composites for structural pipeline repair. Cyanate ester resins were evaluated as a replacement for epoxy in composites for high-temperature pipe repair applications, and as the basis for adhesives for resin infusion repair of high-temperature composite materials. Carbon fiber/cyanate ester matrix composites and fumed silica/cyanate ester nanocomposites were evaluated for their thermal, mechanical, viscoelastic, and rheological properties as they relate to their structure, chemistry, and processing characteristics. The bisphenol E cyanate ester under investigation possesses a high glass transition temperature, excellent mechanical properties, and unique ambient temperature processability. The incorporate of fumed silica served to enhance the mechanical and rheological properties of the polymer and reduce thermal expansion without sacrificing glass transition or drastically altering curing kinetics. Characterization of the composites included dynamic mechanical analysis, thermomechanical analysis, differential scanning calorimetry, thermogravimetric analysis, rheological and rheokinetic evaluation, and transmission electron microscopy.

  5. Thermosetting polymer-matrix composites for structural repair applications

    Science.gov (United States)

    Goertzen, William Kirby

    2007-12-01

    Several classes of thermosetting polymer matrix composites were evaluated for use in structural repair applications. Initial work involved the characterization and evaluation of woven carbon fiber/epoxy matrix composites for structural pipeline repair. Cyanate ester resins were evaluated as a replacement for epoxy in composites for high-temperature pipe repair applications, and as the basis for adhesives for resin infusion repair of high-temperature composite materials. Carbon fiber/cyanate ester matrix composites and fumed silica/cyanate ester nanocomposites were evaluated for their thermal, mechanical, viscoelastic, and rheological properties as they relate to their structure, chemistry, and processing characteristics. The bisphenol E cyanate ester under investigation possesses a high glass transition temperature, excellent mechanical properties, and unique ambient temperature processability. The incorporation of fumed silica served to enhance the mechanical and rheological properties of the polymer and reduce thermal expansion without sacrificing glass transition or drastically altering curing kinetics. Characterization of the composites included dynamic mechanical analysis, thermomechanical analysis, differential scanning calorimetry, thermogravimetric analysis, rheological and rheokinetic evaluation, and transmission electron microscopy.

  6. New generation fiber reinforced polymer composites incorporating carbon nanotubes

    Science.gov (United States)

    Soliman, Eslam

    The last five decades observed an increasing use of fiber reinforced polymer (FRP) composites as alternative construction materials for aerospace and infrastructure. The high specific strength of FRP attracted its use as non-corrosive reinforcement. However, FRP materials were characterized with a relatively low ductility and low shear strength compared with steel reinforcement. On the other hand, carbon nanotubes (CNTs) have been introduced in the last decade as a material with minimal defect that is capable of increasing the mechanical properties of polymer matrices. This dissertation reports experimental investigations on the use of multi-walled carbon nanotubes (MWCNTs) to produce a new generation of FRP composites. The experiments showed significant improvements in the flexure properties of the nanocomposite when functionalized MWCNTs were used. In addition, MWCNTs were used to produce FRP composites in order to examine static, dynamic, and creep behavior. The MWCNTs improved the off-axis tension, off-axis flexure, FRP lap shear joint responses. In addition, they reduced the creep of FRP-concrete interface, enhanced the fracture toughness, and altered the impact resistance significantly. In general, the MWCNTs are found to affect the behaviour of the FRP composites when matrix failure dominates the behaviour. The improvement in the mechanical response with the addition of low contents of MWCNTs would benefit many industrial and military applications such as strengthening structures using FRP composites, composite pipelines, aircrafts, and armoured vehicles.

  7. Conducting polymer/carbon nanocoil composite electrodes for efficient supercapacitors

    KAUST Repository

    Baby, Rakhi Raghavan

    2012-01-01

    Herein, we report for the first time, conducting polymer (polyaniline (PANI) and polypyrrole (PPY)) coated carbon nanocoils (CNCs) as efficient binder-free electrode materials for supercapacitors. CNCs act as a perfect backbone for the uniform distribution of the conducting polymers in the composites. In two electrode configuration, the samples exhibited high specific capacitance with the values reaching up to 360 and 202 F g -1 for PANI/CNCs and PPY/CNCs respectively. The values obtained for specific capacitance and maximum storage energy per unit mass of the composites were found to be comparable to one of the best reported values for polymer coated multi-walled carbon nanotubes. In addition, the fabricated PANI/CNC based supercapacitors exhibited a high value of 44.61 Wh kg -1 for maximum storage energy per unit mass. Although the devices exhibit an initial capacitance loss due to the instability of the polymer, the specific capacitance stabilizes at a fixed value after 500 charge-discharge cycles. © 2012 The Royal Society of Chemistry.

  8. Nanocellulose in Polymer Composites and Biomedical: Research and Applications

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yuan [ORNL; Tekinalp, Halil L [ORNL; Peter, William H [ORNL; Eberle, Cliff [ORNL; Naskar, Amit K [ORNL; Ozcan, Soydan [ORNL

    2014-01-01

    Nanocellulose materials are nano-sized cellulose fibers or crystals that are produced by bacteria or derived from plants. These materials exhibit exceptional strength characteristics, light weight, transparency, and excellent biocompatibility. Compared to some other nanomaterials, nanocellulose is renewable and less expensive to produce. As such, a wide range of applications for nanocellulose has been envisioned. Most extensively studied areas include polymer composites and biomedical applications. Cellulose nanofibrils and nanocrystals have been used to reinforce both thermoplastic and thermoset polymers. Given the hydrophilic nature of these materials, the interfacial properties with most polymers are often poor. Various surface modification procedures have thus been adopted to improve the interaction between polymer matrix and cellulose nanofibrils or nanocrystals. In addition, the applications of nanocellulose as biomaterials have been explored including wound dressing, tissue repair, and medical implants. Nanocellulose materials for wound healing and periodontal tissue recovery have become commercially available, demonstrating the great potential of nanocellulose as a new generation of biomaterials. In this review, we highlight the applications of nanocellulose as reinforcing fillers for composites and the effect of surface modification on the mechanical properties as well as the application as biomaterials.

  9. Cryogenic performance of single polymer polypropylene composites

    Science.gov (United States)

    Atli-Veltin, Bilim

    2018-03-01

    The main objective of the experimental study detailed in this paper is to investigate the performance of fully recyclable, lightweight, low-cost, thermoplastic Polypropylene (PP) composite tapes at low temperatures. Coupons made of [±45] and [0/90] laminates are subjected to tensile and 3-point bending tests at room temperature as well as at -196 °C. In addition to that, cryogenic low velocity impact tests at 268 J and 777 J impact energies are performed on tubular structures. The results are indicating that the laminates made of PP tapes have sufficient ductility for cryogenic applications. Low velocity impact tests showed that the viscoelastic behavior of the material is preserved, even at such low temperatures and more than 72% of impact energy is absorbed by the material.

  10. Study on the structure of pitch-polymer compositions by fluorescence microscope

    OpenAIRE

    Makomaski, Grzegorz

    2014-01-01

    In this work, the results of studies on the evaluation of colloidal structure of coal-tar pitch compositions with selected waste polymers by fluorescence microscope. For pitch-polymer compositions containing 10?50?wt% waste polymer, softening point, coking value and content of components insoluble in toluene and quinoline were carried out. The results indicate that pitch-polymer compositions can be treated as microheterogeneous systems, colloidal and biphase, generally exhibiting uniform disp...

  11. Polymer-Cement Composites Containing Waste Perlite Powder

    Directory of Open Access Journals (Sweden)

    Paweł Łukowski

    2016-10-01

    Full Text Available Polymer-cement composites (PCCs are materials in which the polymer and mineral binder create an interpenetrating network and co-operate, significantly improving the performance of the material. On the other hand, the need for the utilization of waste materials is a demand of sustainable construction. Various mineral powders, such as fly ash or blast-furnace slag, are successfully used for the production of cement and concrete. This paper deals with the use of perlite powder, which is a burdensome waste from the process of thermal expansion of the raw perlite, as a component of PCCs. The results of the testing of the mechanical properties of the composite and some microscopic observations are presented, indicating that there is a possibility to rationally and efficiently utilize waste perlite powder as a component of the PCC. This would lead to creating a new type of building material that successfully meets the requirements of sustainable construction.

  12. Manufacturing Energy Intensity and Opportunity Analysis for Fiber-Reinforced Polymer Composites and Other Lightweight Materials

    Energy Technology Data Exchange (ETDEWEB)

    Liddell, Heather; Brueske, Sabine; Carpenter, Alberta; Cresko, Joseph

    2016-09-22

    With their high strength-to-weight ratios, fiber-reinforced polymer (FRP) composites are important materials for lightweighting in structural applications; however, manufacturing challenges such as low process throughput and poor quality control can lead to high costs and variable performance, limiting their use in commercial applications. One of the most significant challenges for advanced composite materials is their high manufacturing energy intensity. This study explored the energy intensities of two lightweight FRP composite materials (glass- and carbon-fiber-reinforced polymers), with three lightweight metals (aluminum, magnesium, and titanium) and structural steel (as a reference material) included for comparison. Energy consumption for current typical and state-of-the-art manufacturing processes were estimated for each material, deconstructing manufacturing process energy use by sub-process and manufacturing pathway in order to better understand the most energy intensive steps. Energy saving opportunities were identified and quantified for each production step based on a review of applied R&D technologies currently under development in order to estimate the practical minimum energy intensity. Results demonstrate that while carbon fiber reinforced polymer (CFRP) composites have the highest current manufacturing energy intensity of all materials considered, the large differences between current typical and state-of-the-art energy intensity levels (the 'current opportunity') and between state-of-the-art and practical minimum energy intensity levels (the 'R&D opportunity') suggest that large-scale energy savings are within reach.

  13. Non-destructive inspection of polymer composite products

    Science.gov (United States)

    Anoshkin, A. N.; Sal’nikov, A. F.; Osokin, V. M.; Tretyakov, A. A.; Luzin, G. S.; Potrakhov, N. N.; Bessonov, V. B.

    2018-02-01

    The paper considers the main types of defects encountered in products made of polymer composite materials for aviation use. The analysis of existing methods of nondestructive testing is carried out, features of their application are considered taking into account design features, geometrical parameters and internal structure of objects of inspection. The advantages and disadvantages of the considered methods of nondestructive testing used in industrial production are shown.

  14. Electron Beam Curing of Polymer Matrix Composites - CRADA Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Janke, C. J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Howell, Dave [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Norris, Robert E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    1997-05-01

    The major cost driver in manufacturing polymer matrix composite (PMC) parts and structures, and one of the elements having the greatest effect on their quality and performance, is the standard thermal cure process. Thermal curing of PMCs requires long cure times and high energy consumption, creates residual thermal stresses in the part, produces volatile toxic by-products, and requires expensive tooling that is tolerant of the high cure temperatures.

  15. Effects of mechanical properties of polymer on ceramic-polymer composite thick films fabricated by aerosol deposition

    Science.gov (United States)

    Kwon, Oh-Yun; Na, Hyun-Jun; Kim, Hyung-Jun; Lee, Dong-Won; Nam, Song-Min

    2012-05-01

    Two types of ceramic-polymer composite thick films were deposited on Cu substrates by an aerosol deposition process, and their properties were investigated to fabricate optimized ceramic-based polymer composite thick films for application onto integrated substrates with the advantage of plasticity. When polymers with different mechanical properties, such as polyimide (PI) and poly(methyl methacrylate) (PMMA), are used as starting powders together with α-Al2O3 powder, two types of composite films are formed with different characteristics - surface morphologies, deposition rates, and crystallite size of α-Al2O3. Through the results of micro-Vickers hardness testing, it was confirmed that the mechanical properties of the polymer itself are associated with the performances of the ceramic-polymer composite films. To support and explain these results, the microstructures of the two types of polymer powders were observed after planetary milling and an additional modeling test was carried out. As a result, we could conclude that the PMMA powder is distorted by the impact of the Al2O3 powder, so that the resulting Al2O3-PMMA composite film had a very small amount of PMMA and a low deposition rate. In contrast, when using PI powder, the Al2O3-PI composite film had a high deposition rate due to the cracking of PI particles. Consequently, it was revealed that the mechanical properties of polymers have a considerable effect on the properties of the resulting ceramic-polymer composite thick films.

  16. Magnetoimpedance of cobalt-based amorphous ribbons/polymer composites

    Energy Technology Data Exchange (ETDEWEB)

    Semirov, A.V., E-mail: semirov@mail.ru [Irkutsk State University, Irkutsk (Russian Federation); Derevyanko, M.S.; Bukreev, D.A.; Moiseev, A.A.; Kudryavtsev, V.O. [Irkutsk State University, Irkutsk (Russian Federation); Safronov, A.P. [Ural Federal University, Yekaterinburg (Russian Federation)

    2016-10-01

    The combined influence of the temperature, the elastic tensile stress and the external magnetic field on the total impedance and impedance components were studied for rapidly quenched amorphous Co{sub 75}Fe{sub 5}Si{sub 4}B{sub 16} ribbons. Both as-cast amorphous ribbons and Co{sub 75}Fe{sub 5}Si{sub 4}B{sub 16}/polymer amorphous ribbon based composites were considered. Following polymer coverings were studied: modified rubber solution in o-xylene, solution of butyl methacrylate and methacrylic acid copolymer in isopropanol and solution of polymethylphenylsiloxane resin in toluene. All selected composites showed very good adhesion of the coverings and allowed to provide temperature measurements from 163 K up to 383 K under the applied deforming tensile force up to 30 N. The dependence of the modulus of the impedance and its components on the external magnetic field was influenced by the elastic tensile stresses and was affected by the temperature of the samples. It was shown that maximal sensitivity of the impedance and its components to the external magnetic field was observed at minimal temperature and maximal deforming force depended on the frequency of an alternating current. - Highlights: • Impedance and its components of amorphous Co{sub 75}Fe{sub 5}Si{sub 4}B{sub 16} ribbons were studied. • MI sensitivity to the magnetic field depends on a temperature and a deforming force. • Polymer covering can affect the functional properties of the composite.

  17. Application of atmospheric pressure plasma in polymer and composite adhesion

    Science.gov (United States)

    Yu, Hang

    An atmospheric pressure helium and oxygen plasma was used to investigate surface activation and bonding in polymer composites. This device was operated by passing 1.0-3.0 vol% of oxygen in helium through a pair of parallel plate metal electrodes powered by 13.56 or 27.12 MHz radio frequency power. The gases were partially ionized between the capacitors where plasma was generated. The reactive species in the plasma were carried downstream by the gas flow to treat the substrate surface. The temperature of the plasm gas reaching the surface of the substrate did not exceed 150 °C, which makes it suitable for polymer processing. The reactive species in the plasma downstream includes ~ 1016-1017 cm-3 atomic oxygen, ~ 1015 cm-3 ozone molecule, and ~ 10 16 cm-3 metastable oxygen molecule (O2 1Deltag). The substrates were treated at 2-5 mm distance from the exit of the plasma. Surface properties of the substrates were characterized using water contact angle (WCA), atomic force microscopy (AFM), infrared spectroscopy (IR), and X-ray photoelectron spectroscopy (XPS). Subsequently, the plasma treated samples were bonded adhesively or fabricated into composites. The increase in mechanical strength was correlated to changes in the material composition and structure after plasma treatment. The work presented hereafter establishes atmospheric pressure plasma as an effective method to activate and to clean the surfaces of polymers and composites for bonding. This application can be further expanded to the activation of carbon fibers for better fiber-resin interactions during the fabrication of composites. Treating electronic grade FR-4 and polyimide with the He/O2 plasma for a few seconds changed the substrate surface from hydrophobic to hydrophilic, which allowed complete wetting of the surface by epoxy in underfill applications. Characterization of the surface by X-ray photoelectron spectroscopy shows formation of oxygenated functional groups, including hydroxyl, carbonyl, and

  18. Peculiarities of Shape Recovery in Polymer Composites with Compacting Filler

    Directory of Open Access Journals (Sweden)

    V. A. Beloshenko

    2011-01-01

    Full Text Available Peculiarities of the shape memory effect development in composites based on the epoxy polymer and various fillers, such as thermoexpanded graphite, aerosils, metallized graphite, and basalt flakes, have been investigated. It has been determined that straining followed by the shape recovery of composites is accompanied by changes in their volume. Extent and character of the changes depend on the ability of fillers to compaction under pressure, deformation scheme, adsorption ability of the filler. It is shown that the combined deformation consisting of compression and stretching of specimens in different sequence gives structural states for which the longitudinal strain-transverse strain ratio can take zero, positive, or negative values.

  19. A healable, semitransparent silver nanowire-polymer composite conductor.

    Science.gov (United States)

    Gong, Chaokun; Liang, Jiajie; Hu, Wei; Niu, Xiaofan; Ma, Sungwon; Hahn, H Thomas; Pei, Qibing

    2013-08-14

    A quick recovery: A semitransparent composite conductor comprising a layer of silver nanowire percolation network inlaid in the surface layer of a Diels-Alder-based healable polymer film is fabricated. The composite is flexible and highly conductive, and is capable of both structural and electrical healing via heating. Cut samples that completely lose their conductivity can recover 97% of it within 5 minutes of heating at 110 °C. The cutting and healing can be repeated at the same location for multiple cycles. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Wood-Polymer composites obtained by gamma irradiation

    Science.gov (United States)

    Gago, J.; López, A.; Santiago, J.; Acevedo, M.; Rodríguez, J.

    2007-10-01

    In this work we impregnate three Peruvian woods (Calycophy spruceanum Be, Aniba amazonica Meiz and Hura crepitans L) with styrene-polyester resin and methyl methacrylate. The polymerization of the system was promoted by gamma radiation and the experimental optimal condition was obtained with styrene-polyester 1:1 and 15 kGy. The obtained composites show reduced water absorption and better mechanical properties compared to the original wood. The structure of the wood-polymer composites was studied by light microscopy. Water absorption and hardness were also obtained.

  1. Wood-Polymer composites obtained by gamma irradiation

    International Nuclear Information System (INIS)

    Gago, J.; Lopez, A.; Rodriguez, J.; Santiago, J.; Acevedo, M.

    2007-01-01

    In this work we impregnate three Peruvian woods (Calycophy spruceanum Be, Aniba amazonica Meiz and Hura crepitans L) with styrene-polyester resin and methyl methacrylate. The polymerization of the system was promoted by gamma radiation and the experimental optimal condition was obtained with styrene-polyester 1:1 and 15 kGy. The obtained composites show reduced water absorption and better mechanical properties compared to the original wood. The structure of the wood-polymer composites was studied by light microscopy. Water absorption and hardness were also obtained

  2. Inorganic Polymer Matrix Composite Strength Related to Interface Condition

    Directory of Open Access Journals (Sweden)

    John Bridge

    2009-12-01

    Full Text Available Resin transfer molding of an inorganic polymer binder was successfully demonstrated in the preparation of ceramic fiber reinforced engine exhaust valves. Unfortunately, in the preliminary processing trials, the resulting composite valves were too brittle for in-engine evaluation. To address this limited toughness, the effectiveness of a modified fiber-matrix interface is investigated through the use of carbon as a model material fiber coating. After sequential heat treatments composites molded from uncoated and carbon coated fibers are compared using room temperature 3-point bend testing. Carbon coated Nextel fiber reinforced geopolymer composites demonstrated a 50% improvement in strength, versus that of the uncoated fiber reinforced composites, after the 250 °C postcure.

  3. Thermal conductivity of polymer composites with oriented boron nitride

    International Nuclear Information System (INIS)

    Ahn, Hong Jun; Eoh, Young Jun; Park, Sung Dae; Kim, Eung Soo

    2014-01-01

    Highlights: • Thermal conductivity depended on the orientation of BN in the polymer matrices. • Hexagonal boron nitride (BN) particles were treated by C 27 H 27 N 3 O 2 and C 14 H 6 O 8 . • Amphiphilic-agent-treated BN particles are more easily oriented in the composite. • BN/PVA composites with C 14 H 6 O 8 -treated BN showed the highest thermal conductivity. • Thermal conductivity of the composites was compared with several theoretical models. - Abstract: Thermal conductivity of boron nitride (BN) with polyvinyl alcohol (PVA) and/or polyvinyl butyral (PVB) was investigated as a function of the degree of BN orientation, the numbers of hydroxyl groups in the polymer matrices and the amphiphilic agents used. The composites with in-plane orientation of BN showed a higher thermal conductivity than the composites with out-of-plane orientation of BN due to the increase of thermal pathway. For a given BN content, the composites with in-plane orientation of BN/PVA showed higher thermal conductivity than the composites with in-plane orientation of BN/PVB. This result could be attributed to the improved degree of orientation of BN, caused by a larger number of hydroxyl groups being present. Those treated with C 14 H 6 O 8 amphiphilic agent demonstrated a higher thermal conductivity than those treated by C 27 H 27 N 3 O 2 . The measured thermal conductivity of the composites was compared with that predicted by the several theoretical models

  4. Cold spray of metal-polymer composite coatings onto carbon fiber-reinforced polymer (CFRP)

    OpenAIRE

    Bortolussi, Vincent; Borit, François; Chesnaud, Anthony; Jeandin, Michel; Faessel, Matthieu; Figliuzzi, Bruno; Willot, François; Roche, K.; Surdon, G.

    2016-01-01

    International audience; The growing use of Polymer-Matrix Composite (PMC) materials within transport industry raises new security concerns, especially those due to lightning. To protect these electrically insulating materials, conductive coatings can be applied. Due to the high level of required properties, cold spray is believed to be an effective way to achieve these coatings. Recent studies showed that obstacles remained to be overcome when cold spraying metallic particles onto Carbon Fibe...

  5. Advances in ferroelectric polymers for shock compression sensors

    International Nuclear Information System (INIS)

    Bauer, F.; Moulard, H.; Samara, G.

    1997-01-01

    Our studies of the shock compression response of PVDF polymer are continuing in order to understand the physical properties under shock loading and to develop high fidelity, reproducible, time-resolved dynamic stress gauges. New PVDF technology, new electrode configurations and piezoelectric analysis have resulted in enhanced precision gauges. Our new standard gauges have a precision of better than 1% in electric charge release under shock up to 15 GPa. The piezoelectric response of shock compressed PVDF gauges 1 mm 2 in active area has been studied and yielded well-behaved reproducible data up to 20 GPa. Analysis of the response of these gauges in the open-quotes thin mode regimeclose quotes using a Lagrangian hydrocode will be presented. P(VDF-TrFE) copolymers exhibit unique piezoelectric properties over a wide range of temperature depending on the composition. Their properties and phase transitions are being investigated. Emphasis of the presentation will be on key results and implications

  6. Advances in Ceramic Supports for Polymer Electrolyte Fuel Cells

    Directory of Open Access Journals (Sweden)

    Oran Lori

    2015-08-01

    Full Text Available Durability of catalyst supports is a technical barrier for both stationary and transportation applications of polymer-electrolyte-membrane fuel cells. New classes of non-carbon-based materials were developed in order to overcome the current limitations of the state-of-the-art carbon supports. Some of these materials are designed and tested to exceed the US DOE lifetime goals of 5000 or 40,000 hrs for transportation and stationary applications, respectively. In addition to their increased durability, the interactions between some new support materials and metal catalysts such as Pt result in increased catalyst activity. In this review, we will cover the latest studies conducted with ceramic supports based on carbides, oxides, nitrides, borides, and some composite materials.

  7. Polymer Composite and Nanocomposite Dielectric Materials for Pulse Power Energy Storage

    Directory of Open Access Journals (Sweden)

    Hans-Conrad zur Loye

    2009-10-01

    Full Text Available This review summarizes the current state of polymer composites used as dielectric materials for energy storage. The particular focus is on materials: polymers serving as the matrix, inorganic fillers used to increase the effective dielectric constant, and various recent investigations of functionalization of metal oxide fillers to improve compatibility with polymers. We review the recent literature focused on the dielectric characterization of composites, specifically the measurement of dielectric permittivity and breakdown field strength. Special attention is given to the analysis of the energy density of polymer composite materials and how the functionalization of the inorganic filler affects the energy density of polymer composite dielectric materials.

  8. Flexible, Penetrating Brain Probes Enabled by Advances in Polymer Microfabrication

    Directory of Open Access Journals (Sweden)

    Ahuva Weltman

    2016-10-01

    Full Text Available The acquisition of high-fidelity, long-term neural recordings in vivo is critically important to advance neuroscience and brain–machine interfaces. For decades, rigid materials such as metal microwires and micromachined silicon shanks were used as invasive electrophysiological interfaces to neurons, providing either single or multiple electrode recording sites. Extensive research has revealed that such rigid interfaces suffer from gradual recording quality degradation, in part stemming from tissue damage and the ensuing immune response arising from mechanical mismatch between the probe and brain. The development of “soft” neural probes constructed from polymer shanks has been enabled by advancements in microfabrication; this alternative has the potential to mitigate mismatch-related side effects and thus improve the quality of recordings. This review examines soft neural probe materials and their associated microfabrication techniques, the resulting soft neural probes, and their implementation including custom implantation and electrical packaging strategies. The use of soft materials necessitates careful consideration of surgical placement, often requiring the use of additional surgical shuttles or biodegradable coatings that impart temporary stiffness. Investigation of surgical implantation mechanics and histological evidence to support the use of soft probes will be presented. The review concludes with a critical discussion of the remaining technical challenges and future outlook.

  9. Fique Fabric: A Promising Reinforcement for Polymer Composites

    Directory of Open Access Journals (Sweden)

    Sergio Neves Monteiro

    2018-02-01

    Full Text Available A relatively unknown natural fiber extracted from the leaves of the fique plant, native of the South American Andes, has recently shown potential as reinforcement of polymer composites for engineering applications. Preliminary investigations indicated a promising substitute for synthetic fibers, competing with other well-known natural fibers. The fabric made from fique fibers have not yet been investigated as possible composite reinforcement. Therefore, in the present work a more thorough characterization of fique fabric as a reinforcement of composites with a polyester matrix was performed. Thermal mechanical properties of fique fabric composites were determined by dynamic mechanical analysis (DMA. The ballistic performance of plain woven fique fabric-reinforced polyester matrix composites was investigated as a second layer in a multilayered armor system (MAS. The results revealed a sensible improvement in thermal dynamic mechanical behavior. Both viscoelastic stiffness and glass transition temperature were increased with the amount of incorporated fique fabric. In terms of ballistic results, the fique fabric composites present a performance similar to that of the much stronger KevlarTM as an MAS second layer with the same thickness. A cost analysis indicated that armor vests with fique fabric composites as an MAS second layer would be 13 times less expensive than a similar creation made with Kevlar™.

  10. Multiscale simulation of polymer nano-composites (PNC) using molecular dynamics (MD) and generalized interpolation material point method (GIMP)

    Science.gov (United States)

    Nair, Abilash R.

    Recent mechanical characterization experiments with pultruded E-Glass / polypropylene (PP) and compression molded E-Glass/Nylon-6 composite samples with 3-4 weight% nanoclay and baseline polymer (polymer without nanoclay) confirmed significant improvements in compressive strength (˜122%) and shear strength (˜60%) in the nanoclay modified nanocomposites, in comparison with baseline properties. Uniaxial tensile tests showed a small increase in tensile strength (˜3.4%) with 3 wt % nanoclay loading. While the synergistic reinforcing influence of nanoparticle reinforcement is obvious, a simple rule-of-mixtures approach fails to quantify the dramatic increase in mechanical properties. Consequently, there is an immediate need to investigate and understand the mechanisms at the nanoscale that are responsible for such unprecedented strength enhancements. In this work, an innovative and effective method to model nano-structured components in a thermoplastic polymer matrix is proposed. Effort will be directed towards finding fundamental answers to the reasons for significant changes in mechanical properties of nanoparticle-reinforced thermoplastic composites. This research ensues a multiscale modeling approach in which (a) a concurrent simulations scheme is developed to visualize atomistic behavior of polymer molecules as a function of continuum scale loading conditions and (b) a novel nanoscale damage mechanics model is proposed to capture the constitutive behavior of polymer nano composites (PNC). The proposed research will contribute towards the understanding of advanced nanostructured composite materials, which should subsequently benefit the composites manufacturing industry.

  11. Multifunctional fiber reinforced polymer composites using carbon and boron nitride nanotubes

    Science.gov (United States)

    Ashrafi, Behnam; Jakubinek, Michael B.; Martinez-Rubi, Yadienka; Rahmat, Meysam; Djokic, Drazen; Laqua, Kurtis; Park, Daesun; Kim, Keun-Su; Simard, Benoit; Yousefpour, Ali

    2017-12-01

    Recent progress in nanotechnology has made several nano-based materials available with the potential to address limitations of conventional fiber reinforced polymer composites, particularly in reference to multifunctional structures. Carbon nanotubes (CNTs) are the most prevalent case and offer amazing properties at the individual nanotube level. There are already a few high-profile examples of the use of CNTs in space structures to provide added electrical conductivity for static dissipation and electromagnetic shielding. Boron nitride nanotubes (BNNTs), which are structurally analogous to CNTs, also present a range of attractive properties. Like the more widely explored CNTs, individual BNNTs display remarkable mechanical properties and high thermal conductivity but with contrasting functional attributes including substantially higher thermal stability, high electrical insulation, polarizability, high neutron absorption and transparency to visible light. This presents the potential of employing either or both BNNTs and CNTs to achieve a range of lightweight, functional composites for space structures. Here we present the case for application of BNNTs, in addition to CNTs, in space structures and describe recent advances in BNNT production at the National Research Council Canada (NRC) that have, for the first time, provided sufficiently large quantities to enable commercialization of high-quality BNNTs and accelerate development of chemistry, composites and applications based on BNNTs. Early demonstrations showing the fabrication and limited structural testing of polymer matrix composites, including glass fiber-reinforced composite panels containing BNNTs will be discussed.

  12. Long fiber polymer composite property calculation in injection molding simulation

    Science.gov (United States)

    Jin, Xiaoshi; Wang, Jin; Han, Sejin

    2013-05-01

    Long fiber filled polymer composite materials have attracted a great attention and usage in recent years. However, the injection and compression molded long fiber composite materials possess complex microstructures that include spatial variations in fiber orientation and length. This paper presents the recent implemented anisotropic rotary diffusion - reduced strain closure (ARD-RSC) model for predicting fiber orientation distribution[1] and a newly developed fiber breakage model[2] for predicting fiber length distribution in injection and compression molding simulation, and Eshelby-Mori-Tanaka model[3,4] with fiber-matrix de-bonding model[5] have been implemented to calculate the long fiber composite property distribution with predicted fiber orientation and fiber length distributions. A validation study on fiber orientation, fiber breakage and mechanical property distributions are given with injection molding process simulation.

  13. Nano-Fiber Reinforced Enhancements in Composite Polymer Matrices

    Science.gov (United States)

    Chamis, Christos C.

    2009-01-01

    Nano-fibers are used to reinforce polymer matrices to enhance the matrix dependent properties that are subsequently used in conventional structural composites. A quasi isotropic configuration is used in arranging like nano-fibers through the thickness to ascertain equiaxial enhanced matrix behavior. The nano-fiber volume ratios are used to obtain the enhanced matrix strength properties for 0.01,0.03, and 0.05 nano-fiber volume rates. These enhanced nano-fiber matrices are used with conventional fiber volume ratios of 0.3 and 0.5 to obtain the composite properties. Results show that nano-fiber enhanced matrices of higher than 0.3 nano-fiber volume ratio are degrading the composite properties.

  14. Preparation of graphene/polymer composite photocathode for QDSSC

    Science.gov (United States)

    Wang, Qiandi; Shen, Yue; Tan, Jie; Xu, Kai; Shen, Tan; Cao, Meng; Gu, Feng; Wang, Linjun

    2013-12-01

    Graphene (rGO) was fabricated by modified Hummers method and a reducing process. Conductive polymer/graphene films were obtained by scalpel technology and used as photocathode in CdS quantum dot-sensitized solar cell (QDSSC). Polymers used in this paper were ethyl cellulose (EC), polyphenyl vinyl (PPV) and polyvinyl butyral (PVB), respectively. The obtained composite films were investigated by X-ray diffraction, Raman spectroscopy technology and scanning electron microscope (SEM). The photoelectric properties of QDSSCs were tested under AM 1.5 irradiation. Test results show that the film performance of the EC/rGO and PPV/rGO photocathode have been improved effectively. Power conversion efficiency (PCE) of the relative QDSSCs under AM 1.5 irradiation were 0.81% and 0.86%, respectively.

  15. The dynamic response of carbon fiber-filled polymer composites

    Science.gov (United States)

    Dattelbaum, D. M.; Gustavsen, R. L.; Sheffield, S. A.; Stahl, D. B.; Scharff, R. J.; Rigg, P. A.; Furmanski, J.; Orler, E. B.; Patterson, B.; Coe, J. D.

    2012-08-01

    The dynamic (shock) responses of two carbon fiber-filled polymer composites have been quantified using gas gun-driven plate impact experimentation. The first composite is a filament-wound, highly unidirectional carbon fiber-filled epoxy with a high degree of porosity. The second composite is a chopped carbon fiber- and graphite-filled phenolic resin with little-to-no porosity. Hugoniot data are presented for the carbon fiber-epoxy (CE) composite to 18.6 GPa in the through-thickness direction, in which the shock propagates normal to the fibers. The data are best represented by a linear Rankine-Hugoniot fit: Us = 2.87 + 1.17 ×up(ρ0 = 1.536g/cm3). The shock wave structures were found to be highly heterogeneous, both due to the anisotropic nature of the fiber-epoxy microstructure, and the high degree of void volume. Plate impact experiments were also performed on a carbon fiber-filled phenolic (CP) composite to much higher shock input pressures, exceeding the reactants-to-products transition common to polymers. The CP was found to be stiffer than the filament-wound CE in the unreacted Hugoniot regime, and transformed to products near the shock-driven reaction threshold on the principal Hugoniot previously shown for the phenolic binder itself. [19] On-going research is focused on interrogating the direction-dependent dyanamic response and dynamic failure strength (spall) for the CE composite in the TT and 0∘ (fiber) directions.

  16. The dynamic response of carbon fiber-filled polymer composites

    Directory of Open Access Journals (Sweden)

    Patterson B.

    2012-08-01

    Full Text Available The dynamic (shock responses of two carbon fiber-filled polymer composites have been quantified using gas gun-driven plate impact experimentation. The first composite is a filament-wound, highly unidirectional carbon fiber-filled epoxy with a high degree of porosity. The second composite is a chopped carbon fiber- and graphite-filled phenolic resin with little-to-no porosity. Hugoniot data are presented for the carbon fiber-epoxy (CE composite to 18.6 GPa in the through-thickness direction, in which the shock propagates normal to the fibers. The data are best represented by a linear Rankine-Hugoniot fit: Us = 2.87 + 1.17 ×up(ρ0 = 1.536g/cm3. The shock wave structures were found to be highly heterogeneous, both due to the anisotropic nature of the fiber-epoxy microstructure, and the high degree of void volume. Plate impact experiments were also performed on a carbon fiber-filled phenolic (CP composite to much higher shock input pressures, exceeding the reactants-to-products transition common to polymers. The CP was found to be stiffer than the filament-wound CE in the unreacted Hugoniot regime, and transformed to products near the shock-driven reaction threshold on the principal Hugoniot previously shown for the phenolic binder itself. [19] On-going research is focused on interrogating the direction-dependent dyanamic response and dynamic failure strength (spall for the CE composite in the TT and 0∘ (fiber directions.

  17. Recent advances in ion and electron spectroscopy of polymer surfaces

    Science.gov (United States)

    Gardella, Joseph A.

    1988-01-01

    The structure of microdomains and bonding at multicomponent polymer material interfaces has been studied using a variety of surface sensitive spectroscopic techniques. In our laboratory, low energy ion scattering spectroscopy (ISS) and static secondary ion mass spectrometry (SIMS) serve to complement results from angular dependent X-ray photoelectron spectroscopy (XPS or ESCA), Fourier transform infrared (FTIR) with attenuated total reflectance (ATR) sampling and SEM techniques to provide a quantitative picture of the relationships between structure, bonding, morphology and microdomain formation in near surface regions of polymeric systems. The added surface sensitivity of ISS can yield quantitative information at a sampling depth of 3-5 Å, which, with ESCA and FTIR analysis yields a "non-destructive" depth profile of domain formation in copolymer and blend systems. These studies will be illustrated with results from siloxane and siloxane/polycarbonate copolymer systems, where a complete picture of surface domain formation and morphology as a function of composition and polymer crystallinity has been developed. ISS can also yield information regarding the orientation of surface functional groups which ESCA and FTIR do not have either sensitivity and/or sufficient detection limits to analyze. These studies will be illustrated by the analysis of plasma hydrolysis/oxidation of stereoregular poly(methyl-methacrylate). The effects of functional group orientation on reactivity will be explored using results from ISS, ESCA and FTIR for stereoregular (isotatic, syndiotactic) and random (atactic) PMMA. Electron energy loss spectroscopy at high resolution (HREELS) has recently been extended to the examination of polymer and organic surfaces. Vibrational information from this experiment can yield very precise results about surface functional groups (1-20 Å) but at much lower resolution than is typical from IR and Raman techniques. However, the promise of evaluating surface

  18. LDEF results for polymer matrix composite experiment AO 180

    Science.gov (United States)

    Tennyson, R. C.

    1992-01-01

    This report represents a summary of the results obtained to-date on a polymer matrix composite experiment (AO 180) located at station D-12, about 82 deg off the 'ram' direction. Different material systems comprised of graphite, boron, and aramid (Kevlar) fiber reinforcements were studied. Although previous results were presented on in-situ thermal-vacuum cycling effects, particularly dimensional changes associated with outgassing, additional comparative data will be shown from ground-based tests on control and flight samples. The system employed was fully automated for thermal-vacuum cycling using a laser interferometer for monitoring displacements. Erosion of all three classes of materials due to atomic oxygen (AO) will also be discussed, including angle of incidence effects. Data from this experiment will be compared to published results for similar materials in other LDEF experiments. Composite materials' erosion yields will be presented on an AO design nomogram useful for estimating total material loss for given exposure conditions in low Earth orbit (LEO). Optical properties of these materials will also be compared with control samples. A survey of the damage caused by micrometeoroids/debris impacts will be addressed as they relate to polymer matrix composites. Correlations between hole size and damage pattern will be given. Reference to a new nomogram for estimating the number distribution of micrometeoroid/debris impacts for a given space structure as a function of time in LEO will be addressed based on LDEF data.

  19. Thermal Conductivity of Polymer Composite poypropilene-Sand

    International Nuclear Information System (INIS)

    Betha; Mashuri; Sudirman; Karo Karo, Aloma

    2001-01-01

    Thermal conductivity composite materials polypropylene (PP)-sand have been investigated. PP composite with sand to increase thermal conductivity from the polymer. The composite in this observation is done by mixing matrix (PP melt flow 2/10)and filler sand)by means tool labo plastomil. The result of thermal conductivity is composite of PP-sand which is obtained increase and followed by the raising of filler particle volume fraction. The analysis of thermal conductivity based on the model Cheng and Vachon, model Lewis and Nielsen where this model has the function to support experiment finding. It is proved that Lewis' and Nielsen's model almost approach experiment result. And then thermal conductivity raising will be analyzed by the model of pararel-series conductive with the two (2)phases system. It is showed that sand in PP MF 2 composite have the big role to increase the thermal conductivity than sand in PP MF 10 composition, but it is not easy to shape conductive medium

  20. Performance of aged cement - polymer composite immobilizing borate waste simulates during flooding scenarios

    International Nuclear Information System (INIS)

    Eskander, S.B.; Bayoumi, T.A.; Saleh, H.M.

    2012-01-01

    An advanced composite of cement and water extended polyester based on the recycled Poly(ethylene terephthalate) waste was developed to incorporate the borate waste. Previous studies have reported the characterizations of the waste composite (cement-polymer composite immobilizing borate waste simulates) after 28 days of curing time. The current work studied the performance of waste composite aged for seven years and subjected to flooding scenario during 260 days using three types of water. The state of waste composite was assessed at the end of each definite interval of the water infiltration through visual examination and mechanical measurement. Scanning electron microscopy, infrared spectroscopy, X-ray diffraction and thermal analyses were used to investigate the changes that may occur in the microstructure of the waste composite under aging and flooding effects. The actual experimental results indicated reasonable evidence for the waste composite. Acceptable consistency was confirmed for the waste composite even after aging seven years and exposure to flooding scenario for 260 days.

  1. Preparation of wood-polymer composites by using ionizing radiation

    International Nuclear Information System (INIS)

    Kaldirimci, C.; Bas, N.; Yoentem, Z.

    1982-01-01

    Radiation-initiated polymerization of styrene and acrylic acid in poplar wood were investigated for the preparation of wood-polymer composites. The direct irradiation method was applied to the monomer adsorbed poplar wood specimens. 8000 Ci 60 Co source at a dose rate of about 0.4 Mrad/h was used. Furthermore the effects of carbon tetrachloride, methanol, dioxane and acrylonitrile on styrene polymerization were investigated and the reaction rates were calculated for each case. The influence of CCl 4 (10%) on acrylic acid polymerization in poplar wood was also determined. (author)

  2. Molecular composites from liquid crystalline polymers and liquid crystalline thermosets

    Energy Technology Data Exchange (ETDEWEB)

    Benicewicz, B.C.; Douglas, E.P.; Hjelm, R.P. Jr.

    1993-07-01

    We propose a new approach to molecular composites. This approach uses a mixture of a liquid crystalline polymer and a liquid crystalline thermoset to enhance the miscibility. Preliminary neutron scattering data is presented on a system of short and long rod aromatic amides. The data is interpreted using the interpenetrating phase model of Debye and Bueche. The analysis indicates that the scattering is consistent with this model and shows a characteristic length scale in the range of 70 to 80 A. The intensity of the scattering is lower than calculated for the strong segregation limit, suggesting that there is some intermixing of the components.

  3. Effect of particle morphology on the mechanical and thermo-mechanical behavior of polymer composites

    OpenAIRE

    Oréfice, R. L.; Hench, L. L.; Brennan, A. B.

    2001-01-01

    Fiber reinforced polymer composites have been used in many applications, such as in automobile, aerospace and naval industries, due basically to their high strength-to-weight and modulus-to-weight, among other properties. Even though particles are usually not able to lead to the level of reinforcement of fibers, particle reinforced polymer composites have been proposed for many new applications due to their low cost, easy fabrication and isotropic properties. In this work, polymer composites ...

  4. Investigation of Bending Test Procedures for Engineered Polymer Composite Railroad Ties

    Science.gov (United States)

    2016-12-01

    ER D C/ CE RL C R- 16 -6 Investigation of Bending Test Procedures for Engineered Polymer Composite Railroad Ties Co ns tr uc tio n En...Test Procedures for Engineered Polymer Composite Railroad Ties Claire G. Ball CTL Group 5400 Old Orchard Road Skokie, IL 60077 Final report...conducting in- vestigations to help develop and evaluate engineered polymer composite railroad ties since 1993. Recent efforts, through funding and

  5. Dependence of mechanical characteristics from composition and structure and optimization of mechanical fracture energy of polymer composite material based on high-molecular rubbers

    Directory of Open Access Journals (Sweden)

    E. Nurullaev

    2017-07-01

    Full Text Available By means of numerical experiment the authors investigate dependence of conventional rupturing stress and mechanical fracture energy at uniaxial tension from fractional composition of dispersed filler, plasticizer volume fraction in polymer binder, effective density of transverse bonds, applied to development of covering for different purposes and with advanced service life in temperature range from 223 to 323 K. They compare mechanical characteristics of polymer composite materials (PCMs based on high- and low-molecular rubbers. It was shown that rupturing stress of high-molecular rubber-based PCM is of a higher magnitude than the stress of low-molecular rubber-based one at almost invariable rupturing deformation. Numerical simulation by variation of composition parameters and molecular structure enables evaluation of its maximum fracture energy which is 1000 times higher than mechanical fracture energy of similar composites based on low-molecular rubbers.

  6. AC Electric Field Activated Shape Memory Polymer Composite

    Science.gov (United States)

    Kang, Jin Ho; Siochi, Emilie J.; Penner, Ronald K.; Turner, Travis L.

    2011-01-01

    Shape memory materials have drawn interest for applications like intelligent medical devices, deployable space structures and morphing structures. Compared to other shape memory materials like shape memory alloys (SMAs) or shape memory ceramics (SMCs), shape memory polymers (SMPs) have high elastic deformation that is amenable to tailored of mechanical properties, have lower density, and are easily processed. However, SMPs have low recovery stress and long response times. A new shape memory thermosetting polymer nanocomposite (LaRC-SMPC) was synthesized with conductive fillers to enhance its thermo-mechanical characteristics. A new composition of shape memory thermosetting polymer nanocomposite (LaRC-SMPC) was synthesized with conductive functionalized graphene sheets (FGS) to enhance its thermo-mechanical characteristics. The elastic modulus of LaRC-SMPC is approximately 2.7 GPa at room temperature and 4.3 MPa above its glass transition temperature. Conductive FGSs-doped LaRC-SMPC exhibited higher conductivity compared to pristine LaRC SMP. Applying an electric field at between 0.1 Hz and 1 kHz induced faster heating to activate the LaRC-SMPC s shape memory effect relative to applying DC electric field or AC electric field at frequencies exceeding1 kHz.

  7. Polymer composites with graphene nanofillers: electrical properties and applications.

    Science.gov (United States)

    Tjong, Sie Chin

    2014-02-01

    Graphene with extraordinary high elastic modulus and excellent electrical conductivity has good prospects for use as the filler material for fabricating novel polymer composites designed for electrostatic discharge and EMI shielding protection, field emission, gas sensor, and fuel cell applications. Large amounts of graphene oxide (GO) can be obtained by wet chemical oxidation of graphite into a mixture of concentrated sulfuric acid, sodium nitrate and potassium permanganate. Accordingly, carbon atoms in the basal plane and edges of GO are decorated with oxygenated functional groups, forming an electrical insulator. To restore electrical conductivity, chemical reduction or thermal annealing is needed to eliminate oxygenated groups of GO. However, such treatments induce internal defects and remove oxygenated atoms of GO partially. The remnant-oxygenated groups affect electrical conductivity of graphene greatly. Nevertheless, reduced graphene oxide and thermally reduced graphene oxide are sufficiently conductive to form polymer nanocomposites at very low percolation threshold. This review provides the fundamentals and state-of-the-art developments in the fabrication methods and electrical property characterizations as well as the applications of novel graphene/polymer nanocomposites. Particular attention is paid to their processing-structural-electrical property relationships.

  8. Hybrid and hierarchical nanoreinforced polymer composites: Computational modelling of structure–properties relationships

    DEFF Research Database (Denmark)

    Mishnaevsky, Leon; Dai, Gaoming

    2014-01-01

    Hybrid and hierarchical polymer composites represent a promising group of materials for engineering applications. In this paper, computational studies of the strength and damage resistance of hybrid and hierarchical composites are reviewed. The reserves of the composite improvement are explored...... by using computational micromechanical models. It is shown that while glass/carbon fibers hybrid composites clearly demonstrate higher stiffness and lower weight with increasing the carbon content, they can have lower strength as compared with usual glass fiber polymer composites. Secondary...

  9. Polymers as advanced materials for desiccant applications, 1988

    Energy Technology Data Exchange (ETDEWEB)

    Czanderna, A.W.; Neidlinger, H.H.

    1990-09-01

    This report documents work to identify a next-generation, low-cost material with which solar energy or heat from another low-cost energy source can be used for regenerating the water vapor sorption activity of the desiccant. The objective of the work is to determine how the desired sorption performance of advanced desiccant materials can be predicted by understanding the role of the material modifications and material surfaces. The work concentrates on solid materials to be used for desiccant cooling systems and which process water vapor in an atmosphere to produce cooling. The work involved preparing modifications of polystyrene sulfonic acid sodium salt, synthesizing a hydrogel, and evaluating the sorption performances of these and similar commercially available polymeric materials; all materials were studied for their potential application in solid commercial desiccant cooling systems. Background information is also provided on desiccant cooling systems and the role of a desiccant material within such a system, and it includes the use of polymers as desiccant materials. 31 refs., 16 figs., 5 tabs.

  10. Polymer-Cement Composites with Self-Healing Ability for Geothermal and Fossil Energy Applications

    Energy Technology Data Exchange (ETDEWEB)

    Childers, M. Ian; Nguyen, Manh-Thuong; Rod, Kenton A.; Koech, Phillip K.; Um, Wooyong; Chun, Jaehun; Glezakou, Vassiliki-Alexandra; Linn, Diana; Roosendaal, Timothy J.; Wietsma, Thomas W.; Huerta, Nicolas John; Kutchko, Barbara G.; Fernandez, Carlos A.

    2017-05-18

    Sealing of wellbores in geothermal and tight oil/gas reservoirs by filling the annulus with cement is a well-established practice. Failure of the cement as a result of physical and/or chemical stress is a common problem with serious environmental and financial consequences. Numerous alternative cement blends have been proposed for the oil and gas industry. Most of these possess poor mechanical properties, or are not designed to work in high temperature environments. This work reports on a novel polymer-cement composite with remarkable self-healing ability that maintains the required properties of typical wellbore cements and may be stable at most geothermal temperatures. We combine for the first time experimental analysis of physical and chemical properties with density functional theory simulations to evaluate cement performance. The thermal stability and mechanical strength are attributed to the formation of a number of chemical interactions between the polymer and cement matrix including covalent bonds, hydrogen bonding, and van der Waals interactions. Self-healing was demonstrated by sealing fractures with 0.3–0.5 mm apertures, 2 orders of magnitude larger than typical wellbore fractures. This polymer-cement composite represents a major advance in wellbore cementing that could improve the environmental safety and economics of enhanced geothermal energy and tight oil/gas production.

  11. Ionic polymer metal composites with polypyrrole-silver electrodes

    Science.gov (United States)

    Cellini, F.; Grillo, A.; Porfiri, M.

    2015-03-01

    Ionic polymer metal composites (IPMCs) are a class of soft active materials that are finding increasing application in robotics, environmental sensing, and energy harvesting. In this letter, we demonstrate the fabrication of IPMCs via in-situ photoinduced polymerization of polypyrrole-silver electrodes on an ionomeric membrane. The composition, morphology, and sheet resistance of the electrodes are extensively characterized through a range of experimental techniques. We experimentally investigate IPMC electrochemistry through electrochemical impedance spectroscopy, and we propose a modified Randle's model to interpret the impedance spectrum. Finally, we demonstrate in-air dynamic actuation and sensing and assess IPMC performance against more established fabrication methods. Given the simplicity of the process and the short time required for the formation of the electrodes, we envision the application of our technique in the development of a rapid prototyping technology for IPMCs.

  12. Composites of 3D-Printed Polymers and Textile Fabrics*

    Science.gov (United States)

    Martens, Yasmin; Ehrmann, Andrea

    2017-08-01

    3D printing belongs to the rapidly emerging technologies of our time. Due to its recent drawback - the technology is relatively slow compared with other primary shaping methods, such as injection molding -, 3D printing is often not used for creating complete large components but to add specific features to existing larger objects. One of the possibilities to create such composites with an additional value consists in combining 3D printed polymers with textile fabrics. Several attempts have been made to enhance the adhesion between both materials, a task which is still challenging for diverse material combinations. Our paper reports about new experiments combining 3D printed embossed designs, snap fasteners and zip fasteners with different textile base materials, showing the possibilities and technical limits of these novel composites.

  13. Electrostatically Induced Carbon Nanotube Alignment for Polymer Composite Applications

    Science.gov (United States)

    Chapkin, Wesley Aaron

    We have developed a non-invasive technique utilizing polarized Raman spectroscopy to measure changes in carbon nanotube (CNT) alignment in situ and in real time in a polymer matrix. With this technique, we have confirmed the prediction of faster alignment for CNTs in higher electric fields. Real-time polarized Raman spectroscopy also allows us to demonstrate the loss of CNT alignment that occurs after the electric field is removed, which reveals the need for fast polymerization steps or the continued application of the aligning force during polymerization to lock in CNT alignment. Through a study on the effect of polymer viscosity on the rate of CNT alignment, we have determined that shear viscosity serves as the controlling mechanism for CNT rotation. This finding matches literature modeling of rigid rod mobility in a polymer melt and demonstrates that the rotational mobility of CNTs can be explained by a continuum model even though the diameters of single-walled CNTs are 1-2 nm. The viscosity dependence indicates that the manipulation of temperature (and indirectly viscosity) will have a direct effect on the rate of CNT alignment, which could prove useful in expediting the manufacturing of CNT-reinforced composites cured at elevated temperatures. Using real-time polarized Raman spectroscopy, we also demonstrate that electric fields of various strengths lead not only to different speeds of CNT rotation but also to different degrees of alignment. We hypothesize that this difference in achievable alignment results from discrete populations of nanotubes based on their length. The results are then explained by balancing the alignment energy for a given electric field strength with the randomizing thermal energy of the system. By studying the alignment dynamics of different CNT length distributions, we show that different degrees of alignment achieved as a function of the applied electric field strength are directly related to the square of the nanotube length. This

  14. Effect of binder polymer structures used in composite cathodes on interfacial charge transfer processes in lithium polymer batteries

    International Nuclear Information System (INIS)

    Seki, Shiro; Tabata, Sei-ichiro; Matsui, Shohei; Watanabe, Masayoshi

    2004-01-01

    The effect of binder polymer structures used in composite cathodes on the interfacial charge transfer processes in lithium polymer batteries (LPB) has been studied in detail. A cross-linked comb-copolymer, consisting of ethylene oxide (EO), 2-(2-methoxyethoxy)ethyl glycidyl ether (MEEGE), and allyl glycidyl ether (AGE), was used as a solid polymer electrolyte (SPE). LiCoO 2 composite cathodes were fabricated using binder comb-copolymers, consisting of EO and MEEGE with different compositions. Ionic conductivity of the SPE, and the interfacial charge transfer processes between the SPE and metallic lithium and between the SPE and the composite cathode at several cathode potentials versus Li/Li + , were electrochemically explored. With increasing MEEGE composition in the binder copolymers, the interfacial resistances between the SPE and the composite cathode appreciably decreased. As the result, discharge capacity of the LPB also enhanced with increasing the MEEGE composition. The introduction of the branched-side-chains to the polymer backbone to the binder polymers for the composite cathodes caused to facilitate the interfacial charge transport processes, while the introduction had also been found to be very effective in terms of the enhancement of ionic conductivity of SPE

  15. A Review on Potentiality of Nano Filler/Natural Fiber Filled Polymer Hybrid Composites

    Directory of Open Access Journals (Sweden)

    Naheed Saba

    2014-08-01

    Full Text Available The increasing demand for greener and biodegradable materials leading to the satisfaction of society requires a compelling towards the advancement of nano-materials science. The polymeric matrix materials with suitable and proper filler, better filler/matrix interaction together with advanced and new methods or approaches are able to develop polymeric composites which shows great prospective applications in constructions and buildings, automotive, aerospace and packaging industries. The biodegradability of the natural fibers is considered as the most important and interesting aspects of their utilization in polymeric materials. Nanocomposite shows considerable applications in different fields because of larger surface area, and greater aspect ratio, with fascinating properties. Being environmentally friendly, applications of nanocomposites offer new technology and business opportunities for several sectors, such as aerospace, automotive, electronics, and biotechnology industries. Hybrid bio-based composites that exploit the synergy between natural fibers in a nano-reinforced bio-based polymer can lead to improved properties along with maintaining environmental appeal. This review article intended to present information about diverse classes of natural fibers, nanofiller, cellulosic fiber based composite, nanocomposite, and natural fiber/nanofiller-based hybrid composite with specific concern to their applications. It will also provide summary of the emerging new aspects of nanotechnology for development of hybrid composites for the sustainable and greener environment.

  16. Advanced composites--a new application of electron beam curing

    International Nuclear Information System (INIS)

    Sun Dakuan

    2007-01-01

    Consisting of a matrix phase of epoxy resin and reinforcement phase of high performance synthetic fiber, advanced composites have a number of engineering merits, such as high specific strength and specific modulus, light weight, fatigue resistance, corrosion resistance and dimensional stability, etc. Advanced composites have been applied in aerospace/aircraft industry, military industry, high pressure vessels, automobile industry and sports apparatus. Nowadays, advanced composites are produced by electron beam curing, an environment-friendly technology with greater safety and energy efficiency than conventional curing techniques. This paper gives a review on progresses of electron beam cured advanced composites. (authors)

  17. APPLICATION OF ADDITIVELY MANUFACTURED POLYMER COMPOSITE PROTOTYPES IN FOUNDRY

    Directory of Open Access Journals (Sweden)

    Wiesław Kuczko

    2015-05-01

    Full Text Available The paper presents a method, developed by the authors, for manufacturing polymer composites with the matrix manufactured in a layered manner (via 3D printing – Fused Deposition Modeling out of a thermoplastic material. As an example of practical application of this method, functional prototypes are presented, which were used as elements of foundry tooling – patterns for sand molding. In case of manufacturing prototype castings or short series of products, foundries usually cooperate with modeling studios, which produce patterns by conventional, subtractive manufacturing technologies. If patterns have complex shapes, this results in high manufacturing costs and significantly longer time of tooling preparation. The method proposed by the authors allows manufacturing functional prototypes in a short time thanks to utilizing capabilities of additive manufacturing (3D printing technology. Thanks to using two types of materials simultaneously (ABS combined with chemically hardened resins, the produced prototypes are capable of carrying increased loads. Moreover, the method developed by the authors is characterized by manufacturing costs lower than in the basic technology of Fused Deposition Modeling. During the presented studies, the pattern was produced as a polymer composite and it was used to prepare a mold and a set of metal castings.

  18. Design Fatigue Lives of Polypropylene Fibre Reinforced Polymer Concrete Composites

    Directory of Open Access Journals (Sweden)

    Raman Bedi

    2014-09-01

    Full Text Available Flexural fatigue behavior of Poly-propylene fibre reinforced polymer concrete composites (PFRPCC has been investigated at various stress levels and the statistical analysis of the data thus obtained has been carried out. Polymer Concrete Composite (PCC samples without addition of any type of fibres were also tested for flexural fatigue.  Forty specimens of PCC and One hundred and Forty One specimens of PFRPCC containing 0.5%, 1.0% and 2.0% polypropylene fibres were tested in fatigue using a MTS servo controlled test system. Fatigue life distributions of PCC as well as PFRPCC are observed to approximately follow a two parameter Weibull distribution with correlation coefficient exceeding 0.9. The parameters of the Weibull distribution have been obtained by various methods. Failure probability, which is an important parameter in the fatigue design of materials, has been used to obtain the design fatigue lives for the material. Comparison of design fatigue life of PCC and PFRPCC has been carried out and it is observed that addition of fibres enhances the design fatigue life of PCC.

  19. Stress-tuned conductor-polymer composite for use in sensors

    Science.gov (United States)

    Martin, James E; Read, Douglas H

    2013-10-22

    A method for making a composite polymeric material with electrical conductivity determined by stress-tuning of the conductor-polymer composite, and sensors made with the stress-tuned conductor-polymer composite made by this method. Stress tuning is achieved by mixing a miscible liquid into the polymer precursor solution or by absorbing into the precursor solution a soluble compound from vapor in contact with the polymer precursor solution. The conductor may or may not be ordered by application of a magnetic field. The composite is formed by polymerization with the stress-tuning agent in the polymer matrix. The stress-tuning agent is removed following polymerization to produce a conductor-polymer composite with a stress field that depends on the amount of stress-tuning agent employed.

  20. Effect of Polymer Matrix on the Structure and Electric Properties of Piezoelectric Lead Zirconatetitanate/Polymer Composites

    Directory of Open Access Journals (Sweden)

    Rui Li

    2017-08-01

    Full Text Available Piezoelectric lead zirconatetitanate (PZT/polymer composites were prepared by two typical polymer matrixes using the hot-press method. The micromorphology, microstructure, dielectric properties, and piezoelectric properties of the PZT/polymer composites were characterized and investigated. The results showed that when the condition of frequency is 103 Hz, the dielectric and piezoelectric properties of PZT/poly(vinylidene fluoride were both better than that of PZT/polyvinyl chloride (PVC. When the volume fraction of PZT was 50%, PZT/PVDF prepared by the hot-press method had better comprehensive electric property.

  1. Polymers Containing 1, 3, 4-Oxadiazole Rings for Advanced Materials

    OpenAIRE

    Mariana-Dana Damaceanu; Radu-Dan Rusu; Maria Bruma

    2011-01-01

    This paper presents the synthesis, properties and potential applications of new polymers containing 1, 3, 4-oxadiazole rings, tacking into account the requirements of the modern technologies. Two classes of polymers containing oxadiazole rings were approached: polyamides and polyimides. All the polymers were characterized with respect to the identification of their chemical structure, solubility, molecular weights, film forming ability, thermal, dielectric and optical properties, and the beha...

  2. Polymers Containing 1, 3, 4-Oxadiazole Rings for Advanced Materials

    Directory of Open Access Journals (Sweden)

    Mariana-Dana Damaceanu

    2011-10-01

    Full Text Available This paper presents the synthesis, properties and potential applications of new polymers containing 1, 3, 4-oxadiazole rings, tacking into account the requirements of the modern technologies. Two classes of polymers containing oxadiazole rings were approached: polyamides and polyimides. All the polymers were characterized with respect to the identification of their chemical structure, solubility, molecular weights, film forming ability, thermal, dielectric and optical properties, and the behaviour of polyoxadiazole films upon irradiation with pulsed KrF laser. All the properties were discussed in correlation with their chemical structure and compared with those of related polymers.

  3. Release characteristics of selected carbon nanotube polymer composites

    Science.gov (United States)

    Multi-walled carbon nanotubes (MWCNTs) are commonly used in polymer formulations to improve strength, conductivity, and other attributes. A developing concern is the potential for carbon nanotube polymer nanocomposites to release nanoparticles into the environment as the polymer ...

  4. Shock Compression and Strain Rate Effect in Composites and Polymers

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Eric [Los Alamos National Laboratory

    2012-06-20

    Polymers are increasingly being utilized as monolithic materials and composite matrices for structural applications historically reserved for metals. High strain and high strain-rate applications in aerospace, defense, and automotive industries have lead to interest in utilizing the ability of many polymers to withstand extensions to failure of several hundred percent, often without localization or necking and their strong rate dependence. A broad range of characterization techniques will be presented for semi-crystalline polymers and composites including elastic-plastic fracture, split Hopkinson pressure bar (SHPB), plate impact including soft-recovery and lateral gage measurements and Taylor Impact. Gas-launched, plate impact experiments have been performed on pedigreed PTFE 7C, mounted in momentum-trapped, shock assemblies, with impact pressures above and below the phase II to phase III crystalline transition to probe subtle changes in the crystallinity, microstructure, and mechanical response of PTFE. Observed strong anisotropy on the hugoniot and spall behavior of fiber-reinforced composites will be discussed. Polymers are known to exhibit a strong dependence of the yield stress on temperature and strain-rate that are often observed to be linear for temperature and logarithmic for strain-rate. Temperature and strain-rate dependence will be reviewed in terms of classic time-temperature superposition and an empirical mapping function for superposition between temperature and strain-rate. The recent extension of the new Dynamic-Tensile-Extrusion (Dyn-Ten-Ext) technique to probe the dynamic tensile responses of polymers will be discussed, where more irregular deformation and stochastic-based damage and failure mechanisms than the stable plastic elongation and shear instabilities observed that in metals. The opportunity to use of Dyn-Ten-Ext to probe incipient damage at very high strain-rate by linking in situ and post mortem experimental observations with high

  5. Advanced Manufacturing Technologies (AMT): Composites Integrated Modeling

    Data.gov (United States)

    National Aeronautics and Space Administration — The Composites Integrated Modeling (CIM) Element developed low cost, lightweight, and efficient composite structures, materials and manufacturing technologies with...

  6. Effect of domain size and interface characteristics on the impact resistance of selected polymer composites

    Science.gov (United States)

    Viratyaporn, Wantinee

    Nanocomposite technology has advanced considerably in recent years and excellent engineering properties have been achieved in numerous systems. In multiphase materials the enhancement of properties relies heavily on the nature at the interphase region between polymer domains and nanoparticle reinforcements. Strong adhesion between the phases provides excellent load-transfer and good mechanical elastic modulus and strength, whereas weak interaction contributes to crack deflection mechanisms and toughness. Polymer molecules are large and the presence of comparably sized filler particles affects chain gyration, which in turn influences the conformation of the polymer and the properties of the composite. Nanoparticles were incorporated into a poly(methyl methacrylate) matrix by means of in situ free radical (bulk) polymerization. Aluminum oxide and zinc oxide nanoparticles were added to study the effects of particle chemistry and shape on selected mechanical properties such as impact resistance, which showed significant improvement at a certain loading of zinc oxide. The elongated shape of zinc oxide particles appears to promote crack deflection processes and to introduce a pull-out mechanism similar to that observed in fiber composite systems. Moreover, the thermal stability of PMMA was improved with the addition of nanoparticles, apparently by steric hindrance of polymer chain motion and a second mechanism related to the dipole inducing effect of the oxide particles. The sensitivity of infrared spectroscopy to changes in molecular dipoles was used to study the nature of the polymer/particle interface. The results revealed some interesting aspects of the secondary bonds between polymers and oxides. Raman spectroscopy was used to investigate the extent of polymerization and changes in polymer conformation. A degree of polymerization of 93% was achieved in neat PMMA, and even when 5.0 v/o of PGMEA was introduced into the system no monomer was detected. However, when

  7. Hybrid polymer composite membrane for an electromagnetic (EM) valveless micropump

    Science.gov (United States)

    Said, Muzalifah Mohd; Yunas, Jumril; Bais, Badariah; Azlan Hamzah, Azrul; Yeop Majlis, Burhanuddin

    2017-07-01

    In this paper, we report on a hybrid membrane used as an actuator in an electromagnetically driven valveless micropump developed using MEMS processes. The membrane structure consists of the combination of a magnetic polymer composite membrane and an attached bulk permanent magnet which is expected to have a compact structure and a strong magnetic force with maintained membrane flexibility. A soft polymeric material made of polydimethylsiloxane (PDMS) is initially mixed with neodymium magnetic particles (NdFeB) to form a magnetic polymer composite membrane. The membrane is then bonded with the PDMS based microfluidic part, developed using soft lithography process. The developed micropump was tested in terms of the actuator membrane deflection capability and the fluidic flow of the injected fluid sample through the microfluidic channel. The experimental results show that the magnetic composite actuator membrane with an attached bulk permanent magnet is capable of producing a maximum membrane deflection of up to 106 µm. The functionality test of the electromagnetic (EM) actuator for fluid pumping purposes was done by supplying an AC voltage with various amplitudes, signal waves and frequencies. A wide range of sample injection rates from a few µl min-1 to tens of nl min-1 was achieved with a maximum flow rate of 6.6 µl min-1. The injection flow rate of the EM micropump can be controlled by adjusting the voltage amplitude and frequency supplied to the EM coil, to control the membrane deflection in the pump chamber. The designed valveless EM micropump has a very high potential to enhance the drug delivery system capability in biomedical applications.

  8. Mechanical properties of heterophase polymer blends of cryogenically fractured soy flour composite filler and poly(styrene-butadiene)

    Science.gov (United States)

    Reinforcement effect of cryogenically fractured soy Flour composite filler in soft polymer was investigated in this study. Polymer composites were prepared by melt-mixing polymer and soy flour composite fillers in an internal mixer. Soy flour composite fillers were prepared by blending aqueous dis...

  9. Advances in synthetic optically active condensation polymers - A review

    Directory of Open Access Journals (Sweden)

    2011-02-01

    Full Text Available The study of optically active polymers is a very active research field, and these materials have exhibited a number of interesting properties. Much of the attention in chiral polymers results from the potential of these materials for several specialized utilizations that are chiral matrices for asymmetric synthesis, chiral stationary phases for the separation of racemic mixtures, synthetic molecular receptors and chiral liquid crystals for ferroelectric and nonlinear optical applications. Recently, highly efficient methodologies and catalysts have been developed to synthesize various kinds of optically active compounds. Some of them can be applied to chiral polymer synthesis. In a few synthetic approaches for optically active polymers, chiral monomer polymerization has essential advantages in applicability of monomer, apart from both asymmetric polymerization of achiral or prochiral monomers and enantioselective polymerization of a racemic monomer mixture. The following are the up to date successful approaches to the chiral synthetic polymers by condensation polymerization reaction of chiral monomers.

  10. STUDY OF SINGLE WALLED CARBON NANOTUBE REINFORCED POLYMER COMPOSITES BY HANSEN SOLUBILITY PARAMETERS

    DEFF Research Database (Denmark)

    Ma, Jing

    reinforcement of the polymer by the addition of SWNTs. Existence of agglomerates, voids, and the lower glass transition temperature of epoxy resin, may give the negative effect on the mechanical properties of nanocomposite materials. In the design aspect of the composite material, HSP could help match SWNTs......Single Walled carbon nanotubes (SWNTs) possess superior mechanical, thermal and electrical properties. The use of SWNTs as a reinforcement in polymer matrix is a hot research topic. However, the poor dispersion of SWNTs in polymers and the weak interface between the nanotubes and polymers are two...... major challenges which limit the use of SWNTs for reinforced polymer composites. The main objectives of this PhD work are to design, fabricate SWNTs/polymer composites and characterize the mechanical properties of the composite materials. This study uses the Hansen solubility parameters (HSP) to predict...

  11. Self-Healing Composite of Thermoset Polymer and Programmed Super Contraction Fibers

    Science.gov (United States)

    Li, Guoqiang (Inventor); Meng, Harper (Inventor)

    2016-01-01

    A composition comprising thermoset polymer, shape memory polymer to facilitate macro scale damage closure, and a thermoplastic polymer for molecular scale healing is disclosed; the composition has the ability to resolve structural defects by a bio-mimetic close-then heal process. In use, the shape memory polymer serves to bring surfaces of a structural defect into approximation, whereafter use of the thermoplastic polymer for molecular scale healing allowed for movement of the thermoplastic polymer into the defect and thus obtain molecular scale healing. The thermoplastic can be fibers, particles or spheres which are used by heating to a level at or above the thermoplastic's melting point, then cooling of the composition below the melting temperature of the thermoplastic. Compositions of the invention have the ability to not only close macroscopic defects, but also to do so repeatedly even if another wound/damage occurs in a previously healed/repaired area.

  12. Effect of Material Parameters on Mechanical Properties of Biodegradable Polymers/Nanofibrillated Cellulose (NFC) Nano Composites

    Science.gov (United States)

    Yottha Srithep; Ronald Sabo; Craig Clemons; Lih-Sheng Turng; Srikanth Pilla; Jun Peng

    2012-01-01

    Using natural cellulosic fibers as fillers for biodegradable polymers can result in fully biodegradable composites. Biodegradable composites were prepared using nanofibrillated cellulose (NFC) as the reinforcement and poly (3-hydroxybutyrate-co-3-hydroxyvalerate, PHBV) as the polymer matrix. The objective of this study was to determine how various additives (i.e.,...

  13. ROMP-based polymer composites and biorenewable rubbers

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Wonje [Iowa State Univ., Ames, IA (United States)

    2009-01-01

    This research is divided into two related topics. In the first topic, the synthesis and characterization of novel composite materials reinforced with MWCNTs by ring-opening metathesis polymerization (ROMP) is reported for two ROMP based monomers: dicyclopentadiene (DCPD) and 5-ethylidene-2-norbornene (ENB). Homogeneous dispersion of MWCNTs in the polymer matrices is achieved by grafting norbornene moieties onto the nanotube surface. For the DCPD-based system, the investigation of mechanical properties of the composites shows a remarkable increase of tensile toughness with just 0.4 wt % of functionalized MWCNTs (f-MWCNTs). To our knowledge, this represents the highest toughness enhancement efficiency in thermosetting composites ever reported. DMA results show that there is a general increase of thermal stability (rg) with the addition of f-MWCNTs, which means that covalently bonded f-MWCNTs can reduce the local chain mobility of the matrix by interfacial interactions. The ENB system also shows significant enhancement of the toughness using just 0.8 wt % f-MWCNTs. These results indicate that the ROMP approach for polyENB is also very effective. The second topic is an investigation of the biorenewable rubbers synthesized by the tandem ROMP and cationic polymerization. The resin consists of a norbornenyl-modified linseed oil and a norbornene diester. Characterization of the bio-based rubbers includes dynamic mechanical analysis, tensile testing, and thermogravimetric analysis. The experimental results show that there is a decrease in glass transition temperature and slight increase of elongation with increased diester loading.

  14. Thermomechanical behavior of fiber reinforced shape memory polymer composite

    Science.gov (United States)

    Lan, Xin; Liu, Yanju; Leng, Jinsong; Du, Shanyi

    2007-07-01

    Carbon fiber fabric reinforced shape memory polymer composite (SMPC) is studied in this paper. The shape memory polymer (SMP) is a thermoset styrene-based resin. In order to discuss the basic thermomechanical properties of SMPC, the investigation is conducted with the following methods: dynamic mechanical analyzer (DMA), three-point bending test, shape recovery tests and scanning electron microscope (SEM). Results indicate that SMPC exhibits a higher glass transition temperature (T g) and a higher storage modulus than pure SMP. SMPC shows high bending modulus before the glass transition in SMP, while exhibits low bending modulus within the range of glass transition in SMP. Moreover, shape recovery velocity and ratio rise remarkably with the increase of shape recovery temperature, while they increase in a weak trend with the increase of pre-deformation temperature. In addition, electrically conductive SMPC shows favorable recovery performances during the thermomechanical cycles. In the end, under the bending deformation, all the buckled fibers in inner surface break at the same time, which make it regular for the fracture section of buckled fiber tow. However, the cross sections of these buckled fibers are relatively rough and located in 45°C direction along fiber. By contrast, the tensile fibers in outer surface break unorderly, which make it irregular for the fracture section of tensile fiber tow. But the cross sections of these tensile fibers are relatively smooth and vertical to fiber.

  15. Advanced organic composite materials for aircraft structures: Future program

    Science.gov (United States)

    1987-01-01

    Revolutionary advances in structural materials have been responsible for revolutionary changes in all fields of engineering. These advances have had and are still having a significant impact on aircraft design and performance. Composites are engineered materials. Their properties are tailored through the use of a mix or blend of different constituents to maximize selected properties of strength and/or stiffness at reduced weights. More than 20 years have passed since the potentials of filamentary composite materials were identified. During the 1970s much lower cost carbon filaments became a reality and gradually designers turned from boron to carbon composites. Despite progress in this field, filamentary composites still have significant unfulfilled potential for increasing aircraft productivity; the rendering of advanced organic composite materials into production aircraft structures was disappointingly slow. Why this is and research and technology development actions that will assist in accelerating the application of advanced organic composites to production aircraft is discussed.

  16. Electromagnetic properties of photodefinable barium ferrite polymer composites

    Directory of Open Access Journals (Sweden)

    Olusegun Sholiyi

    2014-07-01

    Full Text Available This article reports the magnetic and microwave properties of a Barium ferrite powder suspended in a polymer matrix. The sizes for Barium hexaferrite powder are 3–6 μm for coarse and 0.8–1.0 μm for the fine powder. Ratios 1:1 and 3:1 (by mass of ferrite to SU8 samples were characterized and analyzed for predicting the necessary combinations of these powders with SU8 2000 Negative photoresist. The magnetization properties of these materials were equally determined and were analyzed using Vibrating Sample Magnetometer (VSM. The Thru, Reflect, Line (TRL calibration technique was employed in determining complex relative permittivity and permeability of the powders and composites with SU8 between 26.5 and 40 GHz.

  17. Electromechanical modelling of tapered ionic polymer metal composites transducers

    Directory of Open Access Journals (Sweden)

    Rakesha Chandra Dash

    2016-09-01

    Full Text Available Ionic polymer metal composites (IPMCs are relatively new smart materials that exhibit a bidirectional electromechanical coupling. IPMCs have large number of important engineering applications such as micro robotics, biomedical devices, biomimetic robotics etc. This paper presents a comparison between tapered and uniform cantilevered Nafion based IPMCs transducer. Electromechanical modelling is done for the tapered beam. Thickness can be varied according to the requirement of force and deflection. Numerical results pertaining to the force and deflection characteristics of both type IPMCs transducer are obtained. It is shown that the desired amount of force and deflections for tapered IPMCs can be achieved for a given voltage. Different fixed end (t0 and free end (t1 thickness values have been taken to justify the results using MATLAB.

  18. Method of Making an Electroactive Sensing/Actuating Material for Carbon Nanotube Polymer Composite

    Science.gov (United States)

    Ounaies, Zoubeida (Inventor); Park, Cheol (Inventor); Harrison, Joycelyn S. (Inventor); Holloway, Nancy M. (Inventor); Draughon, Gregory K. (Inventor)

    2009-01-01

    An electroactive sensing or actuating material comprises a composite made from a polymer with polarizable moieties and an effective amount of carbon nanotubes incorporated in the polymer for a predetermined electromechanical operation of the composite when such composite is affected by an external stimulus. In another embodiment, the composite comprises a, third component of micro -sized to nano-sized particles of an electroactive ceramic that is also incorporated in the polymer matrix. The method for making the three-phase composite comprises either incorporating the carbon nanotubes in the polymer matrix before incorporation of the particles of ceramic or mixing the carbon nanotubes and particles of ceramic together in a solution before incorporation in the polymer matrix.

  19. Application of advanced composites in tokamak magnet systems

    International Nuclear Information System (INIS)

    Long, C.J.

    1977-11-01

    The use of advanced (high-modulus) composites in superconducting magnets for tokamak fusion reactors is discussed. The most prominent potential application is as the structure in the pulsed poloidal-field coil system, where a significant reduction in eddy currents could be achieved. Present low-temperature data on the advanced composites are reviewed briefly; they are too meager to do more than suggest a broad class of composites for a particular application

  20. Advanced composites characterization with x-ray technologies

    Science.gov (United States)

    Baaklini, George Y.

    1993-12-01

    Recognizing the critical need to advance new composites for the aeronautics and aerospace industries, we are focussing on advanced test methods that are vital to successful modeling and manufacturing of future generations of high temperature and durable composite materials. These newly developed composites are necessary to reduce propulsion cost and weight, to improve performance and reliability, and to address longer-term national strategic thrusts for sustaining global preeminence in high speed air transport and in high performance military aircraft.

  1. Plasma-modified graphene nanoplatelets and multiwalled carbon nanotubes as fillers for advanced rubber composites

    International Nuclear Information System (INIS)

    Sicinski, M; Gozdek, T; Bielinski, D M; Kleczewska, J; Szymanowski, H; Piatkowska, A

    2015-01-01

    In modern rubber industry, there still is a room for new fillers, which can improve the mechanical properties of the composites, or introduce a new function to the material. Modern fillers like carbon nanotubes or graphene nanoplatelets (GnP), are increasingly applied in advanced polymer composites technology. However, it might be hard to obtain a well dispersed system for such systems. The polymer matrix often exhibits higher surface free energy (SFE) level with the filler, which can cause problems with polymer-filler interphase adhesion. Filler particles are not wet properly by the polymer, and thus are easier to agglomerate. As a consequence, improvement in the mechanical properties is lower than expected. In this work, multi-walled carbon nanotubes (MWCNT) and GnP surface were modified with low-temperature plasma. Attempts were made to graft some functionalizing species on plasma-activated filler surface. The analysis of virgin and modified fillers’ SFE was carried out. MWCNT and GnP rubber composites were produced, and ultimately, their morphology and mechanical properties were studied. (paper)

  2. Composite gel polymer electrolyte for lithium ion batteries

    Science.gov (United States)

    Naderi, Roya

    Composite gel polymer electrolyte (CGPE) films, consisting of poly (vinylidene fluoride-hexafluoropropylene) (PVdF-HFP) as the membrane, DMF and PC as solvent and plasticizing agent, mixture of charge modified TiO2 and SiO 2 nano particles as ionic conductors, and LiClO4+LiPF 6 as lithium salts were fabricated. Following the work done by Li et al., CGPE was coated on an O2-plasma treated trilayer polypropylene-polyethylene-polypropylene membrane separator using solution casting technique in order to improve the adhesive properties of gel polymer electrolyte to the separator membrane and its respective ionic conductivity due to decreasing the bulk resistance. In acidic CGPE with, the mixture of acid treated TiO2 and neutral SiO2 nano particles played the role of the charge modified nano fillers with enhanced hydroxyl groups. Likely, the mixture of neutral TiO 2 nano particles with basic SiO2 prepared through the hydrolization of tetraethyl orthosilicate (TEOS) provided a more basic environment due to the residues of NH4OH (Ammonium hydroxide) catalyst. The O2 plasma treated separator was coated with the solution of PVDF-HFP: modified nano fillers: Organic solvents with the mixture ratio of 0.1:0.01:1. After the evaporation of the organic solvents, the dried coated separator was soaked in PC-LiClO4+LiPF6 in EC: DMC:DEC (4:2:4 in volume) solution (300% wt. of PVDF-HFP) to form the final CGPE. Lim et al. has reported the enhanced ionic conductivity of 9.78*10-5 Scm-1 in an acidic composite polystyrene-Al2O3 solid electrolyte system with compared to that of basic and neutral in which the ionic conductivity undergoes an ion hopping process in solid interface rather than a segmental movement of ions through the plasticized polymer chain . Half-cells with graphite anode and Li metal as reference electrode were then assembled and the electrochemical measurements and morphology examinations were successfully carried out. Half cells demonstrated a considerable change in their

  3. Photocatalytic activity of PANI loaded coordination polymer composite materials: Photoresponse region extension and quantum yields enhancement via the loading of PANI nanofibers on surface of coordination polymer

    International Nuclear Information System (INIS)

    Cui, Zhongping; Qi, Ji; Xu, Xinxin; Liu, Lu; Wang, Yi

    2013-01-01

    To enhance photocatalytic property of coordination polymer in visible light region, polyaniline (PANI) loaded coordination polymer photocatalyst was synthesized through in-situ chemical oxidation of aniline on the surface of coordination polymer. The photocatalytic activity of PANI loaded coordination polymer composite material for degradation of Rhodamine B (RhB) was investigated. Compared with pure coordination polymer photocatalyst, which can decompose RhB merely under UV light irradiation, PANI loaded coordination polymer photocatalyst displays more excellent photocatalytic activity in visible light region. Furthermore, PANI loaded coordination polymer photocatalyst exhibits outstanding stability during the degradation of RhB. - Graphical abstract: PANI loaded coordination polymer composite material, which displays excellent photocatalytic activity under visible light was firstly synthesized through in-situ chemical oxidation of aniline on surface of coordination polymer. Display Omitted - Highlights: • This PANI loaded coordination polymer composite material represents the first conductive polymer loaded coordination polymer composite material. • PANI/coordination polymer composite material displays more excellent photocatalytic activity for the degradation of MO in visible light region. • The “combination” of coordination polymer and PANI will enable us to design high-activity, high-stability and visible light driven photocatalyst in the future

  4. Compositional and weave pattern analyses of glass fibers in dental polymer fiber composites.

    Science.gov (United States)

    Vallittu, P K

    1998-09-01

    This study compared weave patterns and glass compositions of five glass fiber materials found in commercial fiber-reinforced dental composites. A scanning electron microscope (SEM) was used to investigate the woven structure of five glass fiber products, and an energy-dispersive x-ray spectrometer (SEM/EDS) was used to determine the elemental composition of these glass fibers in the bulk and at the surface of the fiber. Five fibers of each product were analyzed. The fiber products were either unidirectional rovings or bidirectional weaves. More precisely, the woven structures were linen weave, twill weave, or twill weave ribbon. SEM/EDS analysis revealed that the composition of the glass fibers was typical for E (electrical)-glass fibers with one exception. One product intended for use in fixed prosthodontics included unidirectional fibers with a composition consistent with a modified high-tensile-strength R-glass. Boron oxide found on the surface of glass fibers would likely contribute to an increased potential for corrosion of fiber-reinforced composite. The predominant fiber composition in these products is E-glass. Because the degree of hydrolytic stability of polymer-fiber composites over time may lead to material failure in permanent restorations, this property should be investigated further.

  5. Production of polymer-plaster composite by gamma irradiation

    International Nuclear Information System (INIS)

    Gazineu, Maria Helena Paranhos; Santos, Valdemir Alexandre dos; Dantas, Carlos Costa

    2009-01-01

    The estimated amount of plaster wastes in the construction industry is 45%. The reduction of this waste is of concern, because the cost of lost material and the waste management can affect the competitiveness of the company. The mixture of plaster with a particular resin generates a composite, which gives the pre-molded obtained from this mixture, special properties. In this case, the plasticity of the plaster generates pre-molded products with wealth of details. Additionally, the use of nuclear techniques for the initiation of polymerization reaction for obtaining this type of composite can eliminate the need for a heat source which is the conventional way to obtain polymerization, considerably reducing the costs of the process. As a function of the availability and the cost of styrene monomer, in the initial phase of the research test samples were prepared from plaster composites with this type of material. The test samples, composed of plaster and styrene, were irradiated in the presence of a Cs-137 (662 keV) gamma source for a period of time of two days in an air pressurized chamber. Tests of resistance to compression, tensile strength in bending and water absorption, were based on a type of experimental design, CCRD (Central Composite Rotatable Design). The percent average weight of polymer by weight of the test sample was 14.0%. The presence of a polymerized resin gives the sample qualities such as being highly impervious to water and high mechanical strength, allowing its use in the manufacture of different types of materials. (author)

  6. Surface modified carbon nanoparticle papers and applications on polymer composites

    Science.gov (United States)

    Ouyang, Xilian

    Free-standing paper like materials are usually employed as protective layers, chemical filters, components of electrical batteries or supercapacitors, adhesive layers, and electronic or optoelectric components. Free-standing papers made from carbon nanoparticles have drawn increased interest because they have a variety of superior chemical and physical characteristics, such as light weight, high intrinsic mechanical properties, and extraordinary high electrical conductivity. Nanopapers fabricated from 1- D shape carbon nanofibers (CNFs) and carbon nanotubes (CNTs) are promising reinforcing materials for polymer composites, because the highly porous CNF and CNT nanopapers (porosity ˜80% and ˜70% respectively) can be impregnated with matrix polymers. In the first part of this work, polyaniline (PANI) was used to functionalize the surface of CNFs, and the resultant carbon nanopapers presented impressive mechanical strength and electrical conductivity that it could be used in the in-mold coating (IMC)/ injection molding process to achieve high electromagnetic interference (EMI) shielding effectiveness. Aniline modified (AF) CNT nanopapers were used as a 3D network in gas separation membranes. The resultant composite membranes demonstrated better and stable CO2 permeance and CO 2/H2 selectivity in a high temperature (107°C) and high pressure (15-30 atm) gas separation process, not achievable by conventional polymer membranes. In the second part, we demonstrated that 2-D graphene (GP) or graphene oxide (GO) nanosheets could be tightly packed into a film which was impermeable to most gases and liquids. GP or GO nanopapers could be coated on polymer composites. In order to achieve well-dispersed single-layer graphene in aqueous medium, we developed a facile approach to synthesize functional GP bearing benzenesulfonic acid groups which allow the preparation of nanopapers by water based assembly. With the optimized processing conditions, our best GP nanopapers could reach

  7. Research and Development Progress of National Key Laboratory of Advanced Composites on Advanced Aeronautical Resin Matrix Composites

    Directory of Open Access Journals (Sweden)

    LI Bintai

    2016-06-01

    Full Text Available Applications and research progress in advanced aeronautical resin matrix composites by National Key Laboratory of Advanced Composites (LAC were summarized. A novel interlaminar toughening technology employing ultra-thin TP non-woven fabric was developed in LAC, which significantly improved the compression after impact (CAI performances of composite laminates.Newly designed multilayer sandwich stealth composite structures exhibited a good broadband radar absorbing properties at 1-18 GHz.There were remarkable developments in high toughness and high temperature resin matrix composites, covering major composite processing technologies such as prepreg-autoclave procedure, liquid composite molding and automation manufacture, etc. Finally, numerical simulation and optimization methods were deliberately utilized in the study of composites curing behavior, resin flow and curing deformation. A composite material database was also established.In conclusion, LAC has been a great support for the development of aeronautical equipment, playing such roles as innovation leading, system dominating, foundation supporting and application ensuring of aerocomposites.

  8. Ultra-Broadband THz Antireflective Coating with Polymer Composites

    Directory of Open Access Journals (Sweden)

    Bin Cai

    2017-11-01

    Full Text Available Achieving an ultra-broadband range is an essential development direction in terahertz techniques; however, a method to cover the full terahertz band by using a highly efficient antireflection (AR coating that could greatly increase the efficiency of terahertz radiation is still lacking. It is known that structures possessing a graded-index profile can offer a broadband AR effect, and such structures have been widely used, especially in the visible range. In this paper, first, we tuned the refractive index of a cyclo-olefin polymer (COP by using a TiO2 dopant, and a polymer–TiO2 composite with a refractive index of 3.1 was achieved. We then fabricated a surface-relief structure with a graded-index profile by using a hot-embossing method. The structure on the silicon substrate can provide an excellent AR effect, but the working band is still limited by its scale of sag and swell. To obtain an ultra-broadband AR effect, we then proposed a flat six-layer structure; a graded-index profile was obtained by casting epoxy–TiO2 composites in the order of a high index to lower indices. With a very well controlled refractive index and thickness of each layer, we achieved an AR effect of <2% in the ultra-broadband of 0.2–20 THz.

  9. Mechanical properties evaluation of extruded wood polymer composites

    Science.gov (United States)

    Zaini, A. S. Syah M.; Rus, Anika Zafiah M.; Rahman, Norherman Abdul; Jais, Farhana Hazwanee M.; Fauzan, M. Zarif; Sufian, N. Afiqah

    2017-09-01

    The rapidly expanding of interest in the manufacture of composite materials from waste industrial and agricultural materials is due to high demand for environmentally friendly materials. Wood polymer composite (WPC) are being used in many type of applications such as in the automobile, electronic, aerospace industry and construction. Therefore, this research study is to determine the mechanical properties behaviour of WPC after an extended Ultra Violet (UV) irradiation exposure. The fabricated sample has been used and to be compared in this research is consists of rice husk, waste fibre and polypropylene (PP) with 4 different types of WPC which are wood block waste (WBW), wood block virgin (WBV), wood sheet (WS) and wood sheet waste (WSW). The extruded specimens were tested for mechanical properties such as strength under compression, puncture strength and impact resistance, and density. In addition, the specimen has been irradiated with the UV exposure at 5000 hours, 10000 hours and 15000 hours. Generally, the mechanical properties the WPC which made from the recycled material were lower than the WPC from virgin material but the density was comparable between the two products after UV irradiation exposure.

  10. EB treatment of carbon nanotube-reinforced polymer composites

    International Nuclear Information System (INIS)

    Szebenyi, G.; Romhany, G.; Czvikovszky, T.; Vajna, B.

    2011-01-01

    Complete text of publication follows. A small amount - less than 0.5% - carbon nanotube reinforcement may improve significantly the mechanical properties of epoxy based composite materials. The basic technical problem is on one side the dispersion of the nanotubes into the viscous matrix resin. Namely the fine, powder-like - less than 100 nanometer diameter - nanotubes are prone to form aggregates. On the other side, the good connection between the nanofiber and matrix, - which is determining the success of the reinforcement, - requires some efficient adhesion promoting treatment. After an elaborate masterbatch mixing technology we applied Electron Beam treatment of epoxy-matrix polymer composites containing carbon nanotubes in presence of vinylester resins. The Raman spectra of vinylester-epoxy mixtures treated by an 8 MeV EB showed the advantage of the electron treatment. Even in the case of partially immiscible epoxy and vinylester resins, the anchorage of carbon nanotubes reflects improvement if a reasonable 25 kGy EB dose is applied. Atomic Force Microscopy as well as mechanical tests on flexural and impact properties confirm the benefits of EB treatment. Simultaneous application of multiwall carbon nanotubes and 'conventional' carbon fibers as reinforcement in vinylester modified epoxies results in new types of hybrid nanocomposites as engineering materials. The bending- and interlaminar properties of such hybrid systems showed the beneficial effect of the EB treatment. Acknowledgement: This work has been supported by the New Hungary Development Plan (Project ID: TAMOP-4.2.1/B-09/1/KMR-2010-0002).

  11. Conductive polymer and Si nanoparticles composite secondary particles and structured current collectors for high loading lithium ion negative electrode application

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Gao

    2017-07-11

    Embodiments of the present invention disclose a composition of matter comprising a silicon (Si) nanoparticle coated with a conductive polymer. Another embodiment discloses a method for preparing a composition of matter comprising a plurality of silicon (Si) nanoparticles coated with a conductive polymer comprising providing Si nanoparticles, providing a conductive polymer, preparing a Si nanoparticle, conductive polymer, and solvent slurry, spraying the slurry into a liquid medium that is a non-solvent of the conductive polymer, and precipitating the silicon (Si) nanoparticles coated with the conductive polymer. Another embodiment discloses an anode comprising a current collector, and a composition of matter comprising a silicon (Si) nanoparticle coated with a conductive polymer.

  12. Microbuckling compression failure of a radiation-induced wood/polymer composite

    International Nuclear Information System (INIS)

    Boey, F.Y.C.

    1990-01-01

    A wood/polymer composite was produced by impregnating Ramin wood with methyl methacrylate monomer and subsequently polymerizing it by gamma irradiation. To assess the improvement in compression strength of the wood caused by the polymer impregnation, a microbuckling compression failure mechanism was used to model the compression failure of the composite. Such a mechanism was found to predict a linear relationship between the compression strength and the percentage polymer impregnation (by weight). Uniaxial compression test results at 45(±5)% and 90(±5)% relative humidity levels, after being statistically analysed, showed that such a linear relationship was valid for up to 100% polymer impregnation. (author)

  13. Characteristics of porous polymer composite columns prepared by radiation cast-polymerization

    International Nuclear Information System (INIS)

    Kumakura, Minoru; Kaetsu, Isao; Asami, Kazuhiro; Suzuki, Shuichi

    1989-01-01

    Porous polymer composite columns having porous structure were prepared by radiation cast-polymerization of hydrophilic monomers at low temperature and their characteristics were studied. The porosity of the polymer increased with decreasing monomer concentration. The elution time of water in the polymer column increased with increasing monomer concentration and with decreasing irradiation temperature. The elution time was dependent on the degree of hydration of the polymer. The polymer with a degree of hydration of 0.2 to 0.4 gave the minimum elution time. The elution time decreased with the addition of porous inorganic substances. (author)

  14. Fluorinated Polymers as Smart Materials for Advanced Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Vanessa F. Cardoso

    2018-02-01

    Full Text Available Fluorinated polymers constitute a unique class of materials that exhibit a combination of suitable properties for a wide range of applications, which mainly arise from their outstanding chemical resistance, thermal stability, low friction coefficients and electrical properties. Furthermore, those presenting stimuli-responsive properties have found widespread industrial and commercial applications, based on their ability to change in a controlled fashion one or more of their physicochemical properties, in response to single or multiple external stimuli such as light, temperature, electrical and magnetic fields, pH and/or biological signals. In particular, some fluorinated polymers have been intensively investigated and applied due to their piezoelectric, pyroelectric and ferroelectric properties in biomedical applications including controlled drug delivery systems, tissue engineering, microfluidic and artificial muscle actuators, among others. This review summarizes the main characteristics, microstructures and biomedical applications of electroactive fluorinated polymers.

  15. PEO + PVP blended polymer composite films for multifunctional ...

    Indian Academy of Sciences (India)

    has been noticed from PEO + PVP : Ni2+ polymer film at 373 K. Emission analysis of Co2+: PEO + PVP poly- mer film has exhibited a ... suggested that these TM ions doped PEO + PVP polymer films are found to be potential multifunctional materi- ..... tion of semicircle with the real axis the bulk resistance of the polymer ...

  16. Polymer nanotube nanocomposites: synthesis, properties, and applications

    National Research Council Canada - National Science Library

    Mittal, Vikas

    2010-01-01

    ... in these commercially important areas of polymer technology. It sums up recent advances in nanotube composite synthesis technology, provides basic introduction to polymer nanotubes nanocomposite technology for the readers new to this field, provides valuable...

  17. Composite Laser Ceramics by Advanced Bonding Technology.

    Science.gov (United States)

    Ikesue, Akio; Aung, Yan Lin; Kamimura, Tomosumi; Honda, Sawao; Iwamoto, Yuji

    2018-02-09

    Composites obtained by bonding materials with the same crystal structure and different chemical compositions can create new functions that do not exist in conventional concepts. We have succeeded in bonding polycrystalline YAG and Nd:YAG ceramics without any interstices at the bonding interface, and the bonding state of this composite was at the atomic level, similar to the grain boundary structure in ceramics. The mechanical strength of the bonded composite reached 278 MPa, which was not less than the strength of each host material (269 and 255 MPa). Thermal conductivity of the composite was 12.3 W/mK (theoretical value) which is intermediate between the thermal conductivities of YAG and Nd:YAG (14.1 and 10.2 W/mK, respectively). Light scattering cannot be detected at the bonding interface of the ceramic composite by laser tomography. Since the scattering coefficients of the monolithic material and the composite material formed by bonding up to 15 layers of the same materials were both 0.10%/cm, there was no occurrence of light scattering due to the bonding. In addition, it was not detected that the optical distortion and non-uniformity of the refractive index variation were caused by the bonding. An excitation light source (LD = 808 nm) was collimated to 200 μm and irradiated into a commercial 1% Nd:YAG single crystal, but fracture damage occurred at a low damage threshold of 80 kW/cm². On the other hand, the same test was conducted on the bonded interface of 1% Nd:YAG-YAG composite ceramics fabricated in this study, but it was not damaged until the excitation density reached 127 kW/cm². 0.6% Nd:YAG-YAG composite ceramics showed high damage resistance (up to 223 kW/cm²). It was concluded that composites formed by bonding polycrystalline ceramics are ideal in terms of thermo-mechanical and optical properties.

  18. Nanoscale indentation of polymer and composite polymer-silica core-shell submicrometer particles by atomic force microscopy.

    Science.gov (United States)

    Armini, Silvia; Vakarelski, Ivan U; Whelan, Caroline M; Maex, Karen; Higashitani, Ko

    2007-02-13

    Atomic force microscopy was employed to probe the mechanical properties of surface-charged polymethylmethacrylate (PMMA)-based terpolymer and composite terpolymer core-silica shell particles in air and water media. The composite particles were achieved with two different approaches: using a silane coupling agent (composite A) or attractive electrostatic interactions (composite B) between the core and the shell. Young's moduli (E) of 4.3+/-0.7, 11.1+/-1.7, and 8.4+/-1.7 GPa were measured in air for the PMMA-based terpolymer, composite A, and composite B, respectively. In water, E decreases to 1.6+/-0.2 GPa for the terpolymer; it shows a slight decrease to 8.0+/-1.2 GPa for composite A, while it decreases to 2.9+/-0.6 GPa for composite B. This trend is explained by considering a 50% swelling of the polymer in water confirmed by dynamic light scattering. Close agreement is found between the absolute values of elastic moduli determined by nanoindentation and known values for the corresponding bulk materials. The thickness of the silica coating affects the mechanical properties of composite A. In the case of composite B, because the silica shell consists of separate particles free to move in the longitudinal direction that do not individually deform when the entire composite deforms, the elastic properties of the composites are determined exclusively by the properties of the polymer core. These results provide a basis for tailoring the mechanical properties of polymer and composite particles in air and in solution, essential in the design of next-generation abrasive schemes for several technological applications.

  19. NATO Advanced Research Workshop on Computational Methods for Polymers and Liquid Crystalline Polymers

    CERN Document Server

    Pasini, Paolo; Žumer, Slobodan; Computer Simulations of Liquid Crystals and Polymers

    2005-01-01

    Liquid crystals, polymers and polymer liquid crystals are soft condensed matter systems of major technological and scientific interest. An understanding of the macroscopic properties of these complex systems and of their many and interesting peculiarities at the molecular level can nowadays only be attained using computer simulations and statistical mechanical theories. Both in the Liquid Crystal and Polymer fields a considerable amount of simulation work has been done in the last few years with various classes of models at different special resolutions, ranging from atomistic to molecular and coarse-grained lattice models. Each of the two fields has developed its own set of tools and specialized procedures and the book aims to provide a state of the art review of the computer simulation studies of polymers and liquid crystals. This is of great importance in view of a potential cross-fertilization between these connected areas which is particularly apparent for a number of experimental systems like, e.g. poly...

  20. Effect of Biomass Waste Filler on the Dielectric Properties of Polymer Composites

    Directory of Open Access Journals (Sweden)

    Yew Been Seok

    2016-07-01

    Full Text Available The effect of biomass waste fillers, namely coconut shell (CS and sugarcane bagasse (SCB on the dielectric properties of polymer composite was investigated. The aim of this study is to investigate the potential of CS and SCB to be used as conductive filler (natural source of carbon in the polymer composite. The purpose of the conductive filler is to increase the dielectric properties of the polymer composite. The carbon composition the CS and SCB was determine through carbon, hydrogen, nitrogen and sulphur (CHNS elemental analysis whereas the structural morphology of CS and SCB particles was examined by using scanning electron microscope. Room temperature open-ended coaxial line method was used to determine the dielectric constant and dielectric loss factor over broad band frequency range of 200 MHz-20 GHz. Based on this study, the results found that CS and SCB contain 48% and 44% of carbon, which is potentially useful to be used as conductive elements in the polymer composite. From SEM morphology, presence of irregular shape particles (size ≈ 200 μm and macroporous structure (size ≈ 2.5 μm were detected on CS and SCB. For dielectric properties measurement, it was measured that the average dielectric constant (ε' is 3.062 and 3.007 whereas the average dielectric loss factor (ε" is 0.282 and 0.273 respectively for CS/polymer and SCB/polymer composites. The presence of the biomass waste fillers have improved the dielectric properties of the polymer based composite (ε' = 2.920, ε" = 0.231. However, the increased in the dielectric properties is not highly significant, i.e. up to 4.86 % increase in ε' and 20% increase in ε". The biomass waste filler reinforced polymer composites show typical dielectric relaxation characteristic at frequency of 10 GHz - 20 GHz and could be used as conducting polymer composite for suppressing EMI at high frequency range.

  1. Development of Composite Adsorbent Coating Based Acrylic Polymer/Bentonite for Methylene Blue Removal

    Directory of Open Access Journals (Sweden)

    Syahida Farhan Azha

    2017-07-01

    Full Text Available The development of composite adsorbent coating based acrylic polymer solution (APS mixed with bentonite (ben was investigated. The composite adsorbent coating was prepared and coated to a high surface area substrate, cotton cellulosic fiber (CCF. The APS/ben-CCF was used for a single cationic methylene blue (MB dye adsorption system. Characterization of composition and structure of materials and coating was carried out by X-ray fluorescence (XRF, scanning electron microscopy (SEM, and UV-spectroscopy (UV-VIS. The adsorption properties of the APS/ben-CCF were investigated as a function of solution pH, initial dye concentration and contact time as well as solution temperature of MB dye. The result revealed that the APS/ben-CCF functioned well in solutions of various pH (acidic to alkaline, achieving 100% removal of MB within 2 hours of adsorption for 50 ppm. Kinetic studies showed that APS/ben-CCF is endothermic in nature since the adsorption capacity increased with increasing solution temperature. These results demonstrate that APS/ben-CCF composite adsorbent coating is an advanced adsorbent with advantages such as easy phase separation and capability to remove cationic dyes in a short time period.

  2. Preparation of microgel composite hydrogels by polymer post-crosslinking method

    Directory of Open Access Journals (Sweden)

    2011-05-01

    Full Text Available A novel post-crosslinking method by heating the composite polymer with dispersed reactive microgels was used to prepare microgel composite (MC hydrogels. This MC hydrogels were crosslinked by reactive microgels instead of traditional crosslinkers. The reactive microgels contained hydroxymethyl groups, which acted as post-crosslinkers. They were prepared by inverse emulsion polymerization. The formed MC hydrogels at appropriate conditions had high equilibrium swelling ratio and excellent mechanical properties. The heating conditions and the polymer water content influenced the hydrogel properties. For MC hydrogels prepared by direct heating the as-prepared composite polymers with 75% water content, their properties were influenced by heating conditions. When the heating conditions were 90°C for 4 h, the MC hydrogel had a tensile strength of 32 kPa and a high elongation of 960%. In addition, for MC hydrogels prepared by heating the partly evaporated composite polymers, their properties can be adjusted by the polymer water content. Appropriate reduction of the polymer water content was beneficial to improve the mechanical strength of the MC hydrogels. The appropriate polymer water content was important to prepare MC hydrogels with excellent mechanical properties. When the composite polymer with 50% water content was heated at 90°C for 3 h, the MC hydrogel had high tensile strength of 130 kPa and high tensile elongation of 503%.

  3. Molecular and structural properties of polymer composites filled with activated charcoal particles

    Science.gov (United States)

    Tahir, Dahlang; Liong, Syarifuddin; Bakri, Fahrul

    2016-03-01

    We have studied the molecular properties, structural properties, and chemical composition of composites by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) spectroscopy, and X-ray fluorescence (XRF) spectroscopy, respectively. FTIR spectra shows absorption band of hydroxyl group (-OH), methyl group (-CH3) and aromatic group (C-C). The absorption band for aromatic group (C-C) shows the formation of carbonaceous in composites. XRF shows chemical composition of composites, which the main chemicals are SO3, Cl, and ZnO. The loss on ignition value (LOI) of activated charcoal indicates high carbonaceous matter. The crystallite size for diffraction pattern from hydrogel polymer is about 17 nm and for activated charcoal are about 19 nm. The crystallite size of the polymer is lower than that of activated charcoal, which make possible of the particle from filler in contact with each other to form continuous conducting polymer through polymer matrix.

  4. Molecular and structural properties of polymer composites filled with activated charcoal particles

    Energy Technology Data Exchange (ETDEWEB)

    Tahir, Dahlang, E-mail: dtahir@fmipa.unhas.ac.id; Bakri, Fahrul [Department of Physics, Hasanuddin University, Makassar 90245 Indonesia (Indonesia); Liong, Syarifuddin [Department of Chemistry, Hasanuddin University, Makassar 90245 Indonesia (Indonesia)

    2016-03-11

    We have studied the molecular properties, structural properties, and chemical composition of composites by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) spectroscopy, and X-ray fluorescence (XRF) spectroscopy, respectively. FTIR spectra shows absorption band of hydroxyl group (-OH), methyl group (-CH{sub 3}) and aromatic group (C-C). The absorption band for aromatic group (C-C) shows the formation of carbonaceous in composites. XRF shows chemical composition of composites, which the main chemicals are SO{sub 3}, Cl, and ZnO. The loss on ignition value (LOI) of activated charcoal indicates high carbonaceous matter. The crystallite size for diffraction pattern from hydrogel polymer is about 17 nm and for activated charcoal are about 19 nm. The crystallite size of the polymer is lower than that of activated charcoal, which make possible of the particle from filler in contact with each other to form continuous conducting polymer through polymer matrix.

  5. Metallic Joining to Advanced Ceramic Composites, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The Orion Launch Abort System (LAS) utilizes attitude control motors (ACM) with advanced ceramic composite components that function as a valve control system to...

  6. Metallic Joining to Advanced Ceramic Composites, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Currently, advanced ceramic composites are state-of-the-art for hypersonic airbreathing and space propulsion applications. The Launch Abort System (LAS) of the Orion...

  7. NATO Advanced Research Workshop on Frontiers in Polymerization Catalysis and Polymer Synthesis

    CERN Document Server

    Guyot, A

    1987-01-01

    Due to their specific properties, polymers with well-defined structures have been receiving increasing attention over the last several years. Owing to the wide variability of their properties, these specialty polymers have been used in various areas from biomedical engineering to electronics or energy applications. The synthesis of such polymers necessi­ tates the use of new methods of polymerization which derived from an insight into the mechanism of polymerization reactions. A NATO Advanced Research Workshop on "Frontiers in Polymerization Catalysis and Polymer Synthesis" was held in BANDOl (FRANCE) in February 1987. Its aim was to assess the new polymerization methods, as well as the latest advances in the mechanisms of conventional polymerization reactions together with their applications to the synthesis of new macromolecular structures. The financial support from the NATO Scientific Affairs Division which covered the "lecturers' accomodation and travel expenses as well as the organization charges of th...

  8. Antimicrobial polymers - The antibacterial effect of photoactivated nano titanium dioxide polymer composites

    International Nuclear Information System (INIS)

    Huppmann, T.; Leonhardt, S.; Krampe, E.; Wintermantel, E.; Yatsenko, S.; Radovanovic, I.; Bastian, M.

    2014-01-01

    To obtain a polymer with antimicrobial properties for medical and sanitary applications nanoscale titanium dioxide (TiO 2 ) particles have been incorporated into a medical grade polypropylene (PP) matrix with various filler contents (0 wt %, 2 wt %, 10 wt % and 15 wt %). The standard application of TiO 2 for antimicrobial efficacy is to deposit a thin TiO 2 coating on the surface. In contrast to the common way of applying a coating, TiO 2 particles were applied into the bulk polymer. With this design we want to ensure antimicrobial properties even after application of impact effects that could lead to surface defects. The filler material (Aeroxide® TiO 2 P25, Evonik) was applied via melt compounding and the compounding parameters were optimized with respect to nanoscale titanium dioxide. In a next step the effect of UV-irradiation on the compounds concerning their photocatalytic activity, which is related to the titanium dioxide amount, was investigated. The photocatalytic effect of TiO 2 -PP-composites was analyzed by contact angle measurement, by methylene blue testing and by evaluation of inactivation potential for Escherichia coli (E.coli) bacteria. The dependence of antimicrobial activity on the filler content was evaluated, and on the basis of different titanium dioxide fractions adequate amounts of additives within the compounds were discussed. Specimens displayed a higher photocatalytic and also antimicrobial activity and lower contact angles with increasing titania content. The results suggest that the presence of titania embedded in the PP matrix leads to a surface change and a photocatalytic effect with bacteria killing result

  9. Antimicrobial polymers - The antibacterial effect of photoactivated nano titanium dioxide polymer composites

    Energy Technology Data Exchange (ETDEWEB)

    Huppmann, T., E-mail: teresa.huppmann@tum.de; Leonhardt, S., E-mail: stefan.leonhardt@mytum.de, E-mail: erhard.krampe@tum.de; Krampe, E., E-mail: stefan.leonhardt@mytum.de, E-mail: erhard.krampe@tum.de; Wintermantel, E., E-mail: wintermantel@tum.de [Institute of Medical and Polymer Engineering, Technische Universität München (Germany); Yatsenko, S., E-mail: s.yatsenko@skz.de; Radovanovic, I., E-mail: i.radovanovic@skz.de, E-mail: m.bastian@skz.de; Bastian, M., E-mail: i.radovanovic@skz.de, E-mail: m.bastian@skz.de [SKZ- German Plastics Center, Würzburg (Germany)

    2014-05-15

    To obtain a polymer with antimicrobial properties for medical and sanitary applications nanoscale titanium dioxide (TiO{sub 2}) particles have been incorporated into a medical grade polypropylene (PP) matrix with various filler contents (0 wt %, 2 wt %, 10 wt % and 15 wt %). The standard application of TiO{sub 2} for antimicrobial efficacy is to deposit a thin TiO{sub 2} coating on the surface. In contrast to the common way of applying a coating, TiO{sub 2} particles were applied into the bulk polymer. With this design we want to ensure antimicrobial properties even after application of impact effects that could lead to surface defects. The filler material (Aeroxide® TiO{sub 2} P25, Evonik) was applied via melt compounding and the compounding parameters were optimized with respect to nanoscale titanium dioxide. In a next step the effect of UV-irradiation on the compounds concerning their photocatalytic activity, which is related to the titanium dioxide amount, was investigated. The photocatalytic effect of TiO{sub 2}-PP-composites was analyzed by contact angle measurement, by methylene blue testing and by evaluation of inactivation potential for Escherichia coli (E.coli) bacteria. The dependence of antimicrobial activity on the filler content was evaluated, and on the basis of different titanium dioxide fractions adequate amounts of additives within the compounds were discussed. Specimens displayed a higher photocatalytic and also antimicrobial activity and lower contact angles with increasing titania content. The results suggest that the presence of titania embedded in the PP matrix leads to a surface change and a photocatalytic effect with bacteria killing result.

  10. Advanced composite materials for precision segmented reflectors

    Science.gov (United States)

    Stein, Bland A.; Bowles, David E.

    1988-01-01

    The objective in the NASA Precision Segmented Reflector (PSR) project is to develop new composite material concepts for highly stable and durable reflectors with precision surfaces. The project focuses on alternate material concepts such as the development of new low coefficient of thermal expansion resins as matrices for graphite fiber reinforced composites, quartz fiber reinforced epoxies, and graphite reinforced glass. Low residual stress fabrication methods will be developed. When coupon specimens of these new material concepts have demonstrated the required surface accuracies and resistance to thermal distortion and microcracking, reflector panels will be fabricated and tested in simulated space environments. An important part of the program is the analytical modeling of environmental stability of these new composite materials concepts through constitutive equation development, modeling of microdamage in the composite matrix, and prediction of long term stability (including viscoelasticity). These analyses include both closed form and finite element solutions at the micro and macro levels.

  11. The conductivity and stability of polymer composite solid electrolyte upon addition of graphene

    Science.gov (United States)

    Hamid, Farzana Abd.; Salleh, Fauzani Md.; Mohamed, Nor Sabirin

    2017-12-01

    The effect of graphene composition on the conductivity and stability of polymer composite solid electrolyte was studied. These polymer composite solid electrolytes were synthesized by sol gel method and prepared via the solution-casting technique. The compositions of graphene were varied between 10 wt% to 70 wt%. The changes in the functional group of polymer composite after the addition of graphene were characterized by Fourier Transform InfraRed spectroscopy. Electrochemical impedance spectroscopy was conducted at ambient temperature in the frequency range of 10 Hz to 1 MHz to study the conductivity of the polymer composite. The highest conductivity was obtained at 60 wt% graphene with the value of 2.85×10-4 Scm-1. Sample without the addition of graphene showed the lowest conductivity value of 1.77×10-7 Scm-1 and acts as an insulator. The high conductivity at 60 wt% graphene loading is related to dehydration of cellulose. This is supported by the FTIR spectrum where the absorption peaks of C-O stretching vibrations of polymer composite is weakened and the hydroxyl group is slightly shifted compared to the FTIR spectrum without the addition of graphene. Linear sweep voltammetry results demonstrated that the polymer composite solid electrolyte exhibited electrochemical stability up to 3.2 V.

  12. Antifouling Properties of Fluoropolymer Brushes toward Organic Polymers: The Influence of Composition, Thickness, Brush Architecture, and Annealing.

    Science.gov (United States)

    Wang, Zhanhua; Zuilhof, Han

    2016-07-05

    Fluoropolymer brushes are widely used to prevent nonspecific adsorption of commercial polymeric or biological materials due to their strongly hydrophobic character. Herein, a series of fluoropolymer brushes with different compositions, thicknesses and molecular architectures was prepared via surface-initiated atom transfer radical polymerization (ATRP). Subsequently, the antifouling properties of these fluoropolymer brushes against organic polymers were studied in detail using X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) measurements and polystyrene as a representative fouling polymer. Among all of the molecular architectures studied, homopolymerized methacrylate-based fluoropolymer brushes (PMAF17) show the best antifouling properties. Annealing the fluoropolymer brushes improves the antifouling property dramatically due to the reregulated surface composition. These fluoropolymer brushes can be combined with, e.g., micro- and nanostructuring and other advanced materials properties to yield even better long-term antifouling behavior under harsh environments.

  13. Towards a stable ion-solvating polymer electrolyte for advanced alkaline water electrolysis

    DEFF Research Database (Denmark)

    Aili, David; Wright, Andrew G.; Kraglund, Mikkel Rykær

    2017-01-01

    Advanced alkaline water electrolysis using ion-solvating polymer membranes as electrolytes represents a new direction in the field of electrochemical hydrogen production. Polybenzimidazole membranes equilibrated in aqueous KOH combine the mechanical robustness and gas-tightness of a polymer......-dimensional electrodes completely free from noble metals, they show polarization characteristics comparable to those of commercially available separators and good performance stability over several days....

  14. Relationship between Polymer Dielectric Constant and Percolation Threshold in Conductive Poly(styrene-Type Polymer and Carbon Black Composites

    Directory of Open Access Journals (Sweden)

    Mariana Castro Martínez

    2015-01-01

    Full Text Available We study the effect of dielectric constant of some poly(styrene-type polymer matrix on the percolation threshold in conductive polymer composites with carbon black (CB. We demonstrate that percolation threshold diminishes with an increment of the dielectric constant of polymer matrix. We chose polystyrene and other three polymers similar in structure and molecular weight but with different chemical nature. The corresponding dielectric constant and critical concentration, Xc, in volume fraction of carbon black, v/v CB, were the following: 4MePS (ε=2.43; Xc=0.058, PS (ε=2.60; Xc=0.054, 4BrPS (ε=2.82; Xc=0.051, and 4ClPS (ε=2.77; Xc=0.047. The correlation between both parameters confirms that the percolation threshold decreases while the dielectric constant increases. At microscopic level, this effect is attributed to an enhanced physical interaction of the CB particles with the asymmetric electric density produced by electronegative or inductive atoms/groups. Therefore, by controlling the chemical structure of the polymer matrix, the attraction forces between the polar groups on the carbon black surface particles with those of the polymer matrix can be improved, which in turn induces a better disaggregation and dispersion of those particles into the polymer matrix, allowing the percolation threshold reached at a lower filling fraction.

  15. Preparation of Composite Films of a Conjugated Polymer and C60NWs and Their Photovoltaic Application

    Directory of Open Access Journals (Sweden)

    Takatsugu Wakahara

    2016-01-01

    Full Text Available Composite films of conjugated polymers, such as poly[2-methoxy-5-(3′,7′-dimethyloctyloxy-1,4-phenylenevinylene] (MDMO-PPV and poly(3-hexylthiophene (P3HT, with C60 nanowhiskers (C60NWs were prepared. The photoluminescence originating from the conjugated MDMO-PPV polymers was effectively quenched in the composite film, indicating a strong interaction between the conjugated polymer and C60NWs. The photovoltaic devices were fabricated using C60NW (conjugated polymer composite films, resulting in a power conversion efficiency of ~0.01% for P3HT with short length thin C60NWs, which is higher than that previously reported for thick C60 nanorods. The present study gives new guidance on the selection of the type of C60NWs and the appropriate polymer for new photovoltaic devices.

  16. Do Membranes Dream of Electric Tubes? Advanced Membranes Using Carbon Nanotube - Polymer Nanocomposites

    Science.gov (United States)

    de Lannoy, Charles-Francois Pedro Claude Karolek Ghislain

    Membrane technologies represent an energy efficient, effective solution for treating municipal and commercial waters/wastewaters. Membranes are predominantly polymer-based and despite steady advances in polymeric materials, they continue to suffer from operational problems including biofouling and breakages. This work addresses these two disparate problems by developing novel CNT-polymer nanocomposite materials that contain variously functionalized carbon nanotubes (fCNTs) in low quantities (phase and linked through ionic associations in polymer matrices showed significant (50%) increases in Young's modulus for certain CNT functionalizations and derivatization percent. Membranes formed with high surface electrical conductivity demonstrated almost complete resistance to biofouling (> 95%) in long-term bacterially challenged experiments. CNTs and polymer mixtures that lacked covalent or ionic bonds were susceptible to significant (up to 10%) loss of CNTs during membrane non-solvent gelation and aggressive chemical cleaning treatment. Functionalized carbon nanotubes endow polymer membranes with their unique strength and electrically conductive properties. These added properties were demonstrated to greatly improve membrane operational efficiency and membrane longevity. CNT-polymer nanocomposite membranes offer low-energy, high-efficiency, and long-lifetime alternatives to traditional polymer membranes. With further advances in polymeric nanomaterials, membrane technology has the potential for wide applicability across many fields outside of water filtration and desalination.

  17. Structure and properties of short fiber reinforced polymer composite and hybrid composite fabricated by injection molding process

    OpenAIRE

    UAWONGSUWAN, PUTINUN

    2015-01-01

    Short fiber reinforced polymer composites have found extensive applications in many fields due to their low cost, easy processing and superior mechanical properties over the neat thermoplastics. For interpreting the mechanical properties of composite by several variable parameters, additional measurements are required when changes occur in the composite system variables. Thus, experiments may be time consuming and cost prohibitive. Therefore, theoretical models of determining composite proper...

  18. Sensing of environmental pollutant by conductive composite from prepared from hyperbranched polymer-grafted carbon black and crystalline polymer

    International Nuclear Information System (INIS)

    Taniguchi, Y.; Chen, J.; Ogawa, M.; Yokoyama, K.; Shimizu, H.; Tsubokawa, N.; Maekawa, Y.; Yoshida, M.

    2002-01-01

    Complete text of publication follows. The hyperbranched (HB) polymer-grafted (PG) carbon blacks (CB) have the possibility of utilizing as a support of catalyst and enzyme, and a curing agent of epoxy resin, because they have much terminal amino or hydroxyl groups. The postgrafting of crystalline polymer onto HB PG CB and the sensing of environmental pollutant by the conductive composite prepared from the polymer-postgrafted CB was discussed. The grafting of poly(amidoamide) onto CB surface was achieved by repeating either Michael addition of methyl acrylate to amino group on the surface or the amidation of the resulting terminal methyl ester group with ethylene diamine. HB polyester onto CB surface was grafted by stepwise growth of 2,2-bis(hydroxymethyl)propionic acid (bis-MPA) from surface carboxyl and hydroxyl groups on CB as a core in the presence of p-toluenesulfonic acid (p-TSA). The one-pot grafting of HB polyester onto CB as core was also achieved by the polycondensation of bis-MPA in the presence of p-TSA. Postgrafting of crystalline polymer onto HB polymer-grafted CB was achieved by the reaction of terminal amino or hydroxyl groups of grafted chain with COCl-terminated crystalline polymer. The electric resistance of the composite prepared from crystalline polymer-postgrafted CB was found to increase drastically in hexane, containing environmental pollutant, such as chloroform and trichloroethane, and returned immediately to the initial resistance when it was transferred into pure hexane. Based on the above results, it is concluded that the composite can be used as a novel sensor for environmental pollutant in solution

  19. An external disturbance sensor for ionic polymer metal composite actuators

    Science.gov (United States)

    Bakhtiarpour, Parisa; Parvizi, Amin; Müller, Martin; Shahinpoor, Mohsen; Marti, Othmar; Amirkhani, Masoud

    2016-01-01

    Ionic polymer metal composite (IPMC) is a fast-growing type of smart material with a wide range of applications. IPMC has been used extensively as an actuator, but for effective usage, one must add a self-sensing ability to it. Two common self-sensing techniques are mechanical-to-electrical transducer and surface resistance. The first one cannot be used while the actuator is running, and the second one needs a sample modification. In this work, we present a new self-sensing method, which can measure external disturbance in the presence of actuator voltage without any sample modification. The resistance across an IPMC sample follows Ohm’s law at sufficiently high frequency. We exploit the frequency dependency of the resistance across the sample to design the self-sensing method. In this technique a function generator, a lock-in amplifier and an isolation circuit were employed to measure an external impulse or steady disturbance. As implementing this technique does not require any change to the IPMC specimen or electrical connection (hanger), it can be added to any existing electroactive device.

  20. Composites based on cellulose fiber nonwovens and a water-soluble polymer 2. Strength-deformation characteristics of the composites

    Science.gov (United States)

    Cerpakovska, D.; Kalnins, M.

    2012-09-01

    The relationship between the strength-deformation properties and certain structural characteristics (volume content of polymer and voids, orientation of fibers) of composites prepared by impregnation of cellulose fiber nonwovens (CFNs) with poly(vinyl alcohol) water solutions is discussed. With growth in the volume fraction of polymer to 0.25-0.30, the tensile elastic modulus and ultimate strength of the composites increase compared with those of CFN. As a consequence of enhanced adhesion among the cellulose fibers, the relative values of tensile strength and elastic modulus in the main orientation direction of the fibers is higher than in the perpendicular one. Therefore, with increasing content of polymer in the composite, its degree of anisotropy diminishes significantly. The punching strength almost linearly correlates with the tensile strength. The breaking strain in tension increases considerably with growing content of polymer, but the tearing strength changes only slightly.

  1. Recent advances in high temperature polymers for microelectronic applications

    Energy Technology Data Exchange (ETDEWEB)

    Labadie, J.W.; Hedrick, J.L. (IBM Almaden Research Center, San Jose, CA (USA))

    1989-12-01

    This paper describes research concerned with the synthesis and properties of a variety of new materials based on polyphenylquinoxalines, polyquinoxalones, polybenzoxazoles and polyimide random copolymers containing phenylquinoxaline and benzoxazole moieties. The synthesis of NMP processable phenylquinoxaline and benzoxazole based poly(aryl ethers) was carried out using a novel heterocyclic activated fluoro displacement by bisphenoxides, affording high T(g), melt and solvent processable polymers with tough, ductile mechanical properties. In addition, heterocyclic activated ether synthesis was used to prepare phenylquinoxaline and benzoxazole containing diamines which were used in conventional polyimide syntheses, yielding random copolymers which showed moduli comparable to PMDA/ODA polyimide and elongations ranging from 60 to 120 percent. Polyquinoxalones were synthesized by the step growth polymerization of bis(keto esters) with bis(o-diamines) and represent an interesting new class of linear polyquinoxalines. The thermal and mechanical properties were evaluated for many of these polymers, and were found to be comparable to polyimides. 11 refs.

  2. Numerical Modeling of Macroscopic Behavior of Particulate Composite with Crosslinked Polymer Matrix

    Czech Academy of Sciences Publication Activity Database

    Náhlík, Luboš; Máša, B.; Hutař, Pavel

    2011-01-01

    Roč. 465, - (2011), s. 129-132 ISSN 1013-9826 R&D Projects: GA ČR GA106/08/1409 Institutional research plan: CEZ:AV0Z20410507 Keywords : Particle reinforced composites * polymer matrix composite * mechanical response Subject RIV: JI - Composite Materials

  3. LIPID-POLYMER-CONJUGATES COMPOSITIONS COMPRISING CORTICOSTEROIDS FOR THE TREATMENT OF CANCER

    NARCIS (Netherlands)

    Schiffelers, Raymond M.; Metselaar, J.M.; Molema, Grietje; Storm, Gerrit

    2004-01-01

    The use of long-circulating colloidal carrier compositions comprising a corticosteroid and a lipid-polymer-conjugate, wherein the polymer is a poly((derivatised) amino acid) and optionally a further useful active ingredient, for the manufacture of a medicament useful in the treatment of

  4. Boswellia gum resin/chitosan polymer composites: Controlled delivery vehicles for aceclofenac.

    Science.gov (United States)

    Jana, Sougata; Laha, Bibek; Maiti, Sabyasachi

    2015-01-01

    This study was undertaken to evaluate the effect of Boswellia gum resin on the properties of glutaraldehyde (GA) crosslinked chitosan polymer composites and their potential as oral delivery vehicles for a non-steroidal anti-inflammatory drug, aceclofenac. The incorporation of resinous material caused a significant improvement in drug entrapment efficiency (∼40%) of the polymer composites. Fourier transform infrared (FTIR) spectroscopic analysis confirmed the formation of chitosan-gum resin composites and did not show any evidence of drug-polymer chemical interaction. Field emission scanning electron microscopy (FE-SEM) suggested the formation of particulate polymer composites up to chitosan:gum resin mass ratio of 1:3. Only 8-17% drug was released into HCl solution (pH 1.2) in 2h. The drug release rate of polymer composites was faster in phosphate buffer solution (pH 6.8). The composites released ∼60-68% drug load in 7h. In same duration, the drug release rate suddenly boosted up to 92% as the concentration of gum resin in the composites was raised to 80%. The drug release mechanism deviated from non-Fickian to case-II type with increasing resin concentration in the composites. Hence, GA-treated Boswellia resin-chitosan composites could be considered as alternative vehicles for oral delivery of aceclofenac. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Advanced composites: Design and application. Proceedings of the meeting of the Mechanical Failures Prevention Group

    Science.gov (United States)

    Shives, T. R.; Willard, W. A.

    1979-01-01

    The design and application of advanced composites is discussed with emphasis on aerospace, aircraft, automotive, marine, and industrial applications. Failure modes in advanced composites are also discussed.

  6. Detecting and identifying damage in sandwich polymer composite by using acoustic emission

    DEFF Research Database (Denmark)

    McGugan, M.; Sørensen, Bent F.; Østergaard, R.

    2006-01-01

    Acoustic emission is a useful monitoring tool for extracting extra information during mechanical testing of polymer composite sandwich materials. The study of fracture mechanics within test specimens extracted from wind turbine blade material ispresented. The contribution of the acoustic emission...

  7. Ultra-Low-Density (ULD) Polymer Matrix Composites (PMCs), Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This NASA Phase I SBIR proposal seeks to demonstrate a new class of ultra-low-density (ULD) polymer matrix composites of high specific modulus and specific strength...

  8. Polymer-nanostructured carbon composites as multifunctional sensor materials: design, processing, and properties

    Czech Academy of Sciences Publication Activity Database

    Knite, M.; Hill, A.; Bovtun, Viktor; Teteris, V.; Solovjovs, A.; Shakale, G.; Zavickis, J.; Aulika, I.; Polakovs, B.; Pas, S.J.; Veljko, Sergiy; Noujni, Dmitri; Klemenoks, I.; Zicans, J.; Kiploka, A.; Erts, D.; Petzelt, Jan; Fuith, A.

    -, č. 2 (2006), s. 15-29 ISSN 0868-8257 Institutional research plan: CEZ:AV0Z10100520 Keywords : polymer-nanostructured carbon composites * carbon black * sensors * conductivity * dielectric conductivity Subject RIV: BM - Solid Matter Physics ; Magnetism

  9. Self-healing in single and multiple fiber(s reinforced polymer composites

    Directory of Open Access Journals (Sweden)

    Woldesenbet E.

    2010-06-01

    Full Text Available You Polymer composites have been attractive medium to introduce the autonomic healing concept into modern day engineering materials. To date, there has been significant research in self-healing polymeric materials including several studies specifically in fiber reinforced polymers. Even though several methods have been suggested in autonomic healing materials, the concept of repair by bleeding of enclosed functional agents has garnered wide attention by the scientific community. A self-healing fiber reinforced polymer composite has been developed. Tensile tests are carried out on specimens that are fabricated by using the following components: hollow and solid glass fibers, healing agent, catalysts, multi-walled carbon nanotubes, and a polymer resin matrix. The test results have demonstrated that single fiber polymer composites and multiple fiber reinforced polymer matrix composites with healing agents and catalysts have provided 90.7% and 76.55% restoration of the original tensile strength, respectively. Incorporation of functionalized multi-walled carbon nanotubes in the healing medium of the single fiber polymer composite has provided additional efficiency. Healing is found to be localized, allowing multiple healing in the presence of several cracks.

  10. Advanced composites for aerospace, marine, and land applications

    CERN Document Server

    Srivatsan, T; Peretti, Michael

    2016-01-01

    The papers in this volume cover a broad spectrum of topics that represent the truly diverse nature of the field of composite materials. This collection presents research and findings relevant to the latest advances in composites materials, specifically their use in aerospace, maritime, and even land applications. The editors have made every effort to bring together authors who put forth recent advances in their research while concurrently both elaborating on and thereby enhancing our prevailing understanding of the salient aspects related to the science, engineering, and far-reaching technological applications of composite materials.

  11. The Stress-strain Behavior of Polymer-Nanotube Composites from Molecular Dynamics Simulations

    Science.gov (United States)

    Frankland, S. J. V.; Harik, V. M.; Odegard, G. M.; Brenner, D. W.; Gates, T. S.; Bushnell, Dennis M. (Technical Monitor)

    2002-01-01

    Stress-strain curves of polymer-carbon nanotube composites are derived from molecular dynamics simulations of a single-walled carbon nanotube embedded in polyethylene. A comparison is made between the response to mechanical loading of a composite with a long, continuous nanotube (replicated via periodic boundary conditions) and the response of a composite with a short, discontinuous nanotube. Both composites are mechanically loaded in the direction of and transverse to the NT axis. The long-nanotube composite shows an increase in the stiffness relative to the polymer and behaves anisotropically under the different loading conditions. The short-nanotube composite shows no enhancement relative to the polymer, most probably because of its low aspect ratio. The stress-strain curves are compared with rule-of-mixtures predictions.

  12. Flexible and conductive waste tire-derived carbon/polymer composite paper as pseudocapacitive electrode

    Energy Technology Data Exchange (ETDEWEB)

    Naskar, Amit K.; Paranthaman, Mariappan Parans; Boota, Muhammad; Gogotsi, Yury

    2018-04-10

    A method of making a supercapacitor from waste tires, includes the steps of providing rubber pieces and contacting the rubber pieces with a sulfonation bath to produce sulfonated rubber; pyrolyzing the sulfonated rubber to produce a tire-derived carbon composite comprising carbon black embedded in rubber-derived carbon matrix comprising graphitized interface portions; activating the tire-derived carbon composite by contacting the tire-derived carbon composite with a specific surface area-increasing composition to increase the specific surface area of the carbon composite to provide an activated tire-derived carbon composite; and, mixing the activated tire-derived carbon composite with a monomer and polymerizing the monomer to produce a redox-active polymer coated, activated tire-derived carbon composite. The redox-active polymer coated, activated tire-derived carbon composite can be formed into a film. An electrode and a supercapacitor are also disclosed.

  13. Electron processing of fibre-reinforced advanced composites

    International Nuclear Information System (INIS)

    Singh, A.; Saunders, C.B.; Barnard, J.W.; Lopata, V.J.; Kremers, W.; McDougall, T.E.; Chung, M.; Tateishi, Miyoko

    1996-01-01

    Advanced composites, such as carbon-fibre-reinforced epoxies, are used in the aircraft, aerospace, sporting goods, and transportation industries. Though thermal curing is the dominant industrial process for advanced composites, electron curing of similar composites containing acrylated epoxy matrices has been demonstrated by our work. The main attraction of electron processing technology over thermal technology is the advantages it offers which include ambient temperature curing, reduced curing times, reduced volatile emissions, better material handling, and reduced costs. Electron curing technology allows for the curing of many types of products, such as complex shaped, those containing different types of fibres and up to 15 cm thick. Our work has been done principally with the AECL's 10 MeV, 1 kW electron accelerator; we have also done some comparative work with an AECL Gammacell 220. In this paper we briefly review our work on the various aspects of electron curing of advanced composites and their properties. (Author)

  14. Advanced prepreg ballistic composites for military helmets

    OpenAIRE

    Dimeski, Dimko; Srebrenkoska, Vineta

    2014-01-01

    With the advancement of ballistic materials and technologies, the ballistic prepregs are becoming an essential construction technique for getting the maximum performance out of the high performance fibers. The ballistic prepregs help to maximize the engagement between fibers and high speed projectiles penetrating the ballistic material, thus reducing the amount of ballistic material required to defeat the projectiles. The backbone of lightweight ballistic materials is high perform...

  15. Progressive Failure Analysis of Advanced Composites

    Science.gov (United States)

    2008-07-25

    continuum damage mechanics P.P. Camanho a,*, P. Maimı́ b, C.G. Dávila c a DEMEGI, Faculdade de Engenharia, Universidade do Porto , Rua Dr. Roberto...Progressive Damage in Bolted Composite Joints Hannes Koerber, Pedro P. Camanho DEMEGI, Faculdade de Engenharia, Universidade do Porto Rua Dr...Montilivi s/n, Girona, Spain bDEMEGI, Faculdade de Engenharia, Universidade do Porto , Rua Dr. Roberto Frias, 4200-465, Porto , Portugal Abstract This paper

  16. Plasmon assisted synthesis of highly fluorescing silver quantum cluster / polymer composites for biochemical sensing

    DEFF Research Database (Denmark)

    Bernard, S.; Kutter, J.P.; Mogensen, Klaus Bo

    2014-01-01

    Plasmonics is combined with polymer synthesis for rapid fabrication of highly fluorescing silver quantum cluster / polymer composites inside microfluidic channels. UV-light assisted synthesis of polymers has been investigated by a number of groups previously [1], however, plasmon assisted synthesis...... has not been presented before. This should allow highly localized fabrication of porous polymers that are defined by the location of the nanoplasmonic metal film. Silver quantum clusters (AgQCs) consisting of 2-10 atoms can be highly fluorescing in the visible wavelength range and possess a much...

  17. Plasmon assisted synthesis of highly fluorescing silver quantum cluster/polymer composites for biochemical sensing

    DEFF Research Database (Denmark)

    Bernard, S.; Kutter, J. P.; Mogensen, K. B.

    2014-01-01

    Plasmonics is combined with polymer synthesis for rapid fabrication of highly fluorescing silver quantum cluster/polymer composites inside microfluidic channels. UV-light assisted synthesis of polymers has been investigated by a number of groups previously [1], however, plasmon assisted synthesis...... has not been presented before. This should allow highly localized fabrication of porous polymers that are defined by the location of the nanoplasmonic metal film. Silver quantum clusters (AgQCs) consisting of 2-10 atoms can be highly fluorescing in the visible wavelength range and possess a greater...

  18. Multifunctional Polymers and Composites for Self-Healing Applications

    Science.gov (United States)

    2006-09-30

    plane and analyzed by Fourier transform infrared spectroscopy ( FTIR ). By monitoring the spectra and observing the characteristic peak at 965 cm·1...conditions, maleimide trap 9 was reacted with polymer 6 in toluene at 105 °C and polymer 7 in xylenes at 140 °C (Arnold et al., 1974). After

  19. Studies on conducting polymer and conducting polymerinorganic composite electrodes prepared via a new cathodic polymerization method

    Science.gov (United States)

    Singh, Nikhilendra

    A novel approach for the electrodeposition of conducting polymers and conducting polymer-inorganic composite materials is presented. The approach shows that conducting polymers, such as polypyrrole (PPy) and poly(3,4-ethylenedioxythiophene) (PEDOT) can be electrodeposited by the application of a cathodic bias that generates an oxidizing agent, NO+, via the in-situ reduction of nitrate anions. This new cathodic polymerization method allows for the deposition of PPy and PEDOT as three dimensional, porous films composed of spherical polymer particles. The method is also suitable for the co-deposition of inorganic species producing conducting polymer-inorganic composite electrodes. Such composites are used as high surface area electrodes in Li-ion batteries, electrochemical hydrogen evolution and in the development of various other conducting polymer-inorganic composite electrodes. New Sn-PPy and Sb-PPy composite electrodes where Sn and Sb nanoparticles are well dispersed among the PPy framework are reported. These structures allow for decreased stress during expansion and contraction of the active material (Sn, Sb) during the alloying and de-alloying processes of a Li-ion battery anode, significantly alleviating the loss of active material due to pulverization processes. The new electrochemical synthesis mechanism allows for the fabrication of Sn-PPy and Sb-PPy composite electrodes directly from a conducting substrate and eliminates the use of binding materials and conducting carbon used in modern battery anodes, which significantly simplifies their fabrication procedures. Platinum (Pt) has long been identified as the most efficient catalyst for electrochemical water splitting, while nickel (Ni) is a cheaper, though less efficient alternative to Pt. A new morphology of PPy attained via the aforementioned cathodic deposition method allows for the use of minimal quantities of Pt and Ni dispersed over a very high surface area PPy substrate. These composite electrodes

  20. Thermodynamics of disaggregated polymer composites based on nanosized powders of Ni and NiO

    Directory of Open Access Journals (Sweden)

    N. S. Volodina

    2015-03-01

    Full Text Available Technique to obtain disaggregated composites with uniform distribution of the Ni nanoparticles in a polymer matrix was developed on the example of epoxy resin. Disaggregated and aggregated composites based on butyl methacrylate copolymer with 5 wt% methacrylic acid and Ni and NiO nanoparticles were obtained. Enthalpies of mixing the components compositions in a wide range of compositions were defined using isothermal calorimetry. Parameters adhesive interaction at the interface and glassy polymer structure changes were calculated. The influence of the chemical nature of nanosized filler on interfacial energy was found.

  1. Fatigue behavior and modeling of short fiber reinforced polymer composites

    Science.gov (United States)

    Mortazavian, Seyyedvahid

    This study investigates uniaxial fatigue behavior of two short glass fiber polymer composites including 30 wt% short glass fiber polybutylene terephthalate (PBT) and 35 wt% short glass fiber polyamide-6 (PA6) under a number of load and environmental conditions. The main objectives are to evaluate the behavior of these materials under monotonic and cyclic loadings and present fatigue life prediction methodologies to reduce their development expenses and time. The considered environmental effects include those of low and elevated temperatures as well as moisture (or water absorption) effect. Fatigue behavior is also explored under the action of nonzero mean stress (or R ratio) as well as various cyclic loading frequencies. Material anisotropy and geometrical discontinuity effects (i.e. stress concentration) are also considered in this study. Microscopic failure analysis is also performed, when necessary, to identify failure mechanisms. Tensile tests were performed in various mold flow directions and with two thicknesses at a range of temperatures and strain rates. A shell-core morphology resulting from orientation distribution of fibers influenced the degree of anisotropy. Tensile strength and elastic modulus nonlinearly decreased with specimen angle and Tsai-Hill criterion was found to correlate variation of these properties with the fiber orientation. Kinetics of water absorption was studied and found to follow the Fick's law. Tensile tests were performed at room temperature with specimens in the longitudinal and transverse directions and with various degrees of water absorption. Mathematical relations were developed to represent tensile properties as a function of water content. Mathematical relationships were developed to represent the stress-strain response, as well as tensile properties in terms of strain rate and temperature. Time-temperature superposition principle was also employed to superimpose the effect of temperature and strain rate on tensile strength

  2. Recent Advances in Thermoplastic Puncture-Healing Polymers

    Science.gov (United States)

    Gordon, K. L.; Working, D. C.; Wise, K. E.; Bogert, P. B.; Britton, S. M.; Topping, C.C.; Smith, J. Y.; Siochi, E. J.

    2009-01-01

    Self-healing materials provide a route for enhanced damage tolerance in materials for aerospace applications. In particular, puncture-healing upon impact has the potential to mitigate significant damage caused by high velocity micrometeoroid impacts. This type of material also has the potential to improve damage tolerance in load bearing structures to enhance vehicle health and aircraft durability. The materials being studied are those capable of instantaneous puncture healing, providing a mechanism for mechanical property retention in lightweight structures. These systems have demonstrated healing capability following penetration of fast moving projectiles -- velocities that range from 9 mm bullets shot from a gun (approx.330 m/sec) to close to micrometeoroid debris velocities of 4800 m/sec. In this presentation, we report on a suite of polymeric materials possessing this characteristic. Figure 1 illustrates the puncture healing concept. Puncture healing in these materials is dependent upon how the combination of a polymer's viscoelastic properties responds to the energy input resulting from the puncture event. Projectile penetration increases the temperature in the vicinity of the impact. Self-healing behavior occurs following puncture, whereby energy must be transferred to the material during impact both elastically and inelastically, thus establishing two requirements for puncture healing to occur: a.) The need for the puncture event to produce a local melt state in the polymer material and b.) The molten material has to have sufficient melt elasticity to snap back and close the hole. 1,2 Previous ballistic testing studies revealed that Surlyn materials warmed up to a temperature approx.98 C during projectile puncture (3 C higher than it s melting temperature). 1,2 The temperature increase produces a localized flow state and the melt elasticity to snap back thus sealing the hole. Table 1 lists the commercially polymers studied here, together with their physical

  3. Polymer-carbon black composite sensors in an electronic nose for air-quality monitoring

    Science.gov (United States)

    Ryan, M. A.; Shevade, A. V.; Zhou, H.; Homer, M. L.

    2004-01-01

    An electronic nose that uses an array of 32 polymer-carbon black composite sensors has been developed, trained, and tested. By selecting a variety of chemical functionalities in the polymers used to make sensors, it is possible to construct an array capable of identifying and quantifying a broad range of target compounds, such as alcohols and aromatics, and distinguishing isomers and enantiomers (mirror-image isomers). A model of the interaction between target molecules and the polymer-carbon black composite sensors is under development to aid in selecting the array members and to enable identification of compounds with responses not stored in the analysis library.

  4. Influence of PVP/VA copolymer composition on drug-polymer solubility

    DEFF Research Database (Denmark)

    Rask, Malte Bille; Knopp, Matthias Manne; Olesen, Niels Erik

    2016-01-01

    In this study, the influence of copolymer composition on drug-polymer solubility was investigated. The solubility of the model drug celecoxib (CCX) in various polyvinylpyrrolidone/vinyl acetate (PVP/VA) copolymer compositions (70/30, 60/40, 50/50 and 30/70 w/w) and the pure homopolymers...... dispersion without compromising the drug-polymer solubility. This knowledge could be used advantageously in future development of amorphous drug delivery systems as copolymers could be customized to provide optimal drug-polymer solubility and physical stability....

  5. POLYMER COMPOSITE FILMS WITH SIZE-SELECTED METAL NANOPARTICLES FABRICATED BY CLUSTER BEAM TECHNIQUE

    DEFF Research Database (Denmark)

    Ceynowa, F. A.; Chirumamilla, Manohar; Popok, Vladimir

    2017-01-01

    Formation of polymer films with size-selected silver and copper nanoparticles (NPs) is studied. Polymers are prepared by spin coating while NPs are fabricated and deposited utilizing a magnetron sputtering cluster apparatus. The particle embedding into the films is provided by thermal annealing...... after the deposition. The degree of immersion can be controlled by the annealing temperature and time. Together with control of cluster coverage the described approach represents an efficient method for the synthesis of thin polymer composite layers with either partially or fully embedded metal NPs....... Combining electron beam lithography, cluster beam deposition and thermal annealing allows to form ordered arrays of metal NPs on polymer films. Plasticity and flexibility of polymer host and specific properties added by coinage metal NPs open a way for different applications of such composite materials...

  6. High Temperature Degradation Mechanisms in Polymer Matrix Composites

    Science.gov (United States)

    Cunningham, Ronan A.; McManus, Hugh L.

    1997-01-01

    Polymer matrix composites are increasingly used in demanding structural applications in which they may be exposed to harsh environments. The durability of such materials is a major concern, potentially limiting both the integrity of the structures and their useful lifetimes. The goal of the current investigation is to develop a mechanism-based model of the chemical degradation which occurs, such that given the external chemical environment and temperatures throughout the laminate, laminate geometry, and ply and/or constituent material properties, we can calculate the concentration of diffusing substances and extent of chemical degradation as functions of time and position throughout the laminate. This objective is met through the development and use of analytical models, coupled to an analysis-driven experimental program which offers both quantitative and qualitative information on the degradation mechanism. Preliminary analyses using coupled diffusion/reaction model are used to gain insight into the physics of the degradation mechanisms and to identify crucial material parameters. An experimental program is defined based on the results of the preliminary analysis which allows the determination of the necessary material coefficients. Thermogravimetric analyses are carried out in nitrogen, air, and oxygen to provide quantitative information on thermal and oxidative reactions. Powdered samples are used to eliminate diffusion effects. Tests in both inert and oxidative environments allow the separation of thermal and oxidative contributions to specimen mass loss. The concentration dependency of the oxidative reactions is determined from the tests in pure oxygen. Short term isothermal tests at different temperatures are carried out on neat resin and unidirectional macroscopic specimens to identify diffusion effects. Mass loss, specimen shrinkage, the formation of degraded surface layers and surface cracking are recorded as functions of exposure time. Geometry effects in

  7. Advanced compositional gradient and compartmentalization analysis

    Energy Technology Data Exchange (ETDEWEB)

    Canas, Jesus A.; Petti, Daniela; Mullins, Oliver [Schlumberger Servicos de Petroleo Ltda., Rio de Janeiro, RJ (Brazil)

    2008-07-01

    Acquisition of hydrocarbons samples from the reservoir prior to oil or gas production is essential in order to design production strategies and production facilities. In addition, reservoir compartmentalization and hydrocarbon compositional grading magnify the necessity to map fluid properties vertically and laterally in the reservoir prior to production. Formation testers supply a wealth of information to observe and predict the state of fluids in hydrocarbon reservoirs, through detailed pressure and fluid analysis measurements. With the correct understanding of the state of fluids in the reservoirs, reserve calculations and adequate development plans can be prepared. Additionally, flow barriers may then be revealed. This paper describes a new Downhole Fluid Analysis technology (DFA) for improved reservoir management. DFA is a unique process that combines new fluid identification sensors, which allow real time monitoring of a wide range of parameters as GOR, fluid density, viscosity, fluorescence and composition (CH{sub 4}, C2- C5, C6 +, CO{sub 2}), free gas and liquid phases detection, saturation pressure, as well WBM and OBM filtrate differentiation and pH. This process is not limited to light fluid evaluation and we extended to heavy oil (HO) reservoirs analysis successfully. The combination of DFA Fluid Profiling with pressure measurements has shown to be very effective for compartmentalization characterization. The ability of thin barriers to hold off large depletion pressures has been established, as the gradual variation of hydrocarbon quality in biodegraded oils. In addition, heavy oils can show large compositional variation due to variations in source rock charging but without fluid mixing. Our findings indicates that steep gradients are common in gas condensates or volatile oils, and that biodegradation is more common in HO than in other hydrocarbons, which generate fluid gradients and heavy ends tars near the OWC, limiting the aquifer activity and

  8. Mechanical Property Evaluation of Palm/Glass Sandwiched Fiber Reinforced Polymer Composite in Comparison with few natural composites

    Science.gov (United States)

    Raja Dhas, J. Edwin; Pradeep, P.

    2017-10-01

    Natural fibers available plenty can be used as reinforcements in development of eco friendly polymer composites. The less utilized palm leaf stalk fibers sandwiched with artificial glass fibers was researched in this work to have a better reinforcement in preparing a green composite. The commercially available polyester resin blend with coconut shell filler in nano form was used as matrix to sandwich these composites. Naturally available Fibers of palm leaf stalk, coconut leaf stalk, raffia and oil palm were extracted and treated with potassium permanganate solution which enhances the properties. For experimentation four different plates were fabricated using these fibers adopting hand lay-up method. These sandwiched composite plates are further machined to obtain ASTM standards Specimens which are mechanically tested as per standards. Experimental results reveal that the alkali treated palm leaf stalk fiber based polymer composite shows appreciable results than the others. Hence the developed composite can be recommended for fabrication of automobile parts.

  9. Recent Advances in Polymer Organic Light-Emitting Diodes (PLED) Using Non-conjugated Polymers as the Emitting Layer and Contrasting Them with Conjugated Counterparts

    Science.gov (United States)

    Wong, Michael Y.

    2017-11-01

    Polymer organic light-emitting diodes (PLED) are one of the most studied subjects in flexible electronics thanks to their economical wet fabrication procedure for enhanced price advantage of the product device. In order to optimize PLED efficiency, correlating the polymer structure with the device performance is essential. An important question for the researchers in this field is whether the polymer backbone is conjugated or not as it affects the device performance. In this review, recent advances in non-conjugated polymers employed as the emitting layer in PLED devices are first discussed, followed by their contrast with the conjugated counterparts in terms of polymer synthesis, sample quality, physical properties and device performances. Such comparison between conjugated and non-conjugated polymers for PLED applications is rarely attempted, and; hence, this review shall provide a useful insight of emitting polymers employed in PLEDs.

  10. Comparison of Properties of Polymer Composite Materials Reinforced with Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Zygoń P.

    2015-04-01

    Full Text Available Carbon nanotubes because of their high mechanical, optical or electrical properties, have found use as semiconducting materials constituting the reinforcing phase in composite materials. The paper presents the results of the studies on the mechanical properties of polymer composites reinforced with carbon nanotubes (CNT. Three-point bending tests were carried out on the composites. The density of each obtained composite was determined as well as the surface roughness and the resistivity at room temperature.

  11. NATO Advanced Study Institute on Preparation and Properties of Stereoregular Polymers

    CERN Document Server

    Ciardelli, Francesco

    1980-01-01

    This book contains the texts of the main lectures presented at the NATO Advanced Studies Institute on "Advances in Preparation and Properties of Stereoregular Polymers" held at Tirrenia near Pisa, Italy, from October 3 to 14, 1978. A few contributed papers have also been included because they were concerned with topics not included in the main lectures. The primary objective of the Institute was to assist in the further development of stereoregular polymers because of the ever-increasing demand for new products with exceptional chemical and physical properties. This need has reawakened interest in the field. Indeed there is now a rapidly increasing activity in the study of stereoregular polymerization and the preparation of structurally-ordered polymers with the aim of achieving apprecia­ ble improvements in existing polymeric materials through new developments in synthesis and properties as well as in discovering new polymeric structures. In order to achieve these objectives, a broad interdiscipli­ nary co...

  12. Composite advanced polymers for low moisture and oxygen permeability Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I program addresses NASA?s need for long duration shelf stable food by developing a high oxygen/moisture barrier...

  13. Experimental Characterization and Modeling of Advanced Polymer Composite Window Frames

    DEFF Research Database (Denmark)

    Zajas, Jan Jakub

    Even though the window frames cover a relatively small fraction of the entire building envelope, they are responsible for a major amount of heat loss, due to their poor insulation properties compared to the other envelope elements. With the current trends to reduce energy use in buildings...... radiation. These, and several other solutions, are investigated in the first part of the study. Simulations on simple geometries are conducted to evaluate the potential of different solutions. The results show that by applying different modifications the thermal transmittance of a frame can be significantly...... reduced, but only to a certain extent. To reach further improvement, more drastic changes need to be done. Therefore, an extensive study is done on how to optimize the frame geometry on a broader level. Contemporary frames can be crafted into various shapes, giving the engineers a large freedom of design...

  14. Viscoelastic Properties of Advanced Polymer Composites for Ballistic Protective Applications

    Science.gov (United States)

    1994-09-01

    bibliography; illustration(s); maps; diagrams SUBJECTS COVERED: Petroleum geology /Utah Petroleum geology /Colorado 5AST AUTHOR: Hashemi, S. M. R...Roketsan Missiles Industries Inc, Ankara , Turk Source: Journal of Propulsion and Power v 8 n 5 Sep-Oct 1992 p 1125-1128 Publication Year: 1992 CODEN

  15. Pore Structure of Macroporous Polymers Using Polystyrene/Silica Composite Particles as Pickering Stabilizers.

    Science.gov (United States)

    Tu, Shuhua; Zhu, Chenxu; Zhang, Lingyun; Wang, Haitao; Du, Qiangguo

    2016-12-13

    A novel approach for the preparation of interconnected macroporous polymers with a controllable pore structure was reported. The method was based on the polymerization of water-in-oil Pickering high internal phase emulsion (HIPE) stabilized by polystyrene (PS)/silica composite particles. The composite Pickering stabilizers were facilely obtained by mixing positively charged PS microspheres and negatively charged silica nanoparticles, and their amphiphilicity could be delicately tailored by varying the ratio of PS and silica. The droplet size of Pickering HIPEs was characterized using an optical microscope. The pore structure of polymer foams was observed using a scanning electron microscope. The interconnectivity of macroporous polymers was evaluated upon their gas permeability, which was greatly improved after etching PS microspheres included in the Pickering stabilizers with tetrahydrofuran. As a result, fine tailoring of the pore structure of polymer foams could be realized by simply tuning the ratio of PS to silica particles in the composite stabilizer.

  16. The Cost of Automotive Polymer Composites: A Review and Assessment of DOE's Lightweight Materials Composites Research

    Energy Technology Data Exchange (ETDEWEB)

    Das, S.

    2001-01-26

    Polymer composite materials have been a part of the automotive industry for several decades, with early application in the 1953 Corvette. These materials have been used for applications with low production volumes, because of their shortened lead times and lower investment costs relative to conventional steel fabrication. Important drivers of the growth of polymer composites have been the reduced weight and parts consolidation opportunities the material offers, as well as design flexibility, corrosion resistance, material anisotropy, and mechanical properties. Although these benefits are well recognized by the industry, polymer composite use has been dampened by high material costs, slow production rates, and to a lesser extent, concerns about recyclability. Also impeding large scale automotive applications is a curious mixture of concerns about material issues such as crash energy absorption, recycling challenges, competitive and cost pressures, the industry's general lack of experience and comfort with the material, and industry concerns about its own capabilities (Flynn and Belzowski 1995). Polymer composite materials are generally made of two or more material components--fibers, either glass or carbon, reinforced in the matrix of thermoset or thermoplastic polymer materials. The glass-reinforced thermoset composites are the most commonly used composite in automotive applications today, but thermoplastic composites and carbon fiber-reinforced thermosets also hold potential. It has been estimated that significant use of glass-reinforced polymers as structural components could yield a 20-35% reduction in vehicle weight. More importantly, the use of carbon fiber-reinforced materials could yield a 40-65% reduction in weight.

  17. 3D optical printing of piezoelectric nanoparticle-polymer composite materials.

    Science.gov (United States)

    Kim, Kanguk; Zhu, Wei; Qu, Xin; Aaronson, Chase; McCall, William R; Chen, Shaochen; Sirbuly, Donald J

    2014-10-28

    Here we demonstrate that efficient piezoelectric nanoparticle-polymer composite materials can be optically printed into three-dimensional (3D) microstructures using digital projection printing. Piezoelectric polymers were fabricated by incorporating barium titanate (BaTiO3, BTO) nanoparticles into photoliable polymer solutions such as polyethylene glycol diacrylate and exposing to digital optical masks that could be dynamically altered to generate user-defined 3D microstructures. To enhance the mechanical-to-electrical conversion efficiency of the composites, the BTO nanoparticles were chemically modified with acrylate surface groups, which formed direct covalent linkages with the polymer matrix under light exposure. The composites with a 10% mass loading of the chemically modified BTO nanoparticles showed piezoelectric coefficients (d(33)) of ∼ 40 pC/N, which were over 10 times larger than composites synthesized with unmodified BTO nanoparticles and over 2 times larger than composites containing unmodified BTO nanoparticles and carbon nanotubes to boost mechanical stress transfer efficiencies. These results not only provide a tool for fabricating 3D piezoelectric polymers but lay the groundwork for creating highly efficient piezoelectric polymer materials via nanointerfacial tuning.

  18. The Usage Of Nutshell In The Production of Polypropylene Based on Polymer Composite Panels

    Directory of Open Access Journals (Sweden)

    Selçuk Akbaş

    2013-04-01

    Full Text Available Natural fibers have been commonly utilized to reinforced materials for many years. Recently due to advantages of natural fibers such as low cost, high physical and mechanical resistance are produced plastic-composite materials by mixing various proportions. In addition, plastic composites are used natural fibers include agricultural wastes (wheat straw, rice straw, hemp fiber, shells of various dry fruits, etc.. In this study, polymer composites were manufactured using waste nutshell flour as filler and polypropylene (PP as polymer matrix. The nutshell-PP composites were manufactured via extrusion and compression methods. The final product tested to determine their tensile, flexural, impact strength properties as well as some physical features such as thickness swelling and water absorptions. The best results were obtained composites containing 30% nutshell flour. In addition, composites which were produced nutshell provided the values of ASTM D6662 standard. The data collected in our country which waste a large portion of nutshell allows for the evaluation of the production polymer composites. The incorporation of nutshell flour feasible to produce plastic composites when appropriate formulations were used. As a result hazelnut shell which was considered agricultural waste can be utilized in polymer composite production.

  19. PREFACE: 2015 Global Conference on Polymer and Composite Materials (PCM2015)

    Science.gov (United States)

    Broitman, Esteban

    2015-07-01

    The 2015 Global Conference on Polymer and Composite Materials (PCM2015) sponsored by Wuhan Advanced Materials Society and the Ningbo Adhesives and Products Industry Association was held from May 16-19 2015 in Beijing, the capital of the People's Republic of China and one of the most populous cities in the world. The technical program consisted of seven international keynote speakers, oral presentations, a Mini-Workshop: "Writing a Scientific Publication" and a poster session. The present issue of IOP Conference Series: Materials Science and Engineering (MSE) records the proceedings of PCM2015 and contains 117 specially selected manuscripts submitted to the PCM2015 conference. The electronic submission and handling of manuscripts via the conference website, including the selection of reviewers and evaluation of manuscripts, were identical to the procedures applied to manuscripts submitted as regular contributions for publication. The organization of this conference and the preparation of the proceedings volume would have been impossible without the tremendous efforts and dedication of many individuals, especially from Ms. Lan Mengguo, who oversaw the organization of the conference and the program; and a large team of reviewers with their timely submission of quality reports. We express our sincere thanks to all authors and presenters for their contributions. We also thank our sponsors very much for their generous support. The 2016 Global Conference on Polymer and Composite Materials (PCM2016) will be held from June 17-20 2016 in Shanghai, the largest city in China and one of the largest urban areas in the world; all participants are welcome to the renewed and vibrant PCM2016.

  20. Porphyrin nanorods-polymer composites for solar radiation harvesting applications

    CSIR Research Space (South Africa)

    Mongwaketsi, NP

    2014-09-01

    Full Text Available , using latex technology and electrospinning which gave the possibility of investigating the orientation of nanorods in the polymer. Spectroscopic and microscopic studies were conducted to investigate the optical and morphological properties...

  1. Tunable and processable shape memory composites based on degradable polymers

    NARCIS (Netherlands)

    Zhang, Xi; Geven, Mike A.; Grijpma, Dirk W.; Peijs, Ton; Gautrot, Julien E.

    2017-01-01

    Biodegradable shape memory polymers are attractive materials for the design of biomedical scaffolds as they allow deploying implants remotely with minimal intervention, whilst allowing degradation and tissue repair. However, shape memory properties are difficult to design from common degradable

  2. Polymer composite adsorbents using particles of molecularly imprinted polymers or aluminium oxide nanoparticles for treatment of arsenic contaminated waters.

    Science.gov (United States)

    Önnby, L; Pakade, V; Mattiasson, B; Kirsebom, H

    2012-09-01

    Removal of As(V) by adsorption from water solutions was studied using three different synthetic adsorbents. The adsorbents, (a) aluminium nanoparticles (Alu-NPs, polymers (polymer backbones of pure polyacrylamide (MIP-cryo) were of better stability than the amine containing polymer backbone (Alu-cryo). Both composites worked well in the studied pH range of pH 2-8. Adsorption tested in real wastewater spiked with arsenic showed that co-ions (nitrate, sulphate and phosphate) affected arsenic removal for Alu-cryo more than for MIP-cryo. Both composites still adsorbed well in the presence of counter-ions (copper and zinc) present at low concentrations (μg/l). The unchanged and selective adsorption in realistic water observed for MIP-cryo was concluded to be due to a successful imprinting, here controlled using a non-imprinted polymer (NIP). A development of MIP-cryo is needed, considering its low adsorption capacity. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Addition of magnetic markers for non-destructive evaluation of polymer composites

    Directory of Open Access Journals (Sweden)

    Ana Paula Pereira Fulco

    2011-12-01

    Full Text Available Polymer composite pipes are an appealing option as a substitute for conventional steel pipes, particularly due to their inherent corrosion resistance. However, the composite pipes currently used do not allow non-destructive evaluation (NDE using instrumented devices which operate with magnetic sensors. The present work aims at the development of polymer composites with the addition magnetic markers to allow the application non-destructive evaluation techniques which use magnetic sensors. Glass-polyester composite flat, circular plates were fabricated with the addition of ferrite particles (barium ferrite and strontium ferrite and four types of notches were introduced on the plates' surfaces. The influence of these notches on the measured magnetic properties of each material was measured. X-ray diffraction (XRD, X-ray fluorescence (XRF and Brunauer, Emmett, and Teller (BET nitrogen adsorption were used for the characterization of the ferrite particles. Particle dispersion in the polymer matrix was analyzed by scanning electron microscopy (SEM. According to the results, a particular variation in magnetic field was detected over the region surrounding each type of notch. The results suggest that the proposed technique has great potential for damage detection in polymer composites using magnetic sensors and thus constitute a valuable contribution which may ultimately lead to the development of non-destructive evaluation techniques for assessing the structural integrity polymer composite pipes.

  4. Nanoparticle and gelation stabilized functional composites of an ionic salt in a hydrophobic polymer matrix.

    Directory of Open Access Journals (Sweden)

    Selin Kanyas

    Full Text Available Polymer composites consisted of small hydrophilic pockets homogeneously dispersed in a hydrophobic polymer matrix are important in many applications where controlled release of the functional agent from the hydrophilic phase is needed. As an example, a release of biomolecules or drugs from therapeutic formulations or release of salt in anti-icing application can be mentioned. Here, we report a method for preparation of such a composite material consisted of small KCOOH salt pockets distributed in the styrene-butadiene-styrene (SBS polymer matrix and demonstrate its effectiveness in anti-icing coatings. The mixtures of the aqueous KCOOH and SBS-cyclohexane solutions were firstly stabilized by adding silica nanoparticles to the emulsions and, even more, by gelation of the aqueous phase by agarose. The emulsions were observed in optical microscope to check its stability in time and characterized by rheological measurements. The dry composite materials were obtained via casting the emulsions onto the glass substrates and evaporations of the organic solvent. Composite polymer films were characterized by water contact angle (WCA measurements. The release of KCOOH salt into water and the freezing delay experiments of water droplets on dry composite films demonstrated their anti-icing properties. It has been concluded that hydrophobic and thermoplastic SBS polymer allows incorporation of the hydrophilic pockets/phases through our technique that opens the possibility for controlled delivering of anti-icing agents from the composite.

  5. Nanoparticle and Gelation Stabilized Functional Composites of an Ionic Salt in a Hydrophobic Polymer Matrix

    Science.gov (United States)

    Kanyas, Selin; Aydın, Derya; Kizilel, Riza; Demirel, A. Levent; Kizilel, Seda

    2014-01-01

    Polymer composites consisted of small hydrophilic pockets homogeneously dispersed in a hydrophobic polymer matrix are important in many applications where controlled release of the functional agent from the hydrophilic phase is needed. As an example, a release of biomolecules or drugs from therapeutic formulations or release of salt in anti-icing application can be mentioned. Here, we report a method for preparation of such a composite material consisted of small KCOOH salt pockets distributed in the styrene-butadiene-styrene (SBS) polymer matrix and demonstrate its effectiveness in anti-icing coatings. The mixtures of the aqueous KCOOH and SBS-cyclohexane solutions were firstly stabilized by adding silica nanoparticles to the emulsions and, even more, by gelation of the aqueous phase by agarose. The emulsions were observed in optical microscope to check its stability in time and characterized by rheological measurements. The dry composite materials were obtained via casting the emulsions onto the glass substrates and evaporations of the organic solvent. Composite polymer films were characterized by water contact angle (WCA) measurements. The release of KCOOH salt into water and the freezing delay experiments of water droplets on dry composite films demonstrated their anti-icing properties. It has been concluded that hydrophobic and thermoplastic SBS polymer allows incorporation of the hydrophilic pockets/phases through our technique that opens the possibility for controlled delivering of anti-icing agents from the composite. PMID:24516593

  6. Advanced materials and processes for polymer solar cell devices

    DEFF Research Database (Denmark)

    Petersen, Martin Helgesen; Søndergaard, Roar; Krebs, Frederik C

    2010-01-01

    /fullerene mixtures and evaporated metal electrodes in a flat multilayer geometry. It is likely that significant advances can be found by pursuing many of these novel ideas further and the purpose of this review is to highlight these reports and hopefully spark new interest in materials and methods that may...... be performing less than the current state-of-the-art in their present form but that may have the potential to outperform these pending a larger investment in effort....

  7. Manufacturing Technology of Composite Materials—Principles of Modification of Polymer Composite Materials Technology Based on Polytetrafluoroethylene

    Directory of Open Access Journals (Sweden)

    Anton Panda

    2017-03-01

    Full Text Available The results of the investigations into the technological formation of new wear-resistant polymer composites based on polytetrafluoroethylene (PTFE filled with disperse synthetic and natural compounds are presented. The efficiency of using PTFE composites reinforced with carbon fibers depends on many factors, which influence the significant improvement of physicomechanical characteristics. The results of this research allow stating that interfacial and surface phenomena of the polymer–solid interface and composition play a decisive role in PTFE composites properties. Fillers hinder the relative movement of the PTFE molecules past one another and, in this way, reduce creep or deformation of the parts, reducing the wear rate of parts used in dynamic applications as well as the coefficient of thermal expansion. The necessary structural parameters of such polymer composites are provided by regimes of process equipment.

  8. Composite hydrogels of bio-inspired protein polymers : mechanical and structural characterization

    NARCIS (Netherlands)

    Rombouts, W.H.

    2015-01-01

    In this thesis we presented various combinations of custom-designed protein polymers that formed composite hydrogels. In chapter 2, composite hydrogels were prepared by mixing silk-like block copolymers (CP2SE48CP2) with collagen-like block copolymers (T9CR4T9). We found that by

  9. Polymer composites prepared from heat-treated starch and styrene-butadiene latex

    Science.gov (United States)

    Thermoplastic starch/latex polymer composites were prepared using styrene–butadiene (SB) latex and heat-treated cornstarch. The composites were prepared in a compression mold at 130 °C, with starch content 20%. An amylose-free cornstarch, waxy maize, was used for this research and the heat treatment...

  10. A possible recycling method for high grade steels EAFD in polymer composites.

    Science.gov (United States)

    Niubó, M; Fernández, A I; Chimenos, J M; Haurie, L

    2009-11-15

    This work evaluates the feasibility of incorporating electric arc furnace dust (EAFD), as filler in a polymer matrix, to obtain a moldable heavyweight sheet, useful for acoustic insulation in automotive industry. For this purpose EAFD from a steel factory that manufactures high quality steels, was characterized and different formulations of composites were prepared. Physical and mechanical properties, as well as fire behaviour were tested and compared with a polymer composite compounded with common mineral fillers. Optimum formulation with 25% EAFD fulfils the RoHs Directive used by automotive industry to regulate heavy metals content. Leaching test was also performed on prepared composites to classify the material after use.

  11. Silver-containing polymer composition used in spacecraft and semiconductor optoelectronics control systems

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, A. A., E-mail: alexchemtsu@rambler.ru; Tuev, V. I., E-mail: tvi-retem@main.tusur.ru [Tomsk State University of Control Systems and Radioelectronics, Tomsk, 634050 (Russian Federation)

    2015-10-27

    The copolymer of the vinyl chloride-maleic anhydride and silver nano- and microparticle (70 wt %) composition is offered as a conductive adhesive for fixing various chips on the dielectric substrate. The wiring volume resistivity is up to 3.1×10{sup −8} Ohm×m. The adhesive strength of the silver-containing polymer composition (70% of Ag) applied under a shear on the dielectric substrate is 106 N/mm{sup 2}. Adhesive layers obtained from these substances have a high thermal conductivity up to λ = 199.93 W/m×K that depends on the amount of Ag in the polymer composition.

  12. Performance of aged cement–polymer composite immobilizing borate waste simulates during flooding scenarios

    International Nuclear Information System (INIS)

    Eskander, S.B.; Bayoumi, T.A.; Saleh, H.M.

    2012-01-01

    Highlights: ► Developing of recycled Poly(ethylene terephthalate) waste to incorporate the borate waste. ► Performance of cemented waste form aged for 7 years and subjected to flooding scenario. ► SEM, X-ray diffraction, Thermal and FT-IR investigated the microstructure of cemented waste. - Abstract: An advanced composite of cement and water extended polyester based on the recycled Poly(ethylene terephthalate) waste was developed to incorporate the borate waste. Previous studies have reported the characterizations of the waste form (cement–polymer composite immobilizing borate waste simulates) after 28 days of curing time. The current work studied the performance of waste form aged for 7 years and subjected to flooding scenario during 260 days using three types of water. The state of waste form was assessed at the end of each definite interval of the water infiltration through visual examination and mechanical measurement. Scanning electron microscopy, infrared spectroscopy, X-ray diffraction and thermal analyses were used to investigate the changes that may occur in the microstructure of the waste form under aging and flooding effects. The actual experimental results indicated reasonable evidence for the durable waste form. Acceptable consistency was confirmed for the waste form even after aging 7 years and exposure to flooding scenario for 260 days.

  13. Microstructure-based numerical modeling method for effective permittivity of ceramic/polymer composites

    Science.gov (United States)

    Jylhä, Liisi; Honkamo, Johanna; Jantunen, Heli; Sihvola, Ari

    2005-05-01

    Effective permittivity was modeled and measured for composites that consist of up to 35vol% of titanium dioxide powder dispersed in a continuous epoxy matrix. The study demonstrates a method that enables fast and accurate numerical modeling of the effective permittivity values of ceramic/polymer composites. The model requires electrostatic Monte Carlo simulations, where randomly oriented homogeneous prism-shaped inclusions occupy random positions in the background phase. The computation cost of solving the electrostatic problem by a finite-element code is decreased by the use of an averaging method where the same simulated sample is solved three times with orthogonal field directions. This helps to minimize the artificial anisotropy that results from the pseudorandomness inherent in the limited computational domains. All the required parameters for numerical simulations are calculated from the lattice structure of titanium dioxide. The results show a very good agreement between the measured and numerically calculated effective permittivities. When the prisms are approximated by oblate spheroids with the corresponding axial ratio, a fairly good prediction for the effective permittivity of the mixture can be achieved with the use of an advanced analytical mixing formula.

  14. Apparent Surface Free Energy of Polymer/Paper Composite Material Treated by Air Plasma

    Directory of Open Access Journals (Sweden)

    Konrad Terpiłowski

    2017-01-01

    Full Text Available Surface plasma treatment consists in changes of surface properties without changing internal properties. In this paper composite polymer/paper material is used for production of packaging in cosmetic industry. There are problems with bonding this material at the time of packaging production due to its properties. Composite surface was treated by air plasma for 1, 10, 20, and 30 s. The advancing and receding contact angles of water, formamide, and diiodomethane were measured using both treated and untreated samples. Apparent surface free energy was estimated using the hysteresis (CAH and Van Oss, Good, Chaudhury approaches (LWAB. Surface roughness was investigated using optical profilometry and identification of after plasma treatment emerging chemical groups was made by means of the XPS (X-ray photoelectron spectroscopy technique. After plasma treatment the values of contact angles decreased which is particularly evident for polar liquids. Apparent surface free energy increased compared to that of untreated samples. Changes of energy value are due to the electron-donor parameter of energy. This parameter increases as a result of adding polar groups at the time of surface plasma activation. Changes of surface properties are combination of increase of polar chemical functional groups, increase on the surface, and surface roughness increase.

  15. Study of optical properties of Erbium doped Tellurite glass-polymer composite

    International Nuclear Information System (INIS)

    Sushama, D.

    2014-01-01

    Chalcogenide glasses have wide applications in optical device technology. But it has some disadvantages like thermal instability. Among them Tellurite glasses exhibits high thermal Stability. Doping of rare earth elements into the Tellurite glasses improve its optical properties. To improve its mechanical properties composites of this Tellurite glasses with polymer are prepared. Bulk samples of Er 2 O 3 doped TeO 2 ‐WO 3 ‐La 2 O 3 Tellurite glasses are prepared from high purity oxide mixtures, melting in an alumina crucible in air atmosphere. Composites of this Tellurite glasses with polymer are prepared by powder mixing method and the thin films of these composites are prepared using polymer press. Variations in band gap of these composites are studied from the UV/Vis/NIR absorption

  16. Study of optical properties of Erbium doped Tellurite glass-polymer composite

    Science.gov (United States)

    Sushama, D.

    2014-10-01

    Chalcogenide glasses have wide applications in optical device technology. But it has some disadvantages like thermal instability. Among them Tellurite glasses exhibits high thermal Stability. Doping of rare earth elements into the Tellurite glasses improve its optical properties. To improve its mechanical properties composites of this Tellurite glasses with polymer are prepared. Bulk samples of Er2O3 doped TeO2-WO3-La2O3 Tellurite glasses are prepared from high purity oxide mixtures, melting in an alumina crucible in air atmosphere. Composites of this Tellurite glasses with polymer are prepared by powder mixing method and the thin films of these composites are prepared using polymer press. Variations in band gap of these composites are studied from the UV/Vis/NIR absorption.

  17. Polymer-Ceramic Composite Materials for Pyroelectric Infrared Detectors: An Overview

    Science.gov (United States)

    Aggarwal, M. D; Currie, J. R.; Penn, B. G.; Batra, A. K.; Lal, R. B.

    2007-01-01

    Ferroelectrics:Polymer composites can be considered an established substitute for conventional electroceramics and ferroelectric polymers. The composites have a unique blend of polymeric properties such as mechanical flexibility, high strength, formability, and low cost, with the high electro-active properties of ceramic materials. They have attracted considerable interest because of their potential use in pyroelectric infrared detecting devices and piezoelectric transducers. These flexible sensors and transducers may eventually be useful for their health monitoring applications for NASA crew launch vehicles and crew exploration vehicles being developed. In the light of many technologically important applications in this field, it is worthwhile to present an overview of the pyroelectric infrared detector theory, models to predict dielectric behavior and pyroelectric coefficient, and the concept of connectivity and fabrication techniques of biphasic composites. An elaborate review of Pyroelectric-Polymer composite materials investigated to date for their potential use in pyroelectric infrared detectors is presented.

  18. Nanoparticles Decorated on Resin Particles and Their Flame Retardancy Behavior for Polymer Composites

    Directory of Open Access Journals (Sweden)

    Nour F. Attia

    2017-01-01

    Full Text Available New nanocomposites have been developed by doping of amberlite IR120 resin with spherical TiO2 nanoparticles in the presence of maleate diphosphate. Polystyrene composites of resin, maleate diphosphate, and resin-maleate diphosphate were prepared individually. This is in addition to preparation of polymer nanocomposites of polystyrene-resin doped TiO2 nanoparticles-maleate diphosphate. The flame retardancy and thermal stability properties of these developed polymer composites were evaluated. The inclusion of resin and resin doped nanoparticles improved the fire retardant behavior of polystyrene composites and enhanced their thermal stability. Synergistic behavior between flame retardant, resin, and nanoparticles was detected. The rate of burning of the polymer nanocomposites was recorded as 10.7 mm/min achieving 77% reduction compared to pure polystyrene (46.5 mm/min. The peak heat release rate (PHRR of the new polymer composites has reduced achieving 46% reduction compared to blank polymer. The morphology and dispersion of nanoparticles on resin and in polymer nanocomposites were characterized using transmission and scanning electron microscopy, respectively. The flame retardancy and thermal properties were evaluated using UL94 flame chamber, cone tests, and thermogravimetric analysis, respectively.

  19. Assessment of nanoparticle release and associated health effect of polymer-silicon composites

    International Nuclear Information System (INIS)

    Zhu, H; Irfan, A; Sachse, S; Njuguna, J

    2012-01-01

    Little information is currently available on possible release of nanomaterials or/and nanoparticles (NP) from conventional and novel products and associated health effect. This study aimed to assess the possible release of NP during the application stage of conventional and nanoproducts. NP release was monitored during physical processing of polymer-silicon composites, and the toxicity of both the released NP and the raw silica nanomaterials that were used as fillers in the nanocomposites was assessed in vitro using human lung epithelial A549 cells. This study suggests that 1) NP can be released from the conventional and novel polymer-silicon composites under certain application scenario; 2) the level of NP release from polymer composites could be altered by different reinforcement materials; e.g. nanostructured MMT could reduce the release while SiO2 NP could increase the release; 3) working with polymer composites under certain conditions could risk inhalation of high level of polymer NP; 4) raw nanomaterials appeared to be toxic in the chosen in vitro system. Further study of the effect of novel filler materials on NP release from final polymer products and the effect of released NP on environment and human health will inform design of safe materials and minimization of negative impact on the environment and human health.

  20. Polymer-Derived In- Situ Metal Matrix Composites Created by Direct Injection of a Liquid Polymer into Molten Magnesium

    Science.gov (United States)

    Sudarshan; Terauds, Kalvis; Anilchandra, A. R.; Raj, Rishi

    2014-02-01

    We show that a liquid organic precursor can be injected directly into molten magnesium to produce nanoscale ceramic dispersions within the melt. The castings made in this way possess good resistance to tensile deformation at 673 K (400 °C), confirming the non-coarsening nature of these dispersions. Direct liquid injection into molten metals is a significant step toward inserting different chemistries of liquid precursors to generate a variety of polymer-derived metal matrix composites.

  1. Conductivity of microfibrillar polymer-polymer composites with CNT-loaded microfibrils or compatibilizer: A comparative study

    Directory of Open Access Journals (Sweden)

    S. Fakirov

    2013-07-01

    Full Text Available Conductive polymer composites have wide ranging applications, but when they are produced by conventional melt blending, high conductive filler loadings are normally required, hindering their processability and reducing mechanical properties. In this study, two types of polymer-polymer composites were studied: i microfibrillar composites (MFC of polypropylene (PP and 5 wt% carbon nanotube (CNT loaded poly(butylene terephthalate (PBT as reinforcement, and ii maleic anhydride-grafted polypropylene (PP-g-MA compatibilizer, loaded with 5 wt% CNTs introduced into an MFC of PP and poly(ethylene terephthalate (PET in concentrations of 5 and 10 wt%. For the compatibilized composite type, PP and PET were melt-blended, cold-drawn and pelletized, followed by dry-mixing with PP-g-MA/CNT, re-extrusion at 200°C, and cold-drawing. The drawn blends produced were compression moulded to produce sheets with MFC structure. Using scanning electron microscopy, CNTs coated with PP-g-MA could be observed at the interface between PP matrix and PET microfibrils in the compatibilized blends. The volume resistivities tested by four-point test method were: 2.87•108 and 9.93•107 Ω•cm for the 66.5/28.5/5 and 63/27/10 (by wt% PP/PET/(PP-g-MA/CNT blends, corresponding to total CNT loadings (in the composites of 0.07 vol% (0.24 wt% and 0.14 vol% (0.46 wt%, respectively. For the non-compatibilized MFC types based on PP/(PBT/CNT with higher and lower melt flow grades of PP, the resistivities of 70/(95/5 blends were 1.9•106 and 1.5•107 Ω•cm, respectively, corresponding to a total filler loading (in the composite of 0.44 vol% (1.5 wt% in both MFCs.

  2. Boron/aluminum graphite/resin advanced fiber composite hybrids

    Science.gov (United States)

    Chamis, C. C.; Lark, R. F.; Sullivan, T. L.

    1975-01-01

    Fabrication feasibility and potential of an adhesively bonded metal and resin matrix fiber-composite hybrid are determined as an advanced material for aerospace and other structural applications. The results show that using this hybrid concept makes possible a composite design which, when compared with nonhybrid composites, has greater transverse strength, transverse stiffness, and impact resistance with only a small penalty on density and longitudinal properties. The results also show that laminate theory is suitable for predicting the structural response of such hybrids. The sequence of fracture modes indicates that these types of hybrids can be readily designed to meet fail-safe requirements.

  3. Advanced composite materials based on polyhydroxybutyrate and polylactic acid

    Science.gov (United States)

    Tubaeva, P. M.; Olkhov, A. A.; Podzorova, M. V.; Popov, A. A.

    2017-12-01

    In this paper, we consider the main characteristics of polyhydroxybutyrate (PHB) and polylactic acid (PLA) as well as the prospects and possibility of the medical use of PHB-PLA compositions as these polymers are most relevant to such application. The study establishes the main thermophysical parameters of PHB and PLA. It is found that PHB and PLA are hydrophobic enough. The study by the electron paramagnetic resonance method reveals a small amount of the radical infiltrated in PLA and PHB, which indicates the chain rigidity of both polymeric structures. Mechanical properties of PLA and PHB are characterized by high strength and low elasticity.

  4. Electrically conductive, optically transparent polymer/carbon nanotube composites

    Science.gov (United States)

    Connell, John W. (Inventor); Smith, Jr., Joseph G. (Inventor); Harrison, Joycelyn S. (Inventor); Park, Cheol (Inventor); Watson, Kent A. (Inventor); Ounaies, Zoubeida (Inventor)

    2011-01-01

    The present invention is directed to the effective dispersion of carbon nanotubes (CNTs) into polymer matrices. The nanocomposites are prepared using polymer matrices and exhibit a unique combination of properties, most notably, high retention of optical transparency in the visible range (i.e., 400-800 nm), electrical conductivity, and high thermal stability. By appropriate selection of the matrix resin, additional properties such as vacuum ultraviolet radiation resistance, atomic oxygen resistance, high glass transition (T.sub.g) temperatures, and excellent toughness can be attained. The resulting nanocomposites can be used to fabricate or formulate a variety of articles such as coatings on a variety of substrates, films, foams, fibers, threads, adhesives and fiber coated prepreg. The properties of the nanocomposites can be adjusted by selection of the polymer matrix and CNT to fabricate articles that possess high optical transparency and antistatic behavior.

  5. Quickly Updatable Hologram Images Using Poly(N-vinyl Carbazole (PVCz Photorefractive Polymer Composite

    Directory of Open Access Journals (Sweden)

    Wataru Sakai

    2012-08-01

    Full Text Available Quickly updatable hologram images using photorefractive (PR polymer composite based on poly(N-vinyl carbazole (PVCz is presented. PVCz is one of the pioneer materials of photoconductive polymers. PR polymer composite consists of 44 wt % of PVCz, 35 wt % of 4-azacycloheptylbenzylidene-malonitrile (7-DCST as a nonlinear optical dye, 20 wt % of carbazolylethylpropionate (CzEPA as a photoconductive plasticizer and 1 wt % of 2,4,7-trinitro-9-fluorenone (TNF as a sensitizer. PR composite gives high diffraction efficiency of 68% at E = 45 V μm−1. Response speed of optical diffraction is the key parameter for real-time 3D holographic display. The key parameter for obtaining quickly updatable holographic images is to control the glass transition temperature lower enough to enhance chromophore orientation. Object image of the reflected coin surface recorded with reference beam at 532 nm (green beam in the PR polymer composite is simultaneously reconstructed using a red probe beam at 642 nm. Instead of using a coin object, an object image produced by a computer was displayed on a spatial light modulator (SLM and used for the hologram. The reflected object beam from an SLM was interfered with a reference beam on PR polymer composite to record a hologram and simultaneously reconstructed by a red probe beam.

  6. Effect of the type of radiation on the degradation behavior of polymer matrix composites

    International Nuclear Information System (INIS)

    Egusa, Shigenori

    1992-01-01

    Four kinds of polymer matrix composites (filler: E-glass or carbon fiber cloth; matrix; epoxy or polyimide resin) were irradiated with neutrons and 60 Co γ-rays at room temperature or at 5 K. Three-point bend tests were then carried out at 77 K. Comparison of the neutron and γ-ray irradiation effects shows that the radiation sensitivity of the glass/epoxy and glass/polyimide composites is 1.8-2.6 times higher to neutrons than to γ-rays, indicating a higher sensitivity of the epoxy and polyimide matrix resins to recoil protons than to γ-rays. Absorbed dose calculations, on the other hand, show that the spatial distribution of the microscopic energy deposition in polymer matrix composites is inhomogeneous for neutrons, although almost homogeneous for γ-rays. In addition, the neutron irradiation of boron-containing E-glass fiber composites produces additional radiation damage due to a 10 B(n,α) 7 Li reaction in the glass fibers, thus significantly enhancing a decrease in the composite strength. These facts indicate that as far as polymer matrix composites are concerned, the irradiation effects of neutrons will be rather difficult to simulate with different types of radiation such as protons and carbon ions from an ion accelerator. Thus, it may be prudent that such simulation irradiation be carried out mainly for pure resins to be used as matrix in polymer matrix composites. (author)

  7. Definitions of Terms Related to Polymer Blends, Composites, and Multiphase Polymeric Materials, VII.1

    Directory of Open Access Journals (Sweden)

    Vuković, R.

    2009-09-01

    Full Text Available The document defines the terms most commonly encountered in the field of polymer blends and composites. The scope has been limited to mixtures in which the components differ in chemical composition or molar mass and in which the continuous phase is polymeric. Incidental thermodynamic descriptions are mainly limited to binary mixtures although, in principle, they could be generalized to multicomponent mixtures. The document is organized into three sections. The first defines terms basic to the description of polymer mixtures. The second defines terms commonly encountered in descriptions of phase domain behavior of polymer mixtures. The third defines terms commonly encountered in the descriptions of the morphologies of phase-separated polymer mixtures.

  8. Effect of irradiation on PTC performances of carbon black filled polymer composites

    International Nuclear Information System (INIS)

    Chen Xinfang; Jia Wentao; Tang Hao; Yang Huali; Li Shuhua.

    1995-01-01

    The influences of irradiation on Positive Temperature Coefficient (PTC) functions of polymer-carbon black composites are studied systematically, using HDPE, LDPE, PE/EPDM, PE/EEA as polymer matrixes and carbon black as conductive fillers. The results show that under a certain radiation dose, a remarkable improvement of the PTC intensity and the reproducibility of PTC curves of most polymer blends can be achieved, and Negative Temperature Coefficient (NTC) effects are decreased or eliminated. The mechanism of crosslinking structure on improving and stabilizing the PTC functions of polymer blends is also discussed through modern structural analysis methods. In this paper, an interesting and significant phenomenon is discovered. The PTC curve of PE/EPDM/CB composite presents an obvious NTC phenomenon as the dose exceeding 2 MGy. (author)

  9. Compositional investigation of phenolic polymers isolated from Vitis vinifera L. Cv. Pinot Noir during fermentation.

    Science.gov (United States)

    Aron, Patricia M; Kennedy, James A

    2007-07-11

    Phenolic polymer material extracted during commercial red wine fermentations (Vitis vinifera L. cv. Pinot noir) was isolated and analyzed to characterize its chemical composition. Phenolic polymer isolates were prepared from samples taken throughout fermentation and isolated by adsorption chromatography. Isolates were subjected to phloroglucinolysis to analyze the proanthocyanidin amount as well as the subunit composition. Results of phloroglucinolysis revealed that the proanthocyanidin content of individual phenolic polymer isolates varied from 27 to 54%. Subsequent analyses were done in an attempt to quantify materials other than known proanthocyanidin subunits. Results of all experiments indicate that up to 82% of the phenolic polymer isolates could be accounted for by mass. While this figure accounts for a significant portion of the polymeric phenolic material, further investigation will be needed to qualify the remaining 18%.

  10. Vertically Aligned and Interconnected SiC Nanowire Networks Leading to Significantly Enhanced Thermal Conductivity of Polymer Composites.

    Science.gov (United States)

    Yao, Yimin; Zhu, Xiaodong; Zeng, Xiaoliang; Sun, Rong; Xu, Jian-Bin; Wong, Ching-Ping

    2018-03-21

    Efficient heat removal via thermal management materials has become one of the most critical challenges in the development of modern microelectronic devices. However, previously reported polymer composites exhibit limited enhancement of thermal conductivity, even when highly loaded with thermally conductive fillers, because of the lack of efficient heat transfer pathways. Herein, we report vertically aligned and interconnected SiC nanowire (SiCNW) networks as efficient fillers for polymer composites, achieving significantly enhanced thermal conductivity. The SiCNW networks are produced by freeze-casting nanowire aqueous suspensions followed by thermal sintering to consolidate the nanowire junctions, exhibiting a hierarchical architecture in which honeycomb-like SiCNW layers are aligned. The composite obtained by infiltrating SiCNW networks with epoxy resin, at a relatively low SiCNW loading of 2.17 vol %, represents a high through-plane thermal conductivity (1.67 W m -1 K -1 ) compared to the pure matrix, which is equivalent to a significant enhancement of 406.6% per 1 vol % loading. The orderly SiCNW network which can act as a macroscopic expressway for phonon transport is believed to be the main contributor for the excellent thermal performance. This strategy provides insights for the design of high-performance composites with potential to be used in advanced thermal management materials.

  11. Study of variation of thermal diffusivity of advanced composite ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 32; Issue 1. Study of variation of thermal diffusivity of advanced composite materials of E-glass fibre reinforced plastic (GFRP) in temperature range 5–300 K. Kalobaran Das S M Kamaruzzaman Tapas Ranjan Middya Siddhartha Datta. Ceramics and Glasses Volume 32 ...

  12. Neutron beam measurement of industrial polymer materials for composition and bulk integrity

    International Nuclear Information System (INIS)

    Rogante, M; Rosta, L; Heaton, M E

    2013-01-01

    Neutron beam techniques, among other non-destructive diagnostics, are particularly irreplaceable in the complete analysis of industrial materials and components when supplying fundamental information. In this paper, nanoscale small-angle neutron scattering analysis and prompt gamma activation analysis for the characterization of industrial polymers are considered. The basic theoretical aspects are briefly introduced and some applications are presented. The investigations of the SU-8 polymer in axial airflow microturbines—i.e. microelectromechanical systems—are presented foremost. Also presented are full and feasibility studies on polyurethanes, composites based on cross-linked polymers reinforced by carbon fibres and polymer cement concrete. The obtained results have provided a substantial contribution to the improvement of the considered materials, and indeed confirmed the industrial applicability of the adopted techniques in the analysis of polymers. (paper)

  13. Neutron beam measurement of industrial polymer materials for composition and bulk integrity

    Science.gov (United States)

    Rogante, M.; Rosta, L.; Heaton, M. E.

    2013-10-01

    Neutron beam techniques, among other non-destructive diagnostics, are particularly irreplaceable in the complete analysis of industrial materials and components when supplying fundamental information. In this paper, nanoscale small-angle neutron scattering analysis and prompt gamma activation analysis for the characterization of industrial polymers are considered. The basic theoretical aspects are briefly introduced and some applications are presented. The investigations of the SU-8 polymer in axial airflow microturbines—i.e. microelectromechanical systems—are presented foremost. Also presented are full and feasibility studies on polyurethanes, composites based on cross-linked polymers reinforced by carbon fibres and polymer cement concrete. The obtained results have provided a substantial contribution to the improvement of the considered materials, and indeed confirmed the industrial applicability of the adopted techniques in the analysis of polymers.

  14. Electronic materials high-T(sub c) superconductivity polymers and composites structural materials surface science and catalysts industry participation

    Science.gov (United States)

    1988-01-01

    The fifth year of the Center for Advanced Materials was marked primarily by the significant scientific accomplishments of the research programs. The Electronics Materials program continued its work on the growth and characterization of gallium arsenide crystals, and the development of theories to understand the nature and distribution of defects in the crystals. The High Tc Superconductivity Program continued to make significant contributions to the field in theoretical and experimental work on both bulk materials and thin films and devices. The Ceramic Processing group developed a new technique for cladding YBCO superconductors for high current applications in work with the Electric Power Research Institute. The Polymers and Composites program published a number of important studies involving atomistic simulations of polymer surfaces with excellent correlations to experimental results. The new Enzymatic Synthesis of Materials project produced its first fluorinated polymers and successfully began engineering enzymes designed for materials synthesis. The structural Materials Program continued work on novel alloys, development of processing methods for advanced ceramics, and characterization of mechanical properties of these materials, including the newly documented characterization of cyclic fatigue crack propagation behavior in toughened ceramics. Finally, the Surface Science and Catalysis program made significant contributions to the understanding of microporous catalysts and the nature of surface structures and interface compounds.

  15. Modal analysis of additive manufactured carbon fiber reinforced polymer composite: Experiment and modeling

    Science.gov (United States)

    Krasnoveikin, V. A.; Druzhinin, N. V.; Rubtsov, V. E.; Filippov, A. V.; Tarasov, S. Yu.

    2017-12-01

    Additive manufacturing is a promising process to develop the multicomponent polymer-matrix composites. The carbon-reinforced versions of such composites possess a low weight and a high specific strength. Here we present the results of studies of numerical and experimental modal analyses of a framework structure made of a composite material by both aforementioned approaches. The numerical test results and those obtained from the laser Doppler vibrometry show the good agreement for several oscillation modes.

  16. Synthesis and Characterization of Short Saccaharum Cilliare Fibre Reinforced Polymer Composites

    OpenAIRE

    Singha, A. S.; Thakur, Vijay Kumar

    2009-01-01

    This paper deals with the synthesis of short Saccaharum Cilliare fibre (SC) reinforced Urea-Formaldehyde (UF) matrix based polymer composites. Present work reveals that mechanical properties such as: tensile strength, compressive strength, flexural strength and wear resistance of the UF matrix increase up to 30% fibre loading(in terms of weight) and then decreases for higher loading when fibers are incorporated into the matrix polymer. Morphological and Thermal studies of the matrix, fibre ...

  17. Heterogeneous Configuration of a Ag Nanowire/Polymer Composite Structure for Selectively Stretchable Transparent Electrodes.

    Science.gov (United States)

    Kim, Youngmin; Jun, Sungwoo; Ju, Byeong-Kwon; Kim, Jong-Woong

    2017-03-01

    One of the most important aspects that we need to consider in the design of intrinsically stretchable electrodes is that most electronic devices that can be formed on them are not stretchable themselves. This discrepancy can induce severe stress singularities at the interfaces between stiff devices and stretchable electrodes, leading to catastrophic device delamination when the substrate is stretched. Here, we suggest a novel solution to this challenge which involves introducing a photolithography-based rigid-island approach to fabricate the heterogeneous configuration of a silver nanowire (AgNW)/polymer composite structure. For this, we designed two new transparent polymers: a photopatternable polymer that is rigid yet flexible, and a stretchable polymer, both of which have identical acrylate functional groups. Patterning of the rigid polymer and subsequent overcoating of the soft polymer formed rigid island disks embedded in the soft polymer, resulting in a selectively stretchable transparent film. Strong covalent bonds instead of weak physical interactions between the polymers strengthened the cohesive force at the interface of the rigid/soft polymers. Inverted-layer processing with a percolated AgNW network was used to form a heterogeneous AgNW/polymer composite structure that can be used as a selectively stretchable transparent electrode. An optimized structural configuration prevented the resistance of the rigid electrode from varying up to a lateral strain of 70%. A repeated stretch/release test with 60% strain for 5000 cycles did not cause any severe damage to the structure, revealing that the fabricated structure was mechanically stable and reliable.

  18. STUDY OF THE PROPERTIES OF THE POLYMER COMPOSITIONS USING THE MODIFIED LATEX COAGULUM

    Directory of Open Access Journals (Sweden)

    A. M. Skachkov

    2014-01-01

    Full Text Available Summary. Properties of the latex coagulum formed during the manufacture of styrene-butadiene latices were investigated. Processing conditions coagulum for further use in the composition of the polymer base composites and rubber compounds were grown. Plasticizers latex coagulum system, improving its handling on the process equipment were developed. In the process of changing the structure of the plasticization of the polymer matrix: solid areas appear in images taken with a scanning probe microscope. Ability to manufacture polymer composites based on treated latex coagulum was shown. When creating the polymeric compositions of styrene-butadiene rubber SCS-30-15 ARKM plasticized coagulum optimum ratio of 70:30 has been selected. Influence the type and dosage of plasticizer viscosity compositions latex coagulum with rubber SKS-30-15 ARKM been established. Application consisting of plasticized polymer base coagulum provides physic-mechanical properties of rubber at the control rules of molded rubber products. It is noted that the best combination of properties of rubber and rubber blends possess samples based polymer compositions coagulum plasticized combination of petroleum oils. It has been established that the use of latex coagulum in the polymer base composition causes sufficiently high values of Mooney viscosity and short curing starts. The influence of active chemical additives (derivatives of saturated fatty acids, 2,2-azo-bis-isobutyronitrile to change the properties of the latex coagulum during machining on a mill was studied. Two ways of handling coagulum in the presence of accelerators mastication was proposed. Found that mixing coagulum accelerators advisable to carry out before the stage of the plasticizing coagulum.

  19. Mishap risk control for advanced aerospace/composite materials

    Science.gov (United States)

    Olson, John M.

    1994-01-01

    Although advanced aerospace materials and advanced composites provide outstanding performance, they also present several unique post-mishap environmental, safety, and health concerns. The purpose of this paper is to provide information on some of the unique hazards and concerns associated with these materials when damaged by fire, explosion, or high-energy impact. Additionally, recommended procedures and precautions are addressed as they pertain to all phases of a composite aircraft mishap response, including fire-fighting, investigation, recovery, clean-up, and guidelines are general in nature and not application-specific. The goal of this project is to provide factual and realistic information which can be used to develop consistent and effective procedures and policies to minimize the potential environmental, safety, and health impacts of a composite aircraft mishap response effort.

  20. Synthesis and Characterization of Composite Membranes made of Graphene and Polymers of Intrinsic Microporosity

    Science.gov (United States)

    2016-02-16

    characterization of composite membranes made of graphene and polymers of intrinsic microporosity Yuyoung Shin a, Eric Prestat b, Kai-Ge Zhou a, Patricia Gorgojo c...dx.doi.org/10.1016/j.carbon.2016.02.037 0008-6223/© 2016 The Authors. Published by Elseviea b s t r a c t Polymers of intrinsic microporosity (PIMs) are a...group of polymers with molecular sieve behaviour due to their rigid, contorted macromolecular backbones. They show great potential in organophilic

  1. Enhanced non-volatile and updatable holography using a polymer composite system.

    Science.gov (United States)

    Wu, Pengfei; Sun, Sam Q; Baig, Sarfaraz; Wang, Michael R

    2012-03-12

    Updatable holography is considered as the ultimate technique for true 3D information recording and display. However, there is no practical solution to preserve the required features of both non-volatility and reversibility which conflict with each other when the reading has the same wavelength as the recording. We demonstrate a non-volatile and updatable holographic approach by exploiting new features of molecular transformations in a polymer recording system. In addition, by using a new composite recording film containing photo-reconfigurable liquid-crystal (LC) polymer, the holographic recording is enhanced due to the collective reorientation of LC molecules around the reconfigured polymer chains.

  2. NATO Advanced Study Institute on Photophysical and Photochemical Tools in Polymer Science : Conformation, Dynamics, Morphology

    CERN Document Server

    1986-01-01

    In 1980 the New York Academy of Sciences sponsored a three-day conference on luminescence in biological and synthetic macromolecules. After that meeting, Professor Frans DeSchryver and I began to discuss the possibility of organizing a different kind of meeting, with time for both informal and in-depth discussions, to examine certain aspects of the application of fluorescence and phosphorescence spectroscopy to polymers. Our ideas developed through discussions with many others, particularly Professor Lucien Monnerie. By 1983, when we submitted our proposal to NATO for an Advanced Study Institute, the area had grown enormous ly. It is interesting in retrospect to look back on the points which emerged from these discussions as the basis around which the scientific program would be organized and the speakers chosen. We decided early on to focus on applications of these methods to provide information about polymer molecules and polymer systems: The topics would all relate to the conformation and dynamics of macro...

  3. NATO Advanced Study Institute on Electronic Structure of Polymers and Molecular Crystals

    CERN Document Server

    Ladik, János

    1975-01-01

    The NATO Advanced Study Institute on "Electronic Structure of Polymers and Molecular Crystals" was held at the Facultes Universi­ taires de Namur (F.U.N.) from September 1st till September 14th, 1974. We wish to express our appreciation to the NATO Scientific Affairs Division whose generous support made this Institute possible and to the Facultes Universitaires de Namur and the Societe Chimique de Belgique which provided fellowships and travel grants to a number of students. This volume contains the main lectures about the basic principles of the field and about different recent developments of the theory of the electronic structure of polymers and molecular crystals. The school started with the presentation of the basic SCF-LCAO theory of the electronic structure of periodic polymers and molecular crystals (contributions by Ladik, Andre & Delhalle) showing how a combination of quantum chemical and solid state physical methods can provide band structures for these systems. The numerical aspects of these ...

  4. Processing and properties of ceramic matrix-polymer composites for dental applications

    Science.gov (United States)

    Huang, Hsuan Yao

    The basic composite structure of natural hard tissue was used to guide the design and processing of dental restorative materials. The design incorporates the methodology of using inorganic minerals as the main structural phase reinforced with a more ductile but tougher organic phase. Ceramic-polymer composites were prepared by slip casting a porous ceramic structure, heating and chemical treating the porous preform, infiltrating with monomer and then curing. The three factors that determined the mechanical properties of alumina-polymer composites were the type of polymer used, the method of silane treatments, and the type of bond between particles in the porous preforms. Without the use of silane coupling agents, the composites were measured to have a lower strength. The composite with a more "flexible" porous alumina network had a greater ability to plastically dissipate the energy of propagating cracks. However, the aggressive nature of the alumina particles on opposing enamel requires that these alumina-polymer composites have a wear compatible coating for practical application. A route to dense bioactive apatite wollastonite glass ceramics (AWGC)-polymer composites was developed. The problems associated with glass dissolution into the aqueous medium for slip casting were overcome with the use of silane. The role of heating rate and development of ceramic compact microstructure on composite properties was explored. In general, if isothermal heating was not applied, decreasing heating rate increased glass crystallinity and particle-particle fusion, but decreased pore volume. Also composite strength and fracture toughness decreased while modulus and hardness increased with decreasing heating rate. If isothermal heating was applied, glass crystallinity, pore content, and composite mechanical properties showed relatively little change regardless of the initial heating rate. The potential of AWGC-polymer composites for dental and implant applications was explored

  5. Photovoltaic properties of conjugated polymer/fullerene composites ...

    African Journals Online (AJOL)

    The innovation involves the substrate, which is a polymer foil instead of glass. These devices are based on ultrafast, reversible, metastable photoinduced electron transfer and charge separation. We also present the efficiency and stability studies on large area (6 cm x 6 cm) flexible plastic solar cells with monochromatic ...

  6. Tuning particle biodegradation through polymer-peptide blend composition.

    Science.gov (United States)

    Gunawan, Sylvia T; Kempe, Kristian; Such, Georgina K; Cui, Jiwei; Liang, Kang; Richardson, Joseph J; Johnston, Angus P R; Caruso, Frank

    2014-12-08

    We report the preparation of polymer-peptide blend replica particles via the mesoporous silica (MS) templated assembly of poly(ethylene glycol)-block-poly(2-diisopropylaminoethyl methacrylate-co-2-(2-(2-(prop-2-ynyloxy)ethoxy)ethoxy)ethyl methacrylate) (PEG45-b-P(DPA55-co-PgTEGMA4)) and poly(l-histidine) (PHis). PEG45-b-P(DPA55-co-PgTEGMA4) was synthesized by atom transfer radical polymerization (ATRP), and was coinfiltrated with PHis into poly(methacrylic acid) (PMA)-coated MS particles assembled from different peptide-to-polymer ratios (1:1, 1:5, 1:10, or 1:15). Subsequent removal of the sacrificial templates and PMA resulted in monodisperse, colloidally stable, noncovalently cross-linked polymer-peptide blend replica particles that were stabilized by a combination of hydrophobic interactions between the PDPA and the PHis, hydrogen bonding between the PEG and PHis backbone, and π-π stacking of the imidazole rings of PHis side chains at physiological pH (pH ∼ 7.4). The synergistic charge-switchable properties of PDPA and PHis, and the enzymatic degradability of PHis, make these particles responsive to pH and enzymes. In vitro studies, in simulated endosomal conditions and inside cells, demonstrated that particle degradation kinetics could be engineered (from 2 to 8 h inside dendritic cells) based on simple adjustment of the peptide-to-polymer ratio used.

  7. Characterization of Additively Manufactured Shape Memory Polymer Composites (Preprint)

    Science.gov (United States)

    2017-10-17

    Report Distribution Statement A. Approved for public release: distribution unlimited. (STINFO COPY) AIR FORCE RESEARCH LABORATORY MATERIALS...material was filled with milled carbon fiber and milled glass in a ratio that allowed for the materials to be electrostatic discharge (ESD) compliant...deposition modeling, shape memory polymer, fixity, recovery 1 Distribution A. Approved for public release (PA): distribution unlimited. 1

  8. Patterns of efficiency and degradation of composite polymer solar cells

    NARCIS (Netherlands)

    Jeranko, T; Tributsch, H; Sariciftci, NS; Hummelen, JC

    2004-01-01

    Bulk-heterojunction plastic solar cells (PSC) produced from a conjugated polymer, poly(2-methoxy-5-(3',7'-dimethyloctyl-oxy)-1,4-phenylenevinylene) (MDMO-PPV), and a methanofullerene [6,6]-phenyl C-61-butyric acid methyl ester (PCBM) were investigated using photocurrent imaging techniques to

  9. High Thermal Conductivity Polymer Composites for Low Cost Heat Exchangers

    Energy Technology Data Exchange (ETDEWEB)

    None

    2017-08-01

    This factsheet describes a project that identified and evaluated commercially available and state-of-the-art polymer-based material options for manufacturing industrial and commercial non-metallic heat exchangers. A heat exchanger concept was also developed and its performance evaluated with heat transfer modeling tools.

  10. Research advances in polymer emulsion based on "core-shell" structure particle design.

    Science.gov (United States)

    Ma, Jian-zhong; Liu, Yi-hong; Bao, Yan; Liu, Jun-li; Zhang, Jing

    2013-09-01

    In recent years, quite many studies on polymer emulsions with unique core-shell structure have emerged at the frontier between material chemistry and many other fields because of their singular morphology, properties and wide range of potential applications. Organic substance as a coating material onto either inorganic or organic internal core materials promises an unparalleled opportunity for enhancement of final functions through rational designs. This contribution provides a brief overview of recent progress in the synthesis, characterization, and applications of both inorganic-organic and organic-organic polymer emulsions with core-shell structure. In addition, future research trends in polymer composites with core-shell structure are also discussed in this review. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Luminescent Polymer Electrolyte Composites Using Silica Coated-Y2O3:Eu as Fillers

    Directory of Open Access Journals (Sweden)

    Mikrajuddin Abdullah

    2003-05-01

    Full Text Available Luminescent polymer electrolyte composites composed of silica coated Y2O3:Eu in polyethylene glycol (PEG matrix has been produced by initially synthesizing silica coated Y2O3:Eu and mixing with polyethylene glycol in a lithium salt solution. High luminescence intensity at round 600 nm contributed by electron transitions in Eu3+ (5D0 -> 7F0, 5D0 -> 7F1, and 5D0 -> 7F3 transitions were observed. The measured electrical conductivity was comparable to that reported for polymer electrolyte composites prepared using passive fillers (non luminescent. This approach is therefore promising for production of high intensity luminescent polymer electrolyte composites for use in development of hybrid battery/display.

  12. Luminescent Polymer Composite Films Containing Coal-Derived Graphene Quantum Dots.

    Science.gov (United States)

    Kovalchuk, Anton; Huang, Kewei; Xiang, Changsheng; Martí, Angel A; Tour, James M

    2015-12-02

    Luminescent polymer composite materials, based on poly(vinyl alcohol) (PVA), as a matrix polymer and graphene quantum dots (GQDs) derived from coal, were prepared by casting from aqueous solutions. The coal-derived GQDs impart fluorescent properties to the polymer matrix, and the fabricated composite films exhibit solid state fluorescence. Optical, thermal, and fluorescent properties of the PVA/GQD nanocomposites have been studied. High optical transparency of the composite films (78 to 91%) and excellent dispersion of the nanoparticles are observed at GQD concentrations from 1 to 5 wt %. The maximum intensity of materials photoluminescence has been achieved at 10 wt % GQD content. These materials could be used in light emitting diodes (LEDs), flexible electronic displays, and other optoelectronic applications.

  13. Paving the Thermal Highway with Self-Organized Nanocrystals in Transparent Polymer Composites.

    Science.gov (United States)

    Mu, Liwen; Ji, Tuo; Chen, Long; Mehra, Nitin; Shi, Yijun; Zhu, Jiahua

    2016-10-26

    Phonon transfer is greatly scattered in traditional polymer composites due to the unpaired phonon frequency at the polymer/filler interface. A key innovation of this work is to build continuous crystal network by self-organization and utilize it as "thermal highway" that circumvents the long-existing interfacial thermal barrier issue in traditional composites. By tuning the molecular diffusion rate of dicarboxylic acids (oxalic acid, malonic acid, and succinic acid), different crystal structures including skeletal, dendrite, diffusion-limited aggregates, and spherulite were synthesized in PVA film. These continuous crystal structures benefit the efficient phonon transfer in the composites with minimized interfacial scattering and lead to a significant thermal conductivity enhancement of up to 180% compared to that of pure polymer. Moreover, the transparent feature of these composite films provides additional benefits in display applications. The post heat treatment effect on the thermal conductivity of the composite films shows a time-dependent behavior. These uniquely structured polymer/crystal composites are expected to generate significant impacts in thermal management applications.

  14. Boundary-condition analysis for physics-based modeling of ionic-polymer metal composite electroactive polymers

    Science.gov (United States)

    Bass, Patrick S.; Zhang, Lin; Cheng, Zhongyang

    2017-04-01

    Ionic-polymer metal composites (IPMCs) are a subset of ionic electroactive polymers (EAPs). They produce an actuation response based on the electrically induced flux of mobile ions through a parent-polymer matrix. This response is a result of the accumulation of cations and anions on opposing sides of the matrix and is directly related to the size disparity between the two types of ions. These factors impose a differential expansion across the matrix, which generates the macroscopic bending that is observed. It is well known that the motion of these EAPs is highly nonlinear and time dependent, making for a process that is difficult to model. A simplistic approach to modeling the physics behind this phenomenon and correlating that to experimental results is outlined, herein. This new methodology enables a comprehensive analysis of the boundary conditions (BCs) needed to be considered in order to accurately characterize the IPMC actuation response. The subsequent series of equations developed, which depict the ionic motion under these BCs, is presented. Empirical data for model analysis was acquired from IPMCs created using poly(ethylene oxide) (PEO), a well-known, biodegradable, solid-polymer electrolyte infused with lithium perchlorate, as the ionic salt. Experimental results fitted with this new model returned a favorable average adjusted-R2, goodness-of-fit, of 0.987, 0.994, and 0.992 when PEO films were tested under varying conditions, including: ionic concentration, applied voltage, and testing temperature, respectively.

  15. A testing platform for durability studies of polymers and fiber-reinforced polymer composites under concurrent hygrothermo-mechanical stimuli.

    Science.gov (United States)

    Gomez, Antonio; Pires, Robert; Yambao, Alyssa; La Saponara, Valeria

    2014-12-11

    The durability of polymers and fiber-reinforced polymer composites under service condition is a critical aspect to be addressed for their robust designs and condition-based maintenance. These materials are adopted in a wide range of engineering applications, from aircraft and ship structures, to bridges, wind turbine blades, biomaterials and biomedical implants. Polymers are viscoelastic materials, and their response may be highly nonlinear and thus make it challenging to predict and monitor their in-service performance. The laboratory-scale testing platform presented herein assists the investigation of the influence of concurrent mechanical loadings and environmental conditions on these materials. The platform was designed to be low-cost and user-friendly. Its chemically resistant materials make the platform adaptable to studies of chemical degradation due to in-service exposure to fluids. An example of experiment was conducted at RT on closed-cell polyurethane foam samples loaded with a weight corresponding to ~50% of their ultimate static and dry load. Results show that the testing apparatus is appropriate for these studies. Results also highlight the larger vulnerability of the polymer under concurrent loading, based on the higher mid-point displacements and lower residual failure loads. Recommendations are made for additional improvements to the testing apparatus.

  16. Distinct positive temperature coefficient effect of polymer-carbon fiber composites evaluated in terms of polymer absorption on fiber surface.

    Science.gov (United States)

    Zhang, Xi; Zheng, Shaodi; Zheng, Xiaofang; Liu, Zhengying; Yang, Wei; Yang, Mingbo

    2016-03-21

    In this article, the positive temperature coefficient (PTC) effect was studied for high-density polyethylene (HDPE)/carbon fiber (CF) composites. All of the samples showed a significant PTC effect during the heating processes without a negative temperature coefficient (NTC) effect, even at a temperature much higher than the melting point of the polymer matrix. An ever-increasing PTC intensity with increasing thermal cycles was observed in our study that had never been reported in previous research. The absence of a NTC effect resulted from the increased binding force between the matrix and fillers that contributed to the very special structure of CF surface. We incorporated thermal expansion theory and quantum tunneling effects to explain PTC effect. From the SEM micrographs for the HDPE/CF composites before and after the different thermal cycles, we found that the surface of CF was covered with a layer of polymer which resulted in a change in the gap length between CF and HDPE and its distribution. We believed that the gap change induced by polymer absorption on the fiber surface had a great effect on the PTC effect.

  17. Resin bond to indirect composite and new ceramic/polymer materials: a review of the literature.

    Science.gov (United States)

    Spitznagel, Frank A; Horvath, Sebastian D; Guess, Petra C; Blatz, Markus B

    2014-01-01

    Resin bonding is essential for clinical longevity of indirect restorations. Especially in light of the increasing popularity of computer-aided design/computer-aided manufacturing-fabricated indirect restorations, there is a need to assess optimal bonding protocols for new ceramic/polymer materials and indirect composites. The aim of this article was to review and assess the current scientific evidence on the resin bond to indirect composite and new ceramic/polymer materials. An electronic PubMed database search was conducted from 1966 to September 2013 for in vitro studies pertaining the resin bond to indirect composite and new ceramic/polymer materials. The search revealed 198 titles. Full-text screening was carried out for 43 studies, yielding 18 relevant articles that complied with inclusion criteria. No relevant studies could be identified regarding new ceramic/polymer materials. Most common surface treatments are aluminum-oxide air-abrasion, silane treatment, and hydrofluoric acid-etching for indirect composite restoration. Self-adhesive cements achieve lower bond strengths in comparison with etch-and-rinse systems. Thermocycling has a greater impact on bonding behavior than water storage. Air-particle abrasion and additional silane treatment should be applied to enhance the resin bond to laboratory-processed composites. However, there is an urgent need for in vitro studies that evaluate the bond strength to new ceramic/polymer materials. This article reviews the available dental literature on resin bond of laboratory composites and gives scientifically based guidance for their successful placement. Furthermore, this review demonstrated that future research for new ceramic/polymer materials is required. © 2014 Wiley Periodicals, Inc.

  18. Role of the polymer phase in the mechanics of nacre-like composites

    Science.gov (United States)

    Niebel, Tobias P.; Bouville, Florian; Kokkinis, Dimitri; Studart, André R.

    2016-11-01

    Although strength and toughness are often mutually exclusive properties in man-made structural materials, nature is full of examples of composite materials that combine these properties in a remarkable way through sophisticated multiscale architectures. Understanding the contributions of the different constituents to the energy dissipating toughening mechanisms active in these natural materials is crucial for the development of strong artificial composites with a high resistance to fracture. Here, we systematically study the influence of the polymer properties on the mechanics of nacre-like composites containing an intermediate fraction of mineral phase (57 vol%). To this end, we infiltrate ceramic scaffolds prepared by magnetically assisted slip casting (MASC) with monomers that are subsequently cured to yield three drastically different polymers: (i) poly(lauryl methacrylate) (PLMA), a soft and weak elastomer; (ii) poly(methyl methacrylate) (PMMA), a strong, stiff and brittle thermoplastic; and (iii) polyether urethane diacrylate-co-poly(2-hydroxyethyl methacrylate) (PUA-PHEMA), a tough polymer of intermediate strength and stiffness. By combining our experimental data with finite element modeling, we find that stiffer polymers can increase the strength of the composite by reducing stress concentrations in the inorganic scaffold. Moreover, infiltrating the scaffolds with tough polymers leads to composites with high crack initiation toughness KIC. An organic phase with a minimum strength and toughness is also required to fully activate the mechanisms programmed within the ceramic structure for a rising R-curve behavior. Our results indicate that a high modulus of toughness is a key parameter for the selection of polymers leading to strong and tough bioinspired nacre-like composites.

  19. Multiscale Polymer Composites: A Review of the Interlaminar Fracture Toughness Improvement

    Directory of Open Access Journals (Sweden)

    Vishwesh Dikshit

    2017-10-01

    Full Text Available Composite materials are prone to delamination as they are weaker in the thickness direction. Carbon nanotubes (CNTs are introduced as a multiscale reinforcement into the fiber reinforced polymer composites to suppress the delamination phenomenon. This review paper presents the detailed progress made by the scientific and research community to-date in improving the Mode I and Mode II interlaminar fracture toughness (ILFT by various methodologies including the effect of multiscale reinforcement. Methods of measuring the Mode I and Mode II fracture toughness of the composites along with the solutions to improve them are presented. The use of different methodologies and approaches along with their performance in enhancing the fracture toughness of the composites is summarized. The current state of polymer-fiber-nanotube composites and their future perspective are also deliberated.

  20. Dynamic response of a polymer and polymer composite systems : Experimental studies

    NARCIS (Netherlands)

    Fan, J.

    2015-01-01

    Recently, research on the impact resistance of transparent hybrid glass-polymer systems (layered and particle-matrix systems) has been conducted at the Netherlands Organisation for Applied Scientific Research (TNO), showing the potential of these materials for the application in protection concepts.

  1. Unusually conductive carbon-inherently conducting polymer (ICP) composites: Synthesis and characterization

    Science.gov (United States)

    Bourdo, Shawn Edward

    Two groups of materials that have recently come to the forefront of research initiatives are carbon allotropes, especially nanotubes, and conducting polymers-more specifically inherently conducting polymers. The terms conducting polymers and inherently conducting polymers sometimes are used interchangeably without fully acknowledging a major difference in these terms. Conducting polymers (CPs) and inherently conducting polymers (ICPs) are both polymeric materials that conduct electricity, but the difference lies in how each of these materials conducts electricity. For CPs of the past, an electrically conductive filler such as metal particles, carbon black, or graphite would be blended into a polymer (insulator) allowing for the CP to carry an electric current. An ICP conducts electricity due to the intrinsic nature of its chemical structure. The two materials at the center of this research are graphite and polyaniline. For the first time, a composite between carbon allotropes (graphite) and an inherently conducting polymer (PANI) has exhibited an electrical conductivity greater than either of the two components. Both components have a plethora of potential applications and therefore the further investigation could lead to use of these composites in any number of technologies. Touted applications that use either conductive carbons or ICPs exist in a wide range of fields, including electromagnetic interference (EMI) shielding, radar evasion, low power rechargeable batteries, electrostatic dissipation (ESD) for anti-static textiles, electronic devices, light emitting diodes (LEDs), corrosion prevention, gas sensors, super capacitors, photovoltaic cells, and resistive heating. The main motivation for this research has been to investigate the connection between an observed increase in conductivity and structure of composites. Two main findings have resulted from the research as related to the observed increase in conductivity. The first was the structural evidence from

  2. Morphology and transport in biodegradable polymer compositions based on poly(3-hydroxybutyrate) and polyamide 54C

    Energy Technology Data Exchange (ETDEWEB)

    Zhul' kina, A. L.; Ivantsova, E. L.; Filatova, A. G.; Kosenko, R. Yu.; Gumargalieva, K. Z.; Iordanskii, A. L., E-mail: iordan@chph.ras.ru [Russian Academy of Sciences, Semenov Institute of Chemical Physics (Russian Federation)

    2009-05-15

    Complex investigation of the equilibrium sorption of water, diffusive transport of antiseptic, and morphology of mixed compositions based on polyoxybutirate and polyamide resin 54C has been performed to develop and analyze new biodegradable polymer compositions for controlled release of medicinal substances. Samples of mixtures were prepared by two methods: pressing under pressure and solvent evaporation from a polymer solution. The samples were compared and their morphology was analyzed by scanning electron microscopy. It is shown that the component ratio in the obtained mixtures affects their morphological, transport, and sorption characteristics.

  3. Morphology and transport in biodegradable polymer compositions based on poly(3-hydroxybutyrate) and polyamide 54C

    International Nuclear Information System (INIS)

    Zhul'kina, A. L.; Ivantsova, E. L.; Filatova, A. G.; Kosenko, R. Yu.; Gumargalieva, K. Z.; Iordanskii, A. L.

    2009-01-01

    Complex investigation of the equilibrium sorption of water, diffusive transport of antiseptic, and morphology of mixed compositions based on polyoxybutirate and polyamide resin 54C has been performed to develop and analyze new biodegradable polymer compositions for controlled release of medicinal substances. Samples of mixtures were prepared by two methods: pressing under pressure and solvent evaporation from a polymer solution. The samples were compared and their morphology was analyzed by scanning electron microscopy. It is shown that the component ratio in the obtained mixtures affects their morphological, transport, and sorption characteristics.

  4. Advancing Polymer-Supported Ionogel Electrolytes Formed via Radical Polymerization

    Science.gov (United States)

    Visentin, Adam F.

    Applications ranging from consumer electronics to the electric grid have placed demands on current energy storage technologies. There is a drive for devices that store more energy for rapid consumption in the case of electric cars and the power grid, and safer, versatile design options for consumer electronics. Electrochemical double-layer capacitors (EDLCs) are an option that has garnered attention as a means to address these varied energy storage demands. EDLCs utilize charge separation in electrolytes to store energy. This energy storage mechanism allows for greater power density (W kg -1) than batteries and higher energy density (Wh kg-1) than conventional capacitors - along with a robust lifetime in the range of thousands to millions of charge-discharge cycles. Safety and working voltage windows of EDLCs currently on the market are limited by the organic solvents utilized in the electrolyte. A potential solution lies in the replacement of the organic solvents with ionic liquids, or room-temperature molten salts. Ionic liquids possess many superior properties in comparison to conventional solvents: wide electrochemical window, low volatility, nonflammability, and favorable ionic conductivity. It has been an endeavor of this work to exploit these advantages while altering the liquid form factor into a gel. An ionic liquid/solid support scaffold composite electrolyte, or ionogel, adds additional benefits: flexible device design, lower encapsulation weight, and elimination of electrolyte leakage. This work has focused on investigations of a UV-polymerizable monomer, poly(ethylene glycol) diacrylate, as a precursor for forming ionogels in situ. The trade-off between gaining mechanical stability at the cost of ionic conductivity has been investigated for numerous ionogel systems. While gaining a greater understanding of the interactions between the gel scaffold and ionic liquid, an ionogel with the highest known ionic conductivity to date (13.1 mS cm-1) was

  5. Sol-gel derived polymer composites for energy storage and conversion

    Science.gov (United States)

    Han, Kuo

    Sol-gel process is a simple chemistry to convert the small precursor molecules into an inorganic polymer, which could be applied to synthesize inorganic materials, modify the interface of materials, bridge the organic and inorganic materials, etc. In this dissertation, novel sol-gel derived composites have been developed for high dielectric breakdown capacitors, low high frequency loss capacitors and flexible piezoelectrics. Numerous efforts have been made in the past decades to improve the energy storage capability of composite materials by incorporating nanometer scale ceramic addictives with high dielectric permittivity into dielectric polymers with high breakdown strength. However, most composites suffer from the low breakdown strength and make the potential gain in energy density small. Here, a new chemical strategy is proposed that, through sol-gel reactions between ceramic precursors and functional groups at the end of the functionalized Poly(vinylidene fluoride -co-chlorotrifluoroethylene) chains, amorphous low permittivity ceramics was in-situ generated in the polymer matrix and cross-linked the polymer chains simultaneously. By carefully tuning precursors, the polymer/precursors feeding ratios, a series of nanocomposites were systematically designed. All the samples are comprehensively characterized and the structure-property correlations are well investigated. The optimal samples exhibit higher breakdown strength than the pristine polymer. The enhanced breakdown strength ascribed to low contrast in permittivity, great dispersion and improved electrical and mechanical properties. This newly developed approach has shown great promise for new composite capacitors. The percolative polymer composites have recently exhibited great potential in energy storage due to their high dielectric permittivities at the neighborhood of the percolation threshold. Yet high energy dissipation and poor voltage endurance of the percolative composites resulted from electrical

  6. Fabrication of mesoporous silica/polymer composites through solvent evaporation process and investigation of their excellent low thermal expansion property.

    Science.gov (United States)

    Suzuki, Norihiro; Kiba, Shosuke; Yamauchi, Yusuke

    2011-03-21

    We fabricate mesoporous silica/epoxy polymer composites through a solvent evaporation process. The easy penetration of the epoxy polymers into mesopores is achieved by using a diluted polymer solution including a volatile organic solvent. After the complete solvent evaporation, around 90% of the mesopores are estimated to be filled with the epoxy polymer chains. Here we carefully investigate the thermal expansion behavior of the obtained mesoporous silica/polymer composites. Thermal mechanical analysis (TMA) charts revealed that coefficient of linear thermal expansion (CTE) gradually decreases, as the amount of the doped mesoporous silica increases. Compared with spherical silica particle without mesopores, mesoporous silica particles show a greater effect on lowering the CTE values. Interestingly, it is found that the CTE values are proportionally decreased with the decrease of the total amount of the polymers outside the mesopores. These data demonstrate that polymers embedded inside the mesopores become thermally stable, and do not greatly contribute to the thermal expansion behavior of the composites.

  7. Formation of compositional gradient profiles by using shear-induced polymer migration phenomenon under Couette flow field

    Energy Technology Data Exchange (ETDEWEB)

    Im, Sang Hyuk; Lee, Su Jin [Kyung Hee University, Yongin (Korea, Republic of); Suh, Duck Jong; Park, O Ok [Korea Advanced Institute of Science and Technology (KAIST), Daejeon (Korea, Republic of); Kwon, Moo Hyun [Woosuk University, Wanju (Korea, Republic of)

    2015-07-15

    We investigated whether a graded-index profile, specified by the polymer compositional gradient, could be formed using shear-induced polymer migration phenomenon in a polymer solution. For the presented model system, we generated a shear flow by rotating a glass rod at the center of a polystyrene/methylmethacrylate (PS/MMA) solution and measured the degree of polymer migration by the shear flow field by examining the concentration of polymer solution along the radial direction from the rotating axis to the periphery. Through model experiments, we formed a compositional gradient and controlled its profile in the solution by varying the concentration of polymer solution, molecular weight of polymer, and shear rate. Finally, we solidified the gradient profiles by the polymerization of the PS/MMA solution and confirmed that the gradient profiles were maintained with a compositional gradient twice larger than the mother PS/MMA solution.

  8. Diamond growth on copper rods from polymer composite nanofibres

    Czech Academy of Sciences Publication Activity Database

    Varga, Marián; Potocký, Štěpán; Tesárek, P.; Babchenko, Oleg; Davydova, Marina; Kromka, Alexander

    2014-01-01

    Roč. 312, SEP (2014), s. 220-225 ISSN 0169-4332 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:68378271 Keywords : linear antenna MWCVD * diamond * copper * polymer nanofibres Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.711, year: 2014 http://www.sciencedirect.com/science/article/pii/S0169433214011003

  9. Multifunctional Nanofibers Comprised of Conducting and Ferroelectric Polymer Composites

    Science.gov (United States)

    2015-08-04

    poly(3-hexylthiophene) polymer – (PVDF-TrFE/ P3HT ) were prepared for the first time in air at room temperature using the electrospinning technique...trifluoroethylene)/ poly (3- hexylthiophene) (PVDF-TrFE/ P3HT ) nanofibers via electrospinning , W. Serrano, N.J. Pinto, National Conference on...TrFE); poly(3-hexylthiophene) ( P3HT ); poly(3,4-ethylenedioxthiophene) doped with poly-styrene sulfonic acid (PEDOT-PSSA); and (poly[N,N?-bis(2

  10. Magnetic and Electric Properties of Magneto polymer Composites

    Directory of Open Access Journals (Sweden)

    Jozef Slama

    2004-01-01

    Full Text Available Permeability spectra of MnZn ferrite composite materials, prepared by mixing ferrite particles with PVC, have been studied. As the ferrite filler content decreases in composite, the quasistatic permeability of the rotation component decreases and relaxation and the resonance frequency shift is higher. The real part of the permeability in the ferrite composite materials becomes larger than of sintered ferrite in high frequency region.

  11. Advanced surface chemical analysis of continuously manufactured drug loaded composite pellets.

    Science.gov (United States)

    Hossain, Akter; Nandi, Uttom; Fule, Ritesh; Nokhodchi, Ali; Maniruzzaman, Mohammed

    2017-04-15

    The aim of the present study was to develop and characterise polymeric composite pellets by means of continuous melt extrusion techniques. Powder blends of a steroid hormone (SH) as a model drug and either ethyl cellulose (EC N10 and EC P7 grades) or hydroxypropyl methylcellulose (HPMC AS grade) as polymeric carrier were extruded using a Pharma 11mm twin screw extruder in a continuous mode of operation to manufacture extruded composite pellets of 1mm length. Molecular modelling study using commercial Gaussian 09 software outlined a possible drug-polymer interaction in the molecular level to develop solid dispersions of the drug in the pellets. Solid-state analysis conducted via a differential scanning calorimetry (DSC), hot stage microscopy (HSM) and X-ray powder diffraction (XRPD) analyses revealed the amorphous state of the drug in the polymer matrices. Surface analysis using SEM/energy dispersive X-ray (EDX) of the produced pellets arguably showed a homogenous distribution of the C and O atoms in the pellet matrices. Moreover, advanced chemical surface analysis conducted via atomic force microscopy (AFM) showed a homogenous phase system having the drug molecule dispersed onto the amorphous matrices while Raman mapping confirmed the homogenous single-phase drug distribution in the manufactured composite pellets. Such composite pellets are expected to deliver multidisciplinary applications in drug delivery and medical sciences by e.g. modifying drug solubility/dissolutions or stabilizing the unstable drug (e.g. hormone, protein) in the composite network. Copyright © 2016. Published by Elsevier Inc.

  12. Properties analysis of tensile strength, crystallinity degree and microstructure of polymer composite polypropylene-sand

    International Nuclear Information System (INIS)

    Sudirman; Karo-Karo, Aloma; Ari-Handayani; Bambang-Sugeng; Rukihati; Mashuri

    2004-01-01

    Materials modification base on polymer toward polymer composite is needed by addition of filler. Mechanical properties such as tensile strength, crystallinity degree and microstructure of polymer composite based on polypropylene with sand filler have been investigated. In this work, the polymer composite has been made by mixing the matrix of polypropylene melt flow 2 (PP MF2) or polypropylene melt flow 10 (PP MF 10) with sand filler in a labo plastomill. The composition of sand filler was varied to 10, 30, 40 and 50 % v/v, a then the composite were casted to the film sheets form. The sheets were characterized mechanically i.e tensile strength, crystallinity degree and microstructure. The result showed that the tensile strength decreased by increasing the volume fraction of sand filler, in accordance with microstructure investigation that the matrix area under zone plastic deformation (more cracks), while the filler experienced elastic deformation, so that the strength mechanism of filler did not achieved with expectation (Danusso and Tieghi theory). For filler more than 30 % of volume fraction, the tensile strength of polypropylene melt flow 10 (PP MF 10) was greater than that polypropylene melt flow 2 (PP MF2). It was caused by plasticities in PP MF 10. The tensile strength of PP MF2 was greater than that PP MF 10 for volume fraction of sand filler less than 30 %. It was caused by PP MF2 to be have more degree of crystallinity

  13. Advanced composite structural concepts and materials technologies for primary aircraft structures: Advanced material concepts

    Science.gov (United States)

    Lau, Kreisler S. Y.; Landis, Abraham L.; Chow, Andrea W.; Hamlin, Richard D.

    1993-01-01

    To achieve acceptable performance and long-term durability at elevated temperatures (350 to 600 F) for high-speed transport systems, further improvements of the high-performance matrix materials will be necessary to achieve very long-term (60,000-120,000 service hours) retention of mechanical properties and damage tolerance. This report emphasizes isoimide modification as a complementary technique to semi-interpenetrating polymer networks (SIPN's) to achieve greater processibility, better curing dynamics, and possibly enhanced thermo-mechanical properties in composites. A key result is the demonstration of enhanced processibility of isoimide-modified linear and thermo-setting polyimide systems.

  14. Green Route Fabrication of Graphene Oxide Reinforced Polymer Composites with Enhanced Mechanical Properties

    International Nuclear Information System (INIS)

    Mahendran, R.; Sridharan, D.; Santhakumar, K.; Gnanasekaran, G.

    2016-01-01

    A facile and “Green” route has been applied to fabricate graphene oxide (GO) reinforced polymer composites utilizing “deionized water” as solvent. The GO was reinforced into water soluble poly(vinyl alcohol) (PVA) and poly-2-acrylamido-2-methyl-1-propanesulfonic acid (PAMPS) matrix by ultrasonication followed by mechanical stirring. The incorporation and dispersion of the GO in the polymer matrix were analyzed by XRD, FE-SEM, AFM, FT-IR, and TGA. Further, the FE-SEM and AFM images revealed that the surface roughness and agglomeration of the GO in the polymer matrix increased by increasing its concentration. Ionic exchange capacity, proton conductivity, and tensile texture results showed that the reinforcement of GO in the polymer matrix enhances the physicochemical properties of the host polymer. These PVA/PAMPS/GO nano composites showed improved mechanical stability compared to the pristine polymer, because of strong interfacial interactions within the components and homogeneous dispersion of the GO sheets in the PVA/PAMPS matrix.

  15. Magnetic polymer-silica composites as bioluminescent sensors for bilirubin detection

    Energy Technology Data Exchange (ETDEWEB)

    Timin, Alexander S., E-mail: a_timin@mail.ru [Inorganic Chemistry Department, Ivanovo State University of Chemistry and Technology (ISUCT), 7, Sheremetevsky prosp., 153000, Ivanovo (Russian Federation); RASA Center in Tomsk, Tomsk Polytechnic University, pros. Lenina, 30, Tomsk (Russian Federation); Solomonov, Alexey V. [Inorganic Chemistry Department, Ivanovo State University of Chemistry and Technology (ISUCT), 7, Sheremetevsky prosp., 153000, Ivanovo (Russian Federation); Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot, 7610001 (Israel); Kumagai, Akiko; Miyawaki, Atsushi [Cell Function Dynamics, Brain Science Institute RIKEN, 2-1 Hirosawa, Wako-city, Saitama, 351-0198 (Japan); Khashirova, Svetlana Yu; Zhansitov, Azamat [Kabardino-Balkar State University, 173 Chernyshevskogo St., Nal' chik, 360004, Kabardino-Balkaria (Russian Federation); Rumyantsev, Evgeniy V. [Inorganic Chemistry Department, Ivanovo State University of Chemistry and Technology (ISUCT), 7, Sheremetevsky prosp., 153000, Ivanovo (Russian Federation)

    2016-11-01

    The synthesis of multifunctional nano-sized materials is leading to the rapid development of key application, including improved drug delivery, bioimaging and protein separation. In this work, magnetic silica particles modified with novel guanidine containing co-polymers were manufactured via sol-gel method. To evaluate the chemical composition of our prepared samples, FT-IR spectroscopy and thermogravimetry were conducted. Scanning electron microscopy was used in order to investigate the morphology of final products after modification by guanidine containing co-polymers and iron nanoparticles. In addition, the surface of polymer-silica composites was functionalized by the novel bilirubin-inducible fluorescent protein UnaG. In an aqueous bilirubin solution, the silica particles decorated with the polymer-UnaG have showed bright fluorescence. Synthesis and characterization of these hybrid materials allow developing of new multifunctional nano-sized materials, which will be used for detection and separation of bilirubin, a lipophilic heme catabolite that is a clinical diagnostic for liver function. - Highlights: • Novel magnetic silicas grafted by guanidine containing co-polymers were prepared. • Unag protein was effectively loaded into polymer coated silicas. • The fluorescent properties depend on content of bilirubin.

  16. Enhancing ionic conductivity in composite polymer electrolytes with well-aligned ceramic nanowires

    Science.gov (United States)

    Liu, Wei; Lee, Seok Woo; Lin, Dingchang; Shi, Feifei; Wang, Shuang; Sendek, Austin D.; Cui, Yi

    2017-04-01

    In contrast to conventional organic liquid electrolytes that have leakage, flammability and chemical stability issues, solid electrolytes are widely considered as a promising candidate for the development of next-generation safe lithium-ion batteries. In solid polymer electrolytes that contain polymers and lithium salts, inorganic nanoparticles are often used as fillers to improve electrochemical performance, structure stability, and mechanical strength. However, such composite polymer electrolytes generally have low ionic conductivity. Here we report that a composite polymer electrolyte with well-aligned inorganic Li+-conductive nanowires exhibits an ionic conductivity of 6.05 × 10-5 S cm-1 at 30 ∘C, which is one order of magnitude higher than previous polymer electrolytes with randomly aligned nanowires. The large conductivity enhancement is ascribed to a fast ion-conducting pathway without crossing junctions on the surfaces of the aligned nanowires. Moreover, the long-term structural stability of the polymer electrolyte is also improved by the use of nanowires.

  17. Properties of Multifunctional Hybrid Carbon Nanotube/Carbon Fiber Polymer Matrix Composites

    Science.gov (United States)

    Cano, Roberto J.; Kang, Jin Ho; Grimsley, Brian W.; Ratcliffe, James G.; Siochi, Emilie J.

    2016-01-01

    For aircraft primary structures, carbon fiber reinforced polymer (CFRP) composites possess many advantages over conventional aluminum alloys due to their light weight, higher strength- and stiffness-to-weight ratios, and low life-cycle maintenance costs. However, the relatively low electrical and thermal conductivities of CFRP composites fail to provide structural safety in certain operational conditions such as lightning strikes. Carbon nanotubes (CNT) offer the potential to enhance the multi-functionality of composites with improved thermal and electrical conductivity. In this study, hybrid CNT/carbon fiber (CF) polymer composites were fabricated by interleaving layers of CNT sheets with Hexcel® IM7/8852 prepreg. Resin concentrations from 1 wt% to 50 wt% were used to infuse the CNT sheets prior to composite fabrication. The interlaminar properties of the resulting hybrid composites were characterized by mode I and II fracture toughness testing. Fractographical analysis was performed to study the effect of resin concentration. In addition, multi-directional physical properties like thermal conductivity of the orthotropic hybrid polymer composite were evaluated.

  18. Review on advanced composite materials boring mechanism and tools

    Science.gov (United States)

    Shi, Runping; Wang, Chengyong

    2011-05-01

    With the rapid development of aviation and aerospace manufacturing technology, advanced composite materials represented by carbon fibre reinforced plastics (CFRP) and super hybrid composites (fibre/metal plates) are more and more widely applied. The fibres are mainly carbon fibre, boron fibre, Aramid fiber and Sic fibre. The matrixes are resin matrix, metal matrix and ceramic matrix. Advanced composite materials have higher specific strength and higher specific modulus than glass fibre reinforced resin composites of the 1st generation. They are widely used in aviation and aerospace industry due to their high specific strength, high specific modulus, excellent ductility, anticorrosion, heat-insulation, sound-insulation, shock absorption and high&low temperature resistance. They are used for radomes, inlets, airfoils(fuel tank included), flap, aileron, vertical tail, horizontal tail, air brake, skin, baseboards and tails, etc. Its hardness is up to 62~65HRC. The holes are greatly affected by the fibre laminates direction of carbon fibre reinforced composite material due to its anisotropy when drilling in unidirectional laminates. There are burrs, splits at the exit because of stress concentration. Besides there is delamination and the hole is prone to be smaller. Burrs are caused by poor sharpness of cutting edge, delamination, tearing, splitting are caused by the great stress caused by high thrust force. Poorer sharpness of cutting edge leads to lower cutting performance and higher drilling force at the same time. The present research focuses on the interrelation between rotation speed, feed, drill's geometry, drill life, cutting mode, tools material etc. and thrust force. At the same time, holes quantity and holes making difficulty of composites have also increased. It requires high performance drills which won't bring out defects and have long tool life. It has become a trend to develop super hard material tools and tools with special geometry for drilling

  19. Alignment of carbon nanotubes and reinforcing effects in nylon-6 polymer composite fibers

    Science.gov (United States)

    Rangari, Vijaya K.; Yousuf, Mohammed; Jeelani, Shaik; Pulikkathara, Merlyn X.; Khabashesku, Valery N.

    2008-06-01

    Alignment of pristine carbon nanotubes (P-CNTs) and fluorinated carbon nanotubes (F-CNTs) in nylon-6 polymer composite fibers (PCFs) has been achieved using a single-screw extrusion method. CNTs have been used as filler reinforcements to enhance the mechanical and thermal properties of nylon-6 composite fibers. The composites were fabricated by dry mixing nylon-6 polymer powder with the CNTs as the first step, then followed by the melt extrusion process of fiber materials in a single-screw extruder. The extruded fibers were stretched to their maxima and stabilized using a godet set-up. Finally, fibers were wound on a Wayne filament winder machine and tested for their tensile and thermal properties. The tests have shown a remarkable change in mechanical and thermal properties of nylon-6 polymer fibers with the addition of 0.5 wt% F-CNTs and 1.0 wt% of P-CNTs. To draw a comparison between the improvements achieved, the same process has been repeated with neat nylon-6 polymer. As a result, tensile strength has been increased by 230% for PCFs made with 0.5% F-CNTs and 1% P-CNTs as additives. These fibers have been further characterized by DSC, Raman spectroscopy and SEM which confirm the alignment of CNTs and interfacial bonding to nylon-6 polymer matrix.

  20. Mechanical, Thermomechanical and Reprocessing Behavior of Green Composites from Biodegradable Polymer and Wood Flour.

    Science.gov (United States)

    Morreale, Marco; Liga, Antonio; Mistretta, Maria Chiara; Ascione, Laura; Mantia, Francesco Paolo La

    2015-11-11

    The rising concerns in terms of environmental protection and the search for more versatile polymer-based materials have led to an increasing interest in the use of polymer composites filled with natural organic fillers (biodegradable and/or coming from renewable resources) as a replacement for traditional mineral inorganic fillers. At the same time, the recycling of polymers is still of fundamental importance in order to optimize the utilization of available resources, reducing the environmental impact related to the life cycle of polymer-based items. Green composites from biopolymer matrix and wood flour were prepared and the investigation focused on several issues, such as the effect of reprocessing on the matrix properties, wood flour loading effects on virgin and reprocessed biopolymer, and wood flour effects on material reprocessability. Tensile, Dynamic-mechanical thermal (DMTA), differential scanning calorimetry (DSC) and creep tests were performed, pointing out that wood flour leads to an improvement of rigidity and creep resistance in comparison to the pristine polymer, without compromising other properties such as the tensile strength. The biopolymer also showed a good resistance to multiple reprocessing; the latter even allowed for improving some properties of the obtained green composites.

  1. Mechanical, Thermomechanical and Reprocessing Behavior of Green Composites from Biodegradable Polymer and Wood Flour

    Directory of Open Access Journals (Sweden)

    Marco Morreale

    2015-11-01

    Full Text Available The rising concerns in terms of environmental protection and the search for more versatile polymer-based materials have led to an increasing interest in the use of polymer composites filled with natural organic fillers (biodegradable and/or coming from renewable resources as a replacement for traditional mineral inorganic fillers. At the same time, the recycling of polymers is still of fundamental importance in order to optimize the utilization of available resources, reducing the environmental impact related to the life cycle of polymer-based items. Green composites from biopolymer matrix and wood flour were prepared and the investigation focused on several issues, such as the effect of reprocessing on the matrix properties, wood flour loading effects on virgin and reprocessed biopolymer, and wood flour effects on material reprocessability. Tensile, Dynamic-mechanical thermal (DMTA, differential scanning calorimetry (DSC and creep tests were performed, pointing out that wood flour leads to an improvement of rigidity and creep resistance in comparison to the pristine polymer, without compromising other properties such as the tensile strength. The biopolymer also showed a good resistance to multiple reprocessing; the latter even allowed for improving some properties of the obtained green composites.

  2. Development of ceramic composites from mixture of alumina and ceramic precursor polymer poly (silsesquioxane))

    International Nuclear Information System (INIS)

    Machado, Glauson Aparecido Ferreira

    2009-01-01

    Processing of ceramics materials, by polymer precursors pyrolysis, has been intensively researched over the past decades, due to advantages that this path provides, such as: lower temperature process compared to conventional techniques; structure control at molecular level; synthesis possibility of a wide range of ceramic compounds; obtaining parts with dimensions of the final product etc. The active filler controlled polymer pyrolysis (AFCOP) process, enables the synthesis of ceramic composites, by reaction between added filler (oxides, metals, intermetallic etc.) and solid and gaseous products, from polymer decomposition. In this study, based on this process, samples of alumina, with addition of 10 and 20 mass% of poly silsesquioxane polymer precursor, were manufactured. These samples were pyrolyzed at 900 degree C and thermal treated at temperatures of 1100, 1300 and 1500 degree C. The samples were characterized for bulk density, porosity and hardness, after each stage of thermal treatment. Structural transformations were analyzed by X-ray diffraction, scanning electron microscopy and infrared spectroscopy. Samples treated until 1300 degree C resulted in composites of alumina and silicon oxycarbide, while those treated at 1500 degree C, formed composites of mullite and alumina. The samples with 20% of polymer added started to density around 800 degree C and high retraction rate was observed at 1400 degree C. (author)

  3. The NASA "PERS" Program: Solid Polymer Electrolyte Development for Advanced Lithium-Based Batteries

    Science.gov (United States)

    Baldwin, Richard S.; Bennett, William R.

    2007-01-01

    In fiscal year 2000, The National Aeronautics and Space Administration (NASA) and the Air Force Research Laboratory (AFRL) established a collaborative effort to support the development of polymer-based, lithium-based cell chemistries and battery technologies to address the next generation of aerospace applications and mission needs. The ultimate objective of this development program, which was referred to as the Polymer Energy Rechargeable System (PERS), was to establish a world-class technology capability and U.S. leadership in polymer-based battery technology for aerospace applications. Programmatically, the PERS initiative exploited both interagency collaborations to address common technology and engineering issues and the active participation of academia and private industry. The initial program phases focused on R&D activities to address the critical technical issues and challenges at the cell level. Out of a total of 38 proposals received in response to a NASA Research Announcement (NRA) solicitation, 18 proposals (13 contracts and 5 grants) were selected for initial award to address these technical challenges. Brief summaries of technical approaches, results and accomplishments of the PERS Program development efforts are presented. With Agency support provided through FY 2004, the PERS Program efforts were concluded in 2005, as internal reorganizations and funding cuts resulted in shifting programmatic priorities within NASA. Technically, the PERS Program participants explored, to various degrees over the lifetime of the formal program, a variety of conceptual approaches for developing and demonstrating performance of a viable advanced solid polymer electrolyte possessing the desired attributes, as well as several participants addressing all components of an integrated cell configuration. Programmatically, the NASA PERS Program was very successful, even though the very challenging technical goals for achieving a viable solid polymer electrolyte material or

  4. Characteristics of 1–3-type ferroelectric ceramic/auxetic polymer composites

    International Nuclear Information System (INIS)

    Topolov, V Yu; Bowen, C R

    2008-01-01

    This paper presents modelling and simulation results on 1–3 piezoactive composites comprising a range of ferroelectric ceramics, which are assumed to have variable properties and an auxetic polymer (i.e. a material with a negative Poisson ratio) that improves the hydrostatic piezoelectric response of the composite. Dependences of the effective piezoelectric coefficients and related parameters of the 1–3 composites on the degree of poling, mobility of the 90° domain walls within ceramic grains, on the volume fraction of the ceramic component and on the Poisson ratio of the polymer component have been calculated and analysed. The role of the piezoelectric anisotropy and domain-orientation processes in improving and optimising the effective parameters, piezoelectric activity and sensitivity of 1–3 ferroelectric ceramic/auxetic composites is discussed

  5. Influence of carbon nanoparticles on the properties of screen printed polymer composites

    Science.gov (United States)

    Jakubowska, Małgorzata; Janeczek, Kamil; MłoŻniak, Anna; Kozioł, GraŻyna; Araźna, Aneta

    2013-07-01

    Further development of printed electronics requires investigations of new polymer composites which can be coated on flexible substrates with printing techniques. These composites should exhibit low sheet resistance and high durability to thermal stresses. In this article, the properties of polymer composites prepared by mixing a commercial solution of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) in aliphatic hydrocarbons with multi-wall carbon nanotubes or graphite platelet nanofibers were described. These composites were coated on flexible and low-cost substrates with screen printing techniques. The microstructure of fabricated layers were observed in a top and cross-sectional view and their thickness was measured with a contact profilometer. Their resistance was measured with a four-point-probe method depending on a printing multiplicity and after exposure the tested samples to the influence of temperature variation. Temperature distribution under influence of current flow in the produced layers was also examined.

  6. Zinc Oxide Nanowire Interphase for Enhanced Lightweight Polymer Fiber Composites

    Science.gov (United States)

    Sodano, Henry A.; Brett, Robert

    2011-01-01

    The objective of this work was to increase the interfacial strength between aramid fiber and epoxy matrix. This was achieved by functionalizing the aramid fiber followed by growth of a layer of ZnO nanowires on the fiber surface such that when embedded into the polymer, the load transfer and bonding area could be substantially enhanced. The functionalization procedure developed here created functional carboxylic acid surface groups that chemically interact with the ZnO and thus greatly enhance the strength of the interface between the fiber and the ZnO.

  7. Collaboration of polymer composite reinforcement and cement concrete

    Science.gov (United States)

    Khozin, V. G.; Gizdatullin, A. R.

    2018-04-01

    The results of experimental study of bond strength of cement concrete of different types with fiber reinforcing polymer (FRP) bars are reported. The reinforcing bars were manufactured of glass fibers and had a rebar with different types of the surface relief formed by winding a thin strip impregnated with a binder or by “sanding”. The pullout tests were carried out simultaneously for the steel reinforcing ribbed bars A400. The impact of friction, adhesion and mechanical bond on the strength of bonds between FRP and concrete was studied. The influence of the concrete strength and different operation factors on the bond strength of concrete was evaluated.

  8. Effects of moisture on glass fiber-reinforced polymer composites

    DEFF Research Database (Denmark)

    Alzamora Guzman, Vladimir Joel; Brøndsted, Povl

    2015-01-01

    performance of wind turbine blades over their lifetime. Here, environmental moisture conditions were simulated by immersing glass fiber-reinforced polymer specimens in salt water for a period of up to 8 years. The mechanical properties of specimens were analyzed before and after immersion to evaluate...... the degradation mechanisms. Single-fiber tensile testing was also performed at different moisture conditions. The water-diffusion mechanism was studied to quantify the diffusion coefficients as a function of salt concentration, sample geometry, and fiber direction. Three degradation mechanisms were observed...

  9. Residual stress of particulate polymer composites with reduced thermal expansion

    International Nuclear Information System (INIS)

    Nishino, T; Kotera, M; Sugiura, Y

    2009-01-01

    Thermal expansion behavior was investigated for tangusten zirconium phosphate (Zr 2 (WO 4 )(PO 4 ) 2 (ZWP)) particulate filled poly(ether ether ketone) (PEEK) composite. ZWP is known as ceramic filler with a negative thermal expansion. By incorporating ZWP with 40 volume %, the linear thermal expansion coefficient of the PEEK composite was reduced to almost same value (2.53 X 10 -5 K -1 ) with that of aluminum. This decrease was found to be quite effective for the decrease of the residual stress at the interface between aluminum plate and the composite.

  10. SERIAL SECTIONS THROUGH A CONTINUOUS FIBER-REINFORCED POLYMER COMPOSITE

    Directory of Open Access Journals (Sweden)

    Laurent Bizet

    2011-05-01

    Full Text Available The microstructure of a unidirectional glass-fiber composite material is described seeking especially for the influence of the stitching perpendicular to the reinforcement. Serial cuts are performed through the composite and the microstructure is quantified using global parameters and linear morphological analysis. A key result is that the stitching induces variations in fibers spacing within the yarns and in the matrix volume between the yarns. This can affect noticeably the flow of the resin during the manufacturing process and also the mechanical properties of the composite.

  11. Waste Mineral Powders as a Components of Polymer-Cement Composites

    Directory of Open Access Journals (Sweden)

    Jaworska B.

    2015-12-01

    Full Text Available The introduction of the sustainable development elements in the construction industry leads to finding new ways of using waste minerals that are difficult in storage and recycling. Coal combustion products have been already introduced into building materials as a part of cement or concrete but they have been thought insufficiently compatible with the polymer-cement binders [7]. The paper presents results of the mechanical properties of polymer-cement composites containing two types of mineral additives: waste perlite powder that is generated during the perlite expanding process, and calcium fly ash which is the byproduct of burning coal in conventional furnaces. Mechanical tests of polymer-cement composites modified with wastes were carried out after 28 and 90 days of curing. As a part of preliminary study specific surface area and particle size distribution of mineral wastes were determined.

  12. Conducting polymer and its composite materials based electrochemical sensor for Nicotinamide Adenine Dinucleotide (NADH).

    Science.gov (United States)

    Omar, Fatin Saiha; Duraisamy, Navaneethan; Ramesh, K; Ramesh, S

    2016-05-15

    Nicotinamide Adenine Dinucleotide (NADH) is an important coenzyme in the human body that participates in many metabolic reactions. The impact of abnormal concentrations of NADH significantly causes different diseases in human body. Electrochemical detection of NADH using bare electrode is a challenging task especially in the presence of main electroactive interferences such as ascorbic acid (AA), uric acid (UA) and dopamine (DA). Modified electrodes have been widely explored to overcome the problems of poor sensitivity and selectivity occurred from bare electrodes. This review gives an overview on the progress of using conducting polymers, polyelectrolyte and its composites (co-polymer, carbonaceous, metal, metal oxide and clay) based modified electrodes for the sensing of NADH. In addition, developments on the fabrication of numerous conducting polymer composites based modified electrodes are clearly described. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Polymer-Ceramic Composite Scaffolds: The Effect of Hydroxyapatite and β-tri-Calcium Phosphate

    OpenAIRE

    Boyang Huang; Guilherme Caetano; Cian Vyas; Jonny James Blaker; Carl Diver; Paulo Bártolo

    2018-01-01

    The design of bioactive scaffolds with improved mechanical and biological properties is an important topic of research. This paper investigates the use of polymer-ceramic composite scaffolds for bone tissue engineering. Different ceramic materials (hydroxyapatite (HA) and β-tri-calcium phosphate (TCP)) were mixed with poly-ε-caprolactone (PCL). Scaffolds with different material compositions were produced using an extrusion-based additive manufacturing system. The produced scaffolds were physi...

  14. Microwave heating as a means for carbon fibre recovery from polymer composites: a technical feasibility study

    International Nuclear Information System (INIS)

    Lester, Edward; Kingman, Sam; Wong, Kok Hoong; Rudd, Chris; Pickering, Stephen; Hilal, Nidal

    2004-01-01

    Carbon fibre composites with an epoxy resin matrix were subjected to microwave-heating experiments in order to volatilise the polymer content and to produce clean fibres for potential reuse in high-grade applications. The composites were processed at 3 kW for 8 s in a multimode microwave applicator. The recovered fibres were characterised by tensile tests and electron microscopy. The results compare favourably with virgin fibre properties

  15. Non linear viscoelasticity applied for the study of durability of polymer matrix composites

    Science.gov (United States)

    Cardon, A.; Brinson, H. F.; Hiel, C. C.

    1989-01-01

    A methodology is described for the durability analysis of polymer matrix composites, based on nonlinear viscoelasticity theory. The durability analysis is performed on the basis of a certain number of tests carried out on limited and, if possible, short time scale by the use of accelerating factors. The method was applied to thermomatrix composites under uniaxial and biaxial loadings, showing satisfactory agreement between the life-time predictions and the published data on real-time behavior.

  16. Composite Structure Modeling and Analysis of Advanced Aircraft Fuselage Concepts

    Science.gov (United States)

    Mukhopadhyay, Vivek; Sorokach, Michael R.

    2015-01-01

    NASA Environmentally Responsible Aviation (ERA) project and the Boeing Company are collabrating to advance the unitized damage arresting composite airframe technology with application to the Hybrid-Wing-Body (HWB) aircraft. The testing of a HWB fuselage section with Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) construction is presently being conducted at NASA Langley. Based on lessons learned from previous HWB structural design studies, improved finite-element models (FEM) of the HWB multi-bay and bulkhead assembly are developed to evaluate the performance of the PRSEUS construction. In order to assess the comparative weight reduction benefits of the PRSEUS technology, conventional cylindrical skin-stringer-frame models of a cylindrical and a double-bubble section fuselage concepts are developed. Stress analysis with design cabin-pressure load and scenario based case studies are conducted for design improvement in each case. Alternate analysis with stitched composite hat-stringers and C-frames are also presented, in addition to the foam-core sandwich frame and pultruded rod-stringer construction. The FEM structural stress, strain and weights are computed and compared for relative weight/strength benefit assessment. The structural analysis and specific weight comparison of these stitched composite advanced aircraft fuselage concepts demonstrated that the pressurized HWB fuselage section assembly can be structurally as efficient as the conventional cylindrical fuselage section with composite stringer-frame and PRSEUS construction, and significantly better than the conventional aluminum construction and the double-bubble section concept.

  17. Fabrication and characterization of polymer composites for endodontic use.

    Science.gov (United States)

    Alhashimi, R; Mannocci, F; Foxton, R; Deb, S

    2014-06-01

    To develop a low-density polyethylene-hydroxyapatite (HA-PE) composite with properties tailored to function as a potential root canal filling material. Hydroxyapatite and polyethylene mixed with strontium oxide as a radiopacifier were extruded from a single screw extruder fitted with an appropriate die to form fibres. The composition of the composite was optimized with clinical handling and placement in the canal being the prime consideration. The fibres were characterized using infrared spectroscopy (FTIR), and their thermal properties determined using differential scanning calorimetry (DSC). The tensile strength and elastic modulus of the composite fibres and gutta-percha were compared, dry and after 1 month storage in simulated body fluid (SBF), using a universal testing machine. The radiopacity of the fibres was determined using digital radiography. The interaction of the composites with eugenol was evaluated and compared with gutta-percha. Data of the tensile test were submitted to two-way anova and Bonferroni tests (P composites ranged between 110.5 and 111.2 °C, whereas gutta-percha exhibited a melting point at 52 °C. The tensile strength and elastic modulus of the silanated HA/PE composites were significantly higher than those of gutta-percha (P composites were unchanged. Radiological evaluations demonstrated that silanated HA/PE fibres were sufficiently radiopaque. Promising materials for endodontic applications have been developed, offering relevant benefits over the traditional materials in terms of mechanical and chemical properties. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  18. Multi-Ferroic Polymer Nanoparticle Composites for Next Generation Metamaterials

    Science.gov (United States)

    2015-12-18

    electric circuits from a composite material of silver nanoparticles and elastomeric fibres. Nat Nanotechnol... Conductors Based on Block Copolymer Silver Nanoparticle Composites. Acs Nano 2015, 9 (1), 336-344. 2. (a) Yang, T. I.; Brown, R. N. C.; Kempel, L. C...Stretchable nanoparticle conductors with self-organized conductive pathways. Abstr Pap Am Chem S 2014, 248; (c) Balazs, A. C.; Emrick, T.;

  19. Experimental data on the properties of natural fiber particle reinforced polymer composite material

    Directory of Open Access Journals (Sweden)

    D. Chandramohan

    2017-08-01

    Full Text Available This paper presents an experimental study on the development of polymer bio-composites. The powdered coconut shell, walnut shells and Rice husk are used as reinforcements with bio epoxy resin to form hybrid composite specimens. The fiber compositions in each specimen are 1:1 while the resin and hardener composition 10:1 respectively. The fabricated composites were tested as per ASTM standards to evaluate mechanical properties such as tensile strength, flexural strength, shear strength and impact strength are evaluated in both with moisture and without moisture. The result of test shows that hybrid composite has far better properties than single fibre glass reinforced composite under mechanical loads. However it is found that the incorporation of walnut shell and coconut shell fibre can improve the properties.

  20. Experimental data on the properties of natural fiber particle reinforced polymer composite material.

    Science.gov (United States)

    Chandramohan, D; Presin Kumar, A John

    2017-08-01

    This paper presents an experimental study on the development of polymer bio-composites. The powdered coconut shell, walnut shells and Rice husk are used as reinforcements with bio epoxy resin to form hybrid composite specimens. The fiber compositions in each specimen are 1:1 while the resin and hardener composition 10:1 respectively. The fabricated composites were tested as per ASTM standards to evaluate mechanical properties such as tensile strength, flexural strength, shear strength and impact strength are evaluated in both with moisture and without moisture. The result of test shows that hybrid composite has far better properties than single fibre glass reinforced composite under mechanical loads. However it is found that the incorporation of walnut shell and coconut shell fibre can improve the properties.

  1. Hierarchically Ordered Supramolecular Protein-Polymer Composites with Thermoresponsive Properties

    Directory of Open Access Journals (Sweden)

    Salla Välimäki

    2015-05-01

    Full Text Available Synthetic macromolecules that can bind and co-assemble with proteins are important for the future development of biohybrid materials. Active systems are further required to create materials that can respond and change their behavior in response to external stimuli. Here we report that stimuli-responsive linear-branched diblock copolymers consisting of a cationic multivalent dendron with a linear thermoresponsive polymer tail at the focal point, can bind and complex Pyrococcus furiosus ferritin protein cages into crystalline arrays. The multivalent dendron structure utilizes cationic spermine units to bind electrostatically on the surface of the negatively charged ferritin cage and the in situ polymerized poly(di(ethylene glycol methyl ether methacrylate linear block enables control with temperature. Cloud point of the final product was determined with dynamic light scattering (DLS, and it was shown to be approximately 31 °C at a concentration of 150 mg/L. Complexation of the polymer binder and apoferritin was studied with DLS, small-angle X-ray scattering, and transmission electron microscopy, which showed the presence of crystalline arrays of ferritin cages with a face-centered cubic (fcc, \\( Fm\\overline{3}m \\ Bravais lattice where lattice parameter a = 18.6 nm. The complexation process was not temperature dependent but the final complexes had thermoresponsive characteristics with negative thermal expansion.

  2. Underlying Physics of Conductive Polymer Composites and Force Sensing Resistors (FSRs) under Static Loading Conditions.

    Science.gov (United States)

    Paredes-Madrid, Leonel; Palacio, Carlos A; Matute, Arnaldo; Parra Vargas, Carlos A

    2017-09-14

    Conductive polymer composites are manufactured by randomly dispersing conductive particles along an insulating polymer matrix. Several authors have attempted to model the piezoresistive response of conductive polymer composites. However, all the proposed models rely upon experimental measurements of the electrical resistance at rest state. Similarly, the models available in literature assume a voltage-independent resistance and a stress-independent area for tunneling conduction. With the aim of developing and validating a more comprehensive model, a test bench capable of exerting controlled forces has been developed. Commercially available sensors-which are manufactured from conductive polymer composites-have been tested at different voltages and stresses, and a model has been derived on the basis of equations for the quantum tunneling conduction through thin insulating film layers. The resistance contribution from the contact resistance has been included in the model together with the resistance contribution from the conductive particles. The proposed model embraces a voltage-dependent behavior for the composite resistance, and a stress-dependent behavior for the tunneling conduction area. The proposed model is capable of predicting sensor current based upon information from the sourcing voltage and the applied stress. This study uses a physical (non-phenomenological) approach for all the phenomena discussed here.

  3. General overview of graphene: Production, properties and application in polymer composites

    Energy Technology Data Exchange (ETDEWEB)

    Phiri, Josphat, E-mail: josphat.phiri@aalto.fi [School of Chemical Technology, Department of Forest Products Technology, Aalto University, P.O. Box 16300, 00076 Aalto (Finland); Gane, Patrick [School of Chemical Technology, Department of Forest Products Technology, Aalto University, P.O. Box 16300, 00076 Aalto (Finland); Omya International AG, CH-4665 Oftringen (Switzerland); Maloney, Thad C., E-mail: thaddeus.maloney@aalto.fi [School of Chemical Technology, Department of Forest Products Technology, Aalto University, P.O. Box 16300, 00076 Aalto (Finland)

    2017-01-15

    Highlights: • Three aspects of graphene have been reviewed: properties, fabrication and polymer composites. • Scalability potential of graphite based exfoliation methods is discussed. • Graphene produced via GO and LPE methods is compared in polymer composite applications. - Abstract: Graphene is a new and exciting material that has attracted much attention in the last decade and is being extensively explored because of its properties, which have been described with so many superlatives. Production of graphene for large scale application is still a major challenge. Top-down graphene exfoliation methods from graphite, such as liquid-phase exfoliation which is promising because of low cost and high scalability potential will be briefly discussed. We also analyze the challenges and possibilities of using graphene as a nanofiller in polymer composites which has resulted in enhanced electrical, mechanical and thermal properties. In this review, we take a panoramic approach to give insight on the different aspects of graphene such as properties, graphite-based production methods and also examples of graphene application in polymer composites and which will be beneficial to both novice and experts.

  4. Photochromic LC–polymer composites containing azobenzene chromophores with thermally stable Z-isomers

    Czech Academy of Sciences Publication Activity Database

    Bobrovsky, A.; Shibaev, V.; Cigl, Martin; Hamplová, Věra; Hampl, F.; Elyashevitch, G.

    2014-01-01

    Roč. 2, č. 22 (2014), s. 4482-4489 ISSN 2050-7526 R&D Projects: GA ČR GA13-14133S; GA ČR(CZ) GAP204/11/0723 Institutional support: RVO:68378271 Keywords : liquid crystal * photosensitive * isomerization * polymer composite Subject RIV: CC - Organic Chemistry Impact factor: 4.696, year: 2014

  5. Are reactive thermoplastic polymers suitable for future wind turbine composite materials blades?

    DEFF Research Database (Denmark)

    Raghavalu Thirumalai, Durai Prabhakaran

    2014-01-01

    , it was found that only two potential reactive thermoplastic resin systems qualify for different processing requirements for blade manufacturing. Hence, the article focuses on the issues with the use of reactive polymers like APA-6 (Caprolactam) and CBT (Cyclic Butylene Terephtalate) resin systems for composite...

  6. Evaluation of Criticality of Self-Heating of Polymer Composites by Estimating the Heat Dissipation Rate

    Science.gov (United States)

    Katunin, A.

    2018-03-01

    The critical self-heating temperature at which the structural degradation of polymer composites under cyclic loading begins is evaluated by analyzing the heat dissipation rate. The method proposed is an effective tool for evaluating the degradation degree of such structures.

  7. Water desorption kinetics of polymer composites with cellulose fibers as filler

    Czech Academy of Sciences Publication Activity Database

    Vacková, Taťana; Kroisová, D.; Špatenka, P.

    2009-01-01

    Roč. 48, č. 1 (2009), s. 68-76 ISSN 0022-2348 Institutional research plan: CEZ:AV0Z40500505 Keywords : polymer composites * water desorption kinetics * thermoplastic matrix Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.716, year: 2009

  8. Casein and soybean protein-based thermoplastics and composites as alternative biodegradable polymers for biomedical applications

    NARCIS (Netherlands)

    Vaz, C.M.; Fossen, M.; Tuil, van R.F.; Graaf, de L.A.; Reis, R.L.; Cunha, A.M.

    2003-01-01

    This work reports on the development and characterization of novel meltable polymers and composites based on casein and soybean proteins. The effects of inert (Al2O3) and bioactive (tricalcium phosphate) ceramic reinforcements over the mechanical performance, water absorption, and bioactivity

  9. A new type of magnetocaloric composite based on conductive polymer and magnetocaloric compound

    Energy Technology Data Exchange (ETDEWEB)

    Imamura, W., E-mail: williamimamura@yahoo.com.br [State University of Maringá (UEM)/Department of Mechanical Engineering (DEM-PEM), 87020-900 Maringá, PR (Brazil); Coelho, A.A. [State University of Campinas (Unicamp)/Department of Applied Physics (DFA-IFGW), 13083-859 Campinas, SP (Brazil); Kupfer, V.L. [State University of Maringá (UEM)/Department of Chemistry (DQI-LMSen), 87020-900 Maringá, PR (Brazil); Carvalho, A.M.G. [Brazilian Synchrotron Light Laboratory (LNLS)/Brazilian Center for Research in Energy and Materials (CNPEM), C. P. 6192, 13083-970 Campinas, SP (Brazil); Zago, J.G. [State University of Maringá (UEM)/Department of Mechanical Engineering (DEM-PEM), 87020-900 Maringá, PR (Brazil); Rinaldi, A.W. [State University of Maringá (UEM)/Department of Chemistry (DQI-LMSen), 87020-900 Maringá, PR (Brazil); Favaro, S.L.; Alves, C.S. [State University of Maringá (UEM)/Department of Mechanical Engineering (DEM-PEM), 87020-900 Maringá, PR (Brazil)

    2017-03-01

    We introduce a processing route of the first magnetocaloric composite with conductive polymer – wherein the magnetocaloric reinforcement is a compound Gd{sub 5.09}Ge{sub 2.03}Si{sub 1.88} and the ductile matrix is a conductive polymer polyaniline doped by camphorsulfonic acid (PAni-CSA). This new type of composite combines mechanical, electrical and magnetocaloric properties that can be applied in thermomagnetic machines. - Highlights: • We developed a new type of magnetocaloric composite: PAni-CSA/Gd5.09Ge2.03Si1.88. • We presented a processing route which use a conductive polymer instead of epoxy resins or thermoplastic polymers. • We varied the concentration of PAni-CSA (numerical type) and sintering (categorical type). • We analyzed the matrix (PAni-CSA), the magnetocaloric reinforcement (Gd5.09Ge2.03Si1.88) and the composites. • We presented and discussed mechanical, electrical and magnetocaloric properties.

  10. General overview of graphene: Production, properties and application in polymer composites

    International Nuclear Information System (INIS)

    Phiri, Josphat; Gane, Patrick; Maloney, Thad C.

    2017-01-01

    Highlights: • Three aspects of graphene have been reviewed: properties, fabrication and polymer composites. • Scalability potential of graphite based exfoliation methods is discussed. • Graphene produced via GO and LPE methods is compared in polymer composite applications. - Abstract: Graphene is a new and exciting material that has attracted much attention in the last decade and is being extensively explored because of its properties, which have been described with so many superlatives. Production of graphene for large scale application is still a major challenge. Top-down graphene exfoliation methods from graphite, such as liquid-phase exfoliation which is promising because of low cost and high scalability potential will be briefly discussed. We also analyze the challenges and possibilities of using graphene as a nanofiller in polymer composites which has resulted in enhanced electrical, mechanical and thermal properties. In this review, we take a panoramic approach to give insight on the different aspects of graphene such as properties, graphite-based production methods and also examples of graphene application in polymer composites and which will be beneficial to both novice and experts.

  11. MICRO-CRACK BEHAVIOUR IN POLYMER MATRIX OF PARTICULATE COMPOSITE: INFLUENCE OF NON-LINEAR MATRIX

    Czech Academy of Sciences Publication Activity Database

    Majer, Z.; Náhlík, Luboš

    2012-01-01

    Roč. 106, SUPPL. 3 (2012), S472-S473 ISSN 0009-2770 Institutional support: RVO:68081723 Keywords : polymer matrix composite * fracture behaviour * non-linear matrix * micro-crack Subject RIV: JL - Materials Fatigue, Friction Mechanics OBOR OECD: Audio engineering, reliability analysis Impact factor: 0.453, year: 2012

  12. Analytical and numerical techniques for predicting the interfacial stresses of wavy carbon nanotube/polymer composites

    NARCIS (Netherlands)

    Yazdchi, K.; Salehi, M.; Shokrieh, M.M.

    2009-01-01

    By introducing a new simplified 3D representative volume element for wavy carbon nanotubes, an analytical model is developed to study the stress transfer in single-walled carbon nanotube-reinforced polymer composites. Based on the pull-out modeling technique, the effects of waviness, aspect ratio,

  13. Multiscale computational modeling of size effects in carbon nanotube-polymer composites

    NARCIS (Netherlands)

    Malagu, M.

    2017-01-01

    The development of carbon nanotube(CNT)-polymer composites advocates for a better understanding of their physical and mechanical properties that depend on the diameter of the embedded CNTs. Given that the experimental assessment of size effects is extremely difficult, the use of numerical models can

  14. Electrical properties of composites of hard metal carbides in a polymer matrix

    Czech Academy of Sciences Publication Activity Database

    Vilčáková, J.; Sáha, P.; Hausnerová, B.; Quadrat, Otakar

    2002-01-01

    Roč. 23, č. 5 (2002), s. 942-946 ISSN 0272-8397 R&D Projects: GA ČR GA101/97/0308 Institutional research plan: CEZ:AV0Z4050913 Keywords : polymer composites * hard metal carbides * electric conductivity Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.746, year: 2002

  15. Novel Lead dioxide-Graphite-Polymer composite anode for electrochemical chlorine generation

    Czech Academy of Sciences Publication Activity Database

    Gedam, N.; Neti, R.N.; Kormunda, M.; Šubrt, Jan; Bakardjieva, Snejana

    2015-01-01

    Roč. 169, JUL (2015), s. 109-116 ISSN 0013-4686 Institutional support: RVO:61388980 Keywords : beta-Lead dioxide * Graphite * Polymer composite anode * Chlorine generation * Cyclic voltammetry Subject RIV: CG - Electrochemistry Impact factor: 4.803, year: 2015

  16. Biodegradation of New Polymer Foundry Binders for the Example of the Composition Polyacrylic Acid/Starch

    Directory of Open Access Journals (Sweden)

    Beata Grabowska

    2011-04-01

    Full Text Available The investigations on the biodegradation process pathway of the new polymer binders for the example of water soluble compositionpolyacrylic acid/starch are presented in the hereby paper. Degradation was carried out in water environment and in a soil. Thedetermination of the total oxidation biodegradation in water environment was performed under laboratory conditions in accordance with the static water test system (Zahn-Wellens method, in which the mixture undergoing biodecomposition contained inorganic nutrient,activated sludge and the polymer composition, as the only carbon and energy source. The biodecomposition progress of the polymercomposition sample in water environment was estimated on the basis of the chemical oxygen demand (COD measurements and thedetermination the biodegradation degree, Rt, during the test. These investigations indicated that the composition polyacrylic acid/starchconstitutes the fully biodegradable material in water environment. The biodegradation degree Rt determined in the last 29th day of the test duration achieved 65%, which means that the investigated polymer composition can be considered to be fully biodegradable.During the 6 months biodegradation process of the cross-linked sample of the polymer composition in a garden soil several analysis ofsurface and structural changes, resulting from the sample decomposition, were performed. Those were: thermal analyses (TG-DSC,structural analyses (Raman spectroscopy and microscopic analyses (optical microscopy, AFM.

  17. Piezoelectric and dielectric properties of polymer-ceramic composites for sensors

    NARCIS (Netherlands)

    James, N.K.

    2015-01-01

    The main objective of this PhD thesis is to develop new routes and concepts for manufacturing piezoelectric ceramic-polymer composites with adequate piezoelectric properties while retaining ease of manufacturing and mechanical flexibility and explore new possibilities to maximize especially the

  18. A systematic stiffness-temperature model for polymers and applications to the prediction of composite behavior

    Science.gov (United States)

    Mahieux, Celine Agnes

    Polymer matrix composites (PMC's) are now being used more and more extensively and over wider ranges of service conditions. Large changes in pressure, chemical environment or temperature influence the mechanical response of such composites. In the present effort, we focus on temperature, a parameter of primary interest in almost all engineering applications. In order to design composite structures without having to perform extensive experiments (virtual design), the necessity of establishing theoretical models that relate the macroscopic response of the structure to the microscopic properties of the constituents arises. In the first part of the present work, a new stiffness versus temperature model is established. The model is validated using data from the literature. The influence of the different polymer's properties (Molecular weight, crystallinity, and filler content) on the model are studied by performing experiments on different grades of four polymers PMMA, PEEK, PPS, and PB. This statistical model is proven to be applicable to very different polymers (elastomers, thermoplastics, crystalline, amorphous, cross-linked, linear, filled, unfilled...) over wide temperature ranges (from the glassy state to the flow region). The most attractive feature of the proposed model is the capability to enable a description of the polymer's mechanical behavior within and across the property transition regions. In order to validate the feasibility of using the model to predict the mechanical response of polymer matrix composites, the stiffness-temperature model is used in various micromechanical models (rule of mixtures, compression models for the life prediction of unidirectional PMC's in end-loaded bending...). The model is also inserted in the MRLife prediction code to predict the remaining strength and life of unidirectional PMC's in fatigue bending. End-loaded fatigue experiments were performed. A good correlation between theoretical and experimental results is observed

  19. Bio composites from polypropylene/ clay/eva polymers and kenaf natural fiber

    International Nuclear Information System (INIS)

    Siti Hasnah Kamarudin; Khalina Abdan; Bernard Maringgal; Wan Mohd Zin Wan Yunus

    2009-01-01

    Full text: There is an increasing need to investigate more environmental friendly, sustainable materials to replace existing materials as industry attempts to lessen dependence on petroleum based fuels and products. The natural fiber composites offer specific properties comparable to those of conventional fiber composites. In this experiment, mixing process of polymer/nano clay composites from polypropylene, organo clay and ethylene vinyl acetate were prepared using a Brabender twin screw compounder. The composites sheets were then laminated with kenaf fibers and subjected to hot and cold press machine to form a bio composite. The mechanical properties such as flexural and impact strength are compare favourably between polymers reinforced kenaf fiber and polymers without kenaf fiber. In addition, various analysis techniques were used to characterize the dispersion and the properties of nano composites, using scanning electron micrograph (SEM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). These results suggest that kenaf fibers are a viable alternative to inorganic mineral-based reinforcing fibers as long as the right processing conditions are used and they are used in applications where the higher water absorption is not critical. (author)

  20. Layer-by-Layer technique employed to construct multitask interfaces in polymer composites

    Directory of Open Access Journals (Sweden)

    Luísa Sá Vitorino

    Full Text Available Abstract The properties of glass fiber-reinforced polymer composites are closely related to the fiber-matrix interface. Interfacial treatments to improve mechanical properties are usually limited to enhance interfacial adhesion. In this work, Layer-by-Layer (LbL technique was introduced to build a novel interface in polymer composites. Different numbers of bilayers of poly(diallyldimethylammonium chloride and poly(sodium 4-styrenesulfonate with carbon nanotubes were deposited through LbL on the surface of woven glass fibers (GFs. Polypropylene composites containing the modified GFs were prepared by compression molding. Thermogravimetric analysis, scanning electron microscopy and Raman spectroscopy proved that multilayers of polymers with carbon nanotubes could be deposited on GFs surface. Mechanical tests on composites with modified GFs revealed an increase in Flexural Modulus and toughness. The overall results attested that the LbL technique can be used to design interfaces with different compositions to perform diverse tasks, such as to improve the stiffness of composites and to encapsulate active nanocomponents.

  1. Modeling of an ionic polymer metal composite actuator based on an extended Kalman filter trained neural network

    International Nuclear Information System (INIS)

    Truong, Dinh Quang; Ahn, Kyoung Kwan

    2014-01-01

    An ion polymer metal composite (IPMC) is an electroactive polymer that bends in response to a small applied electric field as a result of mobility of cations in the polymer network and vice versa. This paper presents an innovative and accurate nonlinear black-box model (NBBM) for estimating the bending behavior of IPMC actuators. The model is constructed via a general multilayer perceptron neural network (GMLPNN) integrated with a smart learning mechanism (SLM) that is based on an extended Kalman filter with self-decoupling ability (SDEKF). Here the GMLPNN is built with an ability to autoadjust its structure based on its characteristic vector. Furthermore, by using the SLM based on the SDEKF, the GMLPNN parameters are optimized with small computational effort, and the modeling accuracy is improved. An apparatus employing an IPMC actuator is first set up to investigate the IPMC characteristics and to generate the data for training and validating the model. The advanced NBBM model for the IPMC system is then created with the proper inputs to estimate IPMC tip displacement. Next, the model is optimized using the SLM mechanism with the training data. Finally, the optimized NBBM model is verified with the validating data. A comparison between this model and the previously developed model is also carried out to prove the effectiveness of the proposed modeling technique. (paper)

  2. Carbon fiber polymer-matrix structural composites for electrical-resistance-based sensing

    Science.gov (United States)

    Wang, Daojun

    This dissertation has advanced the science and technology of electrical-resistance-based sensing of strain/stress and damage using continuous carbon fiber epoxy-matrix composites, which are widely used for aircraft structures. In particular, it has extended the technology of self-sensing of carbon fiber polymer-matrix composites from uniaxial longitudinal loading and flexural loading to uniaxial through-thickness loading and has extended the technology from structural composite self-sensing to the use of the composite (specifically a one-lamina composite) as an attached sensor. Through-thickness compression is encountered in the joining of composite components by fastening. Uniaxial through-thickness compression results in strain-induced reversible decreases in the through-thickness and longitudinal volume resistivities, due to increase in the fiber-fiber contact in the through-thickness direction, and minor-damage-induced irreversible changes in these resistivities. The Poisson effect plays a minor role. The effects in the longitudinal resistivity are small compared to those in the through-thickness direction, but longitudinal resistance measurement is more amenable to practical implementation in structures than through-thickness resistance measurement. The irreversible effects are associated with an increase in the through-thickness resistivity and a decrease in the longitudinal resistivity. The through-thickness gage factor is up to 5.1 and decreases with increasing compressive strain above 0.2%. The reversible fractional change in through-thickness resistivity per through-thickness strain is up to 4.0 and decreases with increasing compressive strain. The irreversible fractional change in through-thickness resistivity per unit through-thickness strain is around -1.1 and is independent of the strain. The sensing is feasible by measuring the resistance away from the stressed region, though the effectiveness is less than that at the stressed region. A one

  3. A hybrid method for damage detection and quantification in advanced X-COR composite structures

    Science.gov (United States)

    Neerukatti, Rajesh Kumar; Rajadas, Abhishek; Borkowski, Luke; Chattopadhyay, Aditi; Huff, Daniel W.

    2016-04-01

    Advanced composite structures, such as foam core carbon fiber reinforced polymer composites, are increasingly being used in applications which require high strength, high in-plane and flexural stiffness, and low weight. However, the presence of in situ damage due to manufacturing defects and/or service conditions can complicate the failure mechanisms and compromise their strength and reliability. In this paper, the capability of detecting damages such as delaminations and foam-core separations in X-COR composite structures using non-destructive evaluation (NDE) and structural health monitoring (SHM) techniques is investigated. Two NDE techniques, flash thermography and low frequency ultrasonics, were used to detect and quantify the damage size and locations. Macro fiber composites (MFCs) were used as actuators and sensors to study the interaction of Lamb waves with delaminations and foam-core separations. The results indicate that both flash thermography and low frequency ultrasonics were capable of detecting damage in X-COR sandwich structures, although low frequency ultrasonic methods were capable of detecting through thickness damages more accurately than flash thermography. It was also observed that the presence of foam-core separations significantly changes the wave behavior when compared to delamination, which complicates the use of wave based SHM techniques. Further, a wave propagation model was developed to model the wave interaction with damages at different locations on the X-COR sandwich plate.

  4. Quantifiable Assessment of SWNT Dispersion in Polymer Composites

    Science.gov (United States)

    Park, Cheol; Kim, Jae-Woo; Wise, Kristopher E.; Working, Dennis; Siochi, Mia; Harrison, Joycelyn; Gibbons, Luke; Siochi, Emilie J.; Lillehei, Peter T.; Cantrell, Sean; hide

    2007-01-01

    NASA LaRC has established a new protocol for visualizing the nanomaterials in structural polymer matrix resins. Using this new technique and reconstructing the 3D distribution of the nanomaterials allows us to compare this distribution against a theoretically perfect distribution. Additional tertiary structural information can now be obtained and quantified with the electron tomography studies. These tools will be necessary to establish the structural-functional relationships between the nano and the bulk. This will also help define the critical length scales needed for functional properties. Field ready tool development and calibration can begin by using these same samples and comparing the response. i.e. gold standards of good and bad dispersion.

  5. Plasma deposition of polymer composite films incorporating nanocellulose whiskers

    Science.gov (United States)

    Samyn, P.; Airoudj, A.; Laborie, M.-P.; Mathew, A. P.; Roucoules, V.

    2011-11-01

    In a trend for sustainable engineering and functionalization of surfaces, we explore the possibilities of gas phase processes to deposit nanocomposite films. From an analysis of pulsed plasma polymerization of maleic anhydride in the presence of nanocellulose whiskers, it seems that thin nanocomposite films can be deposited with various patterns. By specifically modifying plasma parameters such as total power, duty cycle, and monomer gas pressure, the nanocellulose whiskers are either incorporated into a buckled polymer film or single nanocellulose whiskers are deposited on top of a polymeric film. The density of the latter can be controlled by modifying the exact positioning of the substrate in the reactor. The resulting morphologies are evaluated by optical microscopy, AFM, contact angle measurements and ellipsometry.

  6. The potential of bamboo in the design of polymer composites

    Directory of Open Access Journals (Sweden)

    Patrícia Santos Delgado

    2012-08-01

    Full Text Available Bamboo is an alternative sustainable material for use in product design and has been incorporated into the concepts of eco-design. Here, we investigated the mechanical properties and morphologies of low density polyethylene (LDPE/bamboo flour (BF composites that were modified with polyethylene-graft-maleic anhydride (PE-g-MA and glycerol. Scanning electron microscopy (SEM and tensile tests of the composites demonstrated poor adhesion between the filler and matrix. Contact angle measurement showed that the surface of LDPE was modified by the presence of the load. The thermal stability of the composites was studied by measuring the oxidation induction time (OIT. Preliminary bacterial penetration tests were performed using culture inoculums of E. coli and S. aureus to investigate the natural antibacterial and bacteriostatic properties attributed to bamboo. Furthermore, bamboo may have interesting antioxidant activity with potential for use in food packaging applications.

  7. COMPOSITES BASED ON SYNTHETIC POLYMERS AND WOOD WASTE

    Directory of Open Access Journals (Sweden)

    Lucia DUMITRESCU

    2015-12-01

    Full Text Available The paper presents the results of the research dedicated to synthesis and characterization of some new, ecological composite materials based on an acrylic copolymer, lignin derivative iron and chromium lignosulfonate and Salix wood sawdust. The FT-IR analysis put into evidence the complex interactions, by esterification and etherification reactions, between the organic functional hydroxyl groups of lignosulfonate and Salix sawdust (the fillers with the organic functional groups (carboxyl, ester from the structure of acrylic copolymer (the matrix and explain the improved properties of the new composites. The proposed new composites are in agreement with the research in the field of recycling lignocellulosic waste to obtain new ecological, environmental friendly materials.

  8. New fabrication technique of conductive polymer/insulating polymer composite films and evaluation of biocompatibility in neuron cultures

    International Nuclear Information System (INIS)

    Onoda, Mitsuyoshi; Abe, Yayoi; Tada, Kazuya

    2009-01-01

    Poly(vinyl alcohol), PVA, produces a flexible composite polymer film with electrical, optical and electrochemical properties very similar to those of polypyrrole (PPy). The rate of electrochemical polymerization depends on the diffusion rate of the electrolyte across the PVA film to the indium tin oxide (ITO) electrode. In particular, a solvent with a hydrophilic nature easily penetrates into the PVA film. By applying this new process, we demonstrate a unique method of forming an electrically conductive pattern in PVA film. It will be possible to develop electrodes for electrical stimulation of the nervous system using the conducting polymer, PPy. Then, by applying a similar technique, we fabricated poly(3,4-ethylenedioxythiophene), PEDOT/PVA, composite films and investigated their basic electrochemical properties. Moreover, in this study, in order to develop a novel cell-culture system which makes it possible to communicate with cultured cells, fibroblasts were cultured on PPy- and PEDOT-coated ITO conductive glass plates for 7 days. The result reveals that the PPy and PEDOT films support the secretory functions of the cells cultured on its surface. The PPy- and PEDOT-coated electrodes may be useful to culture the cells on.

  9. New fabrication technique of conductive polymer/insulating polymer composite films and evaluation of biocompatibility in neuron cultures

    Energy Technology Data Exchange (ETDEWEB)

    Onoda, Mitsuyoshi, E-mail: onoda@eng.u-hyogo.ac.j [Department of Electrical Engineering and Computer Sciences, Graduate School of Engineering, University of Hyogo, Himwji Shosha Campus, 2167 Shosha, Himeji, Hyogo 671-2280 (Japan); Abe, Yayoi; Tada, Kazuya [Department of Electrical Engineering and Computer Sciences, Graduate School of Engineering, University of Hyogo, Himwji Shosha Campus, 2167 Shosha, Himeji, Hyogo 671-2280 (Japan)

    2009-11-30

    Poly(vinyl alcohol), PVA, produces a flexible composite polymer film with electrical, optical and electrochemical properties very similar to those of polypyrrole (PPy). The rate of electrochemical polymerization depends on the diffusion rate of the electrolyte across the PVA film to the indium tin oxide (ITO) electrode. In particular, a solvent with a hydrophilic nature easily penetrates into the PVA film. By applying this new process, we demonstrate a unique method of forming an electrically conductive pattern in PVA film. It will be possible to develop electrodes for electrical stimulation of the nervous system using the conducting polymer, PPy. Then, by applying a similar technique, we fabricated poly(3,4-ethylenedioxythiophene), PEDOT/PVA, composite films and investigated their basic electrochemical properties. Moreover, in this study, in order to develop a novel cell-culture system which makes it possible to communicate with cultured cells, fibroblasts were cultured on PPy- and PEDOT-coated ITO conductive glass plates for 7 days. The result reveals that the PPy and PEDOT films support the secretory functions of the cells cultured on its surface. The PPy- and PEDOT-coated electrodes may be useful to culture the cells on.

  10. Engineered Polymer Composites Through Electrospun Nanofiber Coating of Fiber Tows

    Science.gov (United States)

    Kohlman, Lee W.; Bakis, Charles; Williams, Tiffany S.; Johnston, James C.; Kuczmarski, Maria A.; Roberts, Gary D.

    2014-01-01

    Composite materials offer significant weight savings in many aerospace applications. The toughness of the interface of fibers crossing at different angles often determines failure of composite components. A method for toughening the interface in fabric and filament wound components using directly electrospun thermoplastic nanofiber on carbon fiber tow is presented. The method was first demonstrated with limited trials, and then was scaled up to a continuous lab scale process. Filament wound tubes were fabricated and tested using unmodified baseline towpreg material and nanofiber coated towpreg.

  11. Fabrication of polypeptide-based piezoelectric composite polymer film

    International Nuclear Information System (INIS)

    Farrar, Dawnielle; West, James E.; Busch-Vishniac, Ilene J.; Yu, Seungju M.

    2008-01-01

    A new class of molecular composite piezoelectric material was produced by simultaneous poling and curing of a homogeneous solution comprising poly(γ-benzyl α,L-glutamate) and methylmethacrylate via corona discharge methods. This film exhibited high piezoelectricity (d 33 = 23 pC N -1 ), and its mechanical characteristics (modulus = 450 MPa) were similar to those of low molecular weight poly(methylmethacrylate). As it is produced via solution-based fabrication processes, the composite film is conducive to miniaturization for small sensors with integrated electronics, and could also potentially be used in piezoelectric coating applications

  12. A Review of Structural Performance of Oil Palm Empty Fruit Bunch Fiber in Polymer Composites

    Directory of Open Access Journals (Sweden)

    Reza Mahjoub

    2013-01-01

    Full Text Available According to environmental concerns and financial problems, natural fibers have become interesting and fascinating nowadays to be used as an industrial material and structural material for rehabilitating of structures. Oil palm empty fruit bunch fiber (OPF is a natural fiber which is found a lot in tropical areas. Scientists have used OPF fiber with many types of resins such as epoxy, polypropylene, polyester, and phenol formaldehyde. Therefore, this paper focused on the properties of OPF fiber and gathered mechanical properties of OPF composites (OPF as reinforcement of polymer reported by other researchers in terms of tensile and flexural properties. Furthermore, the chemical surface modification methods to solve the interfacial bonding of fiber and polymer were mentioned. In addition, the results of hybrid composites of OPF were also discussed in this paper. Meanwhile, the results of composites were compared to pure resin properties and also the stress-strain diagram and internal strain energy of composites were considered. Besides, the effects of adding OPF to other composites to make a new hybrid composite were indicated. Finally, it is clear that the use of oil palm fiber composites for structural elements for bearing loads is not recommended but the usage of OPF composites for secondary structural elements may be recommended due to future researches.

  13. Mechanism of radiation-induced degradation in mechanical properties of polymer matrix composites

    International Nuclear Information System (INIS)

    Egusa, Shigenori

    1988-01-01

    Four kinds of polymer matrix composites (filler, E-glass or carbon fibre cloth; matrix, epoxy or polyimide resin) and pure epoxy and polyimide resins were irradiated with 60 Co γ-rays or 2 MeV electrons at room temperature. Mechanical tests were then carried out at 77K and at room temperature. Following irradiation, the Young's (tensile) modulus of these composites and pure resins remains practically unchanged even at 170 MGy for both test temperatures. The ultimate strength, however, decreases appreciably with increasing dose. The dose dependence of the composite strength depends not only on the combination of fibre and matrix in the composite but also on the test temperature. A relationship is found between the composite ultimate strain and the matrix ultimate strain, thus indicating that the dose dependence of the composite strength is virtually determined by a change in the matrix ultimate strain due to irradiation. Based on this finding, we propose a mechanism of radiation-induced degradation of a polymer matrix composite in order to explain the dose dependence of the composite strength measured at 77 K and at room temperature. (author)

  14. Advanced composite structures. [metal matrix composites - structural design criteria for spacecraft construction materials

    Science.gov (United States)

    1974-01-01

    A monograph is presented which establishes structural design criteria and recommends practices to ensure the design of sound composite structures, including composite-reinforced metal structures. (It does not discuss design criteria for fiber-glass composites and such advanced composite materials as beryllium wire or sapphire whiskers in a matrix material.) Although the criteria were developed for aircraft applications, they are general enough to be applicable to space vehicles and missiles as well. The monograph covers four broad areas: (1) materials, (2) design, (3) fracture control, and (4) design verification. The materials portion deals with such subjects as material system design, material design levels, and material characterization. The design portion includes panel, shell, and joint design, applied loads, internal loads, design factors, reliability, and maintainability. Fracture control includes such items as stress concentrations, service-life philosophy, and the management plan for control of fracture-related aspects of structural design using composite materials. Design verification discusses ways to prove flightworthiness.

  15. Cryogenic EBSD reveals structure of directionally solidified ice–polymer composite

    International Nuclear Information System (INIS)

    Donius, Amalie E.; Obbard, Rachel W.; Burger, Joan N.; Hunger, Philipp M.; Baker, Ian; Doherty, Roger D.; Wegst, Ulrike G.K.

    2014-01-01

    Despite considerable research efforts on directionally solidified or freeze-cast materials in recent years, little fundamental knowledge has been gained that links model with experiment. In this contribution, the cryogenic characterization of directionally solidified polymer solutions illustrates, how powerful cryo-scanning electron microscopy combined with electron backscatter diffraction is for the structural characterization of ice–polymer composite materials. Under controlled sublimation, the freeze-cast polymer scaffold structure is revealed and imaged with secondary electrons. Electron backscatter diffraction fabric analysis shows that the ice crystals, which template the polymer scaffold and create the lamellar structure, have a-axes oriented parallel to the direction of solidification and the c-axes perpendicular to it. These results indicate the great potential of both cryo-scanning electron microscopy and cryo-electron backscatter diffraction in gaining fundamental knowledge of structure–property–processing correlations. - Highlights: • Cryo-SEM of freeze-cast polymer solution reveals an ice-templated structure. • Cryo-EBSD reveals the ice crystal a-axis to parallel the solidification direction. • The honeycomb-like polymer phase favors columnar ridges only on one side. • Combining cryo-SEM with EBSD links solidification theory with experiment

  16. Cryogenic EBSD reveals structure of directionally solidified ice–polymer composite

    Energy Technology Data Exchange (ETDEWEB)

    Donius, Amalie E., E-mail: amalie.donius@gmail.com [Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755 (United States); Department of Materials Science and Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Obbard, Rachel W., E-mail: Rachel.W.Obbard@dartmouth.edu [Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755 (United States); Burger, Joan N., E-mail: ridge.of.the.ancients@gmail.com [Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755 (United States); Department of Materials Science and Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Hunger, Philipp M., E-mail: philipp.m.hunger@gmail.com [Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755 (United States); Department of Materials Science and Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Baker, Ian, E-mail: Ian.Baker@dartmouth.edu [Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755 (United States); Doherty, Roger D., E-mail: dohertrd@drexel.edu [Department of Materials Science and Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Wegst, Ulrike G.K., E-mail: ulrike.wegst@dartmouth.edu [Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755 (United States)

    2014-07-01

    Despite considerable research efforts on directionally solidified or freeze-cast materials in recent years, little fundamental knowledge has been gained that links model with experiment. In this contribution, the cryogenic characterization of directionally solidified polymer solutions illustrates, how powerful cryo-scanning electron microscopy combined with electron backscatter diffraction is for the structural characterization of ice–polymer composite materials. Under controlled sublimation, the freeze-cast polymer scaffold structure is revealed and imaged with secondary electrons. Electron backscatter diffraction fabric analysis shows that the ice crystals, which template the polymer scaffold and create the lamellar structure, have a-axes oriented parallel to the direction of solidification and the c-axes perpendicular to it. These results indicate the great potential of both cryo-scanning electron microscopy and cryo-electron backscatter diffraction in gaining fundamental knowledge of structure–property–processing correlations. - Highlights: • Cryo-SEM of freeze-cast polymer solution reveals an ice-templated structure. • Cryo-EBSD reveals the ice crystal a-axis to parallel the solidification direction. • The honeycomb-like polymer phase favors columnar ridges only on one side. • Combining cryo-SEM with EBSD links solidification theory with experiment.

  17. In situ polymerized wood polymer composite: effect of additives and nanoclay on the thermal, mechanical properties

    Directory of Open Access Journals (Sweden)

    Rashmi R Devi

    2013-01-01

    Full Text Available This study concerns the preparation and characterization of wood polymer nanocomposites based on impregnation of styrene acrylonitrile co-polymer-nanoclay intercalating system in presence of glycidyl methacrylate (GMA, a cross linking agent, and vinyl trichloro silane (VTCS as additives into Simul (Bombex ceiba, L., a soft wood. The effect of nanoclay and VTCS on the properties of the resultant wood polymer nanocomposites (WPNC has been evaluated. FTIR spectroscopy shows the interaction among wood, polymers, GMA, nanoclay and VTCS. The penetration of polymer and nanoclay into the wood cell wall is supported by SEM study. The distribution of nanoclay in the SAN polymer matrix present within the wood cell wall has been evidenced by TEM study. TGA results show an improvement in the thermostability of the resultant composites. The inclusion of VTCS enhances the self extinguishing behaviour of the WPNC as revealed by limiting oxygen index (LOI test. Due to treatment, the resultant WPNC exhibits an improvement in all the properties like water repellancy, dimensional stability, hardness, flexural, tensile and thermal stability compared to untreated wood.

  18. In situ polymerized wood polymer composite: effect of additives and nanoclay on the thermal, mechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Devi, Rashmi R; Maji, Tarun K., E-mail: tkm@tezu.ernet.in [Department of Chemical Sciences, Tezpur University, Assam, (India)

    2013-11-01

    This study concerns the preparation and characterization of wood polymer nanocomposites based on impregnation of styrene acrylonitrile co-polymer-nanoclay intercalating system in presence of glycidyl methacrylate (GMA), a cross linking agent, and vinyl trichloro silane (VTCS) as additives into Simul (Bombex ceiba, L.), a soft wood. The effect of nanoclay and VTCS on the properties of the resultant wood polymer nanocomposites (WPNC) has been evaluated. FTIR spectroscopy shows the interaction among wood, polymers, GMA, nanoclay and VTCS. The penetration of polymer and nanoclay into the wood cell wall is supported by SEM study. The distribution of nanoclay in the SAN polymer matrix present within the wood cell wall has been evidenced by TEM study. TGA results show an improvement in the thermostability of the resultant composites. The inclusion of VTCS enhances the self extinguishing behaviour of the WPNC as revealed by limiting oxygen index (LOI) test. Due to treatment, the resultant WPNC exhibits an improvement in all the properties like water repellency, dimensional stability, hardness, flexural, tensile and thermal stability compared to untreated wood. (author)

  19. Additive Manufacturing and Characterization of Ultem Polymers and Composites

    Science.gov (United States)

    Chuang, Kathy C.; Grady, Joseph E.; Draper, Robert D.; Shin, Euy-Sik E.; Patterson, Clark; Santelle, Thomas D.

    2015-01-01

    The objective of this project was to conduct additive manufacturing to produce aircraft engine components by Fused Deposition Modeling (FDM), using commercially available polyetherimides - Ultem 9085 and experimental Ultem 1000 mixed with 10 percent chopped carbon fiber. A property comparison between FDM-printed and injection-molded coupons for Ultem 9085, Ultem 1000 resin and the fiber-filled composite Ultem 1000 was carried out. Furthermore, an acoustic liner was printed from Ultem 9085 simulating conventional honeycomb structured liners and tested in a wind tunnel. Composite compressor inlet guide vanes were also printed using fiber-filled Ultem 1000 filaments and tested in a cascade rig. The fiber-filled Ultem 1000 filaments and composite vanes were characterized by scanning electron microscope (SEM) and acid digestion to determine the porosity of FDM-printed articles which ranged from 25-31 percent. Coupons of Ultem 9085 and experimental Ultem 1000 composites were tested at room temperature and 400 degrees Fahrenheit to evaluate their corresponding mechanical properties.

  20. Nano-apatite/polymer composites: mechanical and physicochemical characteristics

    NARCIS (Netherlands)

    Liu, Qing; de Wijn, J.R.; van Blitterswijk, Clemens

    1997-01-01

    Hydrothermally synthesized acicular nano-apatite (Nap) was used as filler to make composites with a polyethylene glycol/poly(butylene terephthalate) (PEG/PBT) block copolymer (Polyactive™70:30). The Nap had a particle diameter of 9–25 nm and a length of 80–200 nm. The mechanical properties and the