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Sample records for acrylates

  1. Radiation sensitive acrylate composition

    This application relates to radiation-sensitive compositions and more particularly to such compositions comprising acrylated esters. As used in this specification, the term acrylated esters refers to either acrylic or methacrylic acid resins. 3 tabs

  2. Synthesis of acrylic prepolymer

    An acrylic prepolymer was synthesized from glycidyl methacrylate (GMA), butyl methacrylate (BMA), methyl methacrylate (MMA) and acrylic acid (AA). Butyl acetate (BAc), benzoyl peroxide (BzO), 4-methoxyphenol (MPh) and triethylamine (TEA) were used as solvent, initiator, inhibitor and catalyst respectively. Observations of the synthesis leading to the formation of acrylic prepolymer are described. (author)

  3. Silicone/Acrylate Copolymers

    Dennis, W. E.

    1982-01-01

    Two-step process forms silicone/acrylate copolymers. Resulting acrylate functional fluid is reacted with other ingredients to produce copolymer. Films of polymer were formed by simply pouring or spraying mixture and allowing solvent to evaporate. Films showed good weatherability. Durable, clear polymer films protect photovoltaic cells.

  4. Acrylic vessel cleaning tests

    The acrylic vessel as constructed is dirty. The dirt includes blue tape, Al tape, grease pencil, gemak, the glue or residue form these tapes, finger prints and dust of an unknown composition but probably mostly acrylic dust. This dirt has to be removed and once removed, the vessel has to be kept clean or at least to be easily cleanable at some future stage when access becomes much more difficult. The authors report on the results of a series of tests designed: (a) to prepare typical dirty samples of acrylic; (b) to remove dirt stuck to the acrylic surface; and (c) to measure the optical quality and Th concentration after cleaning. Specifications of the vessel call for very low levels of Th which could come from tape residues, the grease pencil, or other sources of dirt. This report does not address the concerns of how to keep the vessel clean after an initial cleaning and during the removal of the scaffolding. Alconox is recommended as the cleaner of choice. This acrylic vessel will be used in the Sudbury Neutrino Observatory

  5. Acrylic purification and coatings

    ,

    2012-01-01

    Radon (Rn) and its decay daughters are a well-known source of background in direct WIMP detection experiments, as either a Rn decay daughter or an alpha particle emitted from a thin inner surface layer of a detector could produce a WIMP-like signal. Different surface treatment and cleaning techniques have been employed in the past to remove this type of contamination. A new method of dealing with the problem has been proposed and used for a prototype acrylic DEAP-1 detector. Inner surfaces of the detector were coated with a layer of ultra pure acrylic, meant to shield the active volume from alphas and recoiling nuclei. An acrylic purification technique and two coating techniques are described: a solvent-borne (tested on DEAP-1) and solvent-less (being developed for the full scale DEAP-3600 detector).

  6. Hyperbranched urethane-acrylates

    Tasić Srba

    2004-01-01

    Full Text Available The synthesis, characterization and UV-curing of hyperbranched urethaneacrylates (HB-UA were investigated in this study. They were evaluated as oli-gomers in model UV curable coatings. HB-UAs were synthesized by reaction of an aliphatic hyperbranched polyester of the second generation (HBRG2 and an isocyanate adduct, obtained by the reaction of isophoronediisocyana-te and different hydroxy alkyl acrylates. Their thermal properties and viscosities depend on the degree of modification of HBRG2 and the type of hydroxy alkyl acrylate used. The introduction of a flexible alkoxylated spacer between the HBP core and acrylate end groups reduces steric hindrance by moving the cross linkable acrylate groups away from the HBP core and increase its reactivity. Due to the presence of abstractable H-atoms in the α-position to the ether links, HB-UAs based on poly(ethylene oxide monoacrylate are very reactive and do not show oxygen inhibition. The obtained coatings combine a high cross linking density with flexible segments between the cross links, which results in a good compromise between hardness and flexibility and have the potential to be used in different UV-curing applications.

  7. [Acrylic resin removable partial dentures

    Baat, C. de; Witter, D.J.; Creugers, N.H.J.

    2011-01-01

    An acrylic resin removable partial denture is distinguished from other types of removable partial dentures by an all-acrylic resin base which is, in principle, solely supported by the edentulous regions of the tooth arch and in the maxilla also by the hard palate. When compared to the other types of

  8. Acrylic Acid and Esters Will Be Oversupply

    Zheng Chengwang

    2007-01-01

    @@ Drastic capacity growth The production capacity of acrylic acid in China has grown drastically in recent years. With the completion of the 80 thousand t/a acrylic acid and 130 thous and t/a acrylic ester project in Shenyang Paraffin Chemical Industrial Co., Ltd., (CCR2006,No. 31) the capacity of acrylic acid in China has reached 882 thousand t/a.

  9. Bonding auto-polymerising acrylic resin to acrylic denture teeth.

    Nagle, Susan

    2009-09-01

    This study investigated the effect of surface treatments on the shear bond strength of an auto-polymerising acrylic resin cured to acrylic denture teeth. The surface treatments included a combination of grit-blasting and\\/or wetting the surface with monomer. Samples were prepared and then stored in water prior to shear testing. The results indicated that the application of monomer to the surface prior to bonding did not influence the bond strength. Grit blasting was found to significantly increase the bond strength.

  10. Poly(lauryl acrylate) and poly(stearyl acrylate) grafted multiwalled carbon nanotubes for polypropylene composites

    Daugaard, Anders Egede; Jankova Atanasova, Katja; Hvilsted, Søren

    2014-01-01

    , polymerizations of lauryl or stearyl acrylate were performed, resulting in two novel polymer modifications on the MWCNT (poly(lauryl acrylate) or poly(stearyl acrylate)). The method was found to give time dependent loading of polymers as a function of time (up to 38 wt% for both acrylates), and showed a plateau...... were found to be substantially improved, where poly(lauryl acrylate) was found to be the superior surface modification, resulting in a conductive composite....

  11. SYNTHESIS OF SOAP-FREE ACRYLIC HYDROSOLS

    Li Jia; Zong-hui Liu; De-qing Wei

    2002-01-01

    Poly(methyl methacrylate/ethyl acrylate/acrylic acid) hydrosols were prepared by employing soap-freepolymerization, and (acrylic acid/butyl acrylate) oligomer was used as the polymeric surfactant. The effect of reactioncondition on the morphology and particle size of the hydrosols was investigated. The minimum amount of acrylic acid in thehydrosols is 2%. The maximum weight average molecular weight (Mw) of polymer that assures soap-free emulsionconversion into hydrosol is about 1.2 × 105-1.3 × 105. The particle transforming process was investigated, and an obviouschange of particle diameter and morphology was observed.

  12. Radiation curing silicone acrylate systems

    Radiation curing silicone systems by either ultra violet light (UV) or electron beam (EB) is introduced. The cure is based on the polymerization of the acrylic C = C double bond via a radical chain reaction. In the EB curing process a sufficient number of radicals for spontaneous polymerization is produced due to the high radiation energy whereas with UV light the energy is not as intensive thus a photo-initiator is required for a UV process. The required high local radical concentration provided by its decay. The radical generation immediate chain-growing leads to rapid and efficient crosslinking even at room temperature. It is for this reason that silicone acrylates cure immediately. All coater capable of handling 100% thermally curing silicones are suitable for the use with Goldschmidt's RC systems

  13. Radiation curing applications of palm oil acrylates

    Various palm oil based urethan acrylate prepolymers (UP) were prepared from palm oil based polyols, diisocyanate compounds and hydroxyl terminated acrylate monomers by following procedure derived from established methods. The products were compared with each other in term of their molecular weights (MW), viscosities, curing speed by UV irradiation, gel contents and film hardness. The molecular structure of diisocyanate compounds and hydroxyl acrylate monomers were tend to determine the molecular weights and hence viscosities of the final products of urethan acrylate prepolymers (UP), whereas, the MW of the UP has no direct effects on the UV curing properties of the prepolymers. (author)

  14. Acrylates and methacrylates of formal-glycerine

    Present article is devoted acrylates and methacrylates of formal-glycerine. The formal-glycerine was obtained in the form of mixture of isomers 1.2 and 1.3 from glycerine and paraform with hydrochloric acid. The structure of obtained acrylates and methacrylates is studied by means of molecular refraction, element analysis and infrared spectroscopy.

  15. Radiopurity measurement of acrylic for DEAP-3600

    The spherical acrylic vessel that contains the liquid argon target is the most critical detector component in the DEAP-3600 dark matter experiment. Alpha decays near the inner surface of the acrylic vessel are one of the main sources of background in the detector. A fraction of the alpha energy, or the recoiling nucleus from the alpha decay, could misreconstruct in the fiducial volume and result in a false candidate dark matter event. Acrylic has low levels of inherent contamination from 238U and 232Th. Another background of particular concern is diffusion of 222Rn during manufacturing, leading to 210Pb contamination. The maximum acceptable concentrations in the DEAP-3600 acrylic vessel are ppt levels of 238U and 232Th equivalent, and 10−8 ppt 210Pb. The impurities in the bulk acrylic will be measured by vaporizing a large quantity of acrylic and counting the concentrated residue with ultra-low background HPGe detectors and a low background alpha spectrometer. An overview of the acrylic assay technique is presented

  16. Radiopurity measurement of acrylic for DEAP-3600

    Nantais, C. M.; Boulay, M. G. [Department of Physics, Engineering Physics, and Astronomy, Queen' s University, Kingston, Ontario K7L 3N6 (Canada); Cleveland, B. T. [SNOLAB, Lively, Ontario P3Y 1N2 Canada and Department of Physics, Laurentian University, Sudbury, Ontario P3E 2C6 (Canada)

    2013-08-08

    The spherical acrylic vessel that contains the liquid argon target is the most critical detector component in the DEAP-3600 dark matter experiment. Alpha decays near the inner surface of the acrylic vessel are one of the main sources of background in the detector. A fraction of the alpha energy, or the recoiling nucleus from the alpha decay, could misreconstruct in the fiducial volume and result in a false candidate dark matter event. Acrylic has low levels of inherent contamination from {sup 238}U and {sup 232}Th. Another background of particular concern is diffusion of {sup 222}Rn during manufacturing, leading to {sup 210}Pb contamination. The maximum acceptable concentrations in the DEAP-3600 acrylic vessel are ppt levels of {sup 238}U and {sup 232}Th equivalent, and 10{sup −8} ppt {sup 210}Pb. The impurities in the bulk acrylic will be measured by vaporizing a large quantity of acrylic and counting the concentrated residue with ultra-low background HPGe detectors and a low background alpha spectrometer. An overview of the acrylic assay technique is presented.

  17. 21 CFR 573.120 - Acrylamide-acrylic acid resin.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Acrylamide-acrylic acid resin. 573.120 Section 573... Food Additive Listing § 573.120 Acrylamide-acrylic acid resin. Acrylamide-acrylic acid resin... acrylamide with partial hydrolysis, or by copolymerization of acrylamide and acrylic acid with the...

  18. Occupational respiratory disease caused by acrylates.

    Savonius, B; Keskinen, H; Tuppurainen, M; Kanerva, L

    1993-05-01

    Acrylates are compounds used in a variety of industrial fields and their use is increasing. They have many features which make them superior to formerly used chemicals, regarding both their industrial use and their possible health effects. Contact sensitization is, however, one of their well known adverse health effects but they may also cause respiratory symptoms. We report on 18 cases of respiratory disease, mainly asthma, caused by different acrylates, 10 cases caused by cyanoacrylates, four by methacrylates and two cases by other acrylates. PMID:8334539

  19. Characterization of electron beam cured epoxy acrylate

    Epoxy resin has wide application in various industrial fields because of their good mechanical strength, superiority adhesion and low shrinkage etc. And the typical curing method for epoxy resins is thermal and press compaction. However, a curing method was used electron beam process in this study. Epoxy acrylate was fabricated from mixture of epoxy, acrylic acid, tetraphenylporphyrin (TPP) and hydroquinone monomethyl ether (MEHQ) with mole ratios. Then electron beam irradiation effect on the curing of the epoxy acrylate resin was investigated various absorption dose in nitrogen atmospheres at room temperature. The dynamic mechanical and thermal properties of the irradiated epoxy acrylate resins were characterized using dynamic mechanical analysis (DMA) and thermogravimetric analyzer (TGA). And the tensile and flexural strength were measured by an universal tensile machine (UTM)

  20. Resistance of acrylic vessel to gamma irradiation

    This paper describes the preliminary studies made in acrylic material in order to verify the effects of radiolysis in acrylic recipients in which the uranium ore standards are conditioned and check if the material is able to keep the 222Rn inside the vessel. The preliminary results after gamma irradiation of two kinds of recipients indicate no differences between the vessels irradiated and the ones no irradiated, related to color changes and tension resistance. (author)

  1. Rapid Output Growth of Special Acrylic Esters

    Wang Lianzhi

    2007-01-01

    @@ Acrylic esters are usually classified into general-purpose varieties and special varieties. The production and application of general-purpose varieties is already quite matured in the world and their output growth tends to be flat. Owing to the development of coatings, electronics, automobiles,textiles, printing and construction sectors, especially the application of radiation curing technology in various sectors, special acrylic esters have developed rapidly.

  2. Resistance of acrylic vessel to gamma irradiation

    Carneiro, Andre Cavalcanti; Menezes, Maria Angela de B.C.; Pereira, Marcio Tadeu; Rocha, Nirlando Antonio; Vilela, Jefferson Jose, E-mail: andreccarneiro@gmail.com, E-mail: menezes@cdtn.br, E-mail: mtp@cdtn.br, E-mail: nar@cdtn.br, E-mail: jjv@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Braga, Mario Roberto Martins S.S., E-mail: mariomartins@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Programa de Pos-Graduacao em Ciencias e Tecnicas Nucleares

    2013-07-01

    This paper describes the preliminary studies made in acrylic material in order to verify the effects of radiolysis in acrylic recipients in which the uranium ore standards are conditioned and check if the material is able to keep the {sup 222}Rn inside the vessel. The preliminary results after gamma irradiation of two kinds of recipients indicate no differences between the vessels irradiated and the ones no irradiated, related to color changes and tension resistance. (author)

  3. Gel time of calcium acrylate grouting material.

    Han, Tong-Chun

    2004-08-01

    Calcium acrylate is a polymerized grout, and can polymerize in an aqueous solution. The polymerization reaction utilizes ammonium persulfate as a catalyst and sodium thiosulfate as the activator. Based on the theory of reaction kinetics, this study on the relation between gel time and concentration of activator and catalyst showed that gel time of calcium acrylate is inversely proportional to activator and catalyst concentration. A formula of gel time is proposed, and an example is provided to verify the proposed formula. PMID:15236477

  4. Photochemistry of Acrylates at 222 nm

    Excimer lamps as monochromatic UV sources with an intense short wavelength mission (specially Kr Cl, 222 nm) allow a photo initiator-free initiation of the acrylate polymerisation. Laser photolysis (Kr Cl excimer laser, pulse width 20 ns, up to 5 ml per pulse) gives rise to similar transient spectra (max << 280 nm) for all acrylates studied. As the rather unspecific spectra do not allow conclusions as to the main reaction channel, a product study has been performed by GC-MS following steady-state photolysis of acrylate solutions in acetonitrile, methanol and n-hexane. Somewhat unexpected, a-cleavage seems to be a main reaction channel, and quantum chemical calculations show that such a reaction can occur from either the excited singlet state or the un relaxed triplet state, but not from the relaxed triplet state that is observed spectroscopically. A reaction scheme accounting for the observed products is presented

  5. Concepts for stereoselective acrylate insertion

    Neuwald, Boris

    2013-01-23

    Various phosphinesulfonato ligands and the corresponding palladium complexes [{((PaO)PdMeCl)-μ-M}n] ([{( X1-Cl)-μ-M}n], (PaO) = κ2- P,O-Ar2PC6H4SO2O) with symmetric (Ar = 2-MeOC6H4, 2-CF3C6H4, 2,6-(MeO)2C6H3, 2,6-(iPrO)2C 6H3, 2-(2′,6′-(MeO)2C 6H3)C6H4) and asymmetric substituted phosphorus atoms (Ar1 = 2,6-(MeO)2C6H 3, Ar2 = 2′-(2,6-(MeO)2C 6H3)C6H4; Ar1 = 2,6-(MeO)2C6H3, Ar2 = 2-cHexOC 6H4) were synthesized. Analyses of molecular motions and dynamics by variable temperature NMR studies and line shape analysis were performed for the free ligands and the complexes. The highest barriers of ΔGa = 44-64 kJ/mol were assigned to an aryl rotation process, and the flexibility of the ligand framework was found to be a key obstacle to a more effective stereocontrol. An increase of steric bulk at the aryl substituents raises the motional barriers but diminishes insertion rates and regioselectivity. The stereoselectivity of the first and the second methyl acrylate (MA) insertion into the Pd-Me bond of in situ generated complexes X1 was investigated by NMR and DFT methods. The substitution pattern of the ligand clearly affects the first MA insertion, resulting in a stereoselectivity of up to 6:1 for complexes with an asymmetric substituted phosphorus. In the consecutive insertion, the stereoselectivity is diminished in all cases. DFT analysis of the corresponding insertion transition states revealed that a selectivity for the first insertion with asymmetric (P aO) complexes is diminished in the consecutive insertions due to uncooperatively working enantiomorphic and chain end stereocontrol. From these observations, further concepts are developed. © 2012 American Chemical Society.

  6. Occupational fingertip eczema from acrylates in a manicurist

    Denitza Zheleva; Razvigor Darlenski

    2015-01-01

    Occupational hand eczema due to acrylates present in the workplace is a disease frequently reported among dentists, printers, and fiberglass workers. Acrylate monomers are used in the production of a great variety of polymers, including nail cosmetics. Our case report demonstrates a rare clinical presentations of allergic contact dermatitis from acrylic nails. Our patient was working as a manicurist and the diagnostic analyses revealed sensitation to some of the (meth) acrylate compounds of h...

  7. 21 CFR 175.210 - Acrylate ester copolymer coating.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylate ester copolymer coating. 175.210 Section... COATINGS Substances for Use as Components of Coatings § 175.210 Acrylate ester copolymer coating. Acrylate ester copolymer coating may safely be used as a food-contact surface of articles intended for...

  8. 40 CFR 721.324 - Alkoxylated acrylate polymer (generic).

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkoxylated acrylate polymer (generic... Substances § 721.324 Alkoxylated acrylate polymer (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkoxylated acrylate...

  9. SYNTHESIS OF BIOCOMPATIBLE ACRYLIC POLYMERS HAVING ASPIRIN-MOIETIES

    LI Fumian; GU Zhongwei; FENG Xinde(S. T. Voong)

    1983-01-01

    Several new monomers, β-(acetylsalicylyloxy)ethyl methacrylate, β-(acetylsalicylyloxy)propyl methacrylate, β-(acetylsalicylyloxy)ethyl acrylate, β-hydroxy-γ-(acetylsalicylyloxy)propyl methacrylate, β-hydroxy-γ-(acetylsalicylyloxy)propyl acrylate have been synthesized from aspirin with corresponding hydroxyalkyl or glycidyl acrylates, and then polymerized by free radical initiator.

  10. 40 CFR 721.5325 - Nickel acrylate complex.

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Nickel acrylate complex. 721.5325... Substances § 721.5325 Nickel acrylate complex. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance nickel acrylate complex (PMN P-85-1034) is subject to reporting...

  11. Probing the cooperative dynamics varying the side-chain length of poly(alkyl acrylate)s: ESR experiments

    Andreozzi, Laura; Autiero, Ciro; Faetti, Massimo; Giordano, Marco; Zulli, Fabio

    2007-01-01

    Abstract The rotational dynamics of the tracer cholestane dissolved in unentangled nearly monodisperse poly(alkyl acrylate) melts has been investigated by means of electron spin resonance spectroscopy. Three samples of almost same molecular weight were selected, poly(methyl acrylate) poly(ethyl acrylate) and poly(n-butyl acrylate), whose linear viscoelastic properties were also characterised. Large temperature intervals were found with power laws relating shear flow relaxation and ...

  12. Radiation-induced graft copolymerization of methyl acrylate and acrylic acid onto rubber wood fiber

    Graft copolymerization of methyl acrylate and acrylic acid monomers onto rubber wood fiber (RWF) was carried out by simultaneous radiation-induced technique. The parameters affecting the grafting reaction were investigated and the optimum conditions for both monomers obtained are as follows: impregnation time = 16 hours, total dose = 30 kGy, methanol : water ratio, 3:1, monomers concentration = 40 v/v % and sulphuric acid concentration = 0.1 mol/L. Fourier Transform Infrared (FTIR), thermogravimetry analysis (TGA), and scanning electron microscope (SEM) analyses used to characterize graft copolymers. The structural investigation by x-ray diffraction (XRD) shows the degree of crystallinity of rubber wood fiber decreased with the incorporation of poly(methyl acrylate) and poly(acrylic acid) grafts. (Author)

  13. UV-Curing of Nanoparticle Reinforced Acrylates

    Polymer reinforcement by silica and alumina nanoparticles evidently yields improved surface hardness. Single mixing of nanoparticles into an acrylate formulations, however, leads to highly viscous solutions inappropriate for coating procedures. The incompatibility of inorganic fillers and organic polymers can be avoided by surface modification providing an interface between the two dissimilar materials. For example, vinyltrimethoxysilane (VTMO) can react via hydrolysis/condensation reactions with hydroxyl groups present on the inorganic surface and should bond via the polymerisation-active vinyl group to an acrylate resin through crosslinking reactions. Grafting reactions of surface OH groups and different trialkoxysilanes were studied by thermogravimetry, infrared, and multinuclear NMR spectroscopy. The copolymeri-zation of modified nanoparticles with the acrylate matrix has been investigated by 13C NMR spectroscopy. UV curing under nitrogen inertization revealed a lower reactivity of vinyl groups of VTMO-modified silica compared to grafted methacryloxypropyl-trimethoxysilane (MEMO) which showed complete conversion of olefinic carbons (signals at 120 - 140 ppm). Under conditions of oxygen inhibition, the effect of the kind and the concentration of photoinitiator on the photopoly-merization reaction was studied. Compared to neat polyacrylate coatings the nanocomposite materials exhibit markedly improved properties, e.g., heat, scratch, and abrasion resistance. However, a much better abrasion resistance was obtained for coatings containing both silica nano-particles and corundum microparticles. In particular cases, radiation curing with 172 nm photons generated by Xe excimer was performed to obtain structured polymer surfaces, i.e., matting of the reinforced acrylate coatings

  14. Thermal Polymerization of N-Butyl Acrylate

    Ingham, J. D.

    1982-01-01

    Simple new polymerization method enables production of n-butyl acrylate polymer of desired high molecular weight, without disadvantages that usually attend more conventional methods. Process, which is hybrid of thermal, solution, and emulsion polymerization methods, involves controlled thermal polymerization of monomer at moderate temperatures without use of catalysts or additives.

  15. Acrylic Tanks for Stunning Chemical Demonstrations

    Mirholm, Alexander; Ellervik, Ulf

    2009-01-01

    We describe the use of acrylic tanks (400 x 450 x 27 mm) for visualization of chemical demonstrations in aqueous solutions. Examples of well-suited demonstrations are oscillating reactions, pH indicators, photochemical reduction of Lauth's violet, and chemoluminiscent reactions. (Contains 1 figure.)

  16. Large Acrylic Spherical Windows In Hyperbaric Underwater Photography

    Lones, Joe J.; Stachiw, Jerry D.

    1983-10-01

    Both acrylic plastic and glass are common materials for hyperbaric optical windows. Although glass continues to be used occasionally for small windows, virtually all large viewports are made of acrylic. It is easy to uderstand the wide use of acrylic when comparing design properties of this plastic with those of glass, and glass windows are relatively more difficult to fabricate and use. in addition there are published guides for the design and fabrication of acrylic windows to be used in the hyperbaric environment of hydrospace. Although these procedures for fabricating the acrylic windows are somewhat involved, the results are extremely reliable. Acrylic viewports are now fabricated to very large sizes for manned observation or optical quality instrumen tation as illustrated by the numerous acrylic submersible vehicle hulls for hu, an occupancy currently in operation and a 3600 large optical window recently developed for the Walt Disney Circle Vision under-water camera housing.

  17. METHACRYLATE AND ACRYLATE ALLERGY IN DENTAL STUDENTS.

    Maya Lyapina

    2013-09-01

    Full Text Available A multitude of acrylic monomers is used in dentistry, and when dental personnel, patients or students of dental medicine become sensitized, it is of great importance to identify the dental ;acrylic preparations to which the sensitized individual can be exposed. Numerous studies confirm high incidence of sensitization to (meth acrylates in dentatal professionals, as well as in patients undergoing dental treatment and exposed to resin-based materials. Quite a few studies are available aiming to evaluate the incidence of sensitization in students of dental medicineThe purpose of the study is to evaluate the incidence of contact sensitization to some (meth acrylates in students of dental medicine at the time of their education, in dental professionals (dentists, nurses and attendants and in patients, the manifestation of co-reactivity.A total of 139 participants were included in the study, divided into four groups: occupationally exposed to (methacrylates and acrylic monomers dental professionals, 3-4 year-of-education students of dental medicine, 6th year–of-education students of dental medicine and patients with suspected or established sensitization to acrylates, without occupational exposure. All of them were patch-tested with methyl methacrylate (MMA, triethyleneglycol dimethacrylate (TREGDMA, ethyleneglycol dimethacrylate (EGDMA, 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy phenyl]propane (bis-GMA, 2-hydroxyethyl methacrylate (2-HEMA, and tetrahidrofurfuril metacrylate. The overall sensitization rates to methacrylates in the studied population are comparative high – from 25.9% for MMA to 31.7% for TREGDMA. Significantly higher incidence of sensitization in the group of 3-4 course students compared to the one in the group of dental professionals for MMA and TREGDMA was observed. Highest was the incidence of sensitization to ethyleneglycol dimethacrylate, BIS-GMA, 2-HEMA and tetrahydrofurfuryl methacrylate in the group of patients, with

  18. Acrylic Bone Cements Modified with Starch

    Krilova, V; Vītiņš, V

    2010-01-01

    The successful result of restorative and replacement surgical operation depends significantly on properties of used bone cement. Acrylic bone cements are usually based on methylmethacrylate polymer, while monomer polymerization begins after mixing of components in mixing device and terminates in living tissue. Polymerization of methylmethacrylate is exothermic process, and temperature increase might cause tissue necrosis with concomitant implant aseptic loosening. Developed non-ionogenic and ...

  19. Radiation-induced polymerization of acrylated systems

    Complete text of publication follows. It has been generally accepted that ionizing radiation induces free radical polymerization in acrylate compounds. It is also reported that, following primary ionization events, acrylates and methacrylates scavenge thermalized electrons to give rise to radical anions and radical cations, which undergo reactions producing the corresponding free radicals. Acrylates have received the most attention in radiation curable pressure sensitive adhesives (PSAs). 2-EHA is well known for its unique pressure-sensitive adhesive properties. An understanding of its primary mechanism of polymerization is of industrial as well as fundamental interest. High entanglement and high molecular weight between crosslinks are crucial for the high shear and peel strength, required of PSAs. Such polymers may be formed using thermal and UV-initiation in solvent or emulsion. Electron beam can also provide these properties when the monomer is polymerized at moderate dose rates and at low temperature. Pulsed electron beam provides a special advantage under conditions where the dose per pulse is below the threshold for overlap (ca. 40 Gy/pulse) and the pulse rate is high enough (>1 kHz) to maintain a quasi-heterogeneous mode at high doses rates. Maintaining low temperature in the early stages of polymerization is important in achieving good properties

  20. Performance comparison of acrylic and thiol-acrylic resins in two-photon polymerization.

    Jiang, Lijia; Xiong, Wei; Zhou, Yushen; Liu, Ying; Huang, Xi; Li, Dawei; Baldacchini, Tommaso; Jiang, Lan; Lu, Yongfeng

    2016-06-13

    Microfabrication by two-photon polymerization is investigated using resins based on thiol-ene chemistry. In particular, resins containing different amounts of a tetrafunctional acrylic monomer and a tetrafunctional thiol molecule are used to create complex microstructures. We observe the enhancement of several characteristics of two-photon polymerization when using thiol-acrylic resins. Specifically, microfabrication is carried out using higher writing velocities and it produces stronger polymeric microstructures. Furthermore, the amount of shrinkage typically observed in the production of three-dimensional microstructures is reduced also. By means of microspectrometry, we confirm that the thiol-acrylate mixture in TPP resins promote monomer conversion inducing a higher degree of cross-linked network formation. PMID:27410383

  1. Palladium (II) catalyized polymerization of norbornene and acrylates

    Sen, Ayusman; Kacker, Smita; Hennis, April; Polley, Jennifer D.

    2000-08-29

    Homopolymers or copolymers of acrylates, homopolymers or copolymers of norbornenes, and copolymers of acrylates with norbornenes, may be prepared by contacting acrylate and/or norbornene monomer reactant under polymerization conditions and in the presence of a solvent with a catalyst system consisting essentially of a Pd(II) dimer component having the formula: [(L)Pd(R)(X)].sub.2, where L is a monodentate phosphorus or nitrogen ligand, X is an anionic group, and R is an alkyl or aryl group.

  2. Palladium (Ii) Catalyzed Polymerization Of Norbornene And Acrylates

    Sen, Ayusman; Kacker, Smita; Hennis, April; Polley, Jennifer D.

    2001-10-09

    Homopolymers or copolymers of acrylates, homopolymers or copolymers of norbornenes, and copolymers of acrylates with norbornenes, may be prepared by contacting acrylate and/or norbornene monomer reactant under polymerization conditions and in the presence of a solvent with a catalyst system consisting essentially of a Pd(II) dimer component having the formula: where L is a monodentate phosphorus or nitrogen ligand, X is an anionic group, and R is an alkyl or aryl group.

  3. Amylase catalyzed synthesis of glycosyl acrylates and their polymerization

    Kloosterman, Wouter M. J.; Jovanovic, Danijela; Brouwer, Sander; Loos, Katja

    2014-01-01

    The enzymatic synthesis of novel (di)saccharide acrylates from starch and 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate and 4-hydroxybutyl acrylate (2-HEA, 2-HEMA and 4-HBA) catalyzed by various commercially available amylase preparations is demonstrated. Both liquefaction and saccharification amylases were tested as biocatalysts. Transglycosidation products were only detected in reaction mixtures containing saccharification amylases. The glycoamylase from Aspergillus niger was found t...

  4. Palm oil based polyols for acrylated polyurethane production

    Palm oil becomes important renewable resources for the production of polyols for the polyurethane manufacturing industry. The main raw materials used for the production of acrylated polyurethane are polyols, isocyanates and hydroxyl terminated acrylate compounds. In these studies, polyurethane based natural polymer (palm oil), i.e., POBUA (Palm Oil Based Urethane Acrylate) were prepared from three different types of palm oil based polyols i.e., epoxidised palm oil (EPOP), palm oil oleic acid and refined, bleached and deodorized (RBD) palm olein based polyols. The performances of these three acrylated polyurethanes when used for coatings and adhesives were determined and compared with each other. (Author)

  5. Radiochemical coupling of acrylic acid to polyvinylchloride

    Acrylic acid was coupled radiochemically to the surface of polyvinylchloride (PVC) foils. A 500 keV electron generator served as radiation source. After neutralization with ammonia, the surface of the PVC foils got hydrophilic properties. Their capacity of water uptake increased from 0,04 mg/cm2 to about 0,5 mg/cm2 and the condensation of water takes place in form of a clear transparent film and not in form of light scattering droplets. 6 refs., 20 figs., 8 tabs

  6. 40 CFR 721.8082 - Polyester polyurethane acrylate.

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polyester polyurethane acrylate. 721... Substances § 721.8082 Polyester polyurethane acrylate. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as polyester polyurethane...

  7. MODIFICATION OF ACRYLIC LACQUER BY DOUBLE-DUTY LYOPHILIC EMULSION

    Ф.Г. Фабуляк

    2012-12-01

    Full Text Available  General useful properties of acrylic lacquers have been studied. References to methods to modify them are given. It has been shown possibility modifying acrylic lacquers with the help of ethylene glycol is a prospective way of improving their properties.

  8. MODIFICATION OF ACRYLIC LACQUER BY DOUBLE-DUTY LYOPHILIC EMULSION

    Фабуляк, Ф.Г.; Національний авіаційний університет; Ульянкіна, Д.С.; Національний авіаційний університет; Таран, Т.В; Національний авіаційний університет

    2012-01-01

     General useful properties of acrylic lacquers have been studied. References to methods to modify them are given. It has been shown possibility modifying acrylic lacquers with the help of ethylene glycol is a prospective way of improving their properties.

  9. Artificial saliva effect on toxic substances release from acrylic resins

    Kostić Milena

    2015-01-01

    Full Text Available Background/Aim. Acrylic-based resins are intensively used in dentistry practice as restorative or denture-base materials. The purpose of this study was to analyze the surface structure of denture base resins and the amount of released potentially toxic substances (PTS immediately upon polymerization and incubation in different types of artificial saliva. Methods. Storage of acrylic samples in two models of artificial saliva were performed in a water bath at the temperature of 37 ± 1°C. Analysis of the surface structure of samples was carried out using scanning electronic microscopy analysis immediately after polymerization and after the 30-day incubation. The amounts of PTS per day, week and month extracts were measured using high-pressure liquid chromatography. Results. Surface design and amount of PTS in acrylic materials were different and depended on the types and duration of polymerization. The surfaces of tested acrylates became flatter after immersing in solutions of artificial saliva. The degree of acrylic materials release was not dependent on the applied model of artificial saliva. Conclusion. In order to improve biological features of acrylic resin materials, it was recommended that dentures lined with soft or hard coldpolymerized acrylates should be kept at least 1 to 7 days in water before being given to a patient. So, as to reach high degree of biocompatibility preparation of prosthetic restorations from heat-polymerized acrylate was unnecessary. [Projekat Ministarstva nauke Republike Srbije, br. 41017

  10. Comparison of the Retinal Straylight in Pseudophakic Eyes with PMMA, Hydrophobic Acrylic, and Hydrophilic Acrylic Spherical Intraocular Lens

    Ya-wen Guo

    2014-01-01

    Full Text Available Purpose. To investigate the intraocular straylight value after cataract surgery. Methods. In this study, 76 eyes from 62 patients were subdivided into three groups. A hydrophobic acrylic, a hydrophilic acrylic, and a PMMA IOL were respectively, implanted in 24 eyes, 28 eyes, and 24 eyes. Straylight was measured using C-Quant at 1 week and 1 month postoperatively in natural and dilated pupils. Results. The hydrophilic acrylic IOLs showed significantly lower straylight values than those of the hydrophobic acrylic IOLs in dilated pupils at 1 week and 1 month after surgery (P0.05. Moreover, no significant difference was found in straylight between natural and dilated pupils in each group at 1 week and 1 month postoperatively (P>0.05. Conclusions. Although the hydrophobic acrylic IOL induced more intraocular straylight, straylight differences among the 3 IOLs were minimal. Pupil size showed no effect on intraocular straylight; the intraocular straylight was stable 1 week after surgery.

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

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

    2003-01-01

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

  12. Use of Acrylic Acid Sodium Acrylate Polymer to Maintain Cocoa Seed Viability

    Pudji Rahardjo

    2010-08-01

    Full Text Available The main problem of cocoa seed storage is moisture content of the seeds because cocoa seeds will germinate if cocoa seeds moisture content is high. The objective of this research is to maintain the cocoa seeds viability in storage using acrylic acid sodium acrylate polymer (AASAP. The function of AASAP is to absorb humidity in storage due to their ability to retain water and to prevent water loss. The experiment was conducted in a laboratory of Indonesian Coffee and Cocoa Research Institute and in Kaliwining Experimental Garden. This experiment was arranged by factorial randomized complete design, in wich AASAP dosages 0%; 0.1% (0.1 g/100 seeds; 0.2% (0.2 g/100 seeds, 0.3% (0.3 g/100 seeds, 0,4% (0,4g/100 seeds, combined with seeds storage period 1, 2, 3 and 4 weeks. The experiment used 3 replications and each repli cation used 100 seeds. Parameter of observation consisted of percentage of seeds germinated in storage, percentage of seeds infected by fungi in storage, seeds moisture content, percentage of seeds germination after storage, and early growth of cocoa seedlings. The results of the experiment showed that AASAP application with some dosages cocoa seeds storage cause to germinate in storage during 2 weeks. AASAP application with some dosages in cocoa seeds storage for 2 weeks would not result in infection by fungi and did not significantly affect seed germination after storage for 1, 2 and 4 weeks, and percentage of germination of cocoa seed after storage for 3 weeks decreased with increase dosage of AASAP. Higher dosage of AASAP would reduce early growth of cocoa seedling. Key words : Theobroma cacao, seed, acrylic acid sodium acrylate, seed storage, viabilty.

  13. Hydrophilic surface modification of acrylate-based biomaterials.

    Arnal-Pastor, M; Comín-Cebrián, S; Martínez-Ramos, C; Monleón Pradas, M; Vallés-Lluch, A

    2016-04-01

    Acrylic polymers have proved to be excellent with regard to cell adhesion, colonization and survival, in vitro and in vivo. Highly ordered and regular pore structures thereof can be produced with the help of polyamide templates, which are removed with nitric acid. This treatment converts a fraction of the ethyl acrylate side groups into acrylic acid, turning poly(ethyl acrylate) scaffolds into a more hydrophilic and pH-sensitive substrate, while its good biological performance remains intact. To quantify the extent of such a modification, and be able to characterize the degree of hydrophilicity of poly(ethyl acrylate), poly(ethyl acrylate) was treated with acid for different times (four, nine and 17 days), and compared with poly(acrylic acid) and a 90/10%wt. EA/AAc copolymer (P(EA-co-AAc)). The biological performance was also assessed for samples immersed in acid up to four days and the copolymer, and it was found that the incorporation of acidic units on the material surface was not prejudicial for cells. This surface modification of 3D porous hydrophobic scaffolds makes easier the wetting with culture medium and aqueous solutions in general, and thus represents an advantage in the manageability of the scaffolds. PMID:26767395

  14. Radiation induced grafting of acrylic acid onto extruded polystyrene surface

    Polystyrene materials with good solubility in liquid scintillation cocktails are used to wipe off different types of surfaces in order to determine the tritium removable contamination with the help of a liquid scintillation counter. This paper analyses hydrophilic surface modifications by radiation induced grafting of acrylic groups onto extruded polystyrene plates. Two grafting methods were used: (a) exposure of extruded polystyrene plates, immersed in aqueous acrylic acid solution, to a gamma radiation of a Co-60 source, and (b) exposure of extruded polystyrene plates to a Co-60 source, followed by the immersion of extruded polystyrene plates in aqueous acrylic acid solution. The grafting of acrylic was proved by IR spectrometry and by radiometric methods using acrylic acid labelled with tritium. - Highlights: ► Polystyrene (PS) is used to determine the removable surface contamination (RSC). ► RSC factor may be increased by PS surface modification. ► PS surface was modified by acrylic acid grafting using γ radiation 60Co source. ► Acrylic fragments insertion was determined by IR, and radiometric. ► Grafted PS discs increase RSC factor in the case of tritium contamination.

  15. Electrochemical characterization of aminated acrylic conducting polymer

    New attempt has been made to synthesize aminated acrylic conducting polymer (AACP) using precursor of phenylvinylsulfoxide (PVS). The process was conducted via the integration of microemulsion and photopolymerization techniques. It has been utilized for covalent immobilization of amino groups by the adding of N-achryiloxisuccinimide (NAS). Thermal eliminating of benzene sulfenic acids from PVS has been done at 250 °C to form electroactive polyacetylene (PA) segment. Characterization of AACP has been conducted using fourier transform infrared (FTIR), scanning electron microscopy (SEM) and linear sweep cyclic voltammetry (CV). A range of 0.3-1.25μm particle size obtained from SEM characterization. A quasi-reversible system performed as shown in electrochemical study

  16. Electrochemical characterization of aminated acrylic conducting polymer

    Rashid, Norma Mohammad; Heng, Lee Yook; Ling, Tan Ling

    2015-09-01

    New attempt has been made to synthesize aminated acrylic conducting polymer (AACP) using precursor of phenylvinylsulfoxide (PVS). The process was conducted via the integration of microemulsion and photopolymerization techniques. It has been utilized for covalent immobilization of amino groups by the adding of N-achryiloxisuccinimide (NAS). Thermal eliminating of benzene sulfenic acids from PVS has been done at 250 °C to form electroactive polyacetylene (PA) segment. Characterization of AACP has been conducted using fourier transform infrared (FTIR), scanning electron microscopy (SEM) and linear sweep cyclic voltammetry (CV). A range of 0.3-1.25μm particle size obtained from SEM characterization. A quasi-reversible system performed as shown in electrochemical study.

  17. Electrochemical characterization of aminated acrylic conducting polymer

    Rashid, Norma Mohammad [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia); Heng, Lee Yook [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia); Southeast Asia Disaster Prevention Research Initiative, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia); Ling, Tan Ling [Southeast Asia Disaster Prevention Research Initiative, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia)

    2015-09-25

    New attempt has been made to synthesize aminated acrylic conducting polymer (AACP) using precursor of phenylvinylsulfoxide (PVS). The process was conducted via the integration of microemulsion and photopolymerization techniques. It has been utilized for covalent immobilization of amino groups by the adding of N-achryiloxisuccinimide (NAS). Thermal eliminating of benzene sulfenic acids from PVS has been done at 250 °C to form electroactive polyacetylene (PA) segment. Characterization of AACP has been conducted using fourier transform infrared (FTIR), scanning electron microscopy (SEM) and linear sweep cyclic voltammetry (CV). A range of 0.3-1.25μm particle size obtained from SEM characterization. A quasi-reversible system performed as shown in electrochemical study.

  18. Radiation hardening of epoxide-acrylate compositions

    Radiation setting of epoxy oligomers modified with vinyl monomers was studied. The setting was accomplished under the effect of γ-radiation of 60Co at the dose rate of 1750 Mrad/s. The content of the gel fraction in the radiation set epoxy-acrylate-styrene compositions increases by 20%, and the phase transition temperature is higher than for compositions set under normal conditions. In all compositions investigated the maximum content of the gel fraction is observed at 8-9 Mrad dose and is 60-70%, on the average. An increase in degree of setting up to 92-98% can be achieved by additional heat treatment of the compositions

  19. Conversion of Lignocellulosic Biomass to Ethanol and Butyl Acrylate

    Binder, Thomas [Archer Daniels Midland Company, Decatur, IL (United States); Erpelding, Michael [Archer Daniels Midland Company, Decatur, IL (United States); Schmid, Josef [Archer Daniels Midland Company, Decatur, IL (United States); Chin, Andrew [Archer Daniels Midland Company, Decatur, IL (United States); Sammons, Rhea [Archer Daniels Midland Company, Decatur, IL (United States); Rockafellow, Erin [Archer Daniels Midland Company, Decatur, IL (United States)

    2015-04-10

    Conversion of Lignocellulosic Biomass to Ethanol and Butyl Acrylate. The purpose of Archer Daniels Midlands Integrated Biorefinery (IBR) was to demonstrate a modified acetosolv process on corn stover. It would show the fractionation of crop residue to distinct fractions of cellulose, hemicellulose, and lignin. The cellulose and hemicellulose fractions would be further converted to ethanol as the primary product and a fraction of the sugars would be catalytically converted to acrylic acid, with butyl acrylate the final product. These primary steps have been demonstrated.

  20. COMPLEX OXIDE CATALYSTS OF ACRYLIC ACID OBTAINING BY ALDOL CONDENSATION METHOD

    Nebesnyi, R.

    2015-01-01

    The present work is dedicated to solving the problem of diversification of the raw materials base for acrylate monomers obtaining,  first of all acrylic acid. Acrylic acid and its derivatives are bulk products of organic synthesis with a wide range of applications. The main industrial method of acrylic acid production is  propylene oxidation. But this method has instable economic indicators as propylene is petroleum origin raw material.It is possible to expand the resource base of acrylic aci...

  1. SYNTHESIS AND CHARACTERIZATION OF POLYURETHANE ACRYLATES FOR UV CURABLE COATING AGENTS

    MI NA PARK; YOUNG SOO KANG; SUN WHA OH; BYUNG HYUN AHN; MYUNG JUN MOON

    2007-01-01

    The single hydroxyl-terminated urethane acrylate oligomers were synthesized from 2-mercaptoethanol (2-MEOH), alkyl (methyl, butyl, and 2-ethylhexyl) acrylate, and 2,2-azobisisobutyronitrile (AIBN, initiator), with dibutyltin dilaurate (DBTDL) as a catalyst. 2-MEOH was used as a functional chain transfer agent. Poly(alkyl urethane) acrylate oligomers were obtained by the reaction of single hydroxyl-terminated polyalkyl acrylates and 2-isocyanatoethyl acrylate. They were characterized by NMR, F...

  2. Rare linking hydrogels based on acrylic acid and carbohydrate esters

    U. Akhmedov

    2012-09-01

    Full Text Available The process of copolymerization of acrylic acid and esters poliallil sucrose; pentaerythritol and sorbitol, some of its laws are identified. The kinetic regularities of copolymerization and the optimum conditions of synthesis was established.

  3. Emulsion Polymerization of Butyl Acrylate: Spin Trapping and EPR Study

    Kim, S.; Westmoreland, D.

    1994-01-01

    The propagating radical in the emulsion polymerization reaction of butyl acrylate was detected by Electron Paramagnetic Resonance spectroscopy using two spin trapping agents, 2-methyl-2nitrosopropane and alpha -N-tert-butylnitrone.

  4. Performance behavior of modified cellulosic fabrics using polyurethane acrylate copolymer.

    Zuber, Mohammad; Shah, Sayyed Asim Ali; Jamil, Tahir; Asghar, Muhammad Irfan

    2014-06-01

    The surface of the cellulosic fabrics was modified using self-prepared emulsions of polyurethane acrylate copolymers (PUACs). PUACs were prepared by varying the molecular weight of polycaprolactone diol (PCL). The PCL was reacted with isophorone diisocyanate (IPDI) and chain was extended with 2-hydroxy ethyl acrylate (HEA) to form vinyl terminated polyurethane (VTPU) preploymer. The VTPU was further co-polymerized through free radical polymerization with butyl acrylate in different proportions. The FT-IR spectra of monomers, prepolymers and copolymers assured the formation of proposed PUACs structure. The various concentrations of prepared PUACs were applied onto the different fabric samples using dip-padding techniques. The results revealed that the application of polyurethane butyl acrylate copolymer showed a pronounced effect on the tear strength and pilling resistance of the treated fabrics. PMID:24661889

  5. [Treatment of acrylate wastewater by electrocatalytic reduction process].

    Yu, Li-Na; Song, Yu-Dong; Zhou, Yue-Xi; Zhu, Shu-Quan; Zheng, Sheng-Zhi; Ll, Si-Min

    2011-10-01

    High-concentration acrylate wastewater was treated by an electrocatalytic reduction process. The effects of the cation exchange membrane (CEM) and cathode materials on acrylate reduction were investigated. It indicated that the acrylate could be reduced to propionate acid efficiently by the electrocatalytic reduction process. The addition of CEM to separator with the cathode and anode could significantly improve current efficiency. The cathode materials had significant effect on the reduction of acrylate. The current efficiency by Pd/Nickel foam, was greater than 90%, while those by nickel foam, the carbon fibers and the stainless steel decreased successively. Toxicity of the wastewater decreased considerably and methane production rate in the biochemical methane potential (BMP) test increased greatly after the electrocatalytic reduction process. PMID:22279908

  6. BARRIER PROPERTY AND STRUCTURE OF ACRYLONITRILE/ACRYLIC COPOLYMERS

    YANG Zhenghua; LI Yuesheng

    1997-01-01

    A series of acrylonitrile (AN) copolymers with methyl acrylate (MA) or ethyl acrylate (EA) as comonomer (5-23 wt%) was prepared by free-radical copolymerization. The permeability coefficients of the copolymers to oxygen and carbon dioxide were measured at 1.0 MPa and at 30 ℃, and those to water vapor also measured at 100% relative humidity and at 30 ℃. All the AN/acrylic copolymers are semicrystalline. As the acrylate content increase, the permeability coefficients of the copolymers to oxygen and carbon dioxide are increased progressively, but those to water vapor are decreased progressively. The gas permeability coefficients of the polymers were correlated with free-volume fractions or the ratio of free volume to cohesive energy.

  7. Construction and properties of acrylic vessels in the RENO detector

    The aim of the RENO (Reactor Experiment for Neutrino Oscillation) is to measure the smallest neutrino mixing angle, θ13. The RENO detector consists of four concentric cylindrical layers: the target, γ-catcher, buffer and veto. Acrylic is used for the target and γ-catcher vessels, both of which contain liquid scintillator. Acrylic was chosen because it has good transmittance in the wavelength range of 400–430nm and also does not react with liquid-scintillating solvents. In order to reduce systematic uncertainties, the target volume should be identical to a level of less than 0.1% between the near and far detectors. Furthermore, the acrylic vessel should not have any leaks. In this paper, we investigate the optical properties, design and construction of the acrylic vessels used in the RENO detector.

  8. [Reaction of 1,8-naphthyridine azides with ethyl acrylate].

    Livi, O; Ferrarini, P L; Bertini, D; Tonetti, I

    1975-12-01

    The reaction of 1,8-naphthyridine azides with ethyl acrylate leads to the formation of 2-pyrazolines instead of 1,2,3-triazolines. Some of the compounds obtained have undergone pharmacological and microbiological (antibacterial) testing. PMID:1204828

  9. Transfer Reactions in Phenyl Carbamate Ethyl Acrylate Polymerizations

    Bennet, Francesca; Roelle, Thomas; Faecke, Thomas; Weiser, Marc-Stephan; Bruder, Friedrich-Karl; Barner-Kowollik, Christopher; Junkers, Thomas

    2013-01-01

    The transfer reactions occurring during polymerization of 2-(phenylcarbamoyloxy)ethyl acrylate (PhCEA) were studied by a detailed product mapping with electrospray ionization mass spectrometry (ESI-MS). Unlike postulated before, PhCEA exhibits the same characteristic transfer reactions as other acrylic monomers at elevated temperatures, resulting in vinyl-terminated and saturated products. Transfer to monomer via abstraction of a hydrogen atom from the ester side chain as suggested before is ...

  10. Synthesis of highly carboxylate acrylic resins for leather impregnation

    Ollé Otero, Lluís; Solé, M.M.; Shendrik, Alexander; Labastida, L.; Bacardit Dalmases, Anna

    2012-01-01

    This work describes the synthesis of new leather finishing acrylic resins. Four resins ware synthesized varying the concentration of ethyl acrylate, and metracrylic acid. Sodium lauryl sulphate was used as emulsifying system. By means of an experimental design, an optimal resin for leather impregnation was defined. The results obtained indicated that the variation of the monomer concentration influences the resin properties, the hardness of the film, and the penetration into the leather. Most...

  11. Durability of concrete protected by an acrylic painting

    Aguiar, J. L. Barroso de; Ramos, Amparo C.; Soares, Helena I.

    2005-01-01

    The fast degradation of concrete is a problem that occurs in some structures. In order to have less degradation, the use of protection systems could be recommended. Acrylic paintings have properties that make possible its use as a protection material of concrete. In our study, one concrete that could be classified as a C33/43, was protected with two coats of an acrylic painting. The durability of the protected concrete was studied. Tests made were: capillarity absorption, oxygen perm...

  12. Artificial saliva effect on toxic substances release from acrylic resins

    Kostić Milena; Krunić Nebojša; Najman Stevo; Nikolić Ljubiša; Nikolić Vesna; Rajković Jelena; Petrović Milica; Igić Marko; Ignjatović Aleksandra

    2015-01-01

    Background/Aim. Acrylic-based resins are intensively used in dentistry practice as restorative or denture-base materials. The purpose of this study was to analyze the surface structure of denture base resins and the amount of released potentially toxic substances (PTS) immediately upon polymerization and incubation in different types of artificial saliva. Methods. Storage of acrylic samples in two models of artificial saliva were performed in a water bath a...

  13. Antimicrobial activity of poly(acrylic acid) block copolymers

    Gratzl, Günther, E-mail: guenther.gratzl@jku.at [Johannes Kepler University Linz, Institute for Chemical Technology of Organic Materials, Altenberger Str. 69, 4040 Linz (Austria); Paulik, Christian [Johannes Kepler University Linz, Institute for Chemical Technology of Organic Materials, Altenberger Str. 69, 4040 Linz (Austria); Hild, Sabine [Johannes Kepler University Linz, Institute of Polymer Science, Altenberger Str. 69, 4040 Linz (Austria); Guggenbichler, Josef P.; Lackner, Maximilian [AMiSTec GmbH and Co. KG, Leitweg 13, 6345 Kössen, Tirol (Austria)

    2014-05-01

    The increasing number of antibiotic-resistant bacterial strains has developed into a major health problem. In particular, biofilms are the main reason for hospital-acquired infections and diseases. Once formed, biofilms are difficult to remove as they have specific defense mechanisms against antimicrobial agents. Antimicrobial surfaces must therefore kill or repel bacteria before they can settle to form a biofilm. In this study, we describe that poly(acrylic acid) (PAA) containing diblock copolymers can kill bacteria and prevent from biofilm formation. The PAA diblock copolymers with poly(styrene) and poly(methyl methacrylate) were synthesized via anionic polymerization of tert-butyl acrylate with styrene or methyl methacrylate and subsequent acid-catalyzed hydrolysis of the tert-butyl ester. The copolymers were characterized via nuclear magnetic resonance spectroscopy (NMR), size-exclusion chromatography (SEC), Fourier transform infrared spectroscopy (FTIR), elemental analysis, and acid–base titrations. Copolymer films with a variety of acrylic acid contents were produced by solvent casting, characterized by atomic force microscopy (AFM) and tested for their antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The antimicrobial activity of the acidic diblock copolymers increased with increasing acrylic acid content, independent of the copolymer-partner, the chain length and the nanostructure. - Highlights: • Acrylic acid diblock copolymers are antimicrobially active. • The antimicrobial activity depends on the acrylic acid content in the copolymer. • No salts, metals or other antimicrobial agents are needed.

  14. Antimicrobial activity of poly(acrylic acid) block copolymers

    The increasing number of antibiotic-resistant bacterial strains has developed into a major health problem. In particular, biofilms are the main reason for hospital-acquired infections and diseases. Once formed, biofilms are difficult to remove as they have specific defense mechanisms against antimicrobial agents. Antimicrobial surfaces must therefore kill or repel bacteria before they can settle to form a biofilm. In this study, we describe that poly(acrylic acid) (PAA) containing diblock copolymers can kill bacteria and prevent from biofilm formation. The PAA diblock copolymers with poly(styrene) and poly(methyl methacrylate) were synthesized via anionic polymerization of tert-butyl acrylate with styrene or methyl methacrylate and subsequent acid-catalyzed hydrolysis of the tert-butyl ester. The copolymers were characterized via nuclear magnetic resonance spectroscopy (NMR), size-exclusion chromatography (SEC), Fourier transform infrared spectroscopy (FTIR), elemental analysis, and acid–base titrations. Copolymer films with a variety of acrylic acid contents were produced by solvent casting, characterized by atomic force microscopy (AFM) and tested for their antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The antimicrobial activity of the acidic diblock copolymers increased with increasing acrylic acid content, independent of the copolymer-partner, the chain length and the nanostructure. - Highlights: • Acrylic acid diblock copolymers are antimicrobially active. • The antimicrobial activity depends on the acrylic acid content in the copolymer. • No salts, metals or other antimicrobial agents are needed

  15. Application of reactive acrylate microgels in water-base coatings

    SA Sheng-shu; ZHANG Bao-hua; YANG Qing; WANG Xia-qin; MAO Zhi-ping

    2009-01-01

    Reactive acrylate microgels with different reactive groups such as carboxyl, hydroxide groups had excellent prop-erties such as quick-dry, low viscosity, high adhesion and hardness, which made them extensively used in preparing paints or in coating-modification. Reactive acrylate microgels were prepared by emulsion co-polymerization with zwitterions surfactant, anionic surfactant and nonionic surfactant as co-emulsifier. The water-base baking paints made from reactive acrylate micro-gels and melamine-formaldehyde resin had excellent combination properties. The aluminium powder can be well-dispersed in the paints. The influences of monomer components on the properties of the water-base baking paints were discussed in this paper. And the baking paints were also compared with the marketing solvent acrylate baking paints. It was found that the water-base acrylate amino baking paints had better combination properties than the organic solvent acrylate baking paints, which means that the water-base baking paints had a bright marketing future.

  16. Advances in acrylic-alkyd hybrid synthesis and characterization

    Dziczkowski, Jamie

    2008-10-01

    In situ graft acrylic-alkyd hybrid resins were formed by polymerizing acrylic and acrylic-mixed monomers in the presence of alkyds by introduction of a free radical initiator to promote graft formation. Two-dimensional NMR, specifically gradient heteronuclear multiple quantum coherence (gHMQC), was used to clarify specific graft sites of the hybrid materials. Both individual and mixed-monomer systems were produced to determine any individual monomer preferences and to model current acrylic-alkyd systems. Different classes of initiators were used to determine any initiator effects on graft location. The 2D-NMR results confirm grafting at doubly allylic hydrogens located on the fatty acid chains and the polyol segment of the alkyd backbone. The gHMQC spectra show no evidence of grafting across double bonds on either pendant fatty acid groups or THPA unsaturation sites for any of the monomer or mixed monomer systems. It was also determined that choice of initiator has no effect on graft location. In addition, a design of experiments using response surface methodology was utilized to obtain a better understanding of this commercially available class of materials and relate both the chemical and physical properties to one another. A Box-Behnkin design was used, varying the oil length of the alkyd phase, the degree of unsaturation in the polyester backbone, and acrylic to alkyd ratio. Acrylic-alkyd hybrid resins were reduced with an amine/water mixture. Hydrolytic stability was tested and viscoelastic properties were obtained to determine crosslink density. Cured films were prepared and basic coatings properties were evaluated. It was found that the oil length of the alkyd is the most dominant factor for final coatings properties of the resins. Acrylic to alkyd ratio mainly influences the resin properties such as acid number, average molecular weight, and hydrolytic stability. The degree of unsaturation in the alkyd backbone has minimal effects on resin and film

  17. Tensile bond strength between auto-polymerized acrylic resin and acrylic denture teeth treated with MF-MA solution

    2016-01-01

    PURPOSE This study evaluated the effect of chemical surface treatment using methyl formate-methyl acetate (MF-MA) solution on the tensile bond strength between acrylic denture teeth and auto-polymerized acrylic resin. MATERIALS AND METHODS Seventy maxillary central incisor acrylic denture teeth for each of three different brands (Yamahachi New Ace; Major Dent; Cosmo HXL) were embedded with incisal edge downwards in auto-polymerized resin in polyethylene pipes and ground with silicone carbide paper on their ridge lap surfaces. The teeth of each brand were divided into seven groups (n=10): no surface treatment (control group), MF-MA solution at a ratio of 25:75 (v/v) for 15 seconds, 30 seconds, 60 seconds, 120 seconds, 180 seconds, and MMA for 180 seconds. Auto-polymerized acrylic resin (Unifast Trad) was applied to the ground surface and polymerized in a pressure cooker. A tensile strength test was performed with a universal testing machine. Statistical analysis of the results was performed using two-way analysis of variance (ANOVA) and post-hoc Dunnett T3 test (α=.05). RESULTS The surface treatment groups had significantly higher mean tensile bond strengths compared with the control group (P.05), except for the Yamahachi New Ace MF-MA 180-second group (Pteeth with auto-polymerized acrylic resin, for both conventional and cross-linked teeth. PMID:27555897

  18. Synthesis and Demulsibility of the Terpolymer Demulsifier of Acryl Resin

    KANG,Wan-Li; MENG,Ling-Wei; ZHANG,Hong-Yan; LIU,Shu-Ren

    2008-01-01

    Terpolymer demulsifier of acryl resin has been synthesized through solution polymerization with water as a dissolvent,potassium persulfate as an initiator and the monomers of methyl methacrylate,butyl acrylate and acrylic acid as starting materials.The effects of the reaction temperature,dripping time,the amount of monomers and initiator on the dehydration rate of the demulsifier were investigated by an orthogonal experiment.It shows that the stronger influence on the dehydration rate among six factors is reaction temperature,dripping time,and amount of catalyst,while monomer has weak influence.The performance of the demulsifier was evaluated under different demulsification time,temperatures and concentrations of the screened demulsifiers.The result shows that the dehydration rate of the demulsifier can reach over 67%,which is better than that by the emulsion polymerization way.

  19. Textile dyestuff adsorption by polysaccharide-g-acrylic acid

    Aimed of this study to determine the ability of polysacharide of banana peel as an adsorbent of textile dyes (Maxilon Yellow) before and after the grafting process. The grafting copolymerization process was done by using acrylic acid as monomer, then irradiated by gamma rays as initiator. Parameters observed were adsorption ability of dye, soaking time with KOH, acrylic acid concentration, irradiation dose and resistance to acids. The results showed the optimum absorption obtained at the time of KOH immersion for 3 hours, the concentration of acrylic acid by 20% and the irradiation dose of 30 kGy. Adsorption percentage of polysacharide to Maxilon Yellow after grafting increased by 18,48% compared to before grafting. Resistance to the acid test increased significantly. The results of this study are expected to overcome the problems of waste dyes in the textile industry. (author)

  20. Biocatalytic functionalization of hydroxyalkyl acrylates and phenoxyethanol via phosphorylation.

    Tasnádi, Gábor; Hall, Mélanie; Baldenius, Kai; Ditrich, Klaus; Faber, Kurt

    2016-09-10

    The enzymatic phosphorylation of phenoxyethanol, 2-hydroxyethyl acrylate and 4-hydroxybutyl acrylate catalyzed by acid phosphatases PhoN-Sf and PiACP at the expense of inorganic di-, tri-, hexameta- or polyphosphate was applied to the preparative-scale synthesis of phosphorylated compounds. The reaction conditions were optimized with respect to enzyme immobilization, substrate concentration, pH and type of phosphate donor. The mild reaction conditions prevented undesired polymerization and hydrolysis of the acrylate ester moiety. Application of a continuous flow system allowed facile scale-up and mono-phosphates were obtained in up to 26% isolated yield with space-time yields of 0.89kgL(-1)h(-1). PMID:27422352

  1. Elastic modulus and flexural strength comparisons of high-impact and traditional denture base acrylic resins

    Nour M. Ajaj-ALKordy

    2014-01-01

    Conclusion: Within the limitations of this study, it can be concluded that the high-impact acrylic resin is a suitable denture base material for patients with clinical fracture of the acrylic denture.

  2. Technology and the use of acrylics for provisional dentine protection.

    Kapusevska, Biljana; Dereban, Nikola; Popovska, Mirjana; Nikolovska, Julijana; Radojkova Nikolovska, Vеrа; Zabokova Bilbilova, Efka; Mijoska, Aneta

    2013-01-01

    Acrylics are compounds polymerized from monomers of acrylic, metacrylic acid or acrylonitrates. The purpose of this paper is to present the technology and use of acrylics for provisional dentine protection in the practice of dental prosthodontics. For this reason, we followed 120 clinical cases from the everyday clinical practice, divided into 4 groups of 30 patients who needed prosthetic reconstruction. The first group included cases in which we applied celluloid crowns for dentine protection, for the second group we used acrylic teeth from a set of teeth for complete dentures; in the third and fourth groups the fabrication was done with the system of an impression matrix and the acrylic resin block technique respectively. In all the examined patients, the gingival index by Silness and Loe and the vitality of the dental pulp were verified clinically, after preparation and 8 days from the placement of the provisional crown. The value for dental sensitivity measured after preparation was 2.59, and 8 days after the placement of the provisional crown it bwas 3.1. From these results we can conclude that after the 8th day from the placement of the provisional crown, there was an adaptation period, characterized by a decrease in the painful sensations. The value of the Silness and Loe gingival index measured after the preparation was 1.34, and 8 days from the placement of the provisional crown was 0.94. The results inclined us to the fact that the provisional acrylic crowns facilitated the reparation of the periodontal tissue. PMID:24566021

  3. The development of epoxidised palm oil acrylate (EPOLA) and its applications

    The topics are discussed briefly. Acrylated palm oil is prepared through acrylation process, whereby, acrylic acid is introduced into oxirane group of the EPOP (epoxidised palm oil products), EPOLA (epoxidised palm oil products acrylate) was found curable when subjected to UV (ultrviolet) light giving soft coatings. EPOLA is used as radiation curable filler/sealer, radiation curable pressure sensitive adhesives and satisfactorily be coated on wood substrates (rubberwood parquets)

  4. Nanopigmented Acrylic Resin Cured Indistinctively by Water Bath or Microwave Energy for Dentures

    L. S. Acosta-Torres; Arenas, M. C.; R. E. Nuñez­-Anita; F. H. Barceló-Santana; C. A. Álvarez-Gayosso; Palacios-Alquisira, J.; J. de la Fuente-Hernández; Marcos Cajero-Juárez; V. M. Castaño

    2014-01-01

    The highlight of this study was the synthesis of nanopigmented poly(methyl methacrylate) nanoparticles that were further processed using a water bath and/or microwave energy for dentures. The experimental acrylic resins were physicochemically characterized, and the adherence of Candida albicans and biocompatibility were assessed. A nanopigmented acrylic resin cured by a water bath or by microwave energy was obtained. The acrylic specimens possess similar properties to commercial acrylic resin...

  5. The Evaluation of Water Sorption/Solubility on Various Acrylic Resins

    Tuna, Suleyman Hakan; Keyf, Filiz; Gumus, Hasan Onder; Uzun, Cengiz

    2008-01-01

    Objectives The absorption of water by acrylic resins is a phenomenon of considerable importance since it is accompanied by dimensional changes, a further undesirable effect of absorbed water in acrylic resins to reduce the tensile strength of the material. Solubility is also an important property because it represents the mass of soluble materials from the polymers. Methods Ten acrylic resin-based materials were evaluated: two heat cure acrylic resins (De Trey QC-20, Meliodent Heat Cure) and ...

  6. Novel azo-peresters radical initiators used for the synthesis of acrylic pressure-sensitive adhesives

    2008-04-01

    Full Text Available Acrylic pressure-sensitive adhesives (PSA based on two monomers: 2-ethylhexyl acrylate and acrylic acid were synthesized in organic solvent ethyl acetate using AIBN (2, 2'-azo-diisobutyronitrile and new synthesized azo-peresters as radical initiators. After polymerization the viscosity, molecular weight and polydispersity of synthesized acrylic PSA were evaluated. The novel synthesized radical azo-perester initiators were synthesized, isolated and compared with industrial predominant usable azo-initiator AIBN.

  7. Triphenylphosphine-Catalyzed Michael Addition of Alcohols to Acrylic Compounds

    LIU, Hai-Ling; JIANG, Huan-Feng; WANG, Yu-Gang

    2007-01-01

    A facile triphenylphosphine-catalyzed Michael addition of alcohols to acrylic compounds was described. The reaction was carried out in open air at refluxing temperature in the presence of 10 mol% PPh3. Michael addition of saturated and unsaturated alcohols to acrylonitrile or acrylates has been examined. The reaction gaveβ-alkoxy derivatives with isolated yields of 5%-79%. PPh3 is cheaper and more stable than those trialkylphosphines previously used for the similar reactions, and the products can be easily separated from the reaction mixture via distillation.

  8. Preparations and applications in UV curing coatings of epoxy acrylates containing carboxyl

    This paper introduces preparations of epoxy acrylates containing carboxyl through the reactions of epoxy acrylates with butanedioic anhydride, pentanedioic anhydride, cis-butenedioic anhydride, phthalic anhydride, tetrabromophthalic anhydride and -tetrahydrophthalic anhydride. These epoxy acrylates containing carboxyl have been applied to UV-curing coatings and their effects on properties of UV-curing coatings have been studied

  9. 40 CFR 721.10192 - Amides, coco, N-[3-(dibutylamino)propyl], acrylates.

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Amides, coco, N- , acrylates. 721... Substances § 721.10192 Amides, coco, N- , acrylates. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amides, coco, N- , acrylates (PMN...

  10. Humidity-responsive starch-poly (methyl acrylate) films.

    Blown films prepared from starch-poly(methyl acrylate) graft copolymers plasticized with urea and water display shrinkage at relative humidities greater than 50%. Shrinkage at relative humidities below approximately 75% is strongly correlated with the urea/starch weight ratio, which controls the eq...

  11. Bond strength between acrylic resin and maxillofacial silicone

    Marcela Filié Haddad

    2012-12-01

    Full Text Available The development of implant dentistry improved the possibilities of rehabilitation with maxillofacial prosthesis. However, clinically it is difficult to bond the silicone to the attachment system. OBJECTIVES: This study aimed to evaluate the effect of an adhesive system on the bond strength between acrylic resin and facial silicone. MATERIAL AND METHODS: A total of 120 samples were fabricated with auto-polymerized acrylic resin and MDX 4-4210 facial silicone. Both materials were bonded through mechanical retentions and/or application of primers (DC 1205 primer and Sofreliner primer S and adhesive (Silastic Medical Adhesive Type A or not (control group. Samples were divided into 12 groups according to the method used to attach the silicone to the acrylic resin. All samples were subjected to a T-peel test in a universal testing machine. Failures were classified as adhesive, cohesive or mixed. The data were evaluated by the analysis of variance (ANOVA and the Tukey's HSD test (α=.05. RESULTS: The highest bond strength values (5.95 N/mm; 3.07 N/mm; 4.75 N/mm were recorded for the samples that received a Sofreliner primer application. These values were significantly higher when the samples had no scratches and did not receive the application of Silastic Medical Adhesive Type A. CONCLUSIONS: The most common type of failure was adhesive. The use of Sofreliner primer increased the bond strength between the auto-polymerized acrylic resin and the Silastic MDX 4-4210 facial silicone.

  12. SYNTHESIS OF ACRYLIC ESTERS IN PTC: KINETICS AND ECOLOGICAL ASPECTS

    G.Torosyan

    2013-06-01

    Full Text Available The synthesis of esters of acrylic acids, which are applied for synthesis of polymeric materials by phase transfer catalysis were discussed (PTC, which is very useful for reduction of reaction consumption of materials and power.This method has substantial advantages including high speed of the process, soft condition of reaction and reduced pollution.

  13. In-situ photopolymerization of oriented liquid-crystalline acrylates

    Broer, Dirk Jan

    1990-01-01

    The scope of this thesis concerns a new method to produce oriented polymers by the in-situ photopolymerization of oriented liquid-crystalline acrylates. The desired macroscopic molecular order is already accomplished in the monomeric state prior to the polymerization. ... Zie: Summary

  14. Design and Synthesis of Novel Fluorine-containing Acrylates

    2005-01-01

    A series of novel fluorine-containing acrylates 6a-6g were synthesized via the condensation of ethyl cyanoacetate and trifluoroacetic anhydride, followed by chloridization and the coupling reaction with amines. These new compounds exhibited some biological activity as preliminary bioassay indicated. A plausible reaction mechanism was outlined and discussed.

  15. Calibration of an Electron Linear Accelerator using an acrylic puppet

    The finality of this work is to find the dose for electron beams using acrylic puppets and inter comparing with the measurements in water, found also its respective conversion factor. With base in this, its may be realize interesting measurements for the good performance of a linear accelerator and special clinical treatments in less time. (Author)

  16. Decarboxylation-based traceless linking with aroyl acrylic acids

    Nielsen, John

    1998-01-01

    beta-Keto carboxylic acids are known to decarboxylate readily. In our pursuit to synthesize beta-indolinyl propiophenones, we have exploited this chemistry as a mean of establishing a traceless handle. 2-Aroyl acrylic acids have been esterified to a trityl resin, after which Michael-type addition...

  17. 21 CFR 173.5 - Acrylate-acrylamide resins.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylate-acrylamide resins. 173.5 Section 173.5 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Polymer Substances and Polymer Adjuvants...

  18. 21 CFR 176.110 - Acrylamide-acrylic acid resins.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylamide-acrylic acid resins. 176.110 Section 176.110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: PAPER AND PAPERBOARD COMPONENTS Substances for Use Only as Components of Paper...

  19. Comparison of classical dermatoscopy and acrylic globe magnifier dermatoscopy

    Lorentzen, Henrik F; Eefsen, Rikke Løvendahl; Weismann, Kaare

    2008-01-01

    % confidence interval 83-97%). Sensitivity for melanoma, benign melanocytic naevi and basal cell carcinoma was 100%, 98% and 85%, respectively. Specificity was 95%, 94% and 100% for melanoma, naevi and basal cell carcinoma. Acrylic globe dermatoscopy enables a diagnostic accuracy similar to epiluminescence...

  20. Analysis and Testing of Bisphenol A—Free Bio-Based Tannin Epoxy-Acrylic Adhesives

    Shayesteh Jahanshahi; Antonio Pizzi; Ali Abdulkhani; Alireza Shakeri

    2016-01-01

    A tannin-based epoxy acrylate resin was prepared from glycidyl ether tannin (GET) and acrylic acid. The influence of the reaction condition for producing tannin epoxy acrylate was studied by FT-MIR, 13C-NMR, MALDI-TOF spectroscopy and shear strength. The best reaction conditions for producing tannin epoxy acrylate resin without bisphenol A was by reaction between GET and acrylic acid in the presence of a catalyst and hydroquinone at 95 °C for 12 h. FT-MIR, 13C-NMR and MALDI-TOF analysis have...

  1. Poly (ethylene oxide)-block-poly (n-butyl acrylate)-blockpoly (acrylic acid) triblock terpolymers with highly asymmetric hydrophilic blocks: synthesis and aqueous solution properties

    Petrov, P; Yoncheva, K. (Krassimira); Mokreva, P. (Pavlina); Konstantinov, S.; J M Irache; Müller, A.H.E. (Axel H.E.)

    2013-01-01

    The synthesis and aggregation behaviour in aqueous media of novel amphiphilic poly(ethylene oxide)- block-poly(n-butyl acrylate)-block-poly(acrylic acid) (PEO–PnBA–PAA) triblock terpolymers were studied. Terpolymers composed of two highly asymmetric hydrophilic PEO (113 monomer units) and PAA (10–17 units) blocks, and a longer soft hydrophobic PnBA block (163 or 223 units) were synthesized by atom transfer radical polymerisation (ATRP) of n-butyl acrylate and tert-butyl acrylate ...

  2. Radioinduced grafting of acrylic acid on expanded polystyrene matrices

    The unfixed surface radioactive contamination for low energy β radionuclides (3H and 14C) is determined by wiping the checked surfaces with sponge of absorbent materials. The activity built up by this sponge is measured by a liquid scintillator spectrometer. In this work, a method of obtaining sponges of expanded polystyrene with hydrophobic surface by radioinduced grafting of the acrylic acid is presented. These sponges have diameters of 28 mm, thicknesses of 1.5 - 2 mm and density of 22 mg/cm3. The samples were immersed in a grafting solution with the following composition: acrylic acid 30%, Cu SO4 1%; water 69% which were deeply impregnated in repeated operations under vacuum and pressure conditions, respectively. Finally, the samples were exposed to γ radiation emitted by a 60Co source (IETI 10 000 - IFIN-HH). The dose rates were 0.3, 0.5 and 1 Mrad/h. The range of the absorbed doses was 1 - 25 Mrad. The yields of radiochemical grafting have been determined by gravimetric, spectrophotometric and radiometric methods. The grafting agent used was 3H labelled acrylic acid. The solvation capacity and the quenching characteristics of the grafted sponges in liquid scintillators, as well as the sampling yields have been analyzed as function of irradiation procedure and the percentage of grafted acrylic fragments. The superficial grafting of the acrylic acid has been carried out by the mentioned technique, leading to the increase of the wiping efficiency of the unfixed surface contaminating activity, without changes of polymer solubility in liquid scintillators and without the perturbation of the radioactivity detection process. (authors)

  3. New oil modified acrylic polymer for pH sensitive drug release: Experimental results and statistical analysis

    Panja, N.; Chattopadhyay, A.K.

    2014-01-01

    We report results of an experimental study, complemented by detailed statistical analysis of the experimental data, on the development of a more effective control method of drug delivery using a pH sensitive acrylic polymer. New copolymers based on acrylic acid and fatty acid are constructed from dodecyl castor oil and a tercopolymer based on methyl methacrylate, acrylic acid and acryl amide were prepared using this new approach. Water swelling characteristics of fatty acid, acrylic acid copo...

  4. Softec HD hydrophilic acrylic intraocular lens: biocompatibility and precision

    Ladan Espandar

    2011-01-01

    Full Text Available Ladan Espandar1, Shameema Sikder2, Majid Moshirfar31Department of Ophthalmology, Tulane University, New Orleans, LA, USA; 2Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA; 3John A Moran Eye Center, University of Utah, Salt Lake City, UT, USAAbstract: Intraocular lens development is driven by higher patient expectations for ideal visual outcomes. The recently US Food and Drug Administration-approved Softec HD™ lens is an aspheric, hydrophilic acrylic intraocular lens (IOL. The hydrophilic design of the lens is optimized to address dysphotopsia while maintaining biocompatibility, optical clarity, resistance to damage, and resistance to biocontamination. Aspheric lenses decrease postoperative spherical aberration. The addition of the Softec lens provides clinicians with another option for IOL placement; however, randomized comparative studies of this lens to others already on the market remain to be completed.Keywords: hydrophilic acrylic intraocular lens, Softec HD intraocular lens, aspheric intraocular lens, IOL

  5. Novel polymer coatings based on plasma polymerized 2-methoxyethyl acrylate

    Wu, Zhenning; Jiang, Juan; Benter, Maike;

    2008-01-01

    properties[4-6]. We have exploited these possibilities and prepared plasma polymerized 2-methoxyethyl acrylate (PPMEA) coatings on various polymer substrates. The PPMEA coatings were optimized using various plasma polymerization conditions and characterized by X-ray photoelectron spectroscopy......Poly(2-methoxyethyl acrylate) (PMEA) is cited as the most blood compatible polyme~l]. Modification of polymer surfaces with PMEA has recently brought to improved materials for such applications[1,2]. Recently PMEA and its block copolymers with PMMA with controlled characteristics have been...... synthesized by Atom Transfer Radical Polymerization (ATRP)[3]. This enabled a surface segregation of the more hydrophilic block to the polymer/air interface and enrichment of the surface with PMEA. Here we present another way to modify a surface with this material - plasma polymerization in a low energy...

  6. A New Process for Acrylic Acid Synthesis by Fermentative Process

    Lunelli, B. H.; Duarte, E. R.; de Toledo, E. C. Vasco; Wolf Maciel, M. R.; Maciel Filho, R.

    With the synthesis of chemical products through biotechnological processes, it is possible to discover and to explore innumerable routes that can be used to obtain products of high addes value. Each route may have particular advantages in obtaining a desired product, compared with others, especially in terms of yield, productivity, easiness to separate the product, economy, and environmental impact. The purpose of this work is the development of a deterministic model for the biochemical synthesis of acrylic acid in order to explore an alternative process. The model is built-up with the tubular reactor equations together with the kinetic representation based on the structured model. The proposed process makes possible to obtain acrylic acid continuously from the sugar cane fermentation.

  7. Plant oil-based shape memory polymer using acrylic monolith

    T. Tsujimoto

    2015-09-01

    Full Text Available This article deals with the synthesis of a plant oil-based material using acrylic monolith. An acrylic monolith bearing oxirane groups was prepared via simple technique that involved the dissolution of poly(glycidyl methacrylate-comethyl methacrylate (PGMA in ethanolic – aqueous solution by heating and subsequent cooling. The PGMA monolith had topologically porous structure, which was attributed to the phase separation of the polymer solution. The PGMA monolith was impregnated by epoxidized soybean oil (ESO containing thermally-latent catalyst, and the subsequent curing produced a crosslinked material with relatively good transparency. The Young’s modulus and the tensile strength of polyESO/PGMA increased compared with the ESO homopolymer. The strain at break of polyESO/PGMA was larger than that of the ESO homopolymer and crosslinked PGMA. Furthermore, polyESO/PGMA exhibited good shape memory-recovery behavior.

  8. Surface modification of nanoparticles for radiation curable acrylate clear coatings

    Bauer, F.; Gläsel, H.-J.; Hartmann, E.; Bilz, E.; Mehnert, R.

    2003-08-01

    To obtain transparent, scratch and abrasion resistant coatings a high content of nanosized silica and alumina filler was embedded in radiation-curable acrylate formulations by acid catalyzed silylation using trialkoxysilanes. 29SiMAS NMR and MALDI-TOF mass spectrometry were employed to elucidate the structure of the surface-grafted methacryloxypropyl-, vinyl- and n-propyl-trimethoxysilane. In accordance with NMR findings, MALDI-TOF MS showed highly condensed oligomeric siloxanes of more than 20 monomeric silane units. A ladder-like structure of bound polysiloxanes is proposed rather than a simplified picture of tridentate silane bonding. Hence, silane coupling agents do not only modify the chemical nature of the filler surface but also strongly effect the rheological properties of the acrylate nanodispersions.

  9. Acryl polymer-silica hybrid for electron beam resist

    Electron beam (EB) resist of acryl polymer-silica hybrid was investigated for fabrication of optical elements. The EB-lithography on the hybrid thin film afforded positive pattern whose depth corresponded to EB exposure dose, indicating that the hybrid was an analog resist. The positive pattern from the hybrids could be transferred to the underlying quartz glass plate by reactive ion etching (RIE) and be coated with metal thin film by its vacuum-deposition owing to the sufficient RIE resistance and heat resistance of the hybrids. The acryl polymer component would be EB sensitive and resist RIE, and the silica matrix would play a role to raise heat resistance and compatibility with the underlying quartz. (author)

  10. Radiation cross-linking of epoxide-acrylic compositions

    The process of hardening of epoxy-acryl compositions on copper, aluminium, iron, and glass substrates has been studied under the action of ionizing radiation (accelerated electrons, γ-radiation). Irradiated samples have been heat treated for 2 hours at 100 and 150 deg C for accelerating posteffect. In the epoxy oligomer-acrylic acid system structurization is completed at a dose of 10-12 Mrad. The content of gel fraction equals 30-62% when irradiation is performed in air and up to 85% when the samples are irradiated under film. The effect has been established of natural epoxy oligomers and various plasticizers on the structurization process. The possibility has been shown of obtaining heat-resistant coatings based on epoxy oligomers

  11. Surface modification of nanoparticles for radiation curable acrylate clear coatings

    To obtain transparent, scratch and abrasion resistant coatings a high content of nanosized silica and alumina filler was embedded in radiation-curable acrylate formulations by acid catalyzed silylation using trialkoxysilanes. 29SiMAS NMR and MALDI-TOF mass spectrometry were employed to elucidate the structure of the surface-grafted methacryloxypropyl-, vinyl- and n-propyl-trimethoxysilane. In accordance with NMR findings, MALDI-TOF MS showed highly condensed oligomeric siloxanes of more than 20 monomeric silane units. A ladder-like structure of bound polysiloxanes is proposed rather than a simplified picture of tridentate silane bonding. Hence, silane coupling agents do not only modify the chemical nature of the filler surface but also strongly effect the rheological properties of the acrylate nanodispersions

  12. Insights on the biodegradation of acrylic reline resins

    Neves, Maria Cristina Bettencourt, 1976-

    2012-01-01

    Acrylic reline resins are extensively used in dentistry, since they readapt dentures to the continuous reabsorbed underlying tissues. Since present in the oral cavity for long periods of time, these materials are objective of the biodegradation phenomena, which represents the change on their chemical, physical and mechanical properties due to the oral environment conditions and its constituents. These processes may permanently alter the properties of the material and compromise its function. ...

  13. Softec HD hydrophilic acrylic intraocular lens: biocompatibility and precision

    Ladan Espandar; Shameema Sikder; Majid Moshirfar

    2011-01-01

    Ladan Espandar1, Shameema Sikder2, Majid Moshirfar31Department of Ophthalmology, Tulane University, New Orleans, LA, USA; 2Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA; 3John A Moran Eye Center, University of Utah, Salt Lake City, UT, USAAbstract: Intraocular lens development is driven by higher patient expectations for ideal visual outcomes. The recently US Food and Drug Administration-approved Softec HD™ lens is an aspheric, hydrophilic acrylic intraocular le...

  14. Hydrogen bonding on the surface of poly(2-methoxyethyl acrylate).

    Li, Guifeng; Ye, Shen; Morita, Shigeaki; Nishida, Takuma; Osawa, Masatoshi

    2004-10-01

    Hydrogen bonding on the interface and in the bulk of a poly(2-methoxyethyl acrylate) (PMEA) thin film has been investigated by sum frequency generation, infrared reflection absorption, and Raman scattering measurements in different kinds of solutions containing hydrogen-bonding donators. These results indicate that the majority of the carbonyl groups on the PMEA surface are hydrogen-bonded with water or ethanol molecules, while the PMEA bulk is still dominated by the free carbonyl group. PMID:15453716

  15. Late opacification of a hydrophilic acrylic intraocular lens

    Al-Bdour Muawyah

    2008-01-01

    Full Text Available Cataract extraction and intraocular lens implantation is considered to be a safe procedure in most cases. However, the new advances in the surgical technique namely phacoemulsification and hence the increased use of foldable intraocular lenses have given rise to new complications including late opacification of intraocular lenses. In this case we report late opacification of a foldable hydrophilic acrylic intraocular lens and the surgical technique for its exchange.

  16. THE IMPORTANCE OF COAGULATION BATH IN ACRYLIC FIBER PRODUCTION

    İsmail TİYEK; BOZDOĞAN, Faruk

    2005-01-01

    In the production of acrylic fibers using wet-spinning method, fiber formation takes places in the coagulation bath. Therefore, physical properties of the fibers, produced by the wet-spinning method, is affected by coagulation bath conditions. For this reason, coagulation bath parameters have to be checked very well. In this paper, both the physical events such as diffusion and phase transition, occured in the coagulation bath, and some coagulation bath parameters that affect these physical e...

  17. Acrylic interpenetrating polymer network dielectric elastomers for energy harvesting

    Brochu, Paul; Niu, Xiaofan; Pei, Qibing

    2011-04-01

    Dielectric elastomer energy harvesters are an emerging technology that promise high power density, low cost, scalability, and the capability of fitting niche markets that have yet to be exploited. To date, materials issues that limit their overall performance have hampered the full potential of these devices. In order to supplant existing technologies, even in niche markets, dielectric elastomer generators must increase their reliability and energy density. Previous work has indicated that stiffer elastomers should be capable of higher energy densities; the increased stiffness of the elastomer films should results in lower Maxwell pressure induced strains, and thus allow the elastomer to relax further, resulting in a larger swing in capacitance and larger energy gains. In this paper we examine the use of VHB-based acrylic interpenetrating polymer network dielectric elastomers with a trimethylolpropane trimethacrylate additive network for energy harvesting purposes. We test films with varying additive content and compare their performance with highly prestrained VHB acrylic elastomers. We show that by increasing additive content, Maxwell induced strains can be suppressed and larger energy gains can be achieved at higher bias fields. Moreover, the introduction of the additive network stabilizes the highly prestrained acrylic elastomers mechanically, thereby increasing their mechanical robustness. However, the interpenetrating polymer network films suffer from an increase in viscoelastic behavior that hinders their overall performance.

  18. Acrylic microspheres-based optosensor for visual detection of nitrite.

    Noor, Nur Syarmim Mohamed; Tan, Ling Ling; Heng, Lee Yook; Chong, Kwok Feng; Tajuddin, Saiful Nizam

    2016-09-15

    A new optosensor for visual quantitation of nitrite (NO2(-)) ion has been fabricated by physically immobilizing Safranine O (SO) reagent onto a self-adhesive poly(n-butyl acrylate) [poly(nBA)] microspheres matrix, which was synthesized via facile microemulsion UV lithography technique. Evaluation and optimization of the optical NO2(-) ion sensor was performed with a fiber optic reflectance spectrophotometer. Scanning electron micrograph showed well-shaped and smooth spherical morphology of the poly(nBA) microspheres with a narrow particles size distribution from 0.6 μm up to 1.8 μm. The uniform size distribution of the acrylic microspheres promoted homogeneity of the immobilized SO reagent molecules on the microspheres' surfaces, thereby enhanced the sensing response reproducibility (<5% RSD) with a linear range obtained from 10 to 100 ppm NO2(-) ion. The micro-sized acrylic immobilization matrix demonstrated no significant barrier for diffusion of reactant and product, and served as a good solid state ion transport medium for reflectometric nitrite determination in food samples. PMID:27080889

  19. Acrylate Functionalized Tetraalkylammonium Salts with Ionic Liquid Properties

    Silvia Janietz

    2012-05-01

    Full Text Available Acrylate functionalized ionic liquids based on tetraalkylammonium salts with terminal acrylates- and methylacrylates were synthesized. Melting points and ionic conductivity of twenty compounds in six groups were determined. Within one group the effect of three different counterions was investigated and discussed. The groups differ in cationic structure elements because of their functional groups such as acrylate and methacrylate, alkyl residues at the nitrogen and number of quaternary ammonium atoms within the organic cation. The effect of these cationic structure elements has been examined concerning the compiled parameters with a view to qualifying them as components for solid state electrolytes. The newly synthesized ionic liquids were characterized by NMR and FTIR analysis. The exchange of halide ions like bromide as counter ions to weakly coordinating [PF6], [OTf] or [TFSI] reduces the melting points significantly and leads to an ion conductivity of about 10−4 S/cm at room temperature. In the case of the dicationic ionic liquid, an ion conductivity of about 10−3 S/cm was observed.

  20. Analysis and Testing of Bisphenol A—Free Bio-Based Tannin Epoxy-Acrylic Adhesives

    Shayesteh Jahanshahi

    2016-04-01

    Full Text Available A tannin-based epoxy acrylate resin was prepared from glycidyl ether tannin (GET and acrylic acid. The influence of the reaction condition for producing tannin epoxy acrylate was studied by FT-MIR, 13C-NMR, MALDI-TOF spectroscopy and shear strength. The best reaction conditions for producing tannin epoxy acrylate resin without bisphenol A was by reaction between GET and acrylic acid in the presence of a catalyst and hydroquinone at 95 °C for 12 h. FT-MIR, 13C-NMR and MALDI-TOF analysis have confirmed that the resin has been prepared under these conditions. The joints bonded with this resin were tested for block shear strength. The results obtained indicated that the best strength performance was obtained by the bioepoxy-acrylate adhesive resin prepared at 95 °C for a 12-h reaction.

  1. Epoxy-acrylic core-shell particles by seeded emulsion polymerization.

    Chen, Liang; Hong, Liang; Lin, Jui-Ching; Meyers, Greg; Harris, Joseph; Radler, Michael

    2016-07-01

    We developed a novel method for synthesizing epoxy-acrylic hybrid latexes. We first prepared an aqueous dispersion of high molecular weight solid epoxy prepolymers using a mechanical dispersion process at elevated temperatures, and we subsequently used the epoxy dispersion as a seed in the emulsion polymerization of acrylic monomers comprising methyl methacrylate (MMA) and methacrylic acid (MAA). Advanced analytical techniques, such as scanning transmission X-ray microscopy (STXM) and peak force tapping atomic force microscopy (PFT-AFM), have elucidated a unique core-shell morphology of the epoxy-acrylic hybrid particles. Moreover, the formation of the core-shell morphology in the seeded emulsion polymerization process is primarily attributed to kinetic trapping of the acrylic phase at the exterior of the epoxy particles. By this new method, we are able to design the epoxy and acrylic polymers in two separate steps, and we can potentially synthesize epoxy-acrylic hybrid latexes with a broad range of compositions. PMID:27078740

  2. Preparation and properties of UV curable acrylic PSA by vinyl bonded graphene oxide

    Pang, Beili; Ryu, Chong-Min; Jin, Xin; Kim, Hyung-Il

    2013-11-01

    Acrylic pressure sensitive adhesives (PSAs) with higher thermal stability for thin wafer handling were successfully prepared by forming composite with the graphene oxide (GO) nanoparticles modified to have vinyl groups via subsequent reaction with isophorone diisocyanate and 2-hydroxyethyl methacrylate. The acrylic copolymer was synthesized as a base resin for PSAs by solution radical polymerization of ethyl acrylate, 2-ethylhexyl acrylate, and acrylic acid followed by further modification with GMA to have the vinyl groups available for UV curing. The peel strength of PSA decreased with the increase of gel content which was dependent on both modified GO content and UV dose. Thermal stability of UV-cured PSA was improved noticeably with increasing the modified GO content mainly due to the strong and extensive interfacial bonding formed between the acrylic copolymer matrix and GO fillers

  3. Development of palm oil-based UV-curable epoxy acrylate and urethane acrylate resins for wood coating application

    Full-text: The trend of using renewable sources such as palm oil as raw material in radiation curing is growing due to the demand from the market to produce a more environmental friendly product. In this study, the radiation curable process was done using epoxy acrylate and urethane acrylate resins which are known as epoxidized palm olein acrylate (EPOLA) and palm oil based urethane acrylate (POBUA), respectively. The purpose of the study was to investigate curing properties and the application of this UV-curable palm oil resins for wood coating. Furthermore, the properties of palm oil based coatings are compared with the petrochemical-based compound such as ebecryl (EB) for example EB264 and EB830. From the experiment done, the resins from petrochemical-based compounds resulted higher degree of crosslinking (up to 80 %) than the palm oil based compounds (up to 70 %), where the different is around 10-15 %. The hardness property from this two type coatings can reached until 50 % at the lower percentage of the oligomer. However, the coatings from petrochemical-based have a high scratch resistance as it can withstand at least up to 3.0 Newton's (N) compared to the palm oil-based compounds which are difficult to withstand the load up to 1.0 N. Finally, the test on the rubber wood substrate showed that the coatings containing benzophenone photo initiator give higher adhesion property and their also showed a higher glossiness property on the glass substrate compared to the coatings containing irgacure-819 photo initiator. This study showed that the palm oil coatings can be a suitable for the replacement of petrochemicals compound for wood coating. The palm oil coatings can be more competitive in the market if the problems of using high percentage palm oil oligomer can be overcome as the palm oil price is cheap enough. (author)

  4. Development of palm oil-based UV-curable epoxy acrylate and urethane acrylate resins for wood coating application

    The trend of using renewable sources such as palm oil as raw material in radiation curing is growing due to the demand from the market to produce a more environmental friendly product. In this study, the radiation curable process was done using epoxy acrylate and urethane acrylate resins which are known as epoxidised palm olein acrylate (EPOLA) and palm oil based urethane acrylate (POBUA), respectively. The purpose of the study was to investigate curing properties and the application of this UV-curable palm oil resins for wood coating. Furthermore, the properties of palm oil based coatings are compared with the petrochemical-based compound such as ebecryl (EB) i.e. EB264 and EB830. From the experiment done, the resins from petrochemical-based compounds resulted higher degree of crosslinking (up to 80%) than the palm oil based compounds (up to 70%), where the different is around 10-15%. The hardness property from this two type coatings can reached until 50% at the lower percentage of the oligomer. However, the coatings from petrochemical-based have a high scratch resistance as it can withstand at least up to 3.0 Newtons (N) compared to the palm oil-based compounds which are difficult to withstand the load up to 1.0 N. Finally, the test on the rubber wood substrate showed that the coatings containing benzophenone photoinitiator give higher adhesion property and their also showed a higher glosiness property on the glass substrate compared to the coatings containing irgacure-819 photoinitiator. This study showed that the palm oil coatings can be a suitable for the replacement of petrochemicals compound for wood coating. The palm oil coatings can be more competitive in the market if the problems of using high percentage palm oil oligomer can be overcome as the palm oil price is cheap enough

  5. Development of palm oil-based UV-curable epoxy acrylate and urethane acrylate resins for wood coating application

    Tajau, Rida; Mahmood, Mohd Hilmi; Salleh, Mek Zah; Salleh, Nik Ghazali Nik [Radiation Processing Technology Division, Malaysian Nuclear Agency (Nuclear Malaysia), Bangi, 43000 Kajang, Selangor (Malaysia); Ibrahim, Mohammad Izzat [Faculty of Science, University of Malaya (UM), 50603 Kuala Lumpur (Malaysia); Yunus, Nurulhuda Mohd [Faculty of Science and Technology, National University Malaysia (UKM), 43600 Bangi, Selangor (Malaysia)

    2014-02-12

    The trend of using renewable sources such as palm oil as raw material in radiation curing is growing due to the demand from the market to produce a more environmental friendly product. In this study, the radiation curable process was done using epoxy acrylate and urethane acrylate resins which are known as epoxidised palm olein acrylate (EPOLA) and palm oil based urethane acrylate (POBUA), respectively. The purpose of the study was to investigate curing properties and the application of this UV-curable palm oil resins for wood coating. Furthermore, the properties of palm oil based coatings are compared with the petrochemical-based compound such as ebecryl (EB) i.e. EB264 and EB830. From the experiment done, the resins from petrochemical-based compounds resulted higher degree of crosslinking (up to 80%) than the palm oil based compounds (up to 70%), where the different is around 10-15%. The hardness property from this two type coatings can reached until 50% at the lower percentage of the oligomer. However, the coatings from petrochemical-based have a high scratch resistance as it can withstand at least up to 3.0 Newtons (N) compared to the palm oil-based compounds which are difficult to withstand the load up to 1.0 N. Finally, the test on the rubber wood substrate showed that the coatings containing benzophenone photoinitiator give higher adhesion property and their also showed a higher glosiness property on the glass substrate compared to the coatings containing irgacure-819 photoinitiator. This study showed that the palm oil coatings can be a suitable for the replacement of petrochemicals compound for wood coating. The palm oil coatings can be more competitive in the market if the problems of using high percentage palm oil oligomer can be overcome as the palm oil price is cheap enough.

  6. Development of palm oil-based UV-curable epoxy acrylate and urethane acrylate resins for wood coating application

    Tajau, Rida; Ibrahim, Mohammad Izzat; Yunus, Nurulhuda Mohd; Mahmood, Mohd Hilmi; Salleh, Mek Zah; Salleh, Nik Ghazali Nik

    2014-02-01

    The trend of using renewable sources such as palm oil as raw material in radiation curing is growing due to the demand from the market to produce a more environmental friendly product. In this study, the radiation curable process was done using epoxy acrylate and urethane acrylate resins which are known as epoxidised palm olein acrylate (EPOLA) and palm oil based urethane acrylate (POBUA), respectively. The purpose of the study was to investigate curing properties and the application of this UV-curable palm oil resins for wood coating. Furthermore, the properties of palm oil based coatings are compared with the petrochemical-based compound such as ebecryl (EB) i.e. EB264 and EB830. From the experiment done, the resins from petrochemical-based compounds resulted higher degree of crosslinking (up to 80%) than the palm oil based compounds (up to 70%), where the different is around 10-15%. The hardness property from this two type coatings can reached until 50% at the lower percentage of the oligomer. However, the coatings from petrochemical-based have a high scratch resistance as it can withstand at least up to 3.0 Newtons (N) compared to the palm oil-based compounds which are difficult to withstand the load up to 1.0 N. Finally, the test on the rubber wood substrate showed that the coatings containing benzophenone photoinitiator give higher adhesion property and their also showed a higher glosiness property on the glass substrate compared to the coatings containing irgacure-819 photoinitiator. This study showed that the palm oil coatings can be a suitable for the replacement of petrochemicals compound for wood coating. The palm oil coatings can be more competitive in the market if the problems of using high percentage palm oil oligomer can be overcome as the palm oil price is cheap enough.

  7. Effect of Nanoclay on Thermal Conductivity and Flexural Strength of Polymethyl Methacrylate Acrylic Resin

    Tahereh Ghaffari; Ali Barzegar; Fahimeh Hamedi Rad; Elnaz Moslehifard

    2016-01-01

    Statement of the Problem: The mechanical and thermal properties of polymethyl methacrylate (PMMA) acrylic resin should be improved to counterweigh its structural deficiencies. Purpose: The aim of this study was to compare the flexural strength and thermal conductivity of conventional acrylic resin and acrylic resin loaded with nanoclay. Materials and Method: The methacrylate monomer containing the 0.5, 1 and 2 wt% of nanoclay was placed in an ultrasonic probe and mixed with the PMMA p...

  8. Late Transition Metal and Aluminum Complexes for the Polymerization of Ethene and Acrylates

    YliheikkilÀ, Katariina

    2006-01-01

    Polyethene, polyacrylates and polymethyl acrylates are versatile materials that find wide variety of applications in several areas. Therefore, polymerization of ethene, acrylates and methacrylates has achieved a lot attention during past years. Numbers of metal catalysts have been introduced in order to control the polymerization and to produce tailored polymer structures. Herein an overview on the possible polymerization pathways for ethene, acrylates and methacrylates is presented. In ...

  9. Effect of Atmospheric Pressure Glow Discharge Treatment on Polymerization of Acrylic Fabric and Its Printing Behavior

    D M El-Zeer

    2014-03-01

    Full Text Available Acrylic fibers have been treated by atmospheric pressure glow discharge (APGD plasma in open air to enhance surface antistatic properties. The treated surfaces are investigated by scanning electron microscopy (SEM, Fourier-Transition Infrared Spectroscopy (FTIR and Atomic Force Microscope (AFM. Plasma treatment of acrylic fabric has been found to increase the surface roughness, modify the nature and density of surface functionalities, and drastically improve the wettability and antistatic ability of acrylic fibers.

  10. Allergic contact dermatitis from sculptured acrylic nails: special presentation with an airborne pattern

    Paula Maio; Rodrigo Carvalho; Cristina Amaro; Raquel Santos; Jorge Cardoso

    2012-01-01

    Methylmethacrylate was first reported in 1941 as a cause of contact dermatitis. Since then, occupational contact allergies to acrylates in dentistry, orthopedic surgery, printing industry and industry have been reported, but few reports are found in the literature as a consequence of the contact with sculptured artificial acrylic nails which are increasingly popular. We describe here 3 patients with contact allergy to acrylates in artificial sculptured nails. Patch tests were performed with t...

  11. Scientific Opinion on the safety evaluation of the active substance, acrylic acid, sodium salt, co-polymer with acrylic acid, methyl ester, methacrylic acid, 2 hydroxypropylester, and acrylic acid cross-linked for use in active food contact materials

    EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF

    2013-04-01

    Full Text Available This scientific opinion of the EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids deals with the safety evaluation of the acrylic acid, sodium salt, co-polymer with acrylic acid, methyl ester, methacrylic acid, 2 hydroxypropylester, and acrylic acid cross-linked (CAS No. 117675-55-5, FCM Substance No 1022, to be used as liquid absorber in the form of fibres in absorbent pads for the packaging of fresh or frozen meat, poultry, and fish as well as fresh fruits and vegetables. The Panel considered that migration is not expected when the absorption capacity of the pads is not exceeded. Therefore no exposure from the consumption of the packed food is expected. The Panel also considered that none of these starting substances and the cross-linked polymer gives rise to concern for genotoxicity. Therefore the CEF Panel concluded that the use of the substance acrylic acid, sodium salt, co-polymer with acrylic acid, methyl ester, methacrylic acid, 2 hydroxypropylester, and acrylic acid cross-linked does not raise a safety concern when used as fibres in absorber pads for the packaging of fresh or frozen meat, poultry, fish, fruits and vegetables under conditions under which the absorption capacity of the pads is not exceeded and mechanical release of the fibres from the pads is excluded.

  12. Acrylic fragmentation in total hip replacements and its biological consequences.

    Jasty, M; Jiranek, W; Harris, W H

    1992-12-01

    Loosening of total joint prostheses is in part related to the fragmentation of the acrylic cement mantle surrounding the prosthesis and the biologic consequences to the particulate acrylic. Fractographic studies of femoral cement mantles retrieved at revision surgery and autopsy showed frequent fractures in varying stages of development in the cement and wear at the fracture surfaces. Defects in the cement mantle, thin mantles, sharp corners on the prosthesis, separation at the cement mantle interface, and pores in the cement were frequently associated with cement fractures. The progressive fractures and wear led to the liberation of particulate acrylic debris into the surrounding tissues. The tissues at the bone-cement interface removed at revision surgery showed that a macrophage, giant-cell foreign-body granulomatous reaction occurs in response to the particulate, but not bulk cement. This tissue can produce a variety of chemical mediators of inflammation and bone resorption, and can resorb bone in organ cultures. A granulomatous tissue reaction with a very similar appearance can be produced in experimental animals using particulate-form polymethylmethacrylate (PMMA), but not the bulk form of PMMA. The tissue reaction is not mediated by the classic cell or humeral immune mechanisms. Subcutaneous injection of particulate PMMA powder into fully immunocompetent C3Hf/SED mice as well as three strains of mice with progressive immunologic deficiencies (nude/nude, SCID, and triple deficient Nu-bg-XID/SED mice) led to a foreign-body reaction in all strains at five weeks as shown by histologic and immunohistochemical examination despite the differences in immune deficiency. This, along with the scarcity of lymphocytes in the human tissues, suggests that the biologic reactions to fragmented cement can be produced and sustained by nonimmune phagocytosis and activation by macrophages and giant cells without significant contribution by the immune system. PMID:1446427

  13. DSC analysis of EB-cured polyurethane-acrylate

    The gel films obtained by electron beam (EB) solid-state polymerization of urethane-acrylate prepolymers were characterized by differential scanning calorimetry (DSC). Two kinds of urethane-acrylates were synthesized by reaction of poly(butylene adipate)diol (PBAD), 4,4'-diphenylmethane diisocyanate (MDI) and 2-hydroxyethyl acrylate (HEA) for this purpose. One is a semicrystalline prepolymer (UA-251M) with a number average molecular weight (M-barn) of 3200, and the other is an amorphous one (UA-071M) with M-barn of 1450. The M-barn varied by changing M-barn of PBAD. UA-251M gel film decreased in glass transition temperature (Tg) and increased in heat capacity change (ΔCp) at Tg with increasing irradiation dose, while the Tg and ΔCp values of UA-071M gel film changed in the opposite way to those of UA-251M gel film. Above 5 Mrad, gel fraction reached more than 90 %, and the Tg and ΔCp values changed steeply for both prepolymers. This steep change in Tg and ΔCp was attributed to the crosslinking of PBAD chains as well as of terminal acryloyl groups. Since the Tg change of UA-071M gel film depends merely on the crosslinking, the crosslinking structure was evaluated using two equations which relate the shift in Tg to crosslinking. The molecular weight between crosslinking junctions was found to be larger than the M-barn of the prepolymer. The crosslinking by the EB polymerization restricted the mobility of the polymer chain less strongly than the crosslinking by the three-functional isocyanate and α,ω-dihydroxy(polypropylene oxide) with a molecular weight of 1000 did. (author)

  14. DSC analysis of EB-cured polyurethane-acrylate

    Ando, Masayuki; Uryu, Toshiyuki

    1987-10-01

    The gel films obtained by electron beam (EB) solid-state polymerization of urethane-acrylate prepolymers were characterized by differential scanning calorimetry (DSC). Two kinds of urethane-acrylates were synthesized by reaction of poly(butylene adipate)diol (PBAD), 4,4'-diphenylmethane diisocyanate (MDI) and 2-hydroxyethyl acrylate (HEA) for this purpose. One is a semicrystalline prepolymer (UA-251M) with a number average molecular weight (M-bar/sub n/) of 3200, and the other is an amorphous one (UA-071M) with M-bar/sub n/ of 1450. The M-bar/sub n/ varied by changing M-bar/sub n/ of PBAD. UA-251M gel film decreased in glass transition temperature (T/sub g/) and increased in heat capacity change (..delta..C/sub p/) at T/sub g/ with increasing irradiation dose, while the T/sub g/ and ..delta..C/sub p/ values of UA-071M gel film changed in the opposite way to those of UA-251M gel film. Above 5 Mrad, gel fraction reached more than 90 %, and the T/sub g/ and ..delta..C/sub p/ values changed steeply for both prepolymers. This steep change in T/sub g/ and ..delta..C/sub p/ was attributed to the crosslinking of PBAD chains as well as of terminal acryloyl groups. Since the T/sub g/ change of UA-071M gel film depends merely on the crosslinking, the crosslinking structure was evaluated using two equations which relate the shift in T/sub g/ to crosslinking. The molecular weight between crosslinking junctions was found to be larger than the M-bar/sub n/ of the prepolymer. The crosslinking by the EB polymerization restricted the mobility of the polymer chain less strongly than the crosslinking by the three-functional isocyanate and ..cap alpha..,..omega..-dihydroxy(polypropylene oxide) with a molecular weight of 1000 did.

  15. Stiffness and strength of composite acrylic bone cements

    I. Knets

    2007-01-01

    Full Text Available Purpose: Different acrylic bone cements based upon PMMA-MMA system are applicable for implant fixation inbone tissue. The aim of present study is the optimisation of the structure of some new bone acrylic cements madeon the basis of PMMA-ethylmethacrylate-triethyleneglycoldimethacrylate and bone cements having additives (HAand radio pacifier, and the finding of the effect of these modifications on the flexural strength and stiffness.Design/methodology/approach: Different new bone cements on the basis of PMMA-EMA-TEGDMA system(ABC were developed experimentally. The stiffness and strength of the samples of these modified cements weredetermined in the special three point bending equipment.Findings: A comparison of the flexural properties of new PMMA-EMA-TEGDMA cements and commercialavailable PMMA-MMA cement showed that commercial bone cement had larger values of ultimate strengthand modulus of elasticity, but the difference is not very important. As concerns the polymerisation peaktemperature, then there is a significant difference between commercial PMMA-MMA cement (~ 800C andPMMA-EMA-TEGDMA modified cements (50 – 600C. The introduction of 10% and 18% of HA into solidphase does not influence essentially strength and modulus of elasticity of the PMMA-EMA-TEGDMA bonecements. The introduction of radio pacifier BaSO4 into bone cement leads to flexural strength diminishing.Low polymerisation peak temperature and appropriate mechanical properties of bone cements developed allowsregarding new 3-D structure acrylic bone cements as promising biomaterials.Research limitations/implications: It is supposed to carry out animal testing to learn more about reaction ofmodified implanted material on the biological environment.Practical implications: The new materials could be efficiently used as bone cements because they will notdamage surrounding biological tissue during curing.Originality/value: Paper is providing the new information about possibilities to

  16. INCIDENCE AND CAUSES OF FRACTURE OF ACRYLIC RESIN COMPLETE DENTURE

    Sampa

    2014-12-01

    Full Text Available CONTEXT (BACKGROUND: Replacement of missing teeth and the associated structures are done with the help of artificial prosthesis. Acrylic resin, by virtue of its excellent properties is widely used as a material of choice for fabrication of denture base. In spite of its higher esthetic quality, tissue compatibility and ease of manipulation, it has an inherent deficiency of proneness to fracture. AIMS: The present study was being undertaken to find out the incidence of fracture of acrylic resin base of complete denture and analyze the cause, so that suitable remedial measures might be suggested to reduce the frequency of denture fracture. SETTINGS AND DESIGN: The present study was conducted over a period of 18 months in the Prosthetic Department of Dr R Ahmed Dental College & Hospital, Kolkata. METHODS AND MATERIAL: The 81 reported fracture cases out of 646 complete dentures were selected for this study. Formally consent followed by detailed history was taken. After intra-oral and physical examination, the dentures were repaired following text book recommended procedure using cold cure acrylic resin and prepared for last phase of survey, which was the intra oral examination like adaptation, retention and stability of the repaired dentures in the second visit of the patients. STATISTICAL ANALYSIS: The data were subjected to SPSS, version 16, and statistically analyzed using cross tab. RESULTS: In the present survey, 81 cases of complete denture fractures have been reported within the survey period. CONCLUSIONS: It appears from the present study, the rate of lower complete denture fracture is more common than upper complete denture fracture

  17. Corrigendum: Softec HD hydrophilic acrylic intraocular lens: biocompatibility and precision

    Espandar L

    2011-02-01

    Full Text Available Espandar L, Sikder S, Moshirfar M. Softec HD hydrophilic acrylic intraocular lens: biocompatibility and precision. Clin Ophthalmol. 2011;5:65–70.There was an error in the reported optic size of Lenstec’s Softec HD intraocular lens, which was reported to be 5.5 mm in Espandar et al’s work, but is 5.75 mm.Please see the specifications on Lenstec’s Web site for further details (see http://www.lenstec.com/lenstec/hd_specs.html.Read the original article

  18. BARRIER PROPERTIES OF VINYLIDENE CHLORIDE/METHYL ACRYLATE COPOLYMER

    LI Yuesheng; WENG Zhixue; PAN Zuren

    1997-01-01

    A series of vinylidene dichloride (VDC) copolymers with methyl acrylate (MA) as comonomer (3-12 wt%), was prepared by free-radical suspension copolymerization. The permeability coefficients of the copolymers to oxygen and carbon dioxide were measured at1.0 MPa and at 30℃, and those to water vapor were measured at 30℃ and 100% relative humidity. All the VDC/MA copolymers studied are semicrystalline. As the MA content increases, the permeability coefficients of the copolymers to oxygen, carbon dioxide, and water vapor are progressively increased, caused by decrease in crystalline fraction and increase in free volume of VDC/MA copolymers.

  19. A Study of an Acrylic Cerenkov Radiation Detector

    Porter, B; De Barbaro, P; Bodek, Arie; Budd, H S

    1999-01-01

    An experiment investigating the angle of Cerenkov light emitted by 3-MeV electrons traversing an acrylic detector has been developed for use in the advanced physics laboratory course at the University of Rochester. In addition to exploring the experimental phenomena of Cerenkov radiation and total internal reflection, the experiment introduces students to several experimental techniques used in actual high energy and nuclear physics experiments, as well as to analysis techniques involving Poisson statistics. [to be published in Am. J. Phys. 67 (Oct/Nov 1999).

  20. Conformational Transition of Poly (Acrylic Acid) Detected by Microcantilever Sensing

    LI Kai; LIU Hong; ZHANG Qing-Chuan; XUE Chang-Guo; WU Xiao-Ping

    2007-01-01

    Poly (acrylic acid) (PAA) chains are grafted on one side of a microcantilever by the self-assembled method and the deflections of the microcantilever are detected as a function of medium pH from 3 to 11. It is found that when the pH varies, the microcantilever deflects because of the changing surface stress. By analysing the electrostatic repulsive effect, the surface stress change is related to the conformation transition of PAA from a collapse state to a swelling state. This method offers the interaction information among the polymer chains during the conformational transition and affords an alternative way to study conformational change of polymers.

  1. PREPARATION AND PROPERTIES OF SILICONE-ACRYLATE COPOLYMER LATEX

    Mu-jie Yang; Wei Zhang

    2004-01-01

    Silicone-acrylate copolymer latex was prepared through three different polymerization processes, i.e., the batch process, preemulsified monomer addition and the monomer addition process. The results revealed that the monomer addition process is a desirable approach to produce narrow particle size distribution latex with higher polymerization conversion and less amount of coagulum. The effect of silicone content on the glossiness and water absorption of latex film was investigated and the results showed that the glossiness of latex film is improved up to a silicone content of 10% of total monomers, but becomes impaired thereafter, whereas water absorption is reduced accordingly.

  2. 133Xe labelling of acrylate for catheter embolisation

    A method for radio-nucleide labelling of histo-acryl/lipiodol with 133Xe gas is described. The method consists of disolving the gas in lipiodol under sterile conditions. After embolisation and angiography, the localisation of the embolising material can be determined by means of a scintillation camera. The labelling method was used in 15 patients. In all patients the position of the embolising material, as demonstrated by scintigraphy, corresponded with the radiological findings. It was not possible to demonstrate escape of the material by scintigraphy. (orig.)

  3. Formation of Methyl Acrylate from CO 2 and Ethylene via Methylation of Nickelalactones

    Bruckmeier, Christian

    2010-05-24

    The nickel-induced coupling of ethylene and CO2 represents a promising pathway toward acrylates. To overcome the high bond dissociation energies of the M-O moieties, we worked out an in situ methylation of nickelalactones to realize the β-hydride elimination and the liberation of the acrylate species. © 2010 American Chemical Society.

  4. Neutral, anionic, cationic, and zwitterionic diblock copolymers featuring poly(2-methoxyethyl acrylate) hydrophobic segments

    Javakhishvili, Irakli; Jankova Atanasova, Katja; Hvilsted, Søren

    2013-01-01

    Amphiphilic diblock copolymers incorporating hydrophobic poly(2-methoxyethyl acrylate) (PMEA) and hydrophilic neutral poly(ethylene glycol) monomethyl ether (mPEG), anionic poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMAA), cationic poly(2-dimethylaminoethyl methacrylate) (PDMAEMA), and...

  5. Synthesis of poly(N-isopropylacrylamide-co-acrylic acid) model compounds for filtration experiments

    Hinge, Mogens; Christensen, Morten Lykkegaard; Scales, Peter;

    2005-01-01

    microgels. Capillary rheometry indicates that the blocks of poly(acrylic acid) are placed on the surface of the microgels. The combination of these three results reveal that the microgels have a core mainly consisting of poly(N-isopropylacrylamide) and a diffuse/cloudy surface consisting mainly of poly(acrylic...

  6. Synthesis of Radiation Curable Palm Oil–Based Epoxy Acrylate: NMR and FTIR Spectroscopic Investigations

    Ashraf M. Salih

    2015-08-01

    Full Text Available Over the past few decades, there has been an increasing demand for bio-based polymers and resins in industrial applications, due to their potential lower cost and environmental impact compared with petroleum-based counterparts. The present research concerns the synthesis of epoxidized palm oil acrylate (EPOLA from an epoxidized palm oil product (EPOP as environmentally friendly material. EPOP was acrylated by acrylic acid via a ring opening reaction. The kinetics of the acrylation reaction were monitored throughout the reaction course and the acid value of the reaction mixture reached 10 mg KOH/g after 16 h, indicating the consumption of the acrylic acid. The obtained epoxy acrylate was investigated intensively by means of FTIR and NMR spectroscopy, and the results revealed that the ring opening reaction was completed successfully with an acrylation yield about 82%. The UV free radical polymerization of EPOLA was carried out using two types of photoinitiators. The radiation curing behavior was determined by following the conversion of the acrylate groups. The cross-linking density and the hardness of the cured EPOLA films were measured to evaluate the effect of the photoinitiator on the solid film characteristics, besides, the thermal and mechanical properties were also evaluated.

  7. The mechanism study on overcoming oxygen inhibition of polyether type multifunctional acrylate

    The high reactive polyester type multifunctional acrylic resin and polyether type multifunctional acrylate was prepared and used for EB cured coatings. The experimental results have showed that when the absorbed dose reaches 60 KGy, the hardness kept to 80%. In order to overcome oxygen inhibition the authors also performed further mechanism study of anti-oxidation

  8. Synthesis, Characterization, and Aqueous Lubricating Properties of Amphiphilic Graft Copolymers Comprising 2-Methoxyethyl Acrylate

    Javakhishvili, Irakli; Røn, Troels; Jankova Atanasova, Katja; Hvilsted, Søren; Lee, Seunghwan

    2014-01-01

    Amphiphilic anionic and cationic graft copolymers possessing poly(2-hydroxyethyl methacrylate) (PHEMA) backbone and poly(methacrylic acid), poly(2-methoxyethyl acrylate-co-methacrylic acid), and poly(2-methoxyethyl acrylate-co-2-(dimethylamino)ethyl methacrylate) grafts are constructed by merging...

  9. Contact-killing of adhering streptococci by a quaternary ammonium compound incorporated in an acrylic resin

    Mei, Li; Ren, Yijin; Loontjens, Ton J. A.; van der Mei, Henny C.; Busscher, Henk J.

    2012-01-01

    Purpose: Acrylates for bonding of joint prostheses and stainless-steel brackets in orthopedics and orthodontics are prone to bacterial adhesion and biofilm formation, respectively, leading to serious infectious complications. Here we describe the preparation of a contact-killing acrylic resin by inc

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

    SHI Youheng; NIE Xuzong

    1988-01-01

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

  11. Preparation and properties of acrylic resin coating modified by functional graphene oxide

    Dong, Rui; Liu, Lili

    2016-04-01

    To improve the dispersion and the strength of filler-matrix interface in acrylic resin, the functional graphene oxide (FGO) was obtained by surface modification of graphene oxide (GO) by γ-methacryloxypropyl trimethoxysilane (KH-570) and then the acrylic nanocomposites containing different loadings of GO and FGO were prepared. The structure, morphology and dispersion/exfoliation of the FGO were characterized by XRD, FT-IR, Raman, XPS, SEM and TEM. The results demonstrated that the KH-570 was successfully grafted onto the surface of GO sheets. Furthermore, the corresponding thermal, mechanical and chemical resistance properties of the acrylic nanocomposites filled with the FGO were studied and compared with those of neat acrylic and GO/acrylic nanocomposites. The results revealed that the loading of FGO effectively enhanced various properties of acrylic resin. These findings confirmed that the dispersion and interfacial interaction were greatly improved by incorporation of FGO, which might be the result of covalent bonds between the FGO and the acrylic matrix. This work demonstrates an in situ polymerization method to construct a flexible interphase structure, strong interfacial interaction and good dispersion of FGO in acrylic nanocomposites, which can reinforce the polymer properties and be applied in research and industrial areas.

  12. Development of radiation curable surface coating based on soybean oil. part I. preparation and characterization of acrylated oil

    An epoxy acrylate was synthesized from epoxidized soybean oil (ESOL) by using acrylic acid monomer. Triethyl amine (TEA) and hydroquinone were used as catalyst and inhibitor respectively. The epoxidized soybean oil acrylate (ESOLA) is done by introducing acrylic acid into oxirane groups of the epoxidized oil (ESOL). This reaction was confirmed by analytical data in terms of oxirane oxygen content, acid value, viscosity and spectroscopically analysis

  13. Effect of Beverages on the Hardness and Tensile Bond Strength of Temporary Acrylic Soft Liners to Acrylic Resin Denture Base

    Safari A.

    2013-12-01

    Full Text Available Statement of Problem: Two potential problems commonly identified with a denture base incorporating a resilient liner are failure of the bond between acrylic resin and soft liner material, and loss of resiliency of the soft liner over time. Since patients may drink different beverages, it is important to evaluate their effects on physical properties of soft lining materials.Purpose: The objective of this in vitro study was to evaluate the effect of different beverages on the hardness of two temporary acrylic-based soft lining materials and their bond strength to the denture base resin.Materials and Method: For the hardness test; a total of 80 rectangular specimens (40mm×10mm×3mm were fabricated from a heat-polymerized polymethylmethacrylate. Two commercially auto-polymerized acrylic resin-based resilient liners; Coe-Soft and Visco-gel were prepared according to the manufacturers’ instructions and applied on the specimens. For the tensile test, 160 cylindrical specimens (30mm×10mm were prepared. The liners were added between specimens with a thickness of 3 mm. The specimens of both soft liners were divided into 4 groups (n=10 and immersed in distilled water as the control group, Coca-Cola, 8% and 50% ethanol. All groups were stored in separate containers at 37oC for 12 days. All beverages were changed daily. The hardness was determined using a Shore A durometer and tensile bond strength was determined in a ZwickRoell testing machine at a cross-head speed of 5mm/min. The results were analyzed using two-way ANOVA.Results: There was no significant interaction between the soft liners and the drinks for both hardness (p= 0.748 and bond strength (p= 0.902. There were statistically signifi-cant differences between all drinks for both hardness (p< 0.001 and bond strength (p< 0.05.Conclusion: Within the limitations of this study, it seems that drinking Coca-Cola and alcoholic beverages would not be potentially causing any problems for the temporary

  14. The study of synthesis and photocuring behaviors of organic silicon modified methylacrylate and acrylate

    Wang, Si-yuan; Zou, Ying-quan

    2012-03-01

    Ten different silicon-containing methyl acrylate and acrylate monomers were synthesized by the substitution reaction of chlorosilanes or chlorosiloxanes with 2-Hydroxyethyl methacrylate or 2-Hydroxyethyl acrylate. Using triethylamine as the catalytic agent, tetrahydrofuran as the solvent, pure products can be obtained with one-step reaction after reduced pressure distillation or column chromatography via controlling raw ratio and reaction time. In this study, one to four silicon contained methyl acrylate and acrylate monomers were synthesized with simple methd and high yield. Monomers' properties were characterized through IR, 1H-NMR, 13C-NMR and their viscosity and thermostability were also characterized. The polymers' have good performance on UV-curing and low surface energy.

  15. Influence of Sea Water Aging on the Mechanical Behaviour of Acrylic Matrix Composites

    Davies, P.; Le Gac, P.-Y.; Le Gall, M.

    2016-07-01

    A new matrix resin was recently introduced for composite materials, based on acrylic resin chemistry allowing standard room temperature infusion techniques to be used to produce recyclable thermoplastic composites. This is a significant advance, particularly for more environmentally-friendly production of large marine structures such as boats. However, for such applications it is essential to demonstrate that composites produced with these resins resist sea water exposure in service. This paper presents results from a wet aging study of unreinforced acrylic and glass and carbon fibre reinforced acrylic composites. It is shown that the acrylic matrix resin is very stable in seawater, showing lower property losses after seawater aging than those of a commonly-used epoxy matrix resin. Carbon fibre reinforced acrylic also shows good property retention after aging, while reductions in glass fibre reinforced composite strengths suggest that specific glass fibre sizing may be required for optimum durability.

  16. The transverse strength of acrylic resin after Coleus amboinicus, Lour extract solution immersion

    Devi Rianti

    2006-12-01

    Full Text Available A laboratoric experimental study was conducted on the transverse strength of acrylic resin after Coleus amboinicus, Lour extract solution immersion. The aim of this study is to know the difference of acrylic resin transverse strengths caused by immersion time variations in a concentrate solution. The study was carried out on unpolished acrylic resin plates with 65 × 10 × 2,5 mm dimension; solution with 15% Coleus amboinicus, Lour extract, and 30, 60, 90 days immersion times to measure the transverse strength and sterilized aquadest was used as control. Acrylic resin plates transverse strength was measured using Autograph AG-10 TE. The data was analyzed using One-Way Anova and LSD with 5% degree of significance. The result showed that longer immersion time will decrease the transverse strength of the acrylic resin plates. After 90 days immersion time, the transverse strength decrease is still above the recommended standard transverse strength.

  17. Biocompatibility of alendronate-loaded acrylic cement for vertebroplasty

    T Calvo-Fernández

    2010-10-01

    Full Text Available This paper reports a biological evaluation of a non-resorbable acrylic cement loaded with alendronate for the treatment of osteoporotic vertebral compression fractures. The cement formulation was based on polymethyl methacrylate and acrylic monomers; one of these had covalently linked vitamin E residues. The same cement in the absence of alendronate was used as a control. The setting of the charged cement presented a maximum polymerization temperature of 44ºC, a setting time of 24 min, a residual monomer content lower than 3 wt.%, a compressive strength of 99±10 MPa and an elastic modulus of 1.2±0.2 GPa. Cytotoxicity studies using human osteoblast cultures revealed that the leachable substances of the alendronate loaded cement collected between 1 and 7 days decreased cell viability to values lower than 80%. However, morphological changes and cellular damage in cells produced by the extracts decreased with the leak time. Cell adhesion and growth on charged cement was significantly lower than on the control. Implantation of the cement paste in the intra-femoral cavity of rabbits showed that initially the osteogenic activity was evident for the cement charged with alendronate, and the osteosynthesis process took place mainly in the trabeculae and was manifested by the presence of a non-mineralised osseous spicule. The interface between material and adjacent bone tissue was initially characterized by a variable fibrous response that in many cases it appeared reduced to thin connective tissue after a 24-week-period.

  18. Desorption of biocides from renders modified with acrylate and silicone.

    Styszko, Katarzyna; Bollmann, Ulla E; Wangler, Timothy P; Bester, Kai

    2014-01-01

    Biocides are used in the building industry to prevent algal, bacterial and fungal growth on polymericrenders and thus to protect buildings. However, these biocides are leached into the environment. To better understand this leaching, the sorption/desorption of biocides in polymeric renders was assessed. In this study the desorption constants of cybutryn, carbendazim, iodocarb, isoproturon, diuron, dichloro-N-octylisothiazolinone and tebuconazole towards acrylate and silicone based renders were assessed at different pH values. At pH 9.5 (porewater) the constants for an acrylate based render varied between 8 (isoproturon) and 9634 (iodocarb) and 3750 (dichloro-N-octylisothiazolinone), respectively. The values changed drastically with pH value. The results for the silicone based renders were in a similar range and usually the compounds with high sorption constants for one polymer also had high values for the other polymer. Comparison of the octanol water partitioning constants (Kow) with the render/water partitioning constants (Kd) revealed similarities, but no strong correlation. Adding higher amounts of polymer to the render material changed the equilibria for dichloro-N-octylisothiazolinone, tebuconazole, cybutryn, carbendazim but not for isoproturon and diuron. PMID:24059976

  19. Water structure and blood compatibility of poly(tetrahydrofurfuryl acrylate).

    Mochizuki, Akira; Hatakeyama, Tatsuko; Tomono, Yuka; Tanaka, Masaru

    2009-01-01

    We previously reported that poly(2-methoxyethyl acrylate) (PMEA), which has excellent blood compatibility, contains a large amount of freezing bound water. In order to confirm the role of freezing bound water in determining blood compatibility, poly(tetrahydrofurfuryl acrylate) (PTHFA) was newly synthesized and the thermal properties of water in PTHFA were investigated by differential scanning calorimetry (DSC), as freezing bound water was observed as cold crystallization in DSC heating curves. In addition, the blood compatibility of PTHFA, including activations of platelets, the coagulation system and the complement system, was investigated. The temperature of cold crystallization of water in PTHFA was higher than that of water in PMEA; moreover, the amount of freezing bound water in PTHFA was smaller than that in PMEA. The effect of freezing bound water on blood compatibility was investigated by comparing PTHFA, PMEA, poly(2-hydroxyethyl methacrylate) (PHEMA) and poly(2-methoxyethyl methacrylate) (PMEMA). The latter two samples showed no cold crystallization. Activations of platelets, the coagulation system and the complement system were enhanced in the following order: PMEA < PHEMA < PTHFA < PMEMA, PMEA < PMEMA < PTHFA < PHEMA and PMEA < PTHFA < PMEMA < PHEMA, respectively. The above results were reasonably explained by the amount and/or the stability of freezing bound water. PMID:19323878

  20. Characteristics and mechanisms of acrylate polymer damage to maize seedlings.

    Chen, Xian; Mao, Xiaoyun; Lu, Qin; Liao, Zongwen; He, Zhenli

    2016-07-01

    Superabsorbent acrylate polymers (SAPs) have been widely used to maintain soil moisture in agricultural management, but they may cause damage to plants, and the mechanisms are not well understood. In this study, seed germination, soil pot culture, hydroponic experiments, and SAPs degradation were conducted to investigate damage characteristics and mechanisms associated with SAPs application. The Results showed that SAPs inhibited maize growth and altered root morphology (irregular and loose arrangement of cells and breakage of cortex parenchyma), and the inhibitory effects were enhanced at higher SAPs rates. After 1h SAP hydrogels treatment, root malondialdehyde (MDA) content was significantly increased, while superoxide dismutase (SOD) and catalase (CAT) content were significantly decreased. Hydroponics experiment indicated that root and shoot growth was inhibited at 2.5mgL(-1) acrylic acid (AA), and the inhibition was enhanced with increasing AA rates. This effect was exacerbated by the presence of Na(+) at a high concentration in the hydrogels. Release and degradation of AA were enhanced at higher soil moisture levels. A complete degradation of AA occurred between 15 and 20 days after incubation (DAI), but it took longer for Na(+) concentration to decrease to a safe level. These results indicate that high concentration of both AA and Na(+) present in the SAPs inhibits plant growth. The finding of this study may provide a guideline for appropriate application of SAPs in agriculture. PMID:27057990

  1. Bond strength of acrylic teeth to denture base resin after various surface conditioning methods before and after thermocycling

    Saavedra, Guilherme; Valandro, Luz Felipe; Leite, Fabiola Pessoa; Amaral, Regina; Oezcan, Mutlu; Bottino, Marco A.; Kimpara, Estevao T.

    2007-01-01

    This study aimed to evaluate the durability of adhesion between acrylic teeth and denture base acrylic resin. The base surfaces of 24 acrylic teeth were flatted and submitted to 4 surface treatment methods: SM1 (control): No SM; SM2: application of a methyl methacrylate-based bonding agent (Vitacol)

  2. Enzyme-catalyzed synthesis of saccharide acrylate monomers from nonedible biomass.

    Kloosterman, Wouter M J; Brouwer, Sander G M; Loos, Katja

    2014-08-01

    Various cellulase preparations were found to catalyze the transglycosidation between cotton linters and 2-hydroxyethyl acrylate. The conversion and enzyme activity were found to be optimal in reaction mixtures that contained 5 vol % of the acrylate. The structures of the products were revealed by using TLC and (1) H and (13) C NMR spectroscopy. The enzyme-catalyzed reaction resulted in two products. The minor product originated from transglycosidation to hemicellulose and was found to be 2-(β-xylosyloxy)-ethyl acrylate. The major product was identified as 2-(β-glucosyloxy)-ethyl acrylate and the yield of the product was 5 wt % based on the amount of consumed cellulose. Glycosidation products with oligosaccharide moieties could not be detected in the reaction mixture. This result can be explained by the hydrolytic activities of the used cellulase preparation. Cellulase from Trichoderma reesei was found to possess, in addition to endoglucanase activity, cellobiosidase and β-glucosidase activities. Five other cellulase preparations from different origins were tested as well for catalysis of oligosaccharide acrylate synthesis. For most cellulase preparations the major transglycosidation product appeared to be 2-(β-glucosyloxy)-ethyl acrylate. Nevertheless, the endo-β-(1,4)-glucanase from Trichoderma longibrachiatum was found to catalyze the synthesis of 2-(β-cellobiosyloxy)-ethyl acrylate. Unlike the other cellulase preparations, endo-β-(1,4)-glucanase from T. longibrachiatum showed no detectable β-glucosidase activity and therefore oligosaccharide acrylate monomers were not further hydrolyzed into the monosaccharide acrylate 2-(β-glucosyloxy)-ethyl acrylate. PMID:24866837

  3. Synthesis of Highly Porous Poly(tert-butyl acrylate)-b-polysulfone-b-poly(tert-butyl acrylate) Asymmetric Membranes

    Xie, Yihui

    2016-03-24

    For the first time, self-assembly and non-solvent induced phase separation was applied to polysulfone-based linear block copolymers, reaching mechanical stability much higher than other block copolymers membranes used in this method, which were mainly based on polystyrene blocks. Poly(tert-butyl acrylate)-b-polysulfone-b-poly(tert-butyl acrylate) (PtBA30k-b-PSU14k-b-PtBA30k) with a low polydispersity of 1.4 was synthesized by combining step-growth condensation and RAFT polymerization. Various advanced electron microscopies revealed that PtBA30k-b-PSU14k-b-PtBA30k assembles into worm-like cylindrical micelles in DMAc and adopts a “flower-like” arrangement with the PSU central block forming the shell. Computational modeling described the mechanism of micelle formation and morphological transition. Asymmetric nanostructured membranes were obtained with a highly porous interconnected skin layer and a sublayer with finger-like macrovoids. Ultrafiltration tests confirmed a water permeance of 555 L m-2 h-1 bar-1 with molecular weight cut-off of 28 kg/mol. PtBA segments on the membrane surface were then hydrolyzed and complexed with metals, leading to cross-linking and enhancement of antibacterial capability.

  4. Gel polymer electrolytes based on nanofibrous polyacrylonitrile–acrylate for lithium batteries

    Kim, Dul-Sun [Department of Chemical and Biological Engineering, Research Institute for Green Energy Convergence Technology, Gyeongsang National University, 900 Gajwa-dong, Jinju 660-701 (Korea, Republic of); Woo, Jang Chang [Department of Textile Engineering, Inha University, 100 Inharo, Nam-gu Incheon 402-751 (Korea, Republic of); Youk, Ji Ho, E-mail: youk@inha.ac.kr [Department of Textile Engineering, Inha University, 100 Inharo, Nam-gu Incheon 402-751 (Korea, Republic of); Manuel, James [Department of Chemical and Biological Engineering, Research Institute for Green Energy Convergence Technology, Gyeongsang National University, 900 Gajwa-dong, Jinju 660-701 (Korea, Republic of); Ahn, Jou-Hyeon, E-mail: jhahn@gnu.ac.kr [Department of Chemical and Biological Engineering, Research Institute for Green Energy Convergence Technology, Gyeongsang National University, 900 Gajwa-dong, Jinju 660-701 (Korea, Republic of); Department of Materials Engineering and Convergence Technology, Gyeongsang National University, 900 Gajwa-dong, Jinju 660-701 (Korea, Republic of)

    2014-10-15

    Graphical abstract: - Highlights: • Nanofibrous polyacrylonitrile–acrylate membranes were prepared by electrospinning. • Trimethylolpropane triacrylate was used as a crosslinking agent of fibers. • The GPE based on PAN–acrylate (1/0.5) showed good electrochemical properties. - Abstract: Nanofibrous membranes for gel polymer electrolytes (GPEs) were prepared by electrospinning a mixture of polyacrylonitrile (PAN) and trimethylolpropane triacrylate (TMPTA) at weight ratios of 1/0.5 and 1/1. TMPTA is used to achieve crosslinking of fibers thereby improving mechanical strength. The average fiber diameters increased with increasing TMPTA concentration and the mechanical strength was also improved due to the enhanced crosslinking of fibers. GPEs based on electrospun membranes were prepared by soaking them in a liquid electrolyte of 1 M LiPF{sub 6} in ethylene carbonate (EC)/dimethyl carbonate (DMC) (1:1, v/v). The electrolyte uptake and ionic conductivity of GPEs based on PAN and PAN–acrylate (weight ratio; 1/1 and 1/0.5) were investigated. Ionic conductivity of GPEs based on PAN–acrylate was the highest for PAN/acrylate (1/0.5) due to the proper swelling of fibers and good affinity with liquid electrolyte. Both GPEs based on PAN and PAN–acrylate membranes show good oxidation stability, >5.0 V vs. Li/Li{sup +}. Cells with GPEs based on PAN–acrylate (1/0.5) showed remarkable cycle performance with high initial discharge capacity and low capacity fading.

  5. Swelling Behaviors of Polyaniline-Poly(Acrylic Acid) Hydrogels

    ZHANG You-wei; ZHAO Jiong-xin; LI Xiao-feng; TAO Yong; WU Cheng-xun

    2005-01-01

    Using poly(acrylic acid) (PAA) aqueous solution, NaOH aqueous solution, aniline(An) and ammonim persulfate(APS), PAn-PAA hydrogels with a semi-interpenetrating structure connected by physical interlocks, chemical ion bonds and hydrogen bonds wcre prepared. The swelling properties of the hydrogels in solutions of different pH values(adjusted by adding NaOH or HCl) were studied. All the hydrogels prepared have similar swelling curves (the curves of equilibrium swelling ratio vs. pH value) and reach their maximum swelling at pH of 8 - 10. The maximum swelling ratio of the hydrogels is dependent on composition, including molecular weight of PAA, polymer content of the hydrogel,and molar ratios of AA to An, APS to An, and NaOH to AA.And the compositional dependence of the swelling capacity of PAn-PAA hydrogels was also studied.

  6. Surface cross-linked humic acid - polysodium acrylate superabsorbent

    Chu, M.; Zhu, S.; Li, H.; Huang, Z.; Zhang, X. [China University of Mining and Technology, Beijing (China)

    2005-03-01

    A novel composite super-absorbent of humic acid-polysodium acrylate was invented by surface cross-linking reaction of lignite humic acid and poly. Humic acid was abstracted from leonardite and poly was synthesized by solution polymerization. Water absorbing mechanism of composite superabsorbent was explored based on FTIR and SEM. The effect of surface cross-linking reaction conditions, such as the ratio of methanol to water, cross-linking agent concentration, and the amount of humic acid on water absorbing were investigated. Experiments show that the water absorbency of superabsorbent can be greatly improved by humic acid. When the mass fraction of humic acid is 10%, the ratio of cross-linking agent to PSA is 0.2%, and the ratio of methanol to water is 1.8, the water absorbency is the best: 750 g/g for deionied water and 260 g/g for running. water. 9 refs., 5 figs., 1 tab.

  7. Temperature dependence of the dielectric constant of acrylic dielectric elastomer

    Sheng, Junjie; Chen, Hualing; Li, Bo; Chang, Longfei [Xi' an Jiaotong University, State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi' an (China); Xi' an Jiaotong University, School of Mechanical Engineering, Xi' an (China)

    2013-02-15

    The dielectric constant is an essential electrical parameter to the achievable voltage-induced deformation of the dielectric elastomer. This paper primarily focuses on the temperature dependence of the dielectric constant (within the range of 173 K to 373 K) for the most widely used acrylic dielectric elastomer (VHB 4910). First the dielectric constant was investigated experimentally with the broadband dielectric spectrometer (BDS). Results showed that the dielectric constant first increased with temperature up to a peak value and then dropped to a relative small value. Then by analyzing the fitted curves, the Cole-Cole dispersion equation was found better to characterize the rising process before the peak values than the Debye dispersion equation, while the decrease process afterward can be well described by the simple Debye model. Finally, a mathematical model of dielectric constant of VHB 4910 was obtained from the fitted results which can be used to further probe the electromechanical stability of the dielectric elastomers. (orig.)

  8. New initiation system for polymerization of acryl acid

    LI Hai-pu; ZHONG Hong; CHEN Qi-yuan; YIN Zhou-lan

    2005-01-01

    The redox initiation system for polyacrylate sodium of high molecular mass was designed and its effect with varying component dosage on the degree of polymerization was investigated. The results show that the proper type and amount of inorganic salt, as well as amine initiator, are conductive to the increase of degree of polymerization. The fine ingredient of the initiation system is as follows:the dosages of amine, persulphate and inorganic salt are 0.75%, 0.10% and 1.00% by mass based on acryl acid respectively, the molar ratio of sulphite to the persulphate is 1:1. Under such conditions the degree of polyacrylate can reach 7.43×107 with a acceptable polymerization time for industrial production.

  9. Laboratory analyses of two explanted hydrophobic acrylic intraocular lenses

    Yunhai Dai

    2014-01-01

    Full Text Available Two three-piece hydrophobic acrylic intraocular lenses (IOLs were explanted from two patients at 7 and 9 years, respectively, after implantation, because of poor fundus visualisation and/or a clinically significant decrease in visual acuity related to their opacified IOLs. In addition to light microscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy, confocal laser scanning microscopy was used for the first time to observe the explanted IOLs. The clinical aspect seemed to correspond to the phenomenon of surface light scattering, while laboratory analyses showed dense glistenings in the central layer of the IOL optic, which had no change next to the surface. Further studies on these phenomena are needed.

  10. Microemulsion polymerization of butyl acrylate irradiated by γ-ray

    Radiation polymerization of butyl acrylate was carried out in microemulsion with high monomer and low emulsifier content. The rate of polymerization shows three intervals--the increasing period, the plateau period and the decreasing period for most cases. The length of nucleation period is independent of monomer content and temperature, and becomes longer with the increase of dose rate and the decrease of emulsifier content. The length of Rp plateau region increases with the increase of monomer and emulsifier content and with the decrease of dose rate. By studying the kinetics, the following formula were derived: Rp ∝ [M]0.93D1.27 [E]-1.07; Mn ∝ [M]0.65D0.28 [E]-1.66. (author)

  11. Radiation curable coatings from palm oil acrylated polyester prepolymer

    Radiation (ultra-violet, UV) curable coatings were prepared by using palm oil acrylated polyester prepolymer (PEPP-1) in combination with different reactive diluents in the presence of photoinitiator Irgacure 184 (Irg184). The effects of viscosity of coating materials, radiation dose and curing behavior were investigated. The UV cured polymeric films properties such as pendulum hardness, wettability (contact angle), gel ,content, swelling character, tensile strength, elongation at break, and deformation stability were then determined. The optimum formulations were also coated on wood substrates after which the gloss and hardness of the cured film on the wood substrate were measured. Some formulations showed promising coatings properties and has a good potential application for the wood coating industry. (Author)

  12. Study on preirradiation grafting of acrylic acid to cotton cellulose

    Grafting copolymerization of acrylic acid to cotton cellulose by using pre-irradiating method was investigated. At lower concentration of monomer (10%) the relationship between grafting yield and total dose, dose rate, reaction time and reaction temperature was measured. It was found that in the temperature range of 294 K to 323 K the grafting yield decreased with increasing of grafting reaction temperature. The grafting yields as a function of above reaction conditions were given by the expression Gr% = 5.9 x 10-10De20.27/RT(1-e-0.313te-6.87/RT), where R 8.314 x 10-3kj·K-1·mol-1, D = irradiation dose, T = reaction temperature, and t = reaction time

  13. Solubility of dense CO2 in two biocompatible acrylate copolymers

    A. R. C. Duarte

    2006-06-01

    Full Text Available Biocompatible polymers and copolymers are frequently being used as part of controlled delivery systems. These systems can be prepared using a "clean and environment friendly" technology like supercritical fluids. One great advantage of this process is that compressed carbon dioxide has excellent plasticizing properties and can swell most biocompatible polymeric matrixes, thus promoting drug impregnation processes. Mass sorption of two acrylate biocompatible copolymers contact with supercritical carbon dioxide is reported. Equilibrium solubility of dense carbon dioxide in poly(methylmethacrylate-co-ethylhexylacrylate and poly(methylmethacrylate-co-ethylhexylacrylate-co-ethyleneglycoldimethacrylate was studied by a static method at 10.0 MPa and 313 K. The reticulated copolymer had Fickean behavior and its diffusion coefficient was calculated, under operating conditions.

  14. Thermal Stability of Poly (acrylonitrile-methyl acrylate) Copolymers

    HAN Na; ZHANG Xing-xiang; WANG Xue-chen

    2008-01-01

    Poly (acrylonitrile-methyl acrylate) copolymer was synthesized by water depositing polymerization and has a typical feed ratio of 85/15. And then 1 - 3 wt% lauryl alcohol maleic anhydride (LAM) was adopted as stabilizer to mix with the acrylonitrile based copolymer. The mixtures were characterized by using Fourier Transform Infrared Spectroscopy (FTIR), Nuclear Magnetic Resonance (1H NMR ), Gel Permeation Chromatography ( GPC ), Differential Scanning Calorimetry (DSC), optic microscope and Ubbelohde viscosimetryr etc. The melting point (Tm) and glass transition temperature (Tg) of the 85/15 AN/MA copolymer mixed with LAM all decrease with the increase of stabilizer content. The lowest Tg and Tm were 116.1 ℃ and 209. 1℃ respectively at the heating rate of 100℃/min when the content of LAM is 2 wt%. The 85°/15 AN/MA copolymer mixed with 1 - 3 w t% LAM possess good thermal stability up to 30 min at 220 ℃.

  15. Polymerisation by acrylamide and acrylic acid inverse suspension

    Sergio Alejandro LLoreda Blanco

    2010-04-01

    Full Text Available This work describes polymerisation by inverse suspension of acrylamide monomers and acrylic acid for forming homopolymers or copolymers This type of polymersitaion's advantages are described and reasons given for why it should be studied. The article stresses the importance of these types of monomer for obtaining materials presenting great affinity for water, such as super-absorbents and controlled liberation mechanism. Important aspects are presented such as type of initiation, monomer composition and continuous phase composition; parameters are described offering an important basis for formulating a system leading to successfully obtaining the desired materials' most relevant characteristics such as particle distribution and size polymerisation kinetics, conversion and water absorption capacity respecting the system's modifiable parameters. The foregoing is important since the product can be modified, bestowing propierties on it which are suitable for its use.

  16. Optimization of cellulose acrylate and grafted 4-vinylpyridine and 1-vinylimidazole synthesis

    Bojanić Vaso

    2010-01-01

    Full Text Available Optimization of cellulose acrylate synthesis by reaction with sodium cellulosate and acryloyl chloride was carried out. Optimal conditions for conducting the synthesis reaction of cellulose acrylate were as follows: the molar ratio of cellulose/potassium-t-butoxide/acryloyl chloride was 1:3:10 and the optimal reaction time was 10 h. On the basis of elemental analysis with optimal conditions for conducting the reaction of cellulose acrylate, the percentage of substitution of glucose units in cellulose Y = 80.7%, and the degree of substitution of cellulose acrylate DS = 2.4 was determined. The grafting reaction of acrylate vinyl monomers onto cellulose in acetonitrile with initiator azoisobutyronitrile (AIBN in a nitrogen atmosphere was performed, by mixing for 5 h at acetonitrile boiling temperature. Radical copolymerization of synthesized cellulose acrylate and 4-vinylpyridine, 1-vinylimidazole, 1-vinyl-2-pyrrolidinone and 9-vinylcarbazole, cellulose-poly-4-vinylpyridine (Cell-PVP, cellulose-poly-1- vinylimidazole (Cell-PVIm and cellulose-poly-1-vinyl-2-pyrrolidinone (Cell-P1V2P and cellulose-poly-9-vinylcarbazole (Cell-P9VK were synthesized. Acrylate cellulose and cellulose grafted copolymers were confirmed by IR spectroscopy, based on elementary analysis and the characteristics of grafted copolymers of cellulose were determined. The mass share of grafted copolymers, X, the relationship of derivative parts/cellulose vinyl group, Z, and the degree of grafting copolymers of cellulose (mass% were determined. In reaction of methyl iodide and cellulose-poly-4-vinylpyridine (Cell-PVP the cellulose-1-methyl-poly-4-vinylpyridine iodide (Cell-1-Me-PVPJ was synthesized. Cellulose acrylate and grafted copolymers were obtained with better thermal, electrochemical and ion-emulation properties for bonding of noble metals Au, Pt, Pd from water solutions. The synthesis optimization of cellulose acrylate was applied as a model for the synthesis of grafted

  17. Flexural Strength of Cold and Heat Cure Acrylic Resins Reinforced with Different Materials

    Bijan Heidari

    2015-10-01

    Full Text Available Objectives: Heat-polymerized acrylic resin has been the most commonly used denture base material for over 60 years. However, the mechanical strength of acrylic resin is not adequate for long-term clinical performance of dentures. Consequently, fracture is a com- mon clinical occurrence, which often occurs in the midline of denture base.This study aimed to evaluate the efficacy of cold cure and heat cure acrylic resins, rein- forced with glass fibers, polyethylene fibers, and metal wire for denture base repair.Materials and Methods: Ninety specimens were prepared and allocated to nine groups. Ten specimens were included in the control group, and 80 were allocated to 8 experi- mental groups. In the experimental groups, the specimens were sectioned into two halves from the middle, and were then divided into two main groups: one group was repaired with heat cure acrylic resin, and the other with cold cure acrylic resin. Each group was di- vided into 4 subgroups: unreinforced, reinforced with glass fibers, polyethylene fibers, and metal wire. All specimens were then subjected to a 3-point bending test, and the flexural strength was calculated.Results: The group repaired with heat cure acrylic resin and reinforced with glass fiber showed the highest flexural strength; however, the group repaired with cold cure acrylic resin and reinforced with polyethylene fibers had the lowest flexural strength. There was no significant difference between the groups repaired with heat cure and cold cure acrylic resins without reinforcement.Conclusion: Repairing denture base with heat cure acrylic resin, reinforced with glass fi- bers increases the flexural strength of denture base.

  18. Mutagenicity assessment of acrylate and methacrylate compounds and implications for regulatory toxicology requirements.

    Johannsen, F R; Vogt, Barbara; Waite, Maureen; Deskin, Randy

    2008-04-01

    Esters of acrylic acid and methacrylic acid, more commonly known as acrylates and methacrylates, respectively, are key raw materials in the coatings and printing industry, with several of its chemical class used in food packaging. The results of over 200 short-term in vitro and in vivo mutagenicity studies available in the open literature have been evaluated. Despite differences in acrylate or methacrylate functionality or in the number of functional groups, a consistent pattern of test response was seen in a typical regulatory battery of mutagenicity tests. No evidence of point mutations was observed when acrylic acid or over 60 acrylates and methacrylates were investigated in Salmonella bacterial tests or in hprt mutation tests mammalian cells, and no evidence of a mutagenic effect was seen when tested in whole animal clastogenicity and/or aneuploidy (chromosomal aberration/micronucleus) studies. Consistent with the in vivo testing results, acrylic acid exhibited no evidence of carcinogenicity in chronic rodent cancer bioassays. In contrast, acrylic acid and the entire acrylate and methacrylate chemical class produced a consistently positive response when tested in the mouse lymphoma assay and/or other in vitro mammalian cell assays designed to detect clastogenicity. The biological relevance of this in vitro response is questioned based on the non-concordance of in vitro results with those of in vivo studies addressing the same mutagenic endpoint (clastogenicity). Thus, in short-term mutagenicity tests, the acrylates and methacrylates behave as a single chemical category, and genotoxicity behavior of a similar chemical can be predicted with confidence by inclusion within this chemical class, thus avoiding unnecessary testing. PMID:18346829

  19. Flexural strength of acrylic resins polymerized by different cycles

    Débora Barros Barbosa

    2007-10-01

    Full Text Available Despite the large number of studies addressing the effect of microwave polymerization on the properties of acrylic resin, this method has received limited clinical acceptance. This study evaluated the influence of microwave polymerization on the flexural strength of a denture base resin. A conventional heat-polymerized (Clássico, a microwave-polymerized (Onda-Cryl and a autopolymerizing acrylic (Jet resins were used. Five groups were established, according to polymerization cycles: A, B and C (Onda-Cryl, short cycle - 500W/3 min, long - 90W/13 min + 500W/90 sec, and manufacturing microwave cycle - 320W/3 min + 0W/3 min + 720W/3 min; T (Clássico, water bath cycle - 74ºC/9h and Q (Jet, press chamber cycle - 50ºC/15 min at 2 bar. Ten specimens (65 x 10 x 3.3mm were prepared for each cycle. The flexural strength of the five groups was measured using a three-point bending test at a cross-head speed of 5 mm/min. Flexural strength values were analyzed by one-way ANOVA and the Tukey's test was performed to identify the groups that were significantly different at 5% level. The microwave-polymerized groups showed the highest means (p<0.05 for flexural strength (MPa (A = 106.97 ± 5.31; B = 107.57 ± 3.99; C = 109.63 ± 5.19, and there were no significant differences among them. The heat-polymerized group (T showed the lowest flexural strength means (84.40 ± 1.68, and differ significantly from all groups. The specimens of a microwavable denture base resin could be polymerized by different microwave cycles without risk of decreasing the flexural strength.

  20. Synthesis and Properties of Poly (n-Octyl Acrylate) with Uniform Polystyrene Grafts

    2007-01-01

    Poly (n-octyl acrylate) with uniform polystyrene grafts (POA-g-PS) was obtained by radical copolymerization of n-octyl acrylate (OA) with PS macromer, in solution. The reactivity ratio and effects of copolymerization conditions on grafting efficiency were studied. The crude products were purified by extraction with cyclohexane and n-butanol successively. POA-g-PS exhibited a very good compatibilizing effect on the acrylic rubber/polystyrene blends. 2%-3% of the graft copolymer was enough for enhancing the tensile strength of the blends. DSC and SEM demonstrated the enhancement of compatibility in the presence of the graft copolymer.

  1. Blends of dissolved cellulose with acrylic acid copolymers or microfibrillated cellulose

    Saarikoski, Eve

    2015-01-01

    The aim of the thesis was to develop dissolved cellulose (dissolved in NaOH/ZnO) based blends with acrylic acid copolymers (poly(ethylene-co-acrylic acid) (PE-co-AA) or poly(acrylamide-co-acrylic acid) (PAA-co-AA)) or microfibrillated cellulose (MFC) in the way they could be used in injection molding or for film/coating applications. This thesis summarizes the research reported in five publications supported by some unpublished results. Rheological studies done in the contexts of this work...

  2. Electron beam curable branched chain polyurethane acrylates for magnetic media coatings

    Electron beam curable binder resins have been studied to realize the high quality magnetic coatings. It was supposed that resins with a higher crosslink density could lead to magnetic coatings with higher abrasion resistance. Branched chain polyurethane acrylates show a higher degree of cure by irradiation with an electron beam in comparison with linear polyurethane acrylates. This paper describes the potential wear resistance between properties of magnetic coatings and the physical properties of the cured unpigmented branched chain polyurethane acrylates that were used as the binder resins. (author)

  3. Assessment of the flexural strength of two heat-curing acrylic resins for artificial eyes

    Aline Úrsula Rocha Fernandes; Aline Portugal; Letícia Rocha Veloso; Marcelo Coelho Goiato; Daniela Micheline dos Santos

    2009-01-01

    Prosthetic eyes are artificial substitutes for the eyeball, made of heat-curing acrylic resin, serving to improve the esthetic appearance of the mutilated patient and his/her inclusion in society. The aim of this study was to assess the flexural strength of two heat-curing acrylic resins used for manufacturing prosthetic eyes. Thirty-six specimens measuring 64 x 10 x 3.3 mm were obtained and divided into four groups: acrylic resin for artificial sclera N1 (Artigos Odontológicos Clássico, São ...

  4. CROSS-REACTION PATTERNS IN GUINEA-PIGS SENSITIZED TO ACRYLIC-MONOMERS

    Clemmensen, S.

    1984-01-01

    The cross-reaction patterns of selected acrylate and methacrylate esters were investigated using the guinea pig maximization test. Methacrylates were less potent sensitizers than acrylates. Cross-sensitization was found between (meth)acrylates with closely related core structures, most extensively...... between hydroxyethyl and hydroxypropyl congeners. The importance of considering not only the functional group but also the core structure when assessing potential interactions was emphasized as butanedioldiglycidylether, hexamethylenediisocyanate and hexanedioldiacrylate - all with linear 6-atom cores...... and different functional groups - cross-reacted....

  5. Synthesis and properties of photo-curable silicone (meth)acrylate oligomers

    Photo-curable resins are widely used in various applications such as coatings, adhesives and inks, due to their high efficiencies, environmental friendly technology and saving of energy. Silicone (meth) acrylate oligomers offer an excellent slip property because of their low surface tension. In addition, they can enhance other properties like chemical resistance and heat resistance. In this research, photo-curable silicone (meth) acrylate oligomers are prepared from modified PDMS (polydimethyl siloxane) polyols, diisocyanate, carboxylic acid and hydroxyl (meth) acrylate to evaluate basic property of these oligomers. (Author)

  6. Effect of silver nanoparticles incorporation on viscoelastic properties of acrylic resin denture base material

    Mahross, Hamada Zaki; Baroudi, Kusai

    2015-01-01

    Objective: The objective was to investigate the effect of silver nanoparticles (AgNPs) incorporation on viscoelastic properties of acrylic resin denture base material. Materials and Methods: A total of 20 specimens (60 × 10 × 2 mm) of heat cured acrylic resin were constructed and divided into four groups (five for each), according to the concentration of AgNPs (1%, 2%, and 5% vol.) which incorporated into the liquid of acrylic resin material and one group without additives (control group). The dynamic viscoelastic test for the test specimens was performed using the computerized material testing system. The resulting deflection curves were analyzed by material testing software NEXYGEN MT. Results: The 5% nanoparticles of silver (NAg) had significantly highest mean storage modulus E’ and loss tangent Tan δ values followed by 2% NAg (P 0.05). Conclusion: The AgNPs incorporation within the acrylic denture base material can improve its viscoelastic properties. PMID:26038651

  7. Synergistic effect of additives including multifunctional acrylates in wood plastic composites

    Wood Plastic Composite (WPC) was prepared with simul (soft wood, density = 0.4g/cc) and butylmethacrylate (BMA) monomer using 10% methanol as the swelling agent. Effect of additives including multifunctional acrylates such as tripropylene glycol diacrylate (TPGDA), trimethylol propane triacrylate (TMPTA), oligomer acrylates like the urethane (UA), epoxy (EA) and polyester (PEA) acrylates and N-vinyl pyrrolidone (NVP) was investigated using 1 to 3 Mrad dose at 0.8 Mrad/h. Synergistic increases in polymer loading yields was achieved in presence of the additives, particularly with the trifunctional acrylate (TMPTA). In addition, acid as well as urea were also used as co-additives and synergistic enhancement in yields of polymer loading were obtained. The synergistic polymer loading by acid addition causes substantial decrease in tensile strength of the composite; but other additives and co-additives increase both the polymer loading and the tensile strength in these systems. (author)

  8. Regiospecific Addition of Uracil to Acrylates Catalyzed by Alkaline Protease from Bacillus subtilis

    Ying CAI; Jian Yi WU; Na WANG; Xiao Feng SUN; Xian Fu LIN

    2004-01-01

    Michael addition reactions of uracil to acrylates were catalyzed by an alkaline protease from Bacillus subtilis in dimethyl sulfoxide at 55 ℃ for 72 h. The adducts were determined by TLC, IR and 1H NMR.

  9. Surface coating of jeungjing wood (Paraserianthes Falcataria (L) NIELSEN) with acrylate resins by using radiation technique

    An experiment on surface coating with acrylate resins has been done by using radiation technique to improve the quality and added value of jeunjing wood (Paraserianthes Falcataria (L) NIELSEN). Doses used in Electron Beam (BE) radiation were 20, 40, and 60 kGy. Epoxy acrylate and ester acrylate resins were used as coating materials after added with tripropylene glycol diacylate (TPGDA) monomer, 2,2-dimethyl-2hidroxy acetophenone (Darocur 1173) photoinitiator and talc as base coat. Top coat consists of este acrylate Setacure AM 548, after added with titanium dioxide OK 412 as additive respectively. Titanium dioxides in the mixture were varied at the concentration level of 0, 2, 4 and 6 % by weight. Conventional coating as comparison was carried out by using varnish as coating material. The results showed that the properties of film on jeunjing wood by EB curing are better than that of conventional one. (authors)

  10. Effect of microwave cured acrylic resin on candidal growth in complete denture

    This study was conducted to evaluate the effect of heat-cured acrylic resin denture base and microwave-cured acrylic resin denture base on candidal growth . Seven completely edentulous male patients with on history of denture wearing participated in this study. all the selected patients were re-habilitated by mucosa supported complete dentures .The dentures were constructed from conventional heat-cured acrylic resin denture base following monoplane concept of occlusion. Before dismissing the patients and one month after denture insertion, salivary samples were collected according to oral rinse technique. one month resting period was allowed so as candidal count can reach to normal, then dentures were re based using microwave-cured acrylic denture base, before denture insertion and one month after denture insertion, salivary sample were collected before and one month following the same oral rinse technique.

  11. CATALYTIC HYDROGENATION OF ACRYLATE ASMMETRIC Dd(Ⅱ)—CHELATING RESINS CONTAINING AMINO ACID LIGANDS

    Wangying; WangHongzuo; 等

    1995-01-01

    The catalytic hydrogenation of palladium chelating resins containing chiral amino acid ligands based on lower crosslinked poly(chloroethyl acrylate) and some effects on the rate of hydrogenation were studied.

  12. FT-RAMAN SPECTROSCOPY FOR MONITORING THE POLYMERIZATION OF ACRYLIC ACID IN AQUEOUS SOLUTION

    Jiang Yu; Hui-zhou Liu; Jia-yong Chen

    1999-01-01

    FT-Raman spectroscopy was used to monitor the polymerization of acrylic acid in aqueous solution. A simple method to avoid the noise in the background during the signal processing via Fourier transformation was used in this work. The effects of the amount of initiator used on the polymerization are studied. When the amount of the initiator in the polymerization was increased, both the rate and extent of polymerization of acrylic acid will be increased.

  13. Intra-oral electron therapy for carcinoma of the oral cavity using transparent acrylic tubes

    Intra-oral electron therapy for carcinoma of the oral cavity is a well-established treatment modality. However, the conventional metallic tubes were inconvenient to use because the irradiation field had to be confirmed by a side mirror. We devised transparent acrylic tubes which enable the positioning easy by confirming the tumor and irradiation field directry. Seven cases of various intra-oral carcinomas were treated with these new transparent acrylic tubes and good results were obtained. (author)

  14. Effect of nanosilver on thermal and mechanical properties of acrylic base complete dentures.

    Fahimeh Hamedi-Rad; Tahereh Ghaffari; Farzad Rezaii; Ali Ramazani

    2014-01-01

    Objective: Polymethyl methacrylate (PMMA), widely used as a prosthodontic base, has many disadvantages, including a high thermal expansion coefficient and low thermal conductivity, a low elasticity coefficient, low impact strength and low resistance to fatigue. This study aimed to make an in vitro comparison of the thermal conductivity, compressive strength, and tensile strength of the acrylic base of complete dentures with those of acrylic reinforced with nanosilver. Materials and Methods: F...

  15. Do flexible acrylic resin lingual flanges improve retention of mandibular complete dentures?

    Ahmed Elmorsy, Ayman Elmorsy; Ahmed Ibraheem, Eman Mostafa; Ela, Alaa Aboul; Fahmy, Ahmed; Nassani, Mohammad Zakaria

    2015-01-01

    Objectives: The aim of this study was to compare the retention of conventional mandibular complete dentures with that of mandibular complete dentures having lingual flanges constructed with flexible acrylic resin “Versacryl.” Materials and Methods: The study sample comprised 10 completely edentulous patients. Each patient received one maxillary complete denture and two mandibular complete dentures. One mandibular denture was made of conventional heat-cured acrylic resin and the other had its ...

  16. Synthesis of acrylic acid derivatives from carbon dioxide and ethylene mediated by molecular nickel complexes

    Lee, Sin Ying Tina

    2013-01-01

    This work aimed at the synthesis of acrylic acid derivatives from ethylene and CO2 and well as the investigation of β-hydride elimination reaction of nickelalactones with methyl iodide and methyl triflate to form methyl acrylate. The oxidative coupling reaction of ethylene and CO2 on nickel center was ligand selective, and gave low yields of nickelalactone product at mild synthetic conditions. Key intermediates identified and characterized in the β-H elimination reaction provided rich insight...

  17. Ligand switch in photoinduced copper-mediated polymerization: synthesis of methacrylate-acrylate block copolymers

    CHUANG, Ya-Mi; Wenn, Benjamin; Gielen, Sam; Ethirajan, Anitha; Junkers, Thomas

    2015-01-01

    The use of photo-induced copper-mediated radical polymerization (photoCMP) to synthesize mixed acrylate/methacrylate (methyl acrylate, MA and methyl methacrylate, MMA) block copolymers is investigated. Reactions in which only one type of ligand (Me6TREN) is used lead to unsuccessful outcomes of polymerization due to a mismatch in reactivity of the two monomers. A ligand exchange to PMDETA for methacrylate is required to obtain good block structures. Due to insufficient re-initiation of polyac...

  18. Acrylic acid obtaining from methanol and acetic acid in the presence of complex oxide catalysts

    Небесний, Роман Володимирович; Піх, Зорян Григорович; Шпирка, Ірина Іванівна; Івасів, Володимир Васильович; Небесна, Юлія Віталіївна; Фуч, Уляна Василівна

    2015-01-01

    The purpose of this work is to research process of single-stage acrylic acid obtaining from methanol and acetic acid, namely: to develop effective catalysts for the process of methanol oxidation to formaldehyde with its further aldol condensation with acetic acid to acrylic acid, and to determine optimum conditions for the process. Complex oxide catalysts consisting of oxides of boron, phosphorus, tungsten and vanadium supported on the silica gel have been investigated. The effect of vanadium...

  19. The effect of various frequencies of ultrasonic cleaner in reducing residual monomer in acrylic resin.

    Charasseangpaisarn, Taksid; Wiwatwarrapan, Chairat

    2015-12-01

    Monomer remaining in denture base acrylic can be a major problem because it may cause adverse effects on oral tissue and on the properties of the material. The purpose of this study was to compare the effect of various ultrasonic cleaner frequencies on the amount of residual monomer in acrylic resin after curing. Forty-two specimens each of Meliodent heat-polymerized acrylic resin (M) and Unifast Trad Ivory auto-polymerized acrylic resin (U) were prepared according to their manufacturer's instructions and randomly divided into seven groups: Negative control (NC); Positive control (PC); and five ultrasonic treatment groups: 28 kHz (F1), 40 kHz (F2), 60 kHz (F3) (M=10 min, U=5 min), and 28 kHz followed by 60 kHz (F4: M=5 min per frequency, U=2.5 min per frequency, and F5: M=10 min followed by 5 min per frequency, U=5 min followed by 2.5 min per frequency). Residual monomer was determined by HPLC following ISO 20795-1. The data were analyzed by One-way ANOVA and Tukey HSD. There was significantly less residual monomer in the auto-polymerized acrylic resin in all ultrasonic treatment groups and the PC group than that of the NC group (p0.05). The amount of residual monomer in heat-polymerized acrylic resin was significantly lower than that of auto-polymerized acrylic resin. In conclusion, ultrasonic treatment at low frequencies is recommended to reduce the residual monomer in auto-polymerized acrylic resin and this method is more practical in a clinical situation than previously recommended methods because of reduced chairside time. PMID:26190059

  20. Direct initiation of the photopolymerization of acrylates by short-wavelength excimer UV radiation

    Investigations on the direct initiation of the photopolymerization of acrylates by irradiation with short-wavelength monochromatic UV light using the 222 nm emission of a KrCl* excimer lamp are reported. The reactivity of various acrylates was studied by real-time FTIR-ATR spectroscopy. Laser photolysis experiments and accompanying quantum chemical calculations were performed in order to propose a possible mechanism of initiation

  1. Rapid Solid-State Photopolymerization of Cyclic Acetal-Containing Acrylates

    Berchtold, Kathryn A.; Hacioğlu, Bilge; Nie, Jun; Cramer, Neil B.; Stansbury, Jeffrey W.; Bowman, Christopher N.

    2009-01-01

    A cyclic acetal-functionalized urethane acrylate monomer is synthesized here and polymerized in a crystalline state without the polymerization kinetics being deleteriously affected by the solid state. Depending on the processing conditions, the cyclic acetal urethane acrylate monomer exists in either a metastable liquid state or a crystalline state at ambient conditions. Due to mobility restrictions, extremely poor polymerization kinetics and functional group conversions are typically achieve...

  2. Antifungal Effect of Zataria multiflora Essence on Experimentally Contaminated Acryl Resin Plates With Candida albicans

    Jafari, Abbas Ali; Falah Tafti, Abbas; Hoseiny, Seyed Mehdi; Kazemi, Abdolhossein

    2015-01-01

    Background: Adherence and colonization of Candida species particularly C. albicans on denture surfaces, forms a microbial biofilm, which may result denture stomatitis in complete denture users. Objectives: The purpose of the present study was to evaluate the antifungal effect Zataria multiflora essence in removing of Candida albicans biofilms on experimentally contaminated resin acryl plates. Materials and Methods: In the present experimental study, 160 resin acrylic plates (10 × 10 × 1 mm) w...

  3. Synthesis and Characterization of Core-Shell Acrylate Based Latex and Study of Its Reactive Blends

    Ying Nie; Min-Feng Tang; Xiao-Dong Fan; Xiang Liu

    2008-01-01

    Techniques in resin blending are simple and efficient method for improving the properties of polymers, and have been used widely in polymer modification field. However, polymer latex blends such as the combination of latexes, especially the latexes with water-soluble polymers, were rarely reported. Here, we report a core-shell composite latex synthesized using methyl methacrylate (MMA), butyl acrylate (BA), 2-ethylhexyl acrylate (EHA) and glycidyl methacrylate (GMA) as monomers and ammonium p...

  4. EFFECTS OF PHENOL RESIN ADDITIVE ON DYNAMIC MECHANICAL PROPERTIES OF ACRYLATE RUBBER AND ITS BLENDS

    Chi-fei Wu

    2003-01-01

    The dynamic mechanical properties of a new blend system consisting of phenol resin and polar polymer (acrylate rubber and/or chlorinated polypropylene) were investigated. It was found that the addition of phenol resin to acrylate rubber and its incompatible blend can cause a remarkable improvement in the temperature dependence of the loss tangent. As a result, the present blends are very good damping materials.

  5. Effect of Amylase, Papaein and Pepsin enzyme solutions on Candida biofilm formed on acrylic resin plates

    A Jafari Nodoushan; A Fallah Tafti; Emami, P; H Ashoori

    2013-01-01

    Abstract:     Background and Aim: Denture stomatitis results from colonization of oral Candida on the surface of denture acrylic base. To control this infection,Candida biofilm formation must be prevented using mechanical and chemical decontamination. The purpose of the present study was to evaluate the effect of Amylase, Papaein and Pepsin solutions on removal of Candida Albicans plaques formed on acrylic resin plates.   Materials and Methods : In this experimental study Candida biofilm was ...

  6. Effect of Amylase, Papaein and Pepsin enzyme solutions on Candida biofilm formed on acrylic resin plates

    AA jafari_nodoushan; FalahTafti A; Emmami P; Ashouri

    2013-01-01

    Background and Aim: Denture stomatitis results from colonization of oral Candida on the surface of denture acrylic base. To control this infection,Candida biofilm formation must be prevented using mechanical and chemical decontamination. The purpose of the present study was to evaluate the effect of Amylase, Papaein and Pepsin solutions on removal of Candida Albicans plaques formed on acrylic resin plates. Materials and Methods: In this experimental study Candida biofilm was formed on 220 ...

  7. Effect of acrylic polymers on physical parameters of spheronized pellets using an aqueous coating system

    Akhter Afsana; Kibria Golam

    2009-01-01

    The aim of this study was to develop ambroxol hydrochloride sustained release pellets by an extrusion-spheronization technique and subsequent coating with acrylic polymers. Acrylic polymers like Eudragit RL 30 D, Eudragit RS 30 D and Eudragit NE 30 D were used as release retarding coating polymers. The release retarding capability of these polymers was also investigated. In each case, 10% polymer on dry basis was loaded. The flow property, surface roughness as well as the drug release ...

  8. Synthesis and Properties of IPN Hydrogels Based on Konjac Glucomannan and Poly(acrylic acid)

    Bing LIU; Zhi Lan LIU; Ren Xi ZHUO

    2006-01-01

    Novel interpenetrating polymer network (IPN) hydrogels based on konjac glucomannan (KGM) and poly(acrylic acid) (PAA) were prepared by polymerization and cross-linking of acrylic acid (AA) in the pre-fabricated KGM gel. The IPN gel was analyzed by FT-IR. The studies on the equilibrium swelling ratio of IPN hydrogels revealed their sensitive response to environmental pH value. The results of in vitro degradation showed that the IPN hydrogels retain the enzymatic degradation character of KGM.

  9. In vitro cytotoxicity of self-curing acrylic resins of different colors

    Luciana Borges Retamoso

    2014-08-01

    Full Text Available OBJECTIVE: The aim of this study was to assess the in vitro cytotoxicity of acrylic resins of different colors over time. METHODS: Specimens were divided into 4 groups (n = 6 according to the color of the acrylic resin (Orto Class, Clássico, Campinas, São Paulo, Brazil: Group 1: clear acrylic resin; group 2: pink acrylic resin; group 3: blue acrylic resin and group 4: green acrylic resin. All specimens were fabricated according to the mass manipulation technique and submitted to mechanical polishing protocol. The control was performed with an amalgam specimen (C+, a glass specimen (C- and cell control (CC. Specimens were immersed in Minimum Eagle's Medium (MEM and incubated for 24 h at 37o C. The extracts from the experimental material were filtered and mixed with L929 fibroblast. Cytotoxicity was evaluated at 4 different times, 24, 48, 72 and 168 h. After contact, cells were incubated for 24 h and added to 100 µ of 0.01% neutral red dye. The cells were incubated for 3 h for pigment incorporation and fixed. Cells viability was determined by a spectroscopic (BioTek, Winooski, Vermont, USA with a 492-nm wavelength λ=492 nm. RESULTS: There were no statistical differences between the experimental groups and the CC and C- groups. CONCLUSION: Clear, pink, blue and green self-curing acrylic resins fabricated by means of the mass manipulation technique and mechanically polished are not cytotoxic. Neither the pigment added to the self-curing acrylic resin nor the factor of time influenced the cytotoxicity of the material.

  10. Silver hollow optical fibers with acrylic silicone resin coating as buffer layer for sturdy structure

    Iwai, Katsumasa; Takaku, Hiroyuki; Miyagi, Mitsunobu; Shi, Yi-Wei; Zhu, Xiao-Song; Matsuura, Yuji

    2016-03-01

    For sturdy silver hollow optical fibers, acrylic silicone resin is newly used as a buffer layer between an inner silver layer and a silica capillary. This acrylic silicone resin film prevents the glass surface from chemical and mechanical micro damages during silver plating process, which deteriorate mechanical strength of the hollow fibers. In addition, it keeps high adhesion of the silver layer with the glass surface. We discuss improvement of mechanical strength of the hollow glass fibers without deterioration of optical properties.

  11. Enzymatic direct synthesis of acrylic acid esters of mono- and disaccharides

    Tsukamoto, Junko; Heabel, Sophie; Valenca, Gustavo P.; Peter, Martin; Franco, Telma

    2010-01-01

    BACKGROUND: There is an increased need to replace materials derived from fossil sources by renewables. Sugar-cane derived carbohydrates are very abundant in Brazil and are the cheapest sugars available in the market, with more than 400 million tons of sugarcane processed in the year 2007. The objective of this work was to study the preparation of sugar acrylates from free sugars and free acrylic acid, thus avoiding the previous preparation of protected sugar derivatives, such as glycosides, o...

  12. Synthesis and characterization of acrylated epoxidized soybean oil for UV cured coatings

    Habib, Firdous; Bajpai, Madhu

    2011-01-01

    This paper investigates the curing of biodegradable polymer films which were synthesized from soybean oil through the ultraviolet radiation and their stability against thermal degradation. In this study the epoxidation of soybean oil has been carried out via peracetic method. Further, an epoxy acrylate resin was synthesized from the epoxidized soybean oil (ESO) by using acrylic acid monomer. Triethylamine (TEA) and hydroquinone were used as a catalyst and inhibitor respectively. The acrylatio...

  13. Radiation-induced grafting of acrylic acid onto polypropylene film and its biodegradability

    Mandal, Dev K.; Bhunia, Haripada; Bajpai, Pramod K.; Chaudhari, C. V.; Dubey, K. A.; Varshney, L.

    2016-06-01

    Polypropylene based commodity polyolefins are widely used in packaging, manufacturing, electrical, pharmaceutical and other applications. The aim of the present work is to study the effect of grafting of acrylic acid on the biodegradability of acrylic acid grafted polypropylene. The effect of different conditions showed that grafting percentage increased with increase in monomer concentration, radiation dose and inhibitor concentration but decreased with increase in radiation dose rate. The maximum grafting of 159.4% could be achieved at optimum conditions. The structure of grafted polypropylene films at different degree of grafting was characterized by EDS, FTIR, TGA, DSC, SEM and XRD. EDS studies showed that the increase in acrylic acid grafting percentage increased the hydrophilicity of the grafted films. FTIR studies indicated the presence of acrylic acid on the surface of polypropylene film. TGA studies revealed that thermal stability decreased with increase in grafting percentage. DSC studies showed that melting temperature and crystallinity of the grafted polypropylene films lower than polypropylene film. SEM studies indicated that increase in acrylic acid grafting percentage increased the wrinkles in the grafted films. The maximum biodegradability could be achieved to 6.85% for 90.5% grafting. This suggested that microorganisms present in the compost could biodegrade acrylic acid grafted polypropylene.

  14. Allergic contact dermatitis from sculptured acrylic nails: special presentation with an airborne pattern

    Paula Maio

    2012-05-01

    Full Text Available Methylmethacrylate was first reported in 1941 as a cause of contact dermatitis. Since then, occupational contact allergies to acrylates in dentistry, orthopedic surgery, printing industry and industry have been reported, but few reports are found in the literature as a consequence of the contact with sculptured artificial acrylic nails which are increasingly popular. We describe here 3 patients with contact allergy to acrylates in artificial sculptured nails. Patch tests were performed with the Portuguese baseline series of contact allergens and an extended series of acrylates were applied. In particular, we tested three female patients with allergic contact dermatitis from sculptured acrylic nails. Two of these patients were both customers and also technical nail beauticians. Two patients developed periungual eczema; one presented only with face and eyelid dermatitis had no other lesions. The tests showed positive reaction to 2-hydroxyethylmethacrylate (2-HEMA and 2-hydroxypropylmethacrylate (2-HPMA in all the three patients. Our cases demonstrate the variety of clinical presentations of allergic contact dermatitis from acrylic sculptured nails. They show the need to warn patients of persistent and sometimes permanent side effects of these products. They also emphasize the importance of cosmetic ingredient labeling.

  15. Dimensional change of acrylic resin plate after the reinforcement of glass fibre

    Dwiyanti Feriana Ratwita

    2007-06-01

    Full Text Available The effect of fibre reinforcement of polymethyl methacrylate was investigated. Glass fibres have been studied as strengthening material added to polymethyl methacrylate. The purpose of this study was to evaluate dimensional change of acrylic resin plate after glass fibre reinforcement. As a research subject is an acrylic resin plate of 65 × 10 × 2.5 mm with the number of 32 samples were distributed randomly in 4 experimental groups. Each group consisted of 8 samples and control groups. Group 1: acrylic resin plate and 1 sheet glass fibre; group 2: acrylic resin plate and 2 sheet glass fibre; group 3: acrylic resin plate and 3 sheet glass fibre. Control group which was not given treatment. Dimensional change was measured by profile projector. The data was analyzed by One-Way ANOVA and LSD test showed that there was significant difference in dimensional change (p < 0.005. The conclusion suggested that dimensional change of the acrylic resin plates after glass fibre reinforcement minimally done 1 sheet glass fibre.

  16. Radiopurity measurement of acrylic for the DEAP-3600 dark matter experiment

    Nantais, Corina Michelle

    2014-05-01

    The liquid argon target of the DEAP-3600 dark matter detector is contained by an extremely radiopure acrylic vessel. Alpha decays from the inner surface of the acrylic vessel are a source of background. If a fraction of the alpha energy is observed, or if the recoiling nucleus from the alpha decay is observed, the event will not be separated from a dark matter candidate event. In addition to the low level of inherent contamination from uranium and thorium, the Pb-210 from Rn-222 diffusion during manufacturing must be measured. The limit for the DEAP-3600 acrylic vessel is 1.1 x 10-20 g/g Pb-210. By vaporizing a large quantity of acrylic and counting the concentrated residue with an ultralow background HPGe well detector and a low background alpha spectrometer, the bulk acrylic was found to have an upper limit of 10 -19 g/g Pb-210. The design, installation, commissioning, operation, and analysis for various aspects of the acrylic assay are described.

  17. Radiation grafting of acrylic acid onto polypropylene films

    A study has been made for the preparation of membranes by the direct radiation grafting of acrylic acid (AAc) onto polypropylene (PP) films. The appropriate reaction conditions were selected under which the graft polymerization was carried out successfully. The effect of different solvents such as benzene, methanol/water mixture, isopropanol/water mixture, dimethyl formamide and distilled water on the swelling and grafting process of AAc onto PP films was investigated. In this grafting system ammonium ferrous sulphate (Mohr's salt) and ferric chloride were used as inhibitors to minimize the homopolymerisation of AAc and the suitable concentration of the inhibitor was found to be 1.0 and 1.5 wt% for Mohr's salt and ferric chloride, respectively. Also, the effect of monomer concentration on the rate of grafting was investigated. The dependence of the grafting rate on monomer concentration was found to be 1.1 order. This grafting system proceeded by diffusion controlled process. Some selected properties of the grafted films such as swelling behaviour, gel determination, mechanical and electrical properties were also investigated. It was found that the grafted membranes possess good hydrophilic properties which may make them promising in some practical applications. (author)

  18. Characterization of Functionalized Acrylic acid /4- Vinyl Pyridine Graft Copolymers

    Properties and characterization of the membranes prepared by radiation grafting of acrylic acid (AAc) or/ and 4-vinyl pyridine (4VP) onto low density polyethylene (LDPE) and polypropylene (PP) films were carried out. The FTIR spectra for the grafted membranes were studied to evaluate the structure change as a result of grafting. The swelling behaviour of the graft copolymer in methanol was studied. It was found that the grafting of AAc and/ or 4- VP onto LDPE and PP resulted in introducing good hydrophilic properties to such polymer substrates. The hydrophilic properties were directly proportional to the amount of functional groups. The mechanical properties (Young's modulus, elongation percent and tensile strength) of the grafted membranes also, have been investigated. As the grafting degree increases, the modulus also increases. Increasing the hydrophilicity of the membranes by chemical treatment enhances its mechanical properties. The thermal parameters of the grafted membranes such as δHm1. δHm2, and Trc have been also studied by using DSC

  19. Studies on thin film materials on acrylics for optical applications

    K Narasimha Rao

    2003-02-01

    Deposition of durable thin film coatings by vacuum evaporation on acrylic substrates for optical applications is a challenging job. Films crack upon deposition due to internal stresses and leads to performance degradation. In this investigation, we report the preparation and characterization of single and multi-layer films of TiO2, CeO2, Substance2 (E Merck, Germany), Al2O3, SiO2 and MgF2 by electron beam evaporation on both glass and PMMA substrates. Optical micrographs taken on single layer films deposited on PMMA substrates did not reveal any cracks. Cracks in films were observed on PMMA substrates when the substrate temperature exceeded 80°C. Antireflection coatings of 3 and 4 layers have been deposited and characterized. Antireflection coatings made on PMMA substrate using Substance2 (H2) and SiO2 combination showed very fine cracks when observed under microscope. Optical performance of the coatings has been explained with the help of optical micrographs.

  20. Radiation induced emulsion polymerization of 2-ethylhexyl acrylate

    The effects of radiation dose rate concentration of emulsifier and monomer content on reaction rate of radiation induced 2-ethylhexyl acrylate (EHA) emulsion polymerization have been studied. Nonionic surfactants, polyoxyethylene alkyl ether peregolo 0 with HLB about 15 and polyoxyethylene nonylphenolether (emulsifier OP) with HLB 15, are used as the emulsifiers in this work. It has been found that the dependence of RP on I (RP proportional to In) is changed with the index n from 0.29 for M/W = 2/8 (monomer/water in volume) to 0.91 for 5/5, where [E] of peregolo 0 is 4%. It has also been found that RP proportional to [E]0.58 for peregolo 0 and RP proportional to [E]0.51 for emulsifier OP. In order to interpret the results sufficiently, both micellar nucleation and micro-droplet nucleation have been taken into account for the emulsion polymerization of the present system irradiated without agitation, especially for the case with a higher M/W value the later may be the main nucleation process

  1. Rat hindlimb joint immobilization with acrylic resin orthoses

    C.A. da Silva

    2006-07-01

    Full Text Available The objective of the present study was to propose an orthosis of light material that would be functional for the animal and that would maintain only the ankle joint immobilized. Male Wistar rats (3 to 4 months old, 250-300 g were divided into 2 groups (N = 6: control and immobilized for 7 days. Rats were anesthetized with sodium pentobarbital (40 mg/kg weight and the left hindlimb was immobilized with the orthoses composed of acrylic resin model, abdominal belt and lateral supports. The following analyses were performed: glycogen content of the soleus, extensor digitorum longus, white gastrocnemius, red gastrocnemius, and tibialis anterior muscles by the phenol sulfuric method, and the weight, fiber area and intramuscular connective tissue of the soleus by the planimetric system. Data were analyzed statistically by the Kolmogorov-Smirnov, Student t and Wilcoxon tests. Immobilization decreased glycogen in all muscles (P < 0.05; soleus: 31.6%, white gastrocnemius: 56.6%, red gastrocnemius: 39%, extensor digitorum longus: 41.7%, tibialis anterior: 45.2% in addition to reducing soleus weight by 34% (P < 0.05. Furthermore, immobilization promoted reduction of the fiber area (43%, P < 0.05 and increased the connective tissue (200%, P < 0.05. The orthosis model was efficient comparing with another alternative immobilization model, like plaster casts, in promoting skeletal muscle alterations, indicating that it could be used as a new model in other studies related to muscle disuse.

  2. Interaction of photosensitive surfactant with DNA and poly acrylic acid

    Zakrevskyy, Yuriy, E-mail: yuriy.zakrevskyy@fh-koeln.de; Paasche, Jens; Lomadze, Nino; Santer, Svetlana, E-mail: santer@uni-potsdam.de [Experimental Physics, Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24-25, D-14476 Potsdam (Germany); Cywinski, Piotr; Cywinska, Magdalena; Reich, Oliver; Löhmannsröben, Hans-Gerd [Physical Chemistry, Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, D-14476 Potsdam (Germany)

    2014-01-28

    In this paper, we investigate interactions and phase transitions in polyelectrolyte-surfactant complexes formed between a cationic azobenzene-containing surfactant and two types of polyelectrolytes: natural (DNA) or synthetic (PAA: poly acrylic acid). The construction of a phase diagram allowed distancing between four major phases: extended coil conformation, colloidally stable compacted globules, colloidal instability range, and surfactant-stabilized compact state. Investigation on the complexes’ properties in different phases and under irradiation with UV light provides information about the role of the surfactant's hydrophobic trans isomers both in the formation and destruction of DNA and PAA globules as well as in their colloidal stabilization. The trans isomer shows much stronger affinity to the polyelectrolytes than the hydrophilic cis counterpart. There is no need for complete compensation of the polyelectrolyte charges to reach the complete compaction. On contrary to the findings previously reported in the literature, we demonstrate – for the first time – complete polyelectrolyte compaction which occurs already at 20% of DNA (and at 50% of PAA) charge compensation. The trans isomer plays the main role in the compaction. The aggregation between azobenzene units in the photosensitive surfactant is a driving force of this process. The decompaction can be realized during UV light irradiation and is strongly influenced by the interplay between surfactant-surfactant and surfactant-DNA interactions in the compacted globules.

  3. Synthesis, characterization and antimicrobial activity of important heterocyclic acrylic copolymers

    2008-10-01

    Full Text Available The acrylate monomer, 7-acryloyloxy-4-methyl coumarin (AMC has been synthesized by reacting 7-hydroxy-4-methyl coumarin, with acryloyl chloride in the presence of NaOH at 0–5°C. Copolymers of 7-acryloyloxy-4-methyl coumarin (AMC with vinyl acetate (VAc were synthesized in DMF (dimethyl formamide solution at 70±1°C using 2,2′-azobisisobutyronitrile (AIBN as an initiator with different monomer-to-monomer ratios in the feed. The copolymers were characterized by Fourier transform infra red (FTIR spectroscopy. The copolymer composition was evaluated by 1H-NMR (proton nuclear magnetic resonance and was further used to determine reactivity ratios. The monomer reactivity ratios for AMC (M1-VAc (M2 pair were determined by the application of conventional linearization methods such as Fineman-Ross (r1 = 0.6924; r2 = 0.6431, Kelen-Tüdõs (r1 = 0.6776; r2 = 0.6374 and extended Kelen-Tüdõs (r1 = 0.6657; r2 = 0.6256. Thermo gravimetric analysis showed that thermal decomposition of the copolymers occurred in single stage in the temperature range of 263–458°C. The molecular weights of the polymers were determined using gel permeation chromatography. The homo and copolymers were tested for their antimicrobial properties against selected microorganisms.

  4. Synthesis of acrylates and methacrylates from coal-derived syngas

    Spivey, J.J.; Gogate, M.R.; Jang, B.W.L. [Bechtel, San Francisco, CA (United States)] [and others

    1995-12-31

    Acrylates and methacrylates are among the most widely used chemical intermediates in the world. One of the key chemicals of this type is methyl methacrylate. Of the 4 billion pounds produced each year, roughly 85% is made using the acetone-cyanohydrin process, which requires handling of large quantities of hydrogen cyanide and produces ammonium sulfate wastes that pose an environmental disposal challenge. The U.S. Department of Energy and Eastman Chemical Company are sharing the cost of research to develop an alternative process for the synthesis of methyl methacrylate from syngas. Research Triangle Institute is focusing on the synthesis and testing of active catalysts for the condensation reactions, and Bechtel is analyzing the costs to determine the competitiveness of several process alternatives. Results thus far show that the catalysts for the condensation of formaldehyde and the propionate are key to selectively producing the desired product, methacrylic acid, with a high yield. These condensation catalysts have both acid and base functions and the strength and distribution of these acid-base sites controls the product selectivity and yield.

  5. Interaction of photosensitive surfactant with DNA and poly acrylic acid

    In this paper, we investigate interactions and phase transitions in polyelectrolyte-surfactant complexes formed between a cationic azobenzene-containing surfactant and two types of polyelectrolytes: natural (DNA) or synthetic (PAA: poly acrylic acid). The construction of a phase diagram allowed distancing between four major phases: extended coil conformation, colloidally stable compacted globules, colloidal instability range, and surfactant-stabilized compact state. Investigation on the complexes’ properties in different phases and under irradiation with UV light provides information about the role of the surfactant's hydrophobic trans isomers both in the formation and destruction of DNA and PAA globules as well as in their colloidal stabilization. The trans isomer shows much stronger affinity to the polyelectrolytes than the hydrophilic cis counterpart. There is no need for complete compensation of the polyelectrolyte charges to reach the complete compaction. On contrary to the findings previously reported in the literature, we demonstrate – for the first time – complete polyelectrolyte compaction which occurs already at 20% of DNA (and at 50% of PAA) charge compensation. The trans isomer plays the main role in the compaction. The aggregation between azobenzene units in the photosensitive surfactant is a driving force of this process. The decompaction can be realized during UV light irradiation and is strongly influenced by the interplay between surfactant-surfactant and surfactant-DNA interactions in the compacted globules

  6. MODIFIED ULTRAVIOLET-CURABLE WATER DISPERSIBLE POLYURETHANE-ACRYLATES

    Jian-wen Yang; Zhi-ming Wang; Zhao-hua Zeng; Hui-ya Yuan; Yong-lie Chen

    2001-01-01

    Three kinds of UV-curable self-emulsified polyurethane-acrylate (PUA) prepolymer, i.e., conventional, chain extended and grafted PUAs, were prepared. The relatively small particle size of the PUA dispersions indicates that the PUA prepolymers exhibit sufficient aqueous dispersibility. The PUA prepolymers can substantially lower the interfacial tension of water. Chain-extended PUA dispersions exhibit pseudoplastic behavior and thixotropy to a greater extent than do their conventional counterpart. The chain-extended and grafted PUA photocure to higher conversion than do the conventional PU equivalent. The results of DSC measurement suggest that there exists phase mixing between the hard and the soft segment phases for the PUAs based on PEG 400 that is the comparatively short soft segment in the prepolymer. For the PUA prepolvmers based on PEG having higher Mn values, chain-extending and grafting could impede the phase separation between the hard and the soft segment domains. The adhesion, impact strength and flexibility of the photocured films were tested.

  7. Effect of cationic monomer on properties of fluorinated acrylate latex

    Li Jun Chen

    2012-01-01

    Cationic fluorinated acrylate latex was prepared via semi-continuous emulsion copolymerization of cationic monomer and other monomers.The resultant latex and its film were characterized with dynamic light scattering detector and contact angle meter.Influences of amount of DMDAAC on the properties of resultant latex and its film were investigated in detail.Results show that the particle size of the latex has the minimum value and the zeta potential of the latex is increased when the amount of DMDAAC is increased.In addition,the particle size of the latex is unimodal distribution when the amount of DMDAAC is not more than 2.5%.However,the particle size of the latex is bimodal distribution when the amount of DMDAAC is more than 2.5%.The contact angle is varied slightly with the increase of amount of DMDAAC when it is not more than 2.5%.Nevertheless,the contact angle is decreased with the increase of the amount of DMDAAC when it is more than 25%.

  8. Aqueous Tape Casting Process with Styrene-acrylic Latex Binder

    CUI Xue-min; OUYANG Shi-xi; HUANG Yong; YU Zhi-yong; ZHAO Shi-ke; WANG Chang-an

    2004-01-01

    A commercial styrene-acrylic latex binder has been investigated as a good binder for aqueous Al2O3 suspensions tape-casting process. This paper focuses on the forming film mechanism of latex binder, the rheological behaviors of the suspensions, physical properties of green tapes and drying process of aqueous slurries with latex binder system. The drying process of the alumina suspensions is shown to follow a two-stage mechanism (the first stage: evaporation controlled process; and the second stage: diffusion controlled process). During the drying stage of the suspensions, the compressive force presses the latex particles and makes them be distorted, which results in cross-linking structure in contacted latex particles of the solidified tapes.A smooth-surface and high-strength green tape was fabricated by aqueous tape casting with latex binder system. The results from the SEM images of the crossing section microstructure of green tapes show that the latex is a very suitable binder for aqueous tape casting.

  9. Preparation and Application of Crosslinked Poly(sodium acrylate)-Coated Magnetite Nanoparticles as Corrosion Inhibitors for Carbon Steel Alloy

    Ayman M. Atta; Gamal A. El-Mahdy; Hamad A. Al-Lohedan; Ashraf M. El-Saeed

    2015-01-01

    This work presents a new method to prepare poly(sodium acrylate) magnetite composite nanoparticles. Core/shell type magnetite nanocomposites were synthesized using sodium acrylate as monomer and N,N-methylenebisacrylamide (MBA) as crosslinker. Microemulsion polymerization was used for constructing core/shell structures with magnetite nanoparticles as core and poly(sodium acrylate) as shell. Fourier transform infrared spectroscopy (FTIR) was employed to characterize the nanocomposite chemical ...

  10. The development of palm oil based acrylated resins and their applications

    Since Malaysia provides 57 and 75% of the world's production and exports of palm oil respectively, it is natural that we should be in the forefront of the research of widening the use of palm oil in oleochemicals industry, which are currently increase in popularity. The presence of unsaturation in the fatty acids of vegetable oils such as palm oil, technically paves the way for the production of acrylated resins. The more unsaturated the oil, the better it will perform in the radiation curing related applications. The first acrylated palm oil was synthesised in early 1989, through acrylation process, whereby, acrylic acid is introduced into oxirane group of the epoxidised palm oil products, EPOP, at 100-130 deg C in the presence of triethylamine, TEA, as a catalyst and 4-methoxyphenol as an inhibitor. The acrylated products namely epoxidised palm oil (olein) acrylate, EPOLA/EPOPA, was found curable when subjected to UV or EB irradiations. The EPOLA based formulated resins were satisfactorily been used as radiation curable coating materials on various substrates such as woods, bamboos, glass, ceramics and metals without any major defects at reasonably fast cure rate. Preliminary investigations also revealed their potentials as radiation curable pressure sensitive adhesives and printing inks. Isocyanation of EPOLAs at 50 to 90deg C with the presence of 1% inhibitor such as 4-methoxyphenol resulted in resins called Palm oil based urethane acrylates, POBUA. This newly synthesised resins possess certain advantages over EPOLA such as higher molecular weight, better crosslinking density, abrasion resistance, tensile properties and also pendulum hardness. Early results might suggest that POBUA is in a better position to be used as resins for radiation curing of surface coating applications

  11. Effect of repeated immersion solution cycles on the color stability of denture tooth acrylic resins

    Paulo Maurício Batista da Silva

    2011-12-01

    Full Text Available OBJECTIVE: Chemical solutions have been widely used for disinfection of dentures, but their effect on color stability of denture tooth acrylic resins after repeated procedures is still unclear. The aim of this in vitro study was to evaluate whether repeated cycles of chemical disinfectants affected the color stability of two denture tooth acrylic resins. MATERIAL AND METHODS: Sixty disc-shaped specimens (40 mm x 3 mm were fabricated from two different brands (Artiplus and Trilux of denture tooth acrylic resin. The specimens from each brand (n=30 were randomly divided into 6 groups (n=5 and immersed in the following solutions: distilled water (control group and 5 disinfecting solutions (1% sodium hypochlorite, 2% sodium hypochlorite, 5.25% sodium hypochlorite, 2% glutaraldehyde, and 4% chlorhexidine gluconate. Tooth color measurements were made by spectrophotometry. Before disinfection, the initial color of each tooth was recorded. Further color measurements were determined after subjecting the specimens to 7, 21, 30, 45, 60, and 90 immersion cycles in each tested solution. Color differences (ΔE* were determined using the CIE L*a*b* color system. Data were analyzed using two-way repeated measures analysis of variance (ANOVA followed by Tukey tests. The significance level was set at 5%. RESULTS: There were statistically significant differences in ΔE* among the 5 disinfectants and water during the 90 cycles of immersion for both denture tooth acrylic resins. Distilled water promoted the greatest color change in both denture tooth acrylic resins, nevertheless none of tested disinfectants promoted ΔE* values higher than 1.0 on these acrylic materials during the 90 cycles of disinfection. CONCLUSIONS: Repeated immersion cycles in disinfecting solutions alter ΔE* values, however these values do not compromise the color of the tested denture tooth acrylic resins because they are imperceptible to the human eye.

  12. Effect of light-curing, pressure, oxygen inhibition, and heat on shear bond strength between bis-acryl provisional restoration and bis-acryl repair materials

    Shim, Ji-Suk; Lee, Jeong-Yol; Choi, Yeon-Jo; Shin, Sang-Wan

    2015-01-01

    PURPOSE This study aimed to discover a way to increase the bond strength between bis-acryl resins, using a comparison of the shear bond strengths attained from bis-acryl resins treated with light curing, pressure, oxygen inhibition, and heat. MATERIALS AND METHODS Self-cured bis-acryl resin was used as both a base material and as a repair material. Seventy specimens were distributed into seven groups according to treatment methods: pressure - stored in a pressure cooker at 0.2 Mpa; oxygen inhibition- applied an oxygen inhibitor around the repaired material,; heat treatment - performed heat treatment in a dry oven at 60℃, 100℃, or 140℃. The shear bond strength was measured with a universal testing machine, and the shear bond strength (MPa) was calculated from the peak load of failure. A comparison of the bond strength between the repaired specimens was conducted using one-way ANOVA and Tukey multiple comparison tests (α=.05). RESULTS There were no statistically significant differences in the shear bond strength between the control group and the light curing, pressure, and oxygen inhibition groups. However, the heat treatment groups showed statistically higher bond strengths than the groups treated without heat, and the groups treated at a higher temperature resulted in higher bond strengths. Statistically significant differences were seen between groups after different degrees of heat treatment, except in groups heated at 100℃ and 140℃. CONCLUSION Strong bonding can be achieved between a bis-acryl base and bis-acryl repair material after heat treatment. PMID:25722837

  13. Comparative evaluation of surface porosities in conventional heat polymerized acrylic resin cured by water bath and microwave energy with microwavable acrylic resin cured by microwave energy

    Sunint Singh

    2013-01-01

    Full Text Available Background: Conventional heat cure poly methyl methacrylate (PMMA is the most commonly used denture base resin despite having some short comings. Lengthy polymerization time being one of them and in order to overcome this fact microwave curing method was recommended. Unavailability of specially designed microwavable acrylic resin made it unpopular. Therefore, in this study, conventional heat cure PMMA was polymerized by microwave energy. Aim and Objectives: This study was designed to evaluate the surface porosities in PMMA cured by conventional water bath and microwave energy and compare it with microwavable acrylic resin cured by microwave energy. Materials and Methods: Wax samples were obtained by pouring molten wax into a metal mold of 25 mm × 12 mm × 3 mm dimensions. These samples were divided into three groups namely C, CM, and M. Group C denotes conventional heat cure PMMA cured by water bath method, CM denotes conventional heat cure PMMA cured by microwave energy, M denotes specially designed microwavable acrylic denture base resin cured by microwave energy. After polymerization, each sample was scanned in three pre-marked areas for surface porosities using the optical microscope. As per the literature available, this instrument is being used for the first time to measure the porosity in acrylic resin. It is a reliable method of measuring area of surface pores. Portion of the sample being scanned is displayed on the computer and with the help of software area of each pore was measured and data were analyzed. Results: Conventional heat cure PMMA samples cured by microwave energy showed maximum porosities than the samples cured by conventional water bath method and microwavable acrylic resin cured by microwave energy. Higher percentage of porosities was statistically significant, but well within the range to be clinically acceptable. Conclusion: Within the limitations of this in-vitro study, conventional heat cure PMMA can be cured by

  14. Synthesis and characterization of cashew gum/acrylic acid nanoparticles

    Silva, Durcilene A. da; Feitosa, Judith P.A. [Departamento de Quimica Organica e Inorganica, Universidade Federal do Ceara - C. Postal 6021, 60.455-760, Fortaleza, CE (Brazil); Paula, Haroldo C.B. [Departamento de Quimica Analitica e Fisico-Quimica, Universidade Federal do Ceara - C. Postal 6021, 60.455-760, Fortaleza, CE (Brazil); Paula, Regina C.M. de [Departamento de Quimica Organica e Inorganica, Universidade Federal do Ceara - C. Postal 6021, 60.455-760, Fortaleza, CE (Brazil)], E-mail: rpaula@dqoi.ufc.br

    2009-03-01

    This paper describes the preparation of nanoparticles from cashew gum (CG) and acrylic acid (AA) by free radical polymerization using cerium (IV) ammonium nitrate (CAN) as an initiator. The yields of the nanoparticles (NP) obtained by varying the R{sub CG/AA} from 0.5 to 2.0 were between 65 and 40%. The FT-IR spectra of the NP samples showed bands characteristic of the cashew gum spectrum and a new band at 1560 cm{sup -1} assigned to the stretching vibration of COO{sup -} groups of polyacrylic acid. On increasing the R{sub CG/AA} from 0.5 to 2.0 an increase in particle size was observed. The NP with an R{sub CG/AA} of 0.5 were smaller and had higher storage stability than the NP with an R{sub CG/AA} of 1.0 or 2.0. The increase in R{sub CG/AA} had no significant effect on the zeta potential of the NP in water. The NP were dried and re-dissolved in water to observe the effect of freeze-drying on particle size. For the NP with an R{sub CG/AA} of 0.5 an increase in particle size was observed from 71 to 402 nm, however, for the NP with an R{sub CG/AA} of 1.0 or 2.0 a small variation in particle diameter was noted. The behavior of the CG/AA NP was also found to be pH sensitive.

  15. Development of carboxymethyl cellulose acrylate for various biomedical applications

    Pal, Kunal; Banthia, A. K.; Majumdar, D. K.

    2006-06-01

    The purpose of this work is to prepare a pH-sensitive hydrogel membrane of sodium carboxymethyl cellulose acrylate for drug delivery and other biomedical applications. The hydrogel was made by esterification of sodium carboxymethyl cellulose (SCMC) and acryloyl chloride (ACl). The esterified product was characterized by FTIR spectroscopy and XRD. Swelling, hemocompatibility, water vapor transmission rate, contact angle and diffusional studies were also done. Biocompatibility of the membrane was established by quantification of cell growth of L929 cells and mice splenocytes. The FTIR spectrum of the hydrogel suggested the formation of ester bonds between the hydroxyl groups of sodium carboxymethyl cellulose and the carbonyl group of acryloyl chloride. Water vapor transmission rate, hemocompatibility, contact angle and swelling studies indicated that the hydrogel can be tried as a wound dressing material. The hydrogel showed pH-dependent swelling behavior arising from the acidic pendant group in the polymer network. The permeability of the hydrogel membrane produced, as shown by salicylic acid diffusion, increased in response to an increase in pH of the external medium. The hydrogel membrane was permeable to salicylic acid at pH 7.2 but not at pH 2.0 (0.01N HCl). The effect of changes of pH on the hydrogel's permeability was found to be reversible. The hydrogel membrane was found to be compatible with the L929 mice fibroblast cell line and mice splenocytes. The esterified product of SCMC and ACl swells on increase of pH indicating its possible use in a pH-sensitive drug delivery system and as a wound dressing material.

  16. Development of carboxymethyl cellulose acrylate for various biomedical applications

    Pal, Kunal [Materials Science Centre, Indian Institute of Technology, Kharagpur 721302 (India); Banthia, A K [Materials Science Centre, Indian Institute of Technology, Kharagpur 721302 (India); Majumdar, D K [Delhi Institute of Pharmaceutical Sciences and Research, Formerly College of Pharmacy, University of Delhi, Pushp Vihar, Sector III, New Delhi 110017 (India)

    2006-06-15

    The purpose of this work is to prepare a pH-sensitive hydrogel membrane of sodium carboxymethyl cellulose acrylate for drug delivery and other biomedical applications. The hydrogel was made by esterification of sodium carboxymethyl cellulose (SCMC) and acryloyl chloride (ACl). The esterified product was characterized by FTIR spectroscopy and XRD. Swelling, hemocompatibility, water vapor transmission rate, contact angle and diffusional studies were also done. Biocompatibility of the membrane was established by quantification of cell growth of L929 cells and mice splenocytes. The FTIR spectrum of the hydrogel suggested the formation of ester bonds between the hydroxyl groups of sodium carboxymethyl cellulose and the carbonyl group of acryloyl chloride. Water vapor transmission rate, hemocompatibility, contact angle and swelling studies indicated that the hydrogel can be tried as a wound dressing material. The hydrogel showed pH-dependent swelling behavior arising from the acidic pendant group in the polymer network. The permeability of the hydrogel membrane produced, as shown by salicylic acid diffusion, increased in response to an increase in pH of the external medium. The hydrogel membrane was permeable to salicylic acid at pH 7.2 but not at pH 2.0 (0.01N HCl). The effect of changes of pH on the hydrogel's permeability was found to be reversible. The hydrogel membrane was found to be compatible with the L929 mice fibroblast cell line and mice splenocytes. The esterified product of SCMC and ACl swells on increase of pH indicating its possible use in a pH-sensitive drug delivery system and as a wound dressing material.

  17. Development of carboxymethyl cellulose acrylate for various biomedical applications

    The purpose of this work is to prepare a pH-sensitive hydrogel membrane of sodium carboxymethyl cellulose acrylate for drug delivery and other biomedical applications. The hydrogel was made by esterification of sodium carboxymethyl cellulose (SCMC) and acryloyl chloride (ACl). The esterified product was characterized by FTIR spectroscopy and XRD. Swelling, hemocompatibility, water vapor transmission rate, contact angle and diffusional studies were also done. Biocompatibility of the membrane was established by quantification of cell growth of L929 cells and mice splenocytes. The FTIR spectrum of the hydrogel suggested the formation of ester bonds between the hydroxyl groups of sodium carboxymethyl cellulose and the carbonyl group of acryloyl chloride. Water vapor transmission rate, hemocompatibility, contact angle and swelling studies indicated that the hydrogel can be tried as a wound dressing material. The hydrogel showed pH-dependent swelling behavior arising from the acidic pendant group in the polymer network. The permeability of the hydrogel membrane produced, as shown by salicylic acid diffusion, increased in response to an increase in pH of the external medium. The hydrogel membrane was permeable to salicylic acid at pH 7.2 but not at pH 2.0 (0.01N HCl). The effect of changes of pH on the hydrogel's permeability was found to be reversible. The hydrogel membrane was found to be compatible with the L929 mice fibroblast cell line and mice splenocytes. The esterified product of SCMC and ACl swells on increase of pH indicating its possible use in a pH-sensitive drug delivery system and as a wound dressing material

  18. Acrylic Rubber Latex in Ferrocement for Strengthening Reinforced Concrete Beams

    D. R. Kumar

    2010-01-01

    Full Text Available Problem statement: In India, the early deterioration of reinforced concrete structures has become a big social problem in recent years. An essential research is needed for the development of effective repair materials and their execution systems comes to an important issue from the viewpoint of the longevity of infrastructures at present. Ferrocement laminates are introduced to enhance the overall performance of Reinforced Concrete (RC structures and these days the use of it is a promising technology for increasing the flexural strength of deficient reinforced concrete members. Approach: The repair system aims to provide quantitative repair enhancement as well as extending the life of deteriorated concrete members. This research in particular inspired the initiation of the present work which aimed to develop a material with unique properties and a very wide range of practical applications. The mechanical properties of mortar through difference in polymer content with Acrilic Latex by ferrocement among three different volume fractions of mesh reinforcement were studied. Following the encouraging progress made in the formulation and evaluation of the polymer modified repair mortar, tests were carried out involving the application of the reinforced repair material to the soffit of the reinforced concrete beams of 3 m length. Results: The levels of damage of the original beams prior to repair did not affect the ultimate load of the strengthened beams tested. The performance of the strengthened beams was compared to the control beams with respect to cracking, deflection and ultimate strength which confirm preeminent results. Conclusion: This accomplished the fact that acrylic rubber latex modified ferrocement is a doable alternative strengthening component for the rehabilitation of reinforced concrete structures. Further developments in these systems will create dramatic improvement into the field of rehabilitation of old privileged structures.

  19. Synthesis of Acrylate Microemulsion Modified by Alkoxy Silane

    SUN Zhijuan; ZHANG Xinya; HUANG Hong; FU Heqing; CHEN Huanqin

    2008-01-01

    An acrylate emulsion was modified by adding vinyltriisopropoxy silane (trade name C-1706).By adding the multiple emulsifier which consists of an anionic emulsifier, sodium dodecyl benzene sulfonate(SDBS) and nonionic emulsifier, octyl phenolic divinyl oxide (OP-10), the acryiosilane microemulsiun was synthesized by seeded emulsion polymerization. The influential factors including the kind and the adding amount of emulsifiers and the monomer variety of alkoxy silane and the added methods which influence on the properties of the microemulsion were investigated. It is found that SDBS and OP-10 as multiple emulsifiers with mass ratio of hl and the adding amount of 2.5%-3.5% can act on co-effect for emulsion polymerization. The C-1706 possesses bulky isopropoxy substituent that can reduce hydrolysis reactivity during the polymerization process, So as to not only make the process smoothly but also advance the store stability of the emulsion.Moreover, the latter-addition mode of C-1706 can restrain its hydrolysis activity and polycondensation reaction during the polymerization process of the emulsion. The structure, the film cross section, the particle size and its distribution of the microemulsion were analyzed by the Fourier Transform Infrared Ray Spectrum (FT-IR), Scanning Electron Microscopy (SEM) and a particle size analyzer, respectively. The results show that the particle diameter of the modified microemulsion can be controlled between 50 and 70 nm and its film hardness is 7.3. Only adding 1.5% of C-1706 into the system of emulsion polymerization can apparently improve the weathering resistance of the microemulsion, which undergo degradation with chromatism(△E) is 1.6 after 3 600 hours of QUV-aging.

  20. Surface morphology changes of acrylic resins during finishing and polishing phases

    Glaucio Serra

    2013-12-01

    Full Text Available INTRODUCTION: The finishing and polishing phases are essential to improve smoothness and shining on the surface of acrylic resins used to make removable orthodontic appliances. A good surface finishing reduces roughness, which facilitates hygiene, prevents staining and provides greater comfort to the patients. OBJECTIVE: The aim of this paper was to analyze the changes on surface morphology of acrylic resins during finishing and polishing phases. METHODS: Thirty discs (10 mm in diameter and 5 mm in length were made with acrylic resin and randomly divided into ten groups. The control group did not receive any treatment while the other groups received gradual finishing and polishing. The last group received the entire finishing and polishing procedures. Surface morphology was qualitatively analyzed through scanning electron microscopy and quantitatively analyzed through a laser profilometer test. RESULTS: The acrylic resin surfaces without treatment showed bubbles which were not observed in the subsequent phases. Wearing out with multilaminated burs, finishing with wood sandpaper and finishing with water sandpaper resulted in surfaces with decreasing irregularities. The surfaces that were polished with pumice and with low abrasive liquids showed high superficial smoothness. CONCLUSION: Highly smooth acrylic resin surfaces can be obtained after mechanical finishing and polishing performed with multilaminated burs, wood sandpaper, water sandpaper, pumice and low abrasive liquids.

  1. Direct Synthesis of Hyperbranched Poly(acrylic acid-co-3-hydroxypropionate

    Efkan Çatıker

    2015-01-01

    Full Text Available Hyperbranched poly(acrylic acid-co-3-hydroxypropionate (PAcHP was synthesized by base-catalyzed hydrogen transfer polymerization of acrylic acid through one step. The copolymers obtained through solution and bulk polymerization were insoluble in water and all organic solvents tried. Structural and compositional characterizations of hyperbranched PAcHP were performed by using FTIR, solid 13C-NMR, TGA, and titrimetric analysis. Acrylate fraction of the hyperbranched PAcHP obtained via bulk polymerization was determined as 60–65% by comparing TGA curves of hyperbranched PAcHP and pure poly(3-hydroxy propionate (PHP. However, analytical titration of the same sample revealed that acrylic acid units were about 47.3%. The results obtained from TGA and analytical titration were used to evaluate the chemical structure of the copolymer. Hyperbranched PAcHP exhibited hydrogel properties. Swelling behavior of the copolymer was investigated at a wide pH range and ionic strength. The dynamic swelling profiles of hyperbranched PAcHP exhibited a fast swelling behavior in the first hour and achieved the equilibrium state within 12 h in PBS. Depending on the conditions, the copolymers exhibited swelling ratios up to 2100%. As the copolymer has easily biodegradable propionate and versatile functional acrylic acid units, it can be used as not only biodegradable material in medical applications but also raw material in personal care commodities.

  2. Graft Polymerization of Acrylic Acid on a Polytetrafluoroethylene Panel by an Inductively Coupled Plasma

    Lan, Yan; You, Qingliang; Cheng, Cheng; Zhang, Suzhen; Ni, Guohua; Nagatsu, M.; Meng, Yuedong

    2011-02-01

    Surface modification on a polytetrafluoroethylene (PTFE) panel was performed with sequential nitrogen plasma treatments and surface-initiated polymerization. By introducing COO- groups to the surface of the PTFE panel through grafting polymerization of acrylic acid (AA), a transparent poly (acrylic acid) (PAA) membrane was achieved from acrylic acid solution. Grafting polymerization initiating from the active groups was achieved on the PTFE panel surface after the nitrogen plasma treatment. Utilizing the acrylic acid as monomers, with COO- groups as cross link sites to form reticulation structure, a transparent poly (acrylic acid) membrane with arborescent macromolecular structure was formed on the PTFE panel surface. Analysis methods, such as fourier transform infrared spectroscopy (FTIR), microscopy and X-ray photoelectron spectroscopy (XPS), were utilized to characterize the structures of the macromolecule membrane on the PTFE panel surface. A contact angle measurement was performed to characterize the modified PTFE panels. The surface hydrophilicities of modified PTFE panels were significantly enhanced after the plasma treatment. It was shown that the grafting rate is related to the treating time and the power of plasma.

  3. Radiation modification of water absorption of cassava starch by acrylic acid/acrylamide

    Graft co polymerizations of acrylamide and/or acrylic acid onto cassava starch by a simultaneous irradiation technique using gamma-rays as the initiator were studied with regard to various parameters of importance: the monomer-to-cassava starch ratio, total dose (kGy), dose rate (kGy h-1), acrylamide-to-acrylic acid ratio, and the addition of nitric acid and maleic acid as the additives. Grafting parameters were determined in relation to the water absorption of the saponified graft copolymer. The water absorption of the saponified graft copolymer in salt and buffer solutions of different ionic strengths was also measured, from which the super absorbent properties are found to be P H sensitive. The starch graft copolymers of acrylamide and acrylic acid give higher water absorption than the starch graft copolymers of either acrylamide or acrylic acid alone. The porosity of the saponified starch graft copolymers prepared by the acrylamide/acrylic acid ratios of 70:30 and 50:50 was much higher than the porosity of copolymers in terms of fine networks. Ionic strength and multi-oxidation states of the saline and buffer solutions markedly decreased the water absorption of the saponified cassava starch grafted super absorbent polymers.

  4. The electrospinning of the copolymer of styrene and butyl acrylate for its application as oil absorbent.

    Xu, Naiku; Cao, Jipeng; Lu, Yuyao

    2016-01-01

    Electrospun polystyrene materials have been employed as oil absorbents, but they have visible drawbacks such as poor strength at low temperature and unreliable integrity because of brittleness and insufficient cohesive force among fibers. Butyl acrylate can polymerize into flexible chains, and its polymer can be used as elastomer and adhesive material. Thereby it is possible to obtain the material that has better performance in comparison with electrospun polystyrene material through the electrospinning of the copolymer of styrene and butyl acrylate. In this work, a polymer was synthesized through suspension polymerization by using styrene and butyl acrylate as comonomers. The synthesis of the copolymer of styrene and butyl acrylate was verified through dissolution and hydrolysis experimental data; as well through nuclear magnetic resonance spectrometry. The viscous flow activation energy of the solution consisting of copolymer and N, N-dimethylformamide was determined via viscosity method and then adopted to establish the entanglement characteristics of butyl acrylate's chain segments. Finally, in order to electrospin the copolymer solution into fibrous membrane, the effects of monomer feed ratio and spinning parameters were investigated. The prepared fibrous membrane was found to have a potential use as oil absorbent. PMID:27610302

  5. Effects of Chairside Polishing and Brushing on Surface Roughness of Acrylic Denture Base Resins

    Seung-Kyun Kim; Ju-Mi Park; Min-Ho Lee; Jae-Youn Jung; Shipu Li; Xinyu Wang

    2009-01-01

    The effects of 3 chairside polishing kits and mechanical brushing on the surface roughness of 3 different acrylic denture base resins were compared. Acrylic denture base resins (auto-polymerizing, heat-polymerizing, injected heat-polymerizing resins) were examined after a tungsten carbide bur, and after chairside polishing using 3 polishing kits and pumice. The specimens were subjected to mechanical brushing using a wear tester to simulate 30 000 strokes of brushing. The surface roughness of the acrylic denture base resin specimens was measured using a contact pro-filometer. After the test, the random polished acrylic resins were evaluated by scanning electron mi-croscopy (SEM) and atomic force microscopy (AFM). Acrylic denture base resins polished using the 3 types of polishing kits had a smoother surface than those finished with the tungsten carbide bur (p <0.05). The surface of the resin polished by a TC cutter exceeded the Ra of 0.2 μm (p<0.05). The auto-polymerizing resin showed a significantly higher surface roughness than the heat-polymerizing resin and injected heat-polymerizing resin (p>0.05). In the case of polishing step wise, there was almost no change in surface roughness after brushing (p>0.05).

  6. Investigation of UV curing reaction of dicyclopentadienyl acrylate by FT-IR

    Dicyclopentadienyl acrylate (DCPA) is characterized by low odor, low volatility, high flash point, low toxicity and low shrinkage on cure. Another advantage of DCPA is its insensitiveness to the inhibiting effect of oxygen. DCPA have wide industrial applications. It was used for the preparation of adhesives, UV-curable coatings and polymer concreted). The advantages of DCPA result from its particular structure. There are two unsaturated bonds, one acrylic double bond and one cyclic double bond, in each DCPA molecule. But, few reports on reaction behavior of the two type double bonds were issued up to date. In this paper, reaction behavior of the acrylic and the cyclic double bond of DCPA during and after LTV-curing were investigated by Fourier Transform-Infrared(FT-IR)

  7. [MORPHOLOGICAL FEATURES OF RAT MUCOUS MEMBRANE OF THE TONGUE EARLY AFFECTED BY ACRYLIC RESIN MONOMER].

    Davydenko, V; Nidzelskiy, M; Starchenko, I; Davydenko, A; Kuznetsov, V

    2016-03-01

    Base materials, made on the basis of various derivatives of acrylic and methacrylic acids, have been widely used in prosthetic dentistry. Free monomer, affecting the tissues of prosthetic bed and the whole body, is always found in dentures. Therefore, study of the effect of acrylic resins' monomer on mucous membrane of the tongue is crucial. Rat tongue is very similar to human tongue, and this fact has become the basis for selecting these animals to be involved into the experiment. The paper presents the findings related to the effect of "Ftoraks" base acrylic resin monomer on the state of rat mucous membrane of the tongue and its regeneration. The microscopy has found that the greatest changes in the mucous membrane of the tongue occur on day 3 and 7 day after applying the monomer and are of erosive and inflammatory nature. Regeneration of tongue epithelium slows down. PMID:27119844

  8. New blends of ethylene-butyl acrylate copolymers with thermoplastic starch. Characterization and bacterial biodegradation.

    Morro, A; Catalina, F; Corrales, T; Pablos, J L; Marin, I; Abrusci, C

    2016-09-20

    Ethylene-butyl acrylate copolymer (EBA) with 13% of butyl acrylate content was used to produce blends with 10, 30 and 60% of thermoplastic starch (TPS) plasticized with glycerol. Ethylene-acrylic acid copolymer (EAA) was used as compatibilizer at 20% content with respect to EBA. The blends were characterized by X-ray diffraction, ATR-Fourier Transform Infrared Spectroscopy (ATR-FTIR), Scanning Electron Microscopy (SEM), water-Contact Angle measurements (CA), Differential Scanning Calorimetry (DSC) and Stress-strain mechanical tests. Initiated autoxidation of the polymer blends was studied by chemiluminescence (CL) confirming that the presence of the polyolefin-TPS interphase did not substantially affect the oxidative thermostability of the materials. Three bacterial species have been isolated from the blend films buried in soil and identified as Bacillus subtilis, Bacillus borstelensis and Bacillus licheniformis. Biodegradation of the blends (28days at 45°C) was evaluated by carbon dioxide measurement using the indirect impedance technique. PMID:27261731

  9. Preparation and characteristics of acrylic acid/styrene composite plasma polymerized membranes

    Plasma polymerization has gained increasing interest for the deposition of functional plasma-polymerized membranes suitable for a wide range of applications on account of its advantageous features. In this work, acrylic acid/styrene composite plasma polymerized membranes were synthesized by plasma polymerization of a mixture of acrylic acid and styrene monomers in a low-frequency after-glow capacitively coupled plasma (CCP) discharge process. The structure and composition of the plasma polymerized membranes were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The results showed that the partial pressure ratio between acrylic acid (AA) and styrene (St), applied discharge power and the energy of the extracted particles have considerable effects on the structure and the content of functional groups of the deposited membranes.

  10. Effects of acrylamide and acrylic acid on creatine kinase activity in the rat brain

    In vitro, both acrylamide and acrylic acid inhibited creatine kinase (CK) activity in rat brain homogenates, and acrylic acid was more potent than acrylamide. In vivo, however, when given i.p. 50 mg/kg per day for 8 days to rats, only acrylamide inhibited CK activity in the brain and caused apparent neurological signs. 14C in the brain 24 h after the injection of 14C-labelled chemicals was more than 7 times greater with acrylamide than with acrylic acid. The inhibition of CK activity by acrylamide varied in eight regions of the brain; from 54% in hypothalamus to 27% in cerebellar vermis. The regional difference of CK inhibition, however, did not agree well with either 14C distribution or with the distribution in regions which appear clinically or pathologically vulnerable to acrylamide. (orig.)

  11. Applications of Blue Light-curing Acrylic Resin to Forensic Sample Preparation and Microtomy.

    Groves, Ethan; Palenik, Christopher S

    2016-03-01

    This study discusses the results of an evaluation of a one-part blue light-curing acrylic resin for embedding trace evidence prior to the preparation of thin sections with a microtome. Through a comparison to several epoxy resins, the physical properties relevant to both trace evidence examination and analytical microscopy in general, including as viscosity, clarity, color, hardness, and cure speed, were explored. Finally, thin sections from paint samples embedded in this acrylic resin were evaluated to determine if, through smearing or impregnation, the resin contributed to the infrared spectra. The results of this study show that blue light-curing acrylic resins provide the desired properties of an embedding medium, generate high-quality thin sections, and can significantly simplify the preparation of paint chips, fibers and a multitude of other types of microscopic samples in the forensic trace evidence laboratory. PMID:27404623

  12. Long-Term Testing and Properties of Acrylic for the Daya Bay Antineutrino Detectors

    Krohn, M; Heeger, K M

    2012-01-01

    The Daya Bay reactor antineutrino experiment has recently measured the neutrino mixing parameter sin22{\\theta}13 by observing electron antineutrino disappearance over kilometer-scale baselines using six antineutrino detectors at near and far distances from reactor cores at the Daya Bay nuclear power complex. Liquid scintillator contained in transparent target vessels is used to detect electron antineutrinos via the inverse beta-decay reaction. The Daya Bay experiment will operate for about five years yielding a precision measurement of sin22{\\theta}13. We report on long-term studies of poly(methyl methacrylate) known as acrylic, which is the primary material used in the fabrication of the target vessels for the experiment's antineutrino detectors. In these studies, acrylic samples are subjected to gaseous and liquid environmental conditions similar to those experienced during construction, transport, and operation of the Daya Bay acrylic target vessels and detectors. Mechanical and optical stability of the ac...

  13. Direct initiation of the photopolymerization of acrylates by 222 nm excimer UV radiation

    Complete text of publication follows. Usually, the photopolymerisation of functionalised monomers and oligomers requires the addition of one or several photoinitiators to the formulation. The light of typically used mercury lamps (1>250 nm) is mainly absorbed by the photoinitiator leading to initiating species (radicals) with a high quantum yield. The introduction of excimer lamps as monochromatic UV sources with an intense short-wavelength emission opens up new possibilities for a photoinitiator-free initiation of the acrylate polymerisation. Like most other organic compounds, acrylates strongly absorb light with a wavelength shorter than about 220 to 240 nm, and they can therefore be directly excited by the 222 nm excimer radiation from a KrCl* lamp. Real-time FTIR-ATR spectroscopy was used to study the reactivity of various neat acrylates. Depending on the absorption coefficient, aliphatic acrylates can be cured up to a thickness of several microns whereas for highly absorbing aromatic acrylates, the depth of cure reaches only some hundred nanometres. Since the radical yield is low, photopolymerisation without photoinitiator has to be performed in an inert atmosphere. Laser photolysis experiments were carried out with a KrCl* excimer laser (pulse width 20 ns, up to 5 mJ per pulse) to investigate the primary processes of the direct initiation. Additionally, quantum chemical calculations were performed to assist the interpretation of the photolysis data. For all acrylates studied, direct excitation at 222 nm first leads to the formation of a triplet state which is highly localized at the vinyl double bond (and not at the carbonyl group). This triplet state may undergo different reactions like inter- and intramolecular hydrogen transfer and biradical formation as well as the addition to a ground state molecule (chain start). Our current interpretation of the experimental results and the quantum chemical calculations will be presented and discussed

  14. Electroactive behavior assessment of poly(acrylic acid)-graphene oxide composite hydrogel in the detection of cadmium

    Bejarano-Jimenez, A.; Escobar-Barrios, V.A.; Kleijn, J.M.; Oritz-Ledon, C.A.; Chazaro-Ruiz, L.F.

    2014-01-01

    Super absorbent polymers of acrylic acid-graphene oxide (PAA-GO) were synthesized with different percentage of chemical neutralization (0, 10, and 20%) of the acrylic acid monomer before its polymerization. The influence of their swelling and adsorption/desorption capacity of cadmium ions in aqueous

  15. The influence of ultrasound on the release of gentamicin from antibiotic-loaded acrylic beads and bone cements

    Ensing, GT; Hendriks, JGE; Jongsma, JE; van Horn, [No Value; van der Mei, HC; Busscher, HJ

    2005-01-01

    Gentamicin-loaded acrylic beads are loosely placed in infected bone cavities, whereas gentamicin-loaded acrylic bone cement is used as a mechanical filler in bone to anchor prosthetic components. Both drug delivery systems are used to decrease infection rates by gentamicin release. The objective of

  16. SYNTHESIS OF 2—HYDROXYETHYL ACRYLATE BY USING STRONG ACIDIC CATION ION EXCHANGE RESIN AS CATALYST

    GAODabin

    1992-01-01

    2-Hydroxyethyl acrylate is synthesized from acrylic acid and ethylene glycol under a simple and mild condition by using strong acidic cation ion exchange resin as a catalyst,which could be recycled as long as 10 times with high activation.

  17. Adherence of Candida albicans to denture base acrylics and silicone-based resilient liner materials with different surface finishes

    Nevzatoglu, Erdem U.; Ozcan, Mutlu; Kulak-Ozkan, Yasemin; Kadir, Tanju

    2007-01-01

    This study evaluated the surface roughness and Candida albicans adherence on denture base acrylic resins and silicone-based resilient liners with different surface finishes. Four commercial denture base acrylic resins ( three heat polymerized and one room temperature polymerized) and five silicone-b

  18. Bone Marrow Nails Created by Percutaneous Osteoplasty for Long Bone Fracture: Comparisons Among Acrylic Cement Alone, Acrylic-Cement–Filled Bare Metallic Stent, and Acrylic-Cement–Filled Covered Metallic Stent

    Purpose: This study was designed to compare the strength among bone marrow nails created to treat long bone fractures using interventional procedures. Methods: Twelve resected intact tibiae of healthy swine were used. A circumferential bone fracture was made in nine tibiae and restored with the following created bone marrow nails: acrylic cement alone (ACA) (n = 3), acrylic-cement–filled bare metallic stent (AC-FBMS) (n = 3), and acrylic-cement–filled covered metallic (AC-FCMS) stent (n = 3). The remaining intact tibiae (n = 3) were used as controls. Results: A bone marrow nail was successfully achieved within 30 min in all swine. The maximum injection volume of acrylic cement for creating ACA, AC-FBMS, and AC-FCMS was 1.7 ± 0.3, 3.2 ± 0.4, and 2.9 ± 0.4 mL, respectively. The thickness of bone marrow nail created in the ACA, AC-FBMS, and AC-FCMS groups was 3.6 ± 1.0, 10.3 ± 0.26, and 9.6 ± 0.32 mm, respectively (AC-FBMS group versus AC-FCMS group, p = 0.038), probably because of leakage of acrylic cement surrounding the interstices. The maximum bending power (kilonewton) and bending strength (newton/mm2) in the normal long bone, ACA, AC-FBMS, and AC-FCMS groups were: 1.70 ± 0.25 and 79.2 ± 16.1; 0.21 ± 0.11 and 8.8 ± 2.8; 0.46 ± 0.06 and 18.2 ± 1.6; and 0.18 ± 0.04 and 7.8 ± 2.7, respectively. Conclusions: Although the maximum bending power and bending strength of AC-FBMS were not satisfactory, it was the most robust of the three marrow nails for restoring fractured long bone.

  19. Cytocompatible antifungal acrylic resin containing silver nanoparticles for dentures

    Acosta-Torres LS

    2012-09-01

    Full Text Available Laura Susana Acosta-Torres,1 Irasema Mendieta,2 Rosa Elvira Nuñez-Anita,3 Marcos Cajero-Juárez,3 Víctor M Castaño41National School of Higher Education, School of Dentistry - Leon Unit, National Autonomus University of Mexico (UNAM, Leon, Guanajuato, 2Neurobiology Institute, National Autonomus University of Mexico (UNAM, Juriquilla, Queretaro, 3Animal Biotechnology Laboratory, Faculty of Veterinary Medicine at San Nicolas de Hidalgo, Michoacán University, Michoacán, 4Molecular Materials Department, Applied Physics and Advanced Technology Center, National Autonomus University of Mexico (UNAM, Juriquilla, Queretaro, MexicoBackground: Inhibition of Candida albicans on denture resins could play a significant role in preventing the development of denture stomatitis. The safety of a new dental material with antifungal properties was analyzed in this work.Methods: Poly(methyl methacrylate [PMMA] discs and PMMA-silver nanoparticle discs were formulated, with the commercial acrylic resin, Nature-CrylTM, used as a control. Silver nanoparticles were synthesized and characterized by ultraviolet-visible spectroscopy, dispersive Raman spectroscopy, and transmission electron microscopy. The antifungal effect was assessed using a luminescent microbial cell viability assay. Biocompatibility tests were carried out using NIH-3T3 mouse embryonic fibroblasts and a Jurkat human lymphocyte cell line. Cells were cultured for 24 or 72 hours in the presence or absence of the polymer formulations and analyzed using three different tests, ie, cellular viability by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay, and cell proliferation by enzyme-linked immunosorbent assay BrdU, and genomic DNA damage (Comet assay. Finally, the samples were evaluated mechanically, and the polymer-bearing silver nanoparticles were analyzed microscopically to evaluate dispersion of the nanoparticles.Results: The results show that PMMA-silver nanoparticle discs

  20. The influence of Copolimers Acrylic Acid onto Poli(Etilene Terephthalate)woven fabric

    To improve suitability of wearing poli etilene terephthalate (PET) wovenfabric, it need to enhance the ability in absorbing of water vapour. For theabove reason acrylic acid (AA) has been grafted onto PET wovenfabric(PET-g-AA). Fourier Transform Infrared (FT-IR) data show that poly(acrylic acid) have grafted onto PET woven fabric. Thermal propertiesobtained from DSC (Differential Scanning Calorimeter) measurements of PET-g-AA show that the grafting does not affect bulk properties of PET. Thedecrease of the tensile strength had occurred to PET-g-MMA, however it ratherinfluenced by the reaction time than the initial concentration of acrylicacid. (author)

  1. Synthesis of Acrylic Acid/Kaoline Powder Superabsorbent Composite by Inverse-suspending Polymerization

    ZHONG Jin-feng; XUE Yi-ming; WU Ji-huai; LIN Jian-ming; WEI Yue-lin

    2004-01-01

    An acrylic acid/kaoline powder superabsorbent composite with a water absorbency of the superabsorbent composite about 1/800 was synthesized by inverse-suspending polymerization reaction between acrylic acid monomer and kaoline ultrafine powder. The influence of the dispersant agent on the configuration of the products in the inverse suspension polymerization is investigated. The influences of the kaoline powder, cross-linker, initiator, neutralization degree and the volume ratio of oil to water phase on the water absorbency of the superabsorbent composites are discussed in the paper.

  2. Hydrophobically Modified Polyelectrolytes: V. Interaction of Fluorocarbon Modified Poly (acrylic acid) with Various Added Surfactants

    ZHOU,Hui(周晖); SONG,Guo-Qaiang(宋国强); GUO,Jin-Feng(郭金峰); ZHANG,Yun-xiang (章云祥); DIEING,Reinhold; MA,Lian(马莲); HAEUSSLING,Lukas

    2001-01-01

    The interactions between fiuorocarbon-medified pol(sodium acrylate) and various kinds of added surfactant have been studied by means of viscometric measurement. Association behavior was found in both hydrogenated and fluorinated anionic, nonionic and cationic surfactants. Among them, the interactions between fluorocarbon-modified poly ( sodium acrylate) and cationic surfactants are the strongest, owing to the cooperation of both electrostatic attractions and hydrophobic associations. The anionic surfactants have the weakest effects on the solution properties because of the existence of unfavorable electrostatic repulsion. The hydrophobic interactions between copolymers and fluorinated surfactants are much stronger than those between copolymers and hydrogenated surfactants.

  3. Comparative examination of radiation polymerization in a thin layer of acrylic and methacrylic esters

    Some features of radiation polymerization of acrylic esters CH2 double-bond CH-COOR (AE) and their methacrylic analogs CH2 double-bond C(CH3)-COOR (ME) in a thin layer have not been explained within the framework of concepts of the radical mechanism of radiation polymerization. To determine the causes of the anomalies, the authors comparatively studied polymerization of a series of AE and ME in a thin layer under the effect of accelerated electrons, butyl acrylate and butyl methacrylate, ethylene glycol diacrylate and ethylene glycol dimethacrylate and diethylene glycol diacrylate and diethylene glycol dimethacrylate

  4. Chemical Fixation of CO{sub 2} to Acrylates Using Low-Valent Molybdenum Sources

    Bernskoetter, Wesley

    2013-09-30

    The kinetic, mechanistic, and reactivity experiments to access the viability and possible reaction design of coupling of carbon dioxide and ethylene at a zerovalent molybdenum for the production of acrylates are described. A general model of the reaction mechanism has been outlined, including assessment of the rate limiting step in the reaction. Kinetic and computational data have valuated the influence of a range of tridentate ligand platforms on the rate of coupling. An in situ reduction and acrylate formation activity screen protocol has also been developed to aid in the technology development of this process. Portions of descriptions of the research products presented here have also been adapted with permission from journal publications.

  5. Gold Nanoparticles Protected with Thiol-Derivatized Amphiphilic Poly( -caprolactone)-b-poly(acrylic acid)

    Javakhishvili, Irakli; Hvilsted, Søren

    2008-01-01

    Amphiphilic poly(c-caprolactone)-b-poly(acrylic acid) (HS-PCL-b-PAA) bearing thiol functionality at the PCL terminal has been synthesized by a combination of ring-opening polymerization (ROP) of c-caprolactone (c-CL), esterification of hydroxy chain end with protected mercaptoacetic acid, subsequ......Amphiphilic poly(c-caprolactone)-b-poly(acrylic acid) (HS-PCL-b-PAA) bearing thiol functionality at the PCL terminal has been synthesized by a combination of ring-opening polymerization (ROP) of c-caprolactone (c-CL), esterification of hydroxy chain end with protected mercaptoacetic acid...

  6. A study on antithrombogenic polymeric dialytic membrane. Irradiation grafting acrylic acid and styrene into polyethylene films

    A new type of antithrombogenic polymeric dialytic membrane with a hydrophilic-hydrophobic microphase structure was prepared by grafting acrylic acid and styrene into polyethylene films, using peroxidation pre-irradiation technique. Various ratios of monomers influencing on properties of the grafted films were examined. Experimental results showed that the grafted films have superior mechanic strength, and their antithrombogenicity and permeability were 30 and 10 times higher than that of the ungrafted films respectively on condition of the volume ratio 1:1 (styrene vs acrylic acid)

  7. Continuous gamma irradiation effects on acrylic staining treated with basic dyes

    Al-Rawi, Anis M.; Al-Harithy, Rafila S.; Muslih, Raad M.

    Gamma photons were used as a tool to enhance colours producing of the acrylic fibres used in the manufacture of textile in Iraq. Acrylic fibres and basic dyes were irradiated at doses up to 5 Mrad. Different fascinating colours were obtained after the dyeing process. Colours were found to depend on the total dose absorbed. Developed colours are stable against decolorization and their staining are comparable to that of the normal non-irradiated material. Computer Nova 3 fortran was used to differentiate between the obtained colours. Further physical and chemical studies are still under investigation in order to view the nature of changes that took place during radiolysis.

  8. Modelling and manufacture of regular microstructures with high aspect ratio in acrylic plastic

    The possibility of manufacture of microstructures with high aspect ratio in industrial acrylic plastic by the method of deep X-ray lithography is investigated. A characteristic dependence of the rate of dissolution of the polymer on the dose of the radiation absorbed is obtained. Processing regimes for the formation of deep structures were selected. A model for computation of the profile of development of structures in view of large exhibition depth was suggested. 25x25 μm through channels were obtained in sheet acrylic plastic 1000 μm thick

  9. The Modification of the Acrylate Emulsion for Water-Based Coatings

    Chen Wei-Feng; Fa-Ai Zhang

    2005-01-01

    @@ 1Introduction The developments of the environment friendly materials and technology are largely promoted recently.There also come some new kinds of coatings including water-based coating, powder coating, high-solid coating and UV-cured coating[1]. The emulsion polymerization is the main method for preparing the polymer for coatings. One of the most widely used polymers is acrylate resin which is not well in some properties, such as weather resistance, endurance and water resistance[2]. We hope to improve the various properties of the acrylic emulsion by adding silicone made from tetraethyl orthosilicate(TEOS), making it better applied in coating field.

  10. A new approach to cure and reinforce cold-cured acrylics

    So, YC; Tsoi, JKH; Matinlinna, JP

    2012-01-01

    Purpose: The low degree of polymerization of cold-cured acrylics has resulted in inferior mechanical properties and fracture vulnerability in orthodontics removable appliances. Methods: In this study, the effect of reinforcement by various concentrations of chopped E-glass fibers (0%, 1%, 2%, 3% and 5% by weight of resin powder) and post-curing microwave irradiation (800 W for 3 min) on the flexural strength of cold-cured acrylics was evaluated at various storage conditions (at room temperatu...

  11. Graft Copolymerization of Acrylic Acid onto Fungal Cell Wall Structural Polysaccharide

    2001-01-01

    Acrylic acid was graft-copolymerized onto Rhi. oryzae's cell wall structural polysacchaxide directly and efficiently in aqueous solution with ceric ammonium nitrate as initiator. The maximal grafting percentage of 135.5% was obtained under the condition of [Ce4+]=5mmol.L-1, [AA]=1mol.L-1, T=60°C and t=3h. Graft copolymerization was suggested to proceed through free radical reaction mechanism. Grafting occurred primarily on chitosan. Acrylic acid was also attempted to be grafted onto Asp. niger cell wall structural polysaccharide, and only 44.2% of grafting percentage was resulted.

  12. Proton Exchange Membrane from the Blend of Copolymers of Vinyl Acetate- Acrylic Ester and Styrene-Acrylic Ester for Power Generation Using Fuel Cell

    Alvaro Realpe

    2014-10-01

    Full Text Available Proton exchange membranes for fuel cells were synthesized from the blend of copolymers of vinyl acetate-acrylic ester and styrene-acrylic ester, which were modified by sulfonation and addition of silica gel. Water uptake, ion exchange capacity, infrared spectroscopy and tensile tests were applied to characterize the prepared membranes. The results show that the prepared membranes with the processes of sulfonation and loaded with silica have the highest water uptake (92,7%. On the other hand, the sulfonation process lead to membranes with high ion exchange capacity and high mechanical strength (0,68 meq/g and 1,29 MPa, respectively. Therefore, the sulfonated membrane represents an alternative for the application as proton exchange membrane in fuel cells.

  13. Extraction Equilibrium of Acrylic Acid by Aqueous Two-Phase Systems Using Hydrophilic Ionic Liquids

    As an effective method for extraction of acrylic acid, aqueous two-phase systems based on morpholinium ionic liquids were used in this study. Effects of the alkyl chain length of cation in morpholinium ionic liquids on phase diagram and extraction efficiencies were investigated. Experimental results show that aqueous two phase systems can be formed by adding appropriate amount of morpholinium ionic liquids to aqueous K2HPO4 solutions. It can be found that the ability of morpholinium ionic liquids for phase separation followed the order [HMMor][Br]>[OMMor][Br]>[BMMor][Br]>[EMMor][Br]. There was little difference between binodal curves of imidazolium ionic liquids and those of morpholinium ionic liquids. 50-90% of the extraction efficiency was observed for acrylic acid by aqueous two phase extraction of acrylic acid with morpholinium ionic liquids. It can be concluded that morpholinium ionic liquids/K2HPO4 were effective for aqueous two phases extraction of acrylic acid comparing to imidazolium ionic liquids/K2HPO4 systems because of their lower cost

  14. The application of FT-IR spectrum method in photocuring process for polyester acrylate

    This paper describes that the UV curing process of polyester acrylate can be monitored by measuring the degree of double bonds conversion with FT-IR spectroscopy. The various factors effect the UV curing rate. The relation between the curing rate and the concentration of photoinitiator, crosslinking agent, UV light intensity was discussed. (author)

  15. Depletion of abundant plasma proteins by poly(N-isopropylacrylamide-acrylic acid) hydrogel particles

    Such-Sanmartín, Gerard; Ventura-Espejo, Estela; Jensen, Ole N

    2014-01-01

    the application of pH-sensitive poly(N-isopropylacrylamide-acrylic acid) hydrogel particles for removal of abundant plasma proteins, prior to proteome analysis by MS. Protein depletion occurs by two separate mechanisms: (1) hydrogel particles incubated with low concentrations of plasma capture...

  16. Novel Polymers Based on Atom Transfer Radical Polymerization of 2-Methoxyethyl Acrylate

    Bednarek, Melania; Jankova Atanasova, Katja; Hvilsted, Søren

    2007-01-01

    Atom transfer radical polymerization (ATRP) has been employed in the polymerization of 2-methoxyethyl acrylate (MEA) initiated by ethyl 2-bromoisobutyrate in bulk or in toluene solution at 90– 95 C with the catalytic systems Cu(I)Br/PMDETA or HMTETA. Kinetics investigations revealed that ATRP of...

  17. 21 CFR 177.1990 - Vinylidene chloride/methyl acrylate copolymers.

    2010-04-01

    .... (2) The weight average molecular weight of the copolymer is not less than 50,000 when determined by... described in ANSI/ASTM D3536-76, “Standard Test Method for Molecular Weight Averages and Molecular Weight... copolymers contain not more than 15 weight-percent of polymer units derived from methyl acrylate....

  18. EB curable coating based on soy-oil fatty acid modified acrylate

    Soy-oil fatty acid was used to synthesize the soy-oil fatty acid modified acrylic coating by esterification reaction. After coating and EB curing, the results showed that the properties of the film were excellent, and it was suitable for the coating of wood furniture cured by EB

  19. Long-term testing and properties of acrylic for the Daya Bay antineutrino detectors

    Krohn, M.; Littlejohn, B. R.; Heeger, K. M.

    2012-08-01

    The Daya Bay reactor antineutrino experiment has recently measured the neutrino mixing parameter sin22θ13 by observing electron antineutrino disappearance over kilometer-scale baselines using six antineutrino detectors at near and far distances from reactor cores at the Daya Bay nuclear power complex. Liquid scintillator contained in transparent target vessels is used to detect electron antineutrinos via the inverse beta-decay reaction. The Daya Bay experiment will operate for about five years yielding a precision measurement of sin22θ13. We report on long-term studies of poly(methyl methacrylate) known as acrylic, which is the primary material used in the fabrication of the target vessels for the experiment's antineutrino detectors. In these studies, acrylic samples are subjected to gaseous and liquid environmental conditions similar to those experienced during construction, transport, and operation of the Daya Bay acrylic target vessels and detectors. Mechanical and optical stability of the acrylic as well as its interaction with detector liquids is reported.

  20. Evaluation of thermal conductivity of heat-cured acrylic resin mixed with A1203

    Ebadian B.

    2002-08-01

    Full Text Available One of the most important characteristics of denture base is thermal conductivity. This property has a major role in secretions of salivary glands and their enzymes, taste of the food and gustatory response. Polymethyl methacrylate used in prosthodontics is relatively an insulator. Different materials such as metal fillers and ceramics have been used to solve this problem. The aim of this study was the evaluation of AI2O3 effect on thermal conductivity of heat-cured acrylic resin. Acrylic resin was mixed with AI2O3 in two different weight rates (15 and 20 % of weight. So, group 1 and 2 were divided on this basis. Samples with pure acrylic resin were considered as control group. 18 cylindrical patterns were made in 9x9 mm dimensions and thermocouple wires embedded in each sample to act as conductor. The specimens were put in water with 70±1°C thermal range for 10 minutes. Then, thermal conductivity was measured. The results were analyzed with variance analysis and Dunken test. There was significant difference between thermal conductivity of all groups in all period times. It the first seconds, thermal conductivity in groups 1 and 2 were more than control group. Therefore, for developing of thermal conductivity of acrylic resin, A1203 can be used. Certainly, other characteristic of new resin should be evaluated.

  1. Synthesis and characterization of poly(sodium acrylate)/ bentonite superabsorbent composite

    Poly(sodium acrylate)/bentonite superabsorbent composite with water absorbency 1562 g·g−1 was synthesized by inverse suspension polymerization. The introduction of bentonite improves the water absorbency and facilitates the particle size even distribution of the composite. The network structure in the superabsorbent hydrogel is confirmed.

  2. Delamination of layered double hydroxides in polar monomers: new LDH-acrylate nanocomposites.

    O'Leary, Shane; O'Hare, Dermot; Seeley, Gordon

    2002-07-21

    The layered double hydroxide Mg2Al(OH)6(C12H25SO4) was delaminated to give high levels of inclusion in acrylate monomers; subsequent polymerisation of the monomers containing the LDH dispersion gave polyacrylates with the inorganic component still in the delaminated form. PMID:12189866

  3. Deep UV patterning of acrylic masters for molding biomimetic dry adhesives

    Sameoto, D.; Menon, C.

    2010-11-01

    We present a novel fabrication method for the production of biomimetic dry adhesives that allows enormous variation in fiber shapes and sizes. The technology is based on deep-UV patterning of commercial acrylic with semi-collimated light available from germicidal lamps, and combined careful processing conditions, material selection and novel developer choices to produce relatively high-aspect-ratio fibers with overhanging caps on large areas. These acrylic fibers are used as a master mold for subsequent silicone rubber negative mold casting. Because the bulk acrylic demonstrates little inherent adhesion to silicone rubbers, the master molds created in this process do not require any surface treatments to achieve high-yield demolding of interlocked structures. Multiple polymers can be cast from silicone rubber negative molds and this process could be used to structure smart materials on areas over multiple square feet. Using direct photopatterning of acrylic allows many of the desired structures for biomimetic dry adhesives to be produced with relative ease compared to silicon-based molding processes, including angled fibers and hierarchical structures. Optimized fiber shapes for a variety of polymers can be produced using this process, and adhesion measurements on a well-characterized polyurethane, ST-1060, are used to determine the effect of fiber geometry on adhesion performance.

  4. Gold Nanoparticles Protected with Thiol-Derivatized Amphiphilic Poly(epsilon-caprolactone)-b-poly(acrylic acid)

    Javakhishvili, Irakli; Hvilsted, Søren

    2009-01-01

    Amphiphilic poly(epsilon-caprolactone)-b-poly(acrylic acid) (HS-PCL-b-PAA) with a thiol functionality in the PCL terminal has been prepared in a novel synthetic cascade. Initially, living anionic ring-opening polymerization (ROP) of epsilon-caprolactone (epsilon-CL) employing the difunctional...

  5. Anionic polymerization of (meth)acrylate monomers with the ligated systems, metalloporphyrin and lanthanocene initiators

    Vlček, Petr

    New York: Nova Science Publishers, Inc, 2006 - (Jagur-Grodzinski, J.), s. 289-342 ISBN 1-59454-330-5 Institutional research plan: CEZ:AV0Z40500505 Keywords : anionic polymerization * copolymers * (meth)acrylates Subject RIV: CD - Macromolecular Chemistry

  6. Deep UV patterning of acrylic masters for molding biomimetic dry adhesives

    We present a novel fabrication method for the production of biomimetic dry adhesives that allows enormous variation in fiber shapes and sizes. The technology is based on deep-UV patterning of commercial acrylic with semi-collimated light available from germicidal lamps, and combined careful processing conditions, material selection and novel developer choices to produce relatively high-aspect-ratio fibers with overhanging caps on large areas. These acrylic fibers are used as a master mold for subsequent silicone rubber negative mold casting. Because the bulk acrylic demonstrates little inherent adhesion to silicone rubbers, the master molds created in this process do not require any surface treatments to achieve high-yield demolding of interlocked structures. Multiple polymers can be cast from silicone rubber negative molds and this process could be used to structure smart materials on areas over multiple square feet. Using direct photopatterning of acrylic allows many of the desired structures for biomimetic dry adhesives to be produced with relative ease compared to silicon-based molding processes, including angled fibers and hierarchical structures. Optimized fiber shapes for a variety of polymers can be produced using this process, and adhesion measurements on a well-characterized polyurethane, ST-1060, are used to determine the effect of fiber geometry on adhesion performance

  7. Copolymers Formation by Photopolymerization of (Meth)acrylates Containing Dissolved Polyheteroarylenes

    Dmitriy A. Sapozhnikov; Tat'yana V. Volkova; Sakharova, Antonina A.; Gasanov, Rashid G.; Vanda Yu. Voytekunas; Abadie, Marc J. M.; Jean-Yves Sanchez; Vygodskii, Yakov S.

    2009-01-01

    Radical photopolymerization of (meth)acrylates in the presence of dissolved polyheteroarylenes has been investigated. The kinetics of radical polymerization of unsaturated monomers in the presence of polyheteroarylenes and model compounds has been studied by Differential Scanning Photocalorimetry and Infrared Spectroscopy. From the results of investigations into the kinetics and the polymer structures (Fourier Transform Infrared Spectroscopy, Nuclear Magnetic Resonance, Size-exclusion Chromat...

  8. Effect of Microwave Cured Acrylic Resin on Candidal Growth in Complete denture

    This study was conducted to evaluate the effect of heat-cured acrylic resin denture base and microwave-cured acrylic resin denture base on Candidal growth. Seven completely edentulous male patients with no history of denture wearing participated in this study. All the selected patients were re-habilitated by mucosa supported complete dentures. The dentures were constructed from conventional heat-cured acrylic resin denture base following monoplane concept of occlusion. Before dismissing the patients and one month after denture insertion, salivary samples were collected according to oral rinse technique. One month resting period was allowed so as Candidal count can reach to normal. Then dentures were re based using microwave-cured acrylic denture base, before denture insertion and one month after denture insertion, salivary sample were collected before and one month following the same oral rinse technique. In the oral rinse technique, the patients were instructed to rinse their mouths with 10 mL of sterile phosphate buffered saline for 60 seconds. The rinse was then expectorated into a universal container and immediately transported to the laboratory for concentration by centrifugation, then cultured on sabouraud's dextrose agar plates which were incubated at 37 degree C for 48 hours. Microscopic examination and germ tube test were carried out for laboratory investigations. In addition, the morphological features of the isolated Candida from the samples tested in this study, were investigated using the scanning electron microscope(SEM)

  9. Effects of preirradiation graft polymerization of acrylic acid onto polyethylene film

    With the aid of preirradiation method of grafting onto low-density polyethylene film, a systematic investigation was made of grafting of aqueous acrylic acid under conditions such as monomer concentrations, irradiation dose, dose rate, reaction time, the effect of concentrations of Mohr's salt and sulphuric acid on the graft reaction. (author)

  10. Epoxy and acrylate stereolithography resins: In-situ measurements of cure shrinkage and stress relaxation

    Guess, T.R.; Chambers, R.S.; Hinnerichs, T.D.; McCarty, G.D.; Shagam, R.N.

    1995-03-01

    Cross-sections of resin strands. Techniques were developed to make in situ measurements of gelled resin to determine linear shrinkage, stress-strain response and stress relaxation of single strands of SL 5170 epoxy and SL 5149 photocurable resins. Epoxy strands shrank approximately 1.4% and the acrylate strands about 1.0% after a single exposure. No forces were measured during cure shrinkage of strands following the first laser exposure. In multiple laser exposures, the acrylate continues to shrink; whereas (University of Dayton data) no additional shrinkage is observed in epoxy strands on a second hit. In force relaxation tests, a strand is drawn and then a 0.5% step strain is applied after different elapsed times. The epoxy initial modulus evolves (increases) with elapsed time following draw of the strand, and this evolution in modulus occurs after linear shrinkage has stopped. On the other hand, acrylates show no evolution of modulus with elapsed time following a single laser draw; i.e., once shrinkage stops after one laser hit, the initial modulus remains stable with elapsed time. Finally, relaxation response times of epoxy strands get larger with increasing elapsed time after laser draw. In acrylate strands there was no evolution in initial modulus with elapsed time after a single draw so relaxation times are not a function of elapsed time after a single hit with the laser.

  11. Polypyrrole-coated styrene-butyl acrylate copolymer composite particles with tunable conductivity

    HUANG Liyan; HOU Wenbo; LIU Zhengping; ZHANG Qingyue

    2005-01-01

    A series of near or monodisperse styrene-butyl acrylate (SBA) copolymer latex particles with different butyl acrylate contents were coated with polypyrrole. The structure of the SBA/PPy composites was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), diffuse reflectance infrared Fourier transform spectroscopy (DRIFT), X-ray photoelectron spectroscopy (XPS), differential scanning calorimetry (DSC) and standard four-probe method. The core-shell morphology of the SBA/PPy composite particles was confirmed. The result of DSC showed that Tg of the composite is mainly determined by the core component. The effects of the concentration of polypyrrole, the butyl acrylate content in SBA copolymer and the nature of the counter-anion on the electrical conductivity of compression-moulded samples were studied. It was first found that the electrical conductivity of the samples can be tuned by varying the butyl acrylate content in SBA copolymer and the highest conductivity of the core-shell composite was 0.17 S·cm-1.

  12. The preparation nad water absorption of a copolymer from konjac-graft-acrylic acid by irradiation

    The konjac and acrylic acid were grafted by 4.0kGy 60Co γ-rays irradiation. The water absorption property of copolymers was studied. The results showed that the optimum feed ratio was konjac powder: acrylic acid: NaOH (9.5mol/L):water=3g: 21ml: 17.8ml: 131ml. And the optimum reation conditions: volume/mass ratio of acrylic acid and konjac was 7:1, neutralization degree of acrylic acid was 55%, gel drying temperature was 30 degree C. The copolymer particle size of 40 ∼ 80 mesh had the largest absorption of water, up to 886.5 times at room temperature. The water-absorption and water-holding capabilities were affected by temperature, and were better at the termperater lower than 60 degree C. The water absorption was also affected by pH and ion concentration of solution, and the ion concentration was the main factor. The largest water absorption at Na2HPO4 - citric acid buffer was only 15.8% of which in distilled water at the optimum pH=6. (authors)

  13. Polymer coating comprising 2-methoxyethyl acrylate units synthesized by surface-initiated atom transfer radical polymerization

    2011-01-01

    Source: US2012184029A The present invention relates to preparation of a polymer coating comprising or consisting of polymer chains comprising or consisting of units of 2-methoxyethyl acrylate synthesized by Surface-Initiated Atom Transfer Radical Polymerization (SI ATRP) such as ARGET SI ATRP or...

  14. 21 CFR 177.2000 - Vinylidene chloride/methyl acrylate/methyl methacrylate polymers.

    2010-04-01

    ... methacrylate polymers. 177.2000 Section 177.2000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF...: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.2000 Vinylidene chloride/methyl acrylate/methyl methacrylate polymers. The vinylidene chloride/methyl...

  15. Selective oxidation of propane to acrylic acid over mixed metal oxide catalysts

    Wei Zheng; Zhenxing Yu; Ping Zhang; Yuhang Zhang; Hongying Fu; Xiaoli Zhang; Qiquan Sun; Xinguo Hu

    2008-01-01

    The effects of metal atomic ratio, water content, oxygen content, and calcination temperature on the catalytic perfor-mances of MoVTeNbO mixed oxide catalyst system for the selective oxidation of propane to acrylic acid have been investigated and discussed. Among the catalysts studied, it was found that the MoVTeNbO catalyst calcined at a temperature of 600 ℃ showed the best performance in terms of propane conversion and selectivity for acrylic acid under an atmosphere of nitrogen. An effective MoVTeNbO oxide catalyst for propane selective oxidation to acrylic acid was obtained with a combination of a preferred metal atomic ratio (Mo1 V0.31Te0.23Nb0.12). The optimum reaction condition for the selective oxidation of propane was the molar ratio of C3H81 :O2 : H2O : N1 = 4.4 : 12.8 : 15.3 : 36.9. Under such conditions, the conversion of propane and the maximum yield of acrylic acid reached about 50% and 21%, respectively.

  16. STUDY OF OPTICAL PROPERTIES OF ACRYLIC HYDROGEL USED IN POLLUTANTS DISPLAY SYSTEMS

    ITIN ALEKSEY L.; LUKIN SERGEY B.; USPENSKAYA MAYA V.; SOLOVIEV VALERY S.

    2012-01-01

    Results of investigations of optical properties of acrylic hydrogel used as a sensitive element in optoelectronic systems of pollutants display are presented. Spectral features and functions of the hydrogel refractive index variation under exposure to different pollutants are measured at various concentrations of polyvalent metals at room temperature.

  17. Inhibition of candida adhesion to denture acrylic byBoesenbergia pandurata

    Thaweboon Sroisiri; Thaweboon Boonyanit

    2010-01-01

    Objective:To investigate effect ofBoesenbergia pandurata (B. pandurata) rhizome extract on adhesion ofCandida albicans (C. albicans) to acrylic surface.Methods: Transparent acrylic strips were prepared and divided into three groups with pretreatment by extract solution ofB. pandurata rhizome at concentration of 25, 50 and 100 mg/mL, respectively. After washing, the strips were then inoculated with two strains ofC. albicans (ATCC13803 and the clinical isolate) (107cells/mL). Normal saline solution and 0.2% chlorhexidine gluconate were used as negative and positive controls, respectively. Stained the strips with modified Gram stain without counterstain. Adherent yeast cells were direct counted under microscope (Olympus-CX31, Japan) in 20 randomly selected fields on each strip. The statistical significance was calculated by Kruskal-Wallis and Mann-Whitney non-parametric tests at a significance level ofP < 0.05.Results: Pretreatment withB. pandurata extract significantly reduced the adhesion of both strains ofC. albicans to acrylic surfaces in a dose dependent manner.Conclusions:This observation indicates thatB. pandurata extract has an inhibitory effect on the ability ofC. albicans to adhere to denture acrylic and could be employed as an antifungal agent for preventing denture stomatitis.

  18. Effect of Phyllanthus emblica Linn. on candida adhesion to oral epithelium and denture acrylic

    Boonyanit Thaweboon; Sroisiri Thaweboon

    2011-01-01

    Objective: To investigate the effect of Phyllanthus emblica (P. emblica) Linn. ethanolic extract on the adhesion of Candida albicans (C. albicans) to human buccal epithelial cells (BECs) and denture acrylic surfaces. Methods: Human BECs and transparent acrylic strips were pretreated with ethanolic extract solution of P. emblica fruits at concentration ranged from 18.7 to 300 mg/mL. After washing BECs and the strips were inoculated with three strains of C. albicans (ATCC 10281 and two clinical isolates) (107 cells/mL). Normal saline solution (NSS) and 0.2%chlorhexidine gluconate were used as negative and positive controls, respectively. BECs were harvested on 12 μm-polycarbonate filters (Millipore, USA). The membrane filters and the strips were stained with Gram stain. Adherent yeast cells on 100 randomly selected epithelial cells and 20 randomly selected fields on each strip were counted under microscope. The statistical significance was calculated by Kruskal-Wallis and Tukey tests at a significant level of P< 0.05.Results:Significant lower numbers of all strains of yeasts adhering to BECs and acrylic strips were observed after exposure to 75-300 mg/mL of plant extract compared with NSS. Conclusions:The present study demonstrates that P. emblica ethanolic extract interferes with the adhesion of C.albicans to BECs and denture acrylic surfaces in vitro.

  19. Polymorphism and polymerisation of acrylic and methacrylic acid at high pressure

    Oswald, Iain D. H.; Urquhart, Andrew J.

    2011-01-01

    The polymorphism and polymerisation of two related acids have been investigated under high pressure conditions. Acrylic acid crystallises as a new polymorph at 0.65 GPa whilst methacrylic acid crystallises in a new polymorph at a higher pressure of 1.5 GPa. Both these new polymorphs exhibit similar...

  20. Morphological alteration of microwave disinfected acrylic resins used for dental prostheses

    Popescu, M. C.; Bita, B. I.; Avram, A. M.; Tucureanu, V.; Schiopu, P.

    2015-02-01

    In this paper we aim to perform a cross section morphological characterization of an acrylic polymer used for dental prostheses subjected to microwave disinfection. The method was largely investigated and the microbiological effectiveness is well established, but there are some issues regarding the in-depth alteration of the material. In our research, the surface roughness is insignificant and the samples were not polished or refined by any means. Two groups of 7 acrylic discs (20 mm diameter, 2 mm thickness) were prepared from a heat-cured powder. Half of the samples embedded a stainless steel reinforcement, in order to observe the changes at the interfaces between the polymer and metallic wire. After the gradual wet microwave treatment, the specimens - including the controls - were frozen in liquid nitrogen and broken into pieces. Fragments were selected for gold metallization to ensure a good contrast for SEM imaging. We examined the samples in cross section employing a high resolution SEM. We have observed the alterations occurred at the surface of the acrylic sample and at the interface with the metallic wire along with the increase of the power and exposure time. The bond configuration of acrylate samples was analysed by FTIR spectrometry.

  1. Effect of Nanoclay on Thermal Conductivity and Flexural Strength of Polymethyl Methacrylate Acrylic Resin

    Tahereh Ghaffari

    2016-06-01

    Full Text Available Statement of the Problem: The mechanical and thermal properties of polymethyl methacrylate (PMMA acrylic resin should be improved to counterweigh its structural deficiencies. Purpose: The aim of this study was to compare the flexural strength and thermal conductivity of conventional acrylic resin and acrylic resin loaded with nanoclay. Materials and Method: The methacrylate monomer containing the 0.5, 1 and 2 wt% of nanoclay was placed in an ultrasonic probe and mixed with the PMMA powder. Scanning electron microscopy was used to verify homogeneous distribution of particles. Twenty-four 20×20×200-mm cubic samples were prepared for flexural strength test; 18 samples containing nanoclay and 6 samples for the control group. Another 24 cylindrical samples of 38×25 mm were prepared for thermal conductivity test. One-way ANOVA was used for statistical analysis, followed by multiple-comparison test (Scheffé’s test. Statistical significance was set at p< 0.05. Results: Increasing the concentration of nanoclay incorporated into the acrylic resin samples increased thermal conductivity but decreased flexural strength (p< 0.05. Conclusion: Based on the results of this study, adding nanoclay particles to PMMA improved its thermal conductivity, while it had a negative effect on the flexural strength.

  2. Assessment of the flexural strength of two heat-curing acrylic resins for artificial eyes.

    Fernandes, Aline Ursula Rocha; Portugal, Aline; Veloso, Letícia Rocha; Goiato, Marcelo Coelho; Santos, Daniela Micheline dos

    2009-01-01

    Prosthetic eyes are artificial substitutes for the eyeball, made of heat-curing acrylic resin, serving to improve the esthetic appearance of the mutilated patient and his/her inclusion in society. The aim of this study was to assess the flexural strength of two heat-curing acrylic resins used for manufacturing prosthetic eyes. Thirty-six specimens measuring 64 x 10 x 3.3 mm were obtained and divided into four groups: acrylic resin for artificial sclera N1 (Artigos Odontológicos Clássico, São Paulo, SP, Brazil), heat-cure water technique (GI) and microwave-cured (GII); colorless acrylic resin for prosthetic eyes (Artigos Odontológicos Clássico, São Paulo, SP, Brazil), heat-cure water technique (GIII) and microwave-cured (GIV). Mechanical tests using three point loads were performed in a test machine (EMIC, São José dos Pinhais, PR, Brazil). The analysis of variance and the Tukey test were used to identify significant differences (p < 0.01). Groups GII and GIV presented, respectively, the highest (98.70 +/- 11.90 MPa) and lowest means (71.07 +/- 8.93 MPa), with a statistically significant difference. The cure method used for the prosthetic eye resins did not interfere in their flexural strength. It was concluded that all the resins assessed presented sufficient flexural strength values to be recommended for the manufacture of prosthetic eyes. PMID:19893960

  3. Monitor of Polymerization of Inverse Microemulsions Containing Methyl Methacrylate and Acrylic Acid

    Xiao LI; Sheng Ping XIA; Wei Jie ZENG; Wei Ying ZHANG; Sheng Xiong DONG

    2006-01-01

    The polymerization of the inverse microemulsions composed of methyl methacrylate,acrylic acid, sodium dodecyl sulfate and water was monitored by refractometer, conductometer and time-resolved light scattering device. The results showed that refractive index, conductivity or intensity distribution of scattered light changed along with polymerization, and different processes of polymerization could be identified.

  4. Syntheses of monomers in the reaction of hexamethylolmelamine with 2-hydroxyethyl acrylate and their photocuring

    A process has been developed for the syntheses of monomers from 2-hydroxyethyl acrylate and hexamethylolmelamine. Their structure were identified by IR and sub 1H-NMR. The photocuring characteristics of these compound and properties of the UV-cured films have been studied

  5. Transdermal thiol-acrylate polyethylene glycol hydrogel synthesis using near infrared light

    Chung, Solchan; Lee, Hwangjae; Kim, Hyung-Seok; Kim, Min-Gon; Lee, Luke P.; Lee, Jae Young

    2016-07-01

    Light-induced polymerization has been widely applied for hydrogel synthesis, which conventionally involves the use of ultraviolet or visible light to activate a photoinitiator for polymerization. However, with these light sources, transdermal gelation is not efficient and feasible due to their substantial interactions with biological systems, and thus a high power is required. In this study, we used biocompatible and tissue-penetrating near infrared (NIR) light to remotely trigger a thiol-acrylate reaction for efficient in vivo gelation with good controllability. Our gelation system includes gold nanorods as a photothermal agent, a thermal initiator, diacrylate polyethylene glycol (PEG), and thiolated PEG. Irradiation with a low-power NIR laser (0.3 W cm-2) could induce gelation via a mixed-mode reaction with a small increase in temperature (~5 °C) under the optimized conditions. We also achieved successful transdermal gelation via the NIR-assisted photothermal thiol-acryl reactions. This new type of NIR-assisted thiol-acrylate polymerization provides new opportunities for in situ hydrogel formation for injectable hydrogels and delivery of drugs/cells for various biomedical applications.Light-induced polymerization has been widely applied for hydrogel synthesis, which conventionally involves the use of ultraviolet or visible light to activate a photoinitiator for polymerization. However, with these light sources, transdermal gelation is not efficient and feasible due to their substantial interactions with biological systems, and thus a high power is required. In this study, we used biocompatible and tissue-penetrating near infrared (NIR) light to remotely trigger a thiol-acrylate reaction for efficient in vivo gelation with good controllability. Our gelation system includes gold nanorods as a photothermal agent, a thermal initiator, diacrylate polyethylene glycol (PEG), and thiolated PEG. Irradiation with a low-power NIR laser (0.3 W cm-2) could induce gelation

  6. The use of epoxidised palm oil products (EPOP) for the synthesis of radiation curable resins 1. Synthesis of epoxidised RBD palm olein acrylate

    The synthesis of acrylated olein utilizing epoxidised refined, bleached and deodorized (RBD) palm olein has been carried out by acrylation reaction. This is done by the introduction of acrylic acid into oxirane group of the epoxidised RBD palm olein. The reaction was confirmed by analytical data i.e. oxirane oxygen content, iodine value and acid value and IR spectrophotometric method. It was found that, oxirane group in triglyceride molecule of epoxidised RBD palm olein (EPOL) is attacked by acrylic acid to yield epoxidised RBD palm olein acrylate (EPOLA). The EPOLA was found curable when subjected to ultraviolet radiation

  7. Multi-functional hybrid coatings containing silica nanoparticles and anti-corrosive acrylate monomer for scratch and corrosion resistance

    Multi-functional hybrid coatings having both anti-corrosion and scratch resistance were prepared from modified silica nanoparticles and functional acrylates. To improve the dispersion properties of silica nanoparticles in the organic/inorganic hybrid coatings, the surface of the nanoparticles was modified with γ-methacryloxypropyltrimethoxysilane. The coating solution could be prepared by mixing modified silica nanoparticles, tetrasiloxane acrylate, di-acrylate monomer containing an anti-corrosion functional group, acrylic acid, and an initiator in a solvent. The mixture was then dip-coated on iron substrates and finally polymerized by ultraviolet (UV) irradiation. Corrosion and scratch resistance of the coated iron was evaluated by electrochemical impedance spectroscopy (EIS) and a pencil hardness test, respectively. From the EIS results, the coatings with tetrasiloxane acrylate and di-acrylate did not show any decrease in impedance or phase angle, even after 50 days' exposure to 0.1 M NaCl electrolyte, whereas the conventional acrylate coatings started to fail after only 24 h. A hybrid coating containing the amine-quinone functional group exhibited excellent corrosion protection properties with 4-5H pencil hardness.

  8. Multi-functional hybrid coatings containing silica nanoparticles and anti-corrosive acrylate monomer for scratch and corrosion resistance

    Seo, Ji Yeon; Han, Mijeong

    2011-01-01

    Multi-functional hybrid coatings having both anti-corrosion and scratch resistance were prepared from modified silica nanoparticles and functional acrylates. To improve the dispersion properties of silica nanoparticles in the organic/inorganic hybrid coatings, the surface of the nanoparticles was modified with γ-methacryloxypropyltrimethoxysilane. The coating solution could be prepared by mixing modified silica nanoparticles, tetrasiloxane acrylate, di-acrylate monomer containing an anti-corrosion functional group, acrylic acid, and an initiator in a solvent. The mixture was then dip-coated on iron substrates and finally polymerized by ultraviolet (UV) irradiation. Corrosion and scratch resistance of the coated iron was evaluated by electrochemical impedance spectroscopy (EIS) and a pencil hardness test, respectively. From the EIS results, the coatings with tetrasiloxane acrylate and di-acrylate did not show any decrease in impedance or phase angle, even after 50 days' exposure to 0.1 M NaCl electrolyte, whereas the conventional acrylate coatings started to fail after only 24 h. A hybrid coating containing the amine-quinone functional group exhibited excellent corrosion protection properties with 4-5H pencil hardness.

  9. Cisplatin-incorporated nanoparticles of poly(acrylic acid-co-methyl methacrylate copolymer

    Lee KD

    2013-08-01

    Full Text Available Kyung Dong Lee,1,* Young-Il Jeong,2,* Da Hye Kim,3,4 Gyun-Taek Lim,2 Ki-Choon Choi5 1Department of Oriental Medicine Materials, Dongshin University, Naju, South Korea; 2Department of Polymer Engineering, Chonnam National University, Gwangju, South Korea; 3Faculty of Life and Environmental Science, Shimane University, Matsue, Japan; 4United Graduate School of Agricultural Sciences, Tottori University, Tottori, Japan; 5Grassland and Forages Division, National Institute of Animal Science, Rural Development Administration, Cheonan, South Korea *These authors contributed equally to this work Background: Although cisplatin is extensively used in the clinical field, its intrinsic toxicity limits its clinical use. We investigated nanoparticle formations of poly(acrylic acid-co-methyl methacrylate (PAA-MMA incorporating cisplatin and their antitumor activity in vitro and in vivo. Methods: Cisplatin-incorporated nanoparticles were prepared through the ion-complex formation between acrylic acid and cisplatin. The anticancer activity of cisplatin-incorporated nanoparticles was assessed with CT26 colorectal carcinoma cells. Results: Cisplatin-incorporated nanoparticles have small particle sizes of less than 200 nm with spherical shapes. Drug content was increased according to the increase of the feeding amount of cisplatin and acrylic acid content in the copolymer. The higher acrylic acid content in the copolymer induced increase of particle size and decrease of zeta potential. Cisplatin-incorporated nanoparticles showed a similar growth-inhibitory effect against CT26 tumor cells in vitro. However, cisplatin-incorporated nanoparticles showed improved antitumor activity against an animal tumor xenograft model. Conclusion: We suggest that PAA-MMA nanoparticles incorporating cisplatin are promising carriers for an antitumor drug-delivery system. Keywords: cisplatin, nanoparticle, poly(acrylic acid-co-methyl methacrylate, ion complexes

  10. Influence of ozone and paracetic acid disinfection on adhesion of resilient liners to acrylic resin

    2016-01-01

    PURPOSE The aim of this study was to evaluate the effect of paracetic acid (PAA) and ozone disinfection on the tensile bond strength (TBS) of silicone-based resilient liners to acrylic resins. MATERIALS AND METHODS One hundred and twenty dumbbell shaped heat-polymerized acrylic resins were prepared. From the mid segment of the specimens, 3 mm of acrylic were grinded off and separated parts were reattached by resilient liners. The specimens were divided into 2 control (control1, control7) and 4 test groups of PAA and ozone disinfection (PAA1, PAA7, ozone1 and ozone7; n=10). While control groups were immersed in distilled water for 10 min (control1) and 7 days (control7), test groups were subjected to PAA (16 g/L) or ozone rich water (4 mg/L) for 1 cycle (10 min for PAA and 60 min for ozone) per day for 7 days prior to tensile tests. Measurements of the TBS were analyzed using 3-way ANOVA and Tukey's HSD test. RESULTS Adhesive strength of Mollosil decreased significantly by application of ozone disinfection. PAA disinfection had no negative effect on the TBS values of Mollosil and Molloplast B to acrylic resin. Single application of ozone disinfection did not have any negative effect on TBS values of Molloplast B, but prolonged exposure to ozone decreased its adhesive strength. CONCLUSION The adhesion of resilient liners to acrylic was not adversely affected by PAA disinfection. Immersion in ozonated water significantly decreased TBS of Mollosil. Prolonged exposure to ozone negatively affects adhesion of Molloplast B to denture base materials. PMID:27555898

  11. Adsorption of uranium ions by crosslinked polyester resin functionalized with acrylic acid from aqueous solutions

    In this paper, the crosslinked polyester resin containing acrylic acid functional groups was used for the adsorption of uranium ions from aqueous solutions. For this purpose, the crosslinked polyester resin of unsaturated polyester in styrene monomer (Polipol 353, Poliya) and acrylic acid as weight percentage at 80 and 20%, respectively was synthesized by using methyl ethyl ketone peroxide (MEKp, Butanox M60, Azo Nobel)-cobalt octoate initiator system. The adsorption of uranium ions on the sample (0.05 g copolymer and 5 mL of U(VI) solution were mixed) of the crosslinked polyester resin functionalized with acrylic acid was carried out in a batch reactor. The effects of adsorption parameters of the contact time, temperature, pH of solution and initial uranium(VI) concentration for U(VI) adsorption on the crosslinked polyester resin functionalized with acrylic acid were investigated. The adsorption data obtained from experimental results depending on the initial U(VI) concentration were analyzed by the Freundlich, Langmuir and Dubinin-Radushkevich (D-R) adsorption isotherms. The adsorption capacity and free energy change were determined by using D-R isotherm. The obtained experimental adsorption data depending on temperature were evaluated to calculate the thermodynamic parameters of enthalpy (ΔHo), entropy (ΔSo) and free energy change (ΔGo) for the U(VI) adsorption on the crosslinked polyester resin functionalized with acrylic acid from aqueous solutions. The obtained adsorption data depending on contact time were analyzed by using adsorption models such as the modified Freundlich, Elovich, pseudo-first order and pseudo-second-order kinetic models. (author)

  12. Degradable thiol-acrylate hydrogels as tunable matrices for three-dimensional hepatic culture.

    Hao, Yiting; Lin, Chien-Chi

    2014-11-01

    A degradable poly(ethylene glycol)-diacrylate (PEGDA) hydrogel system was developed using simple macromer formulations and visible light initiated thiol-acrylate photopolymerization. In addition to PEGDA, other components in this gelation system include eosin-Y as a photo-sensitizer, bi-functional thiol (dithiothreitol, DTT) as a dual-purpose co-initiator and cross-linker, and N-vinylpyrrolidone (NVP) as a co-monomer. Gelation was achieved through a mixed-mode step-chain growth polymerization mechanism under bright visible light exposure. Increasing photo-sensitizer or NVP concentrations accelerated photo-crosslinking and increased final gel stiffness. Increasing bi-functional thiol content in the prepolymer solution only increased gel stiffness to some degree. As the concentration of thiol surpassed certain range, thiol-mediated chain-transfer events caused thiol-acrylate gels to form with lower degree of cross-linking. Pendant peptide, such as integrin ligand RGDS, was more effectively immobilized in the network via a thiol-acrylate reaction (using thiol-bearing peptide Ac-CRGDS. Underline indicates cross-linkable motif) than through homo-polymerization of acrylated peptide (e.g., acryl-RGDS). The incorporation of pendant peptide comes with the expense of a lower degree of gel cross-linking, which was rectified by increasing co-monomer NVP content. Without the use of any readily degradable macromer, these visible light initiated mixed-mode cross-linked hydrogels degraded hydrolytically due to the formation of thiol-ether-ester bonds following thiol-acrylate reactions. An exponential growth relationship was identified between the hydrolytic degradation rate and bifunctional thiol content in the prepolymer solution. Finally, we evaluated the cytocompatibility of these mixed-mode cross-linked degradable hydrogels using in situ encapsulation of hepatocellular carcinoma Huh7 cells. Encapsulated Huh7 cells remained alive and proliferated as time to form cell clusters

  13. The effectiveness of Nigella sativa seed extract in inhibiting Candida albicans on heat cured acrylic resin

    Hanoem EH

    2011-09-01

    Full Text Available Background: Indonesia has a variety of plants that can be used for medicines. One of the medicinal plants is Nigella sativa. Nigella sativa has been used for medicinal purposes, both as medicinal herb and as medicinal oil. It contains saponin and atsiri oils that have antifungal, antimicrobial and antibacterial effects. Nigella sativa has been suggested as denture cleansers since it can inhibit the growth of Candida albicans (C. albicans on heat cured acrylic resin. Purpose: The aim of this research is to know the effectiveness of Nigella sativa seed extract in inhibiting the growth of C. albicans on heat cured acrylic resin. Methods: Eighteen acrylic samples were divided into three groups. Group I was control group, only contaminated with C. albicans without immersing in any solution. Group II was acrylic sample immersed in sterile aquades for one hour. Group III was acrylic sample immersed in Nigella sativa seed extract for one hour. Results: There were significant differences of C. albicans (p < 0.05 among the three groups. The number of Candida albicans was significantly higher in Group I, while that in group II was lower than that in group I, and that in group III was the lowest. Conclusion: Nigella sativa seed extract was effective in inhibiting the growth of C. albicans on heat cured acrylic resin.Latar belakang: Indonesia memiliki berbagai tanaman yang dapat dipakai sebagai obat, salah satu tanaman tersebut adalah jinten hitam (Nigella sativa. Pada beberapa negara jinten hitam telah digunakan untuk berbagai tujuan, baik sebagai obat herbal maupun sebagai minyak. kandungan jinten hitam adalah saponin dan minyak atsiri yang mempunyai efek anti jamur dan anti mikroba. Jinten hitam disarankan sebagai pilihan pembersih gigi tiruan yang dapat menghambat pertumbuhan Candida albicans (C. albicans pada resin akrilik heat cured. Tujuan: Tujuan penelitian ini adalah mengetahui efektivitas dari ekstrak biji jinten hitam dalam menghambat pertumbuhan

  14. Pre-irradiation induced emulsion co-graft polymerization of acrylonitrile and acrylic acid onto a polyethylene nonwoven fabric

    A pre-irradiation induced emulsion co-graft polymerization method was used to introduce acrylonitrile and acrylic acid onto a PE nonwoven fabric. The use of acrylic acid is meant to improve the hydrophilicity of the modified fabric. The kinetics of co-graft polymerization were studied. The existence of polyacrylonitrile (PAN) and poly(acrylic acid) (PAAc) graft chains was proven by Fourier transform infrared spectroscopy (FTIR) analysis. The existence of the nitrile groups in the graft chains indicates that they are ready for further amidoximation and adsorption of heavy metal ions. - Highlights: • Acrylonitrile and acrylic acid were co-grafted onto a PE nonwoven fabric. • Pre-irradiation induced emulsion graft polymerization technique is applied. • The existence of AAc resulted in the increased hydrophilicity of the grafted fabric

  15. Preparation and evaluation of chitosan-poly (acrylic acid hydrogels as stomach specific delivery for amoxicillin and metronidazole

    Hemant Yadav K

    2007-01-01

    Full Text Available The objective of the present work was to develop stomach specific delivery systems for amoxicillin and metronidazole using chitosan and poly(acrylic acid hydrogels. Chitosan and poly(acrylic acid hydrogels were prepared with different composition of copolymers. The hydrogels were evaluated for swelling studies, mucoadhesive studies, in vitro drug release, scanning electron microscopic and FTIR analysis. The effect of chitosan and poly (acrylic acid on swelling and in vitro drug release was carried out. The n value calculated was < 0.5 for all the formulations containing amoxicillin and metronidazole indicating Fickian diffusion mechanism. The hydrogels with chitosan and poly (acrylic acid ratio of 0.25:1 showed greater mucoadhesive property, maximum swelling and complete release of drugs, hence can be used for stomach specific delivery of drugs.

  16. Influence of Methacrylic-Acrylic Copolymer Composition on Plasticiser-free Optode Films for pH Sensors

    Musa Ahmad; Loh Han Chern; Teh Huey Fang; Lee Yook Heng

    2003-01-01

    In this work we have examined the use of plasticiser-free polymeric films incorporating a proton selective chromoionophore for optical pH sensor. Four types of methacrylic-acrylic copolymers containing different compositions of n-butyl acrylate (nBA) and methyl methacrylate (MMA) were synthesised for use as optical sensor films. The copolymers were mixed with appropriate amounts of chromoionophore (ETH5294) and a lipophilic salt before spin coated on glass slides to form films for the evaluat...

  17. A comparative Study of the Masticatory Efficiency in Complete Dentures Using Acrylic and Metal Occlusal Posterior Teeth—Photocolorimetric Analysis

    Awinashe, Vaibhav N.; Nagda, Suhasini J.

    2010-01-01

    Masticatory efficiency is always compromised in complete denture patients. The denture teeth with compromised occlusal anatomy and material further compound the inherent limitations of complete dentures. To compare the masticatory efficiency of patients with complete denture using acrylic and metal occlusal posterior teeth. Ten edentulous patients with well-formed ridges were selected. Complete dentures using acrylic and metal occlusal posterior teeth were fabricated. The masticatory efficien...

  18. A comparative study on patient specific absolute dosimetry using slab phantom, acrylic body phantom and goat head phantom

    Om Prakash Gurjar; Surendra Prasad Mishra

    2015-01-01

    Purpose: To compare the results of patient specific absolute dosimetry using slab phantom, acrylic body phantom and goat head phantom. Methods: Fifteen intensity modulated radiotherapy (IMRT) plans already planned on treatment planning system (TPS) for head-and-neck cancer patients were exported on all three kinds of phantoms viz. slab phantom, acrylic body phantom and goat head phantom, and dose was calculated using anisotropic analytic algorithm (AAA). All the gantry angles were set to zero...

  19. (E)-Ethyl 3-(2-fluoro-anilino)-2-(4-methoxy-phen-yl)acrylate.

    Zheng, Yi; Xiao, Zhu-Ping; Wang, Kai-Rui; Zhu, Hai-Liang

    2008-01-01

    The title compound, C(18)H(18)FNO(3), consists of three individually planar subunits, namely two substituted benzene rings and one amino-acrylate group. The dihedral angle between the two benzene rings is 47.48 (8)°. The amino-acrylate group forms dihedral angles of 57.95 (7) and 11.27 (6)° with the methoxy-phenyl and fluorophenyl rings, respectively. PMID:21201512

  20. A comparison of shear bond strength of ceramic and resin denture teeth on different acrylic resin bases

    Corsalini, Massimo; Venere, Daniela Di; Pettini, Francesco; Stefanachi, Gianluca; Catapano, Santo; Boccaccio, Antonio; Lamberti, Luciano; Pappalettere, Carmine; Carossa, Stefano

    2014-01-01

    The purpose of this study is to compare the shear bond strength of different resin bases and artificial teeth made of ceramic or acrylic resin materials and whether tooth-base interface may be treated with aluminium oxide sandblasting. Experimental measurements were carried on 80 specimens consisting of a cylinder of acrylic resin into which a single tooth is inserted. An ad hoc metallic frame was realized to measure the shear bond strength at the tooth-base interface. A complete factorial pl...

  1. Two Body Wear of Newly Introduced Nanocomposite Teeth and Cross Linked Four Layered Acrylic Teeth: a Comparitive In Vitro Study

    Ilangkumaran, R.; Srinivasan, J.; Baburajan, K.; N.Balaji

    2014-01-01

    Statement of Problem: Wear of complete denture teeth results in compromise in denture esthetics and functions. To counteract this problem, artificial teeth with increased wear resistance had been introduced in the market such as nanocomposite teeth. Purpose: The purpose of this study was to compare the amount of wear between nanocomposite teeth and acrylic teeth. Materials and methods: Fifteen specimens were chosen from each group namely the nanocomposite teeth (SR_-PHONARES) and the acrylic ...

  2. Copolymerization of Indene with Acrylic Acid, Itaconic Acid and Acrylonitrile: Characterization and Reactivity Ratios

    Random copolymers of indene (In) with acrylic acid (AA), itaconic acid (IA) and acrylonitrile (AN) were synthesized by free radical polymerization in dioxane in the presence of azobisisobutyronitrile as an initiator at 60 degree C. The homopolymer of indene and acrylonitrile was prepared using K2MnO4 and sulphuric acid as an initiator, while acrylic acid and itaconic acid were prepared using K2S2O8 solution. The reactivity ratios of the monomers were calculated by different methods. X-ray diffraction as well as thermal analyses were studied. The latter was studied via thermogravimetric analysis and differential thermal analysis. The complexation with metal ions such as Cu+2 and Fe+2 was investigated. The copolymerization and the complexation processes were confirmed by FTIR spectroscopy. Also the activation energy of the prepared copolymers was determined

  3. Applications of Acrylate-based Polymer and Silicone Resin on LPFG-based Devices

    2002-01-01

    Both acrylate-based polymer and silicone resin are proposed as recoating materials surrounding LPFGs for purposes of different applications. For the LPFG recoated with a thin layer of acrylate-based polymer, the range of wavelength shift as much as 60nm is expected when temperature changes from 0~100℃. As for that with surrounding material of silicone resin, the temperature stability is greatly improved depicted as the maximum wavelength shift of about 0.6nm with the same temperature variation. The former is potentially a broadband tunable band rejection filter or temperature sensor with enhanced sensitivity. And the latter could be applied as temperature insensitive filter, demultiplexer or strain sensor.

  4. Oxidative dehydration of glycerol to acrylic acid over vanadium-impregnated zeolite beta

    Pestana, Carolina F.M.; Guerra, Antonio C.O.; Turci, Cassia C. [Universidade Federal do Rio de Janeiro, RJ (Brazil). Inst. de Quimica; Ferreira, Glaucio B. [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Inst. de Quimica; Mota, Claudio J.A., E-mail: cmota@iq.ufrj.br [INCT Energia e Ambiente, Universidade Federal do Rio de Janeiro, RJ (Brazil)

    2013-01-15

    The oxidative dehydration of glycerol to acrylic acid was studied over vanadium-impregnated zeolite Beta. Catalysts were prepared by wet impregnation of ammonium metavanadate over ammonium-exchanged zeolite Beta, followed by air calcination at 823 K. Impregnation reduced the specific surface area, but did not significantly affected the acidity (Bronsted and Lewis) of the zeolites. The catalytic evaluation was carried out in a fixed bed flow reactor using air as the carrier and injecting glycerol by means of a syringe pump. Acrolein was the main product, with acetaldehyde and hydroxy-acetone (acetol) being also formed. Acrylic acid was formed with approximately 25% selectivity at 548 K over the impregnated zeolites. The result can be explained by XPS (X-ray photoelectron spectroscopy) measurements, which indicated a good dispersion of the vanadium inside the pores. (author)

  5. Preparation of poly (acrylic acid)-modified chitosan amphiphilic gels by γ-rays irradiation

    Poly (acrylic acid)-modified chitosan amphiphilic gels were prepared via O-maleoyl-N-phthaloyl- chitosan as an intermediate by grafting with poly (acrylic acid). The reaction was carried out in a homogeneous sys- tem by γ-ray irradiation. Evidence of grafting was obtained from FTIR spectroscopy. The effects for grafting reaction were investigated systematically. Results show that the grafting degree depends on monomer concentration and ab- sorbed dose. The swelling behavior of chitosan samples with different grafting degree was studied in different buffers as a function of pH. It can be found that all the samples swollen slightly at low pH but very well at high pH. More- over, the swelling behavior of chitosan samples in DMF has been evaluated. (authors)

  6. Properties of radiation curable hyperbranched polyurethane acrylate from palm oil oleic acid

    Radiation curable hyperbranched urethane acrylate (HBPUA) from oleic acid of palm oil was synthesized aided by p-toluene sulfonic acid as a catalyst. This mixture was then used as the core (HBP-1) and reacted with palm oil oleic acid to form the hyperbranched polyol (HBP-2). HBPUA was prepared by reacting HBP-2 resin with diisocyanate and hydroxyl-containing acrylate monomer with the presence of 0.1-2 wt% dibutyltin dilaurate as a catalyst. The reaction was confirmed by several analytical data i.e. hydroxyl value (OHV), Fourier Transform infrared (FT IR) spectroscopy gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR) spectroscopy analyses. The HBPUA was easily curable when subjected to electron beam (EB) or ultraviolet (UV) radiation. (authors)

  7. Characterization and copolymerization of cardanyl acrylate from cardanol extracted from cashew nut shell liquid

    Cardanyl acrylate (CA) and its model compounds (hydrogenated cardanyl acrylate (HCA) and cardanyl acetate (Cace)) based on cardanol, a natural alkyl phenol from cashew nut shell liquid, were synthesized. The copolymerization of CA and styrene (S) with methyl ethyl ketone peroxide (MEKP) and cobalt salt as the initiator was studied by means of dynamic and isothermal DSC, FTIR and rheometry. The kinetic parameters for the copolymerization such as heat of reactions, activation energy and reaction orders were evaluated. The Mayo-Lewis, Fineman-Ross and Kelen-Tuedos methods were used to determine the reactivity ratios for the copolymerization of the model compounds. All the calculated results obtained from the three methods are in good agreement. Afterwards, a ternary copolymer model has been built for the copolymerization of CA and styrene. The gel point of the copolymerization was determined by rheological measurements. The thermal behaviour of the copolymers of CA and styrene were also studied. (author)

  8. (E)-Methyl 3-(10-bromo­anthracen-9-yl)acrylate

    Bugenhagen, Bernhard; Al Jasem, Yosef; Hindawi, Bassam al; Al Rawashdeh, Nathir; Thiemann, Thies

    2013-01-01

    In the title mol­ecule, C18H13BrO2, the anthracene unit forms an angle of 46.91 (2)° with the mean plane of the methyl acrylate moiety. In the crystal, the mol­ecules arrange themselves into strands parallel to [010] and, due to the crystal symmetry, there are eight strands crossing the unit cell. In each strand, mol­ecules form short C—H⋯O and C—H⋯π contacts and have their anthracene groups parallel to each other. Neighboring strands, related by a c-glide operation, are connected via C—H⋯O inter­actions and form a layer parallel to (100). The arrangement of the acrylate and anthracene groups in the crystal do not allow for [2 + 2] or [4 + 4] cyclo­addition. PMID:24046689

  9. Grafting of acrylic acid onto polytetrafluoroethylene (PTFE) micropowder via pre-irradiation

    Grafting of acrylic acid (AAc) onto the surface of PTFE micropowder was performed by pre-irradiation method, in order to improve their dispersion in aqueous solution.The effects of various experimental parameters on the degree of grafting(G) were separately investigated, including: volume fraction of AAc, proper addition of concentrated sulfuric acid, mass fraction of inhibitor and reaction time. The result shows that G is increasing with increment of AAc concentration below 50%, and can be enhanced by adding a proper amount of sulfuric acid. Under our experimental conditions, G reached its saturated value when the mass concentration of the inhibitor was 0.8 g/L and the reaction time was 3 h. The introduction of more than 10% of poly(acrylic acid) chain on PTFE micropowder results in the good dispersion of PTFE micropowder in aqueous NaOH solution. (authors)

  10. Determination of Crosslinking and Grafting in Polyurethane-acrylic Hybrid Material and Their Theoretical Calculations

    JIANG Xu-bao; ZHU Xiao-li; ZHANG Zhi-guo; KONG Xiang-zheng; TAN Ye-bang

    2011-01-01

    A theoretical method to calculate the mode of polyurethane(PU) prepolymers grafted to polyacrylic(PAC) was presented. Using hydroxyethyl acrylate(HEA) as coupling agent, polyurethane-acrylics(PU-AC) hybrid latexes were prepared with varying HEA level and the reaction of HEA with PU prepolymers at different temperatures, and PU grafted to PAC was experimentally determined. The results show that PU grafted to PAC regularly increased, and the non-grafted and linear free PU regularly decreased with increase in HEA/NCO(isocyanate group). The grafted PU on PAC was not proportional to HEA. More than half of linear PU prepolymers were grafted to PAC when HEA was at a low level with HEA/NCO at 0.33. While grafted PU increased to 84.80% (mass fraction), when HEA/NCO increased to 1.0. The results were interpreted based on the theoretical calculation of PU grafted to PAC by the present method.

  11. Effect of irradiation on acrylic cement with special reference to fixation of pathological fractures

    Self-curing cement is generally used in conjunction with conventional metallic devices. If the acrylic cement was supplemented, the primary goal would be a rigid immobiliztion of the fracture to alleviate the pain; usually, however, the final aim is toward osteosynthesis. During the course of rehabilitation, it is often desirous to supplement the treatment by irradiation. Although the industrial, dental and surgical literature has adequately dealt with many aspects of bone cement; for example, physical and chemical properties in joint replacement, and so on, the effects of irradiation on the acrylic cement have not been previously reported. It is the purpose of this paper to analyze the experimental studies conducted to evaluate the mechanical properties of the polymethylmethacrylate when subjected to irradiation within a maximum range of a therapeutic dose

  12. Peel/seal properties of poly(ethylene methyl acrylate)/polybutene-1 blend films

    Nowadays, the possibility to easy open a food package is of great interest both from the consumer and food producers’ perspective. In this study, the peel/seal properties of poly (ethylene methyl acrylate) (EMA)/polybutene-1 (PB-1) blend films were investigated. Three blends of EMA/PB-1 with different methyl acrylate (MA) content were prepared using cast extrusion process. Differential Scanning Calorimetry (DSC) was used to investigate the thermal behavior as well as the crystalinity of the blends. The effect of polymer matrix on the crystalline structure of PB-1 was studied using Wide Angle X-ray Diffraction (WAXD) and DSC. T-peel tests were carried out on the heat sealed films at various seal temperatures. The effect of MA content and heat seal temperature on peel/seal properties (i.e. peel initiation temperature, temperature window of sealability and peel strength) of the films were studied

  13. Kinetics characterization of a novel photopolymerizable siloxane-modified acrylic resin

    An experimental study was carried out for the development and characterization of innovative photopolymerizable siloxane-modified acrylic formulations for possible use as protective coatings. The kinetics of the radical photopolymerization mechanism induced by UV and visible radiations in presence of suitable photoinitiators was studied by a calorimetric analysis by varying the testing conditions (temperature, light power emission, atmosphere). The reactivity, expressed in terms of both heat developed and rate of reaction, was generally found to decrease when the photopolymerization was carried out in air, due the inhibiting action of the oxygen towards the free-radical polymerization. The addition of both a silane coupling agent or a high molecular weight polysiloxane monomer to the acrylic resin was found to reduce the heat of reaction. Experimental data were fitted to a kinetic model to quantify the effects of light intensity and temperature on reaction rates and extent of reaction. A good agreement between the experimental data and the theoretical model was generally found.

  14. Effect of Additives on UV-activated Urethane Acrylate Polymerization Composite Coatings

    Zane GRIGALE-SOROCINA

    2016-05-01

    Full Text Available An increased demand for new and improved coating systems, for environmental & health & safety and performance reasons, have appeared during the recent decades. Currently, there is new interest in preparation of thin UV curable urethane acrylate (UA composite coatings with short-term properties. Cellulose based additives: nitrocellulose, cellulose acetate butyrate, sucrose benzoate and silica were evaluated to determine their influence on unreacted composite characteristics (viscosity, pigment suspension stability and characteristics of cured film (ultimate tensile strength, elongation at break, surface gloss, surface scratch resistance and film adhesion loss time. The most suitable additive content was found to provide required viscosity. All additives increase surface scratch resistance, but cellulose based additives increase surface gloss values and decrease the time of adhesion loss. Silica has great effect on the interaction between linear and hyperbranched urethane acrylates, which has crucial influence on the stability of uncured pigmented mixture samples.

  15. Kinetics characterization of a novel photopolymerizable siloxane-modified acrylic resin

    Corcione, C. Esposito, E-mail: carola.corcione@unile.it [Dipartimento di Ingegneria dell' Innovazione, Universita del Salento, via per Monteroni, 73100 Lecce (Italy); Previderio, A.; Frigione, M. [Dipartimento di Ingegneria dell' Innovazione, Universita del Salento, via per Monteroni, 73100 Lecce (Italy)

    2010-09-20

    An experimental study was carried out for the development and characterization of innovative photopolymerizable siloxane-modified acrylic formulations for possible use as protective coatings. The kinetics of the radical photopolymerization mechanism induced by UV and visible radiations in presence of suitable photoinitiators was studied by a calorimetric analysis by varying the testing conditions (temperature, light power emission, atmosphere). The reactivity, expressed in terms of both heat developed and rate of reaction, was generally found to decrease when the photopolymerization was carried out in air, due the inhibiting action of the oxygen towards the free-radical polymerization. The addition of both a silane coupling agent or a high molecular weight polysiloxane monomer to the acrylic resin was found to reduce the heat of reaction. Experimental data were fitted to a kinetic model to quantify the effects of light intensity and temperature on reaction rates and extent of reaction. A good agreement between the experimental data and the theoretical model was generally found.

  16. Investigation of ultraviolet curable waterborne polyurethane acrylate dispersion based on hydroxyl-terminated polybutadiene

    NIU Zhenbin; ZHANG Xingyuan; DAI Jiabing; ZHANG Heping

    2007-01-01

    A new kind of ultraviolet (UV) curable waterborne polyurethane acrylate dispersion was synthesized based on hydroxyl-terminated polybutadiene (HTPB),poly(propylene glycol) (PPG),isophorene diisocyanate (IPDI),2-hydroxy ethyl acrylate (HEA) and dimethylol propionic acid (DMPA) after neutralizing by triethylamine (TEA).2-Hydroxy- 1-[4-(2-hydroxyethoxy) phenyl]-2-methyl-1-propanone (Irgacure 2959) was used as a photoinitiator and deionized water as a diluent.Fourier transform infrared (FTIR) analysis was used to identify the chain structure of the UV-curable polyurethane prepolymer based on HTPB and the curing process.Effects of relative content of HTPB and PPG on emulsion stability,resistance to water and ethanol,thermal stability,compatibility of soft and hard segment,as well as the mechanical property of the cured film were investigated.

  17. Preparation of metal adsorbent from poly(methyl acrylate)-grafted-cassava starch via gamma irradiation

    Suwanmala, Phiriyatorn; Hemvichian, Kasinee; Hoshina, Hiroyuki; Srinuttrakul, Wannee; Seko, Noriaki

    2012-08-01

    Metal adsorbent containing hydroxamic acid groups was successfully synthesized by radiation-induced graft copolymerization of methyl acrylate (MA) onto cassava starch. The optimum conditions for grafting were studied in terms of % degree of grafting (Dg). Conversion of the ester groups present in poly(methyl acrylate)-grafted-cassava starch copolymer into hydroxamic acid was carried out by treatment with hydroxylamine (HA) in the presence of alkaline solution. The maximum percentage conversion of the ester groups of the grafted copolymer, % Dg=191 (7.63 mmol/g of MA), into the hydroxamic groups was 70% (5.35 mmol/g of MA) at the optimum condition. The adsorbent of 191%Dg had total adsorption capacities of 2.6, 1.46, 1.36, 1.15 and 1.6 mmol/g-adsorbent for Cd2+, Al3+, UO22+, V5+ and Pb2+, respectively, in the batch mode adsorption.

  18. Super absorbent Prepared by Radiation Induced Graft Copolymerization of Acrylic Acid onto Cassava Starch

    Full text: Super absorbent was synthesized by radiation-induced graft polymerization of acrylic acid onto cassava starch. Parameters such as the absorbed dose and the amount of monomer were investigated in order to determine the optimum conditions for the grafting polymerization. Water retention, germination percentage and germination energy were determined in order to evaluate the possibility of super absorbent in agricultural applications, especially in arid regions. The graft copolymer was characterized by FTIR. Results indicated that the sand mixed with 0.1%wt super absorbent can absorb more water than the sand without super absorbent. The germination energy of corn seeds mixed with 0.5% super absorbent was obviously higher than those without super absorbent. These experimental results showed that the super absorbent has considerable effect on seed germination and the growth of young plants. Keywords: Super absorbent, Radiation, Acrylic acid, Cassava starch

  19. Preparation of poly(acrylic acid) particles by dispersion polymerization in an ionic liquid.

    Minami, Hideto; Kimura, Akira; Kinoshita, Keigo; Okubo, Masayoshi

    2010-05-01

    Poly(acrylic acid) (PAA) particles were successfully prepared by dispersion polymerization of acrylic acid in ionic liquid, N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium bis(trifluoro-methanesulfonyl)amide ([DEME][TFSA]) at 70 degrees C with low hydrolysis grade (35.4%) poly(vinyl alcohol) as stabilizer. Interestingly, the PAA particles were easily extracted as particle state with water. Thus, the PAA particles had a cross-linked structure during the polymerization without cross-linker. Moreover, it was also noted that the cross-linking density of the PAA particles could be controlled by thermal treatment at various temperatures in [DEME][TFSA] utilizing the advantages of nonvolatility and high thermal stability of the ionic liquid. PMID:20043688

  20. Application of waterborne acrylic emulsions in coated controlled release fertilizer using reacted layer technology

    Yazhen Shen; Cong Zhao; Jianmin Zhou; Changwen Du

    2015-01-01

    Waterborne acrylic emulsions modified with organic siloxanes and aziridine crosslinker were synthesized and applied as coating of controlled release fertilizer. The free films were characterized and the nutrient release pro-files of the coated fertilizers were determined. The results show that methyl silicone oil and methylsilanolate so-dium could not improve water resistance performance and glass transition temperature Tg of coatings, while the firmness is enhanced. Aziridine crosslinker improves the water resistance performance, firmness and Tg. Incorpo-ration of methyl silicone oil and aziridine crosslinker gives an excellent aqueous acrylic emulsion for coated con-trol ed release fertilizer, with the 30-day cumulative nutrient release reduced to 16%and an estimated nutrient release duration over 190 days. Therefore, this waterborne coating is promising to meet the requirements for controlled release of nutrient and environmental protection.

  1. Peel/seal properties of poly(ethylene methyl acrylate)/polybutene-1 blend films

    Mohammdi, Seyedeh Raziyeh; Ajji, Abdellah; Tabatabaei, Seyed H. [Department of Chemical Engineering, École Polytechnique de Montréal, Montréal, Québec, H3C3A7 (Canada)

    2015-05-22

    Nowadays, the possibility to easy open a food package is of great interest both from the consumer and food producers’ perspective. In this study, the peel/seal properties of poly (ethylene methyl acrylate) (EMA)/polybutene-1 (PB-1) blend films were investigated. Three blends of EMA/PB-1 with different methyl acrylate (MA) content were prepared using cast extrusion process. Differential Scanning Calorimetry (DSC) was used to investigate the thermal behavior as well as the crystalinity of the blends. The effect of polymer matrix on the crystalline structure of PB-1 was studied using Wide Angle X-ray Diffraction (WAXD) and DSC. T-peel tests were carried out on the heat sealed films at various seal temperatures. The effect of MA content and heat seal temperature on peel/seal properties (i.e. peel initiation temperature, temperature window of sealability and peel strength) of the films were studied.

  2. Preparation of Conductive Coating Solutions by Blending Waterborne Acrylic Polyurethane Dispersion with Carbon Nanotube

    Waterborne polyurethane dispersion (WPUD) was synthesized from polycarbonate diol (PCD), isophorone diisocyanate (IPDI) and dimethylol propionic acid (DMPA) as starting materials. Then, waterborne acrylic polyurethane dispersion (AUD) was synthesized by reacting the WPUD with an acrylate monomer, methyl methacrylate (MMA). Subsequently, the AUD was mixed with multi-walled carbon nanotube (MWCNT) to yield a conductive coating solution, and the mixture was coated on the polycarbonate substrate. With increasing the amount of MMA in the AUD, the pencil hardness, abrasion resistance and chemical resistance of the coating films were improved, but the electrical conductivity of the coating films was decreased. On the other hand, the pencil hardness, abrasion resistance and chemical resistance of coating films were decreased, but the electrical conductivity was enhanced with increasing the amount of MWCNT in the conductive coating solutions

  3. Oxidative dehydration of glycerol to acrylic acid over vanadium-impregnated zeolite beta

    The oxidative dehydration of glycerol to acrylic acid was studied over vanadium-impregnated zeolite Beta. Catalysts were prepared by wet impregnation of ammonium metavanadate over ammonium-exchanged zeolite Beta, followed by air calcination at 823 K. Impregnation reduced the specific surface area, but did not significantly affected the acidity (Bronsted and Lewis) of the zeolites. The catalytic evaluation was carried out in a fixed bed flow reactor using air as the carrier and injecting glycerol by means of a syringe pump. Acrolein was the main product, with acetaldehyde and hydroxy-acetone (acetol) being also formed. Acrylic acid was formed with approximately 25% selectivity at 548 K over the impregnated zeolites. The result can be explained by XPS (X-ray photoelectron spectroscopy) measurements, which indicated a good dispersion of the vanadium inside the pores. (author)

  4. Preparation of nanoparticles from acrylated palm oil microemulsion using radiation technique

    The use of microemulsion in the development of nanoparticle based on acrylated palm oil product is demonstrated. Acrylated palm oil microemulsions were prepared using ionic surfactant. Combination methods of emulsion polymerization and radiation crosslinking were applied to the microemulsion system for synthesizing nanoparticle. The ionizing radiation technique was introduced to generate a crosslinking reaction in the development of nanoparticle. The nanoparticle was evaluated in terms of particle diameter, surface charge, pH and conductance. Their image was captured using Transmission electron microscopy (TEM). Results show that the size, charge and shape of the particles are influenced by concentration of surfactants, monomer concentration, radiation dose and time of storage. The study showed a promising method to produced nanoparticle. This nano-sized product has the potential to be utilized as controlled-drug-release-carrier. (Author)

  5. Real-time monitoring of graphene oxide reduction in acrylic printable composite inks

    Porro, S.; Giardi, R.; Chiolerio, A.

    2014-06-01

    This work reports the electrical characterization of a water-based graphene oxide/acrylic composite material, which was directly inkjet printed to fabricate dissipative patterns. The graphene oxide filler, which is strongly hydrophilic due to its heavily oxygenated surface and can be readily dispersed in water, was reduced by UV irradiation during photo-curing of the polymeric matrix. The concurrent polymerization of the acrylic matrix and reduction of graphene oxide filler was demonstrated by real-time resistance measurements during UV light irradiation. The presence of graphene filler allowed decreasing the resistance of the pure polymeric matrix by nearly five orders of magnitude. This was explained by the fact that clusters of reduced graphene oxide inside the polymer matrix act as preferential pathways for the mobility of charge carriers, thus leading to an overall decrease of the material's resistance.

  6. CURING KINETICS AND PROPERTIES OF ACRYLIC RESIN CURED WITH AZIRIDINE CROSSLINKER

    Fei Xie; Zong-hui Liu; De-qing Wei

    2002-01-01

    A kind of aziridine crosslinkers was synthesized and used to crosslink acrylate copolymers. The crosslinking properties and curing kinetics of the resin were studied. It was found that with the increase of the content of crosslinker in the emulsion, the mechanical properties and solvent resistance of the resin will be apparently improved, but its glass transition temperature (Tg) is very low. The lowest amount of crosslinker used in the acrylic resin emulsion is 0.25%. Curing kinetics studied by DSC show that this curing reaction occurs readily because the apparent activation energy of the reaction is low(65.1 KJ/mol). These results demonstrate that the aziridine crosslinker is indeed a low temperature crosslinking agent and can be used at room temperature.

  7. Preparation of Styrene-acrylate Latex Used in Ultra-low VOC Building Internal Wall Coating

    CHEN Lijun; WU Fengqin; ZHUANG Xinyu; YANG Jian; LI Rongxian

    2008-01-01

    Styrene-acrylate latex with high glass transition temperature(Tg),low minimum film forming temperature(MFT)and good stability was prepared via core-shell emulsion polymerization.With semicontinuous process,high conversion rate of monomer and low gel rate were achieved.The weight ratio of core monomer to shell monomer was approximately 1.35.It is found that many factors such as emulsifiers,initiators,reaction temperature,pH value and polymerization technology have influences on the permormance of styrene-acrylate latex.The prepared latex was characterized by TEM and FTIR.The obtained latex with T of20.57℃,MFT of 5.0℃,and good stability,had good stability of film forming.

  8. Removal of Dyes from Aqueous Solutions Using Radiation Synthesized (2-Hydroxyethyl Methacrylate/Acrylic acid) Hydrogels

    Acrylic acid/2-hydroxyethyl methacrylate super absorbent hydrogels (AAc/ HEMA) were prepared by γ-radiation copolymerization of 2-hydroxyethyl methacrylate (HEMA) and acrylic acid (AAc). Characterization of AAc/HEMA hydrogel was done by FTIR, TGA, SEM and XRD. The swelling properties were studied as a function of time, ph and irradiation dose. The diffusion behavior of water into these hydrogels followed the Fickian character at all investigated irradiation doses. The adsorption of Direct Congo Red and Direct Blue dyes onto the AAc/ HEMA hydrogel was studied. Physico-chemical parameters like dye concentration, solution ph and temperature were varied to characterize the adsorption phenomenon. Experimental data were modeled by Freundlich isotherm. Thermodynamic parameters ( ΔHo, ΔGo and ΔSo ) were evaluated for the dyes adsorbent systems, which suggest that the adsorption process is a typical physical process and endothermic in nature

  9. In vitro release of doxycycline from bioabsorbable materials and acrylic strips

    Larsen, T

    1990-01-01

    Treatment of marginal periodontitis may include use of local antibiotics. In the present in vitro study the bioabsorbable materials Surgicel, Tissell, and CollaCote and acrylic strips were examined for release of doxycycline into liquids and residual antibacterial activity of the materials. Pieces...... of material were incubated in 1 ml of water or human serum which was exchanged every day for 9 days. The concentration of doxycycline in the liquids was measured spectrophotometrically while the residual antibacterial activity of the materials was determined microbiologically. Surgicel constantly showed very....... In serum the acrylic strip was partly dissolved and Surgicel was totally dissolved after 2 days. Left undisturbed in serum Surgicel was not dissolved for 2 weeks. These results indicate that Surgicel and Tissel may be capable of prolonged release of doxycycline in vivo....

  10. The transversal strength of acrylic resin plate after being immersed soaking in noni fruit (Morinda citrifolia Linn. juice

    Sri Redjeki Indiani

    2008-06-01

    Full Text Available The disadvantages of acrylic resin plate are liquid absorption and porosity, allowing microorganisms to grow and multiply resulting in inflammation in the oral cavity. The juice of the noni fruit (Morinda citrifolia Linn. contains active flavonoid and atsiri oil. Flavonoid is a phenol substance that degrades acrylic resin plate in prolonged contact. The purpose of this study was to examine the transversal strength of acrylic resin plate after being immersed in noni fruit juice. An acrylic resin plate of 65 × 10 × 2.5 mm was immersed in 4%, 6%, 8%, 10%, and 12% concentrations of noni fruit juice and distilled water in a control group for 31, 46, and 61 days. The transversal strength of acrylic resin plate was tested using an autograph with a crosshead speed of 1/10mm/second; the distance for the two supporting parts was 50 mm. The data was analyzed by using a One–Way ANOVA test. There was no significant difference in the transversal strength of the plate after being soaked for 31, 46, and 61 days in 4%, 6%, 8%, 10%, and 12% concentrations of the juice. This study showed that the soaking of acrylic resin plate for 31, 46, and 61 days in 4%, 6%, 8%, 10%, and 12% concentrations of noni fruit juice does not decrease the transversal strength.

  11. Effect of water-aging on the antimicrobial activities of an ORMOSIL-containing orthodontic acrylic resin.

    Gong, Shi-Qiang; Epasinghe, D Jeevanie; Zhou, Bin; Niu, Li-Na; Kimmerling, Kirk A; Rueggeberg, Frederick A; Yiu, Cynthia K Y; Mao, Jing; Pashley, David H; Tay, Franklin R

    2013-06-01

    Quaternary ammonium methacryloxy silicate (QAMS), an organically modified silicate (ORMOSIL) functionalized with polymerizable methacrylate groups and an antimicrobial agent with a long lipophilic alkyl chain quaternary ammonium group, was synthesized through a silane-based sol-gel route. By dissolving QAMS in methyl methacrylate monomer, this ORMOSIL molecule was incorporated into an auto-polymerizing, powder/liquid orthodontic acrylic resin system, yielding QAMS-containing poly(methyl methacrylate). The QAMS-containing acrylic resin showed a predominant contact-killing effect on Streptococcus mutans (ATCC 35668) and Actinomyces naeslundii (ATCC 12104) biofilms, while inhibiting adhesion of Candida albicans (ATCC 90028) on the acrylic surface. The antimicrobial activities of QAMS-containing acrylic resin were maintained after a 3month water-aging period. Bromophenol blue assay showed minimal leaching of quaternary ammonium species when an appropriate amount of QAMS (<4wt.%) was incorporated into the acrylic resin. The results suggest that QAMS is predominantly co-polymerized with the poly(methyl methacrylate) network, and only a minuscule amount of free QAMS molecules is present within the polymer network after water-aging. Acrylic resin with persistent antimicrobial activities represents a promising method for preventing bacteria- and fungus-induced stomatitis, an infectious disease commonly associated with the wearing of removable orthodontic appliances. PMID:23485857

  12. Effect of Additives on UV-Activated Urethane Acrylate Polymerization Composite Coatings

    Zane GRIGALE-SOROCINA; Martins KALNINS; Jana SIMANOVSKA; Elīna VINDEDZE; Ingmars BIRKS; Evita BRAZDAUSKA

    2016-01-01

    An increased demand for new and improved coating systems, for environmental & health & safety and performance reasons, have appeared during the recent decades. Currently, there is new interest in preparation of thin UV curable urethane acrylate (UA) composite coatings with short-term properties. Cellulose based additives: nitrocellulose, cellulose acetate butyrate, sucrose benzoate and silica were evaluated to determine their influence on unreacted composite characteristics (viscosity, pigmen...

  13. Synthesis, Characterization and Evaluation of the Transformations in Hibiscus sabdariffa-graft-poly(butyl acrylate)

    Kaith, B. S.; Chauhan, Aashish

    2008-01-01

    Different reaction parameters for the graft copolymerization of butyl acrylate onto Hibiscus sabdariffa fiber were optimized. Graft copolymers thus obtained were subjected to characterization using XRD, TGA, DTA, SEM and FTIR techniques and were evaluated for physio-chemical changes in the behavior. The percentage crystallinity and crystallinity index were found to decrease with increase in grafting while there was reduction in moisture absorption and increase in chemical, thermal resistance ...

  14. Phacoemulsification and acryl foldable intraocular lens implantation in dogs: 32 cases

    Yi, Na-Young; Park, Shin-Ae; JEONG, Man-Bok; Kim, Won-Tae; Kim, Se-Eun; Chae, Je-Min; Seo, Kang-moon

    2006-01-01

    This study evaluated the surgical outcome and complications of phacoemulsification and the implantation of an acryl foldable intraocular lens (IOL) with a squared edge in dogs with cataracts. Thirty-two eyes from 26 dogs were examined. The mean follow up period was 75.9 days ranging from 23 to 226 days. The complications after phacoemulsification were posterior capsular opacity (PCO) around the IOL (n = 11), ocular hypertension (n = 4), focal posterior synechia (n = 4), hyphema (n = 3) and co...

  15. CHARACTERIZATION OF RADIATION GRAFTING DEGREE OF POLYSTYRENE g-ACRYLIC ACID BY XPS

    CHE Jitai; ZHANG Wanxi

    1990-01-01

    It this work, characterization of radiation grafting degree of polystyrene-g-acrylic acid by XPS was studied. It is found that along with the main peak C1s there is a photoelectron peak at 289.0 eV that appears to be C1s of -C(=O)-OH group and shows the presence ofpolyacrylic acid grafted on the polystyrene.The grafting degree obtained by XPS is in agreement with that from the gravimetric method.

  16. Catalytic routes towards acrylic acid, adipic acid and epsilon-caprolactam starting from biorenewables

    Beerthuis, R.; Rothenberg, G.; Shiju, N.R.

    2015-01-01

    The majority of bulk chemicals are derived from crude oil, but the move to biorenewable resources is gaining both societal and commercial interest. Reviewing this transition, we first summarise the types of today's biomass sources and their economical relevance. Then, we assess the biobased productions of three important bulk chemicals: acrylic acid, adipic acid and epsilon-caprolactam. These are the key monomers for high-end polymers (polyacrylates, nylon 6.6 and nylon 6, respectively) and a...

  17. Synthesis and characterization of thermal energy storage microencapsulated n-dodecanol with acrylic polymer shell

    Two kinds of (microencapsulated phase change materials) MicroPCMs with acrylic-based copolymer as shell and n-dodecanol as core were successfully fabricated via suspension-like polymerization and photo-induced microencapsulation, respectively. Morphology and core–shell structure were observed by (field emission scanning electron microscope) FE-SEM. Thermal properties of the microencapsulated n-dodecanol were investigated by (differential scanning calorimeter) DSC and (thermogravimetric analysis) TGA. The results indicate that the mass ratio of core to shell has great influence on the morphology, inner structure, microencapsulated efficiency and durability of the microcapsules. Besides, the effects of various solvents and UV irridiation time on the microcapsule surface were discussed as well. In the experiment carried out, metal-ion complexation was conducted by the reaction between Mn ion and carboxyl groups on copolymer shell to enhance the performance of the microcapsules with n-dodecanol encapsulated. As the results indicate, the physicochemical properties and thermal conductivity of the shell were improved after Mn ion complexation reaction. Supercooling phenomenon of n-dodecanol was depressed to some extent. In the end, the thermo-regulated fiber containing acrylic-based copolymer microcapsules was fabricated, and thermo-regulated performance test of the fiber was also conducted. - Graphical abstract: (a)∼(d) schematic diagram of microencapsulation and (e) microcapsule with core–shell structure. - Highlights: • Microencapsulated n-dodecanol with acrylic polymer shell. • Microencapsulated n-dodecanol was fabricated by photo-induced microencapsulation. • Acrylic-based copolymer microcapsules with manganese-ion complexation

  18. Loading rate effects on the fracture of Ni/Au nano-coated acrylic particles

    Zhang, Z. L.; He, J. Y.; Nagao, S; Kristiansen, H.

    2012-01-01

    Mechanical failure of monodisperse Ni/Au coated acrylic particles has been investigated by individual compression tests using nanoindentation-based technique equipped with a flat diamond punch. We have found that both fracture property and morphology of particles depend on the compression loading rate. The breaking strain of the metal coating decreases with increasing loading rate, while the breaking stress increases. Two obvious fracture patterns with cracking in meridian or latitude directi...

  19. Inhibitory Effect of Alpha-Mangostin on Adhesion of Candida albicans to Denture Acrylic

    Kaomongkolgit, Ruchadaporn; Jamdee, Kusuma

    2015-01-01

    Objective: Candida-associated denture stomatitis is a very common disease affecting denture wearers. It is characterized by the presence of yeast biofilm on the denture, primarily associated with C. albicans. The investigation of agents that can reduce C. albicans adhesion may represent a significant advancement in the prevention and treatment of this disease. This study aims to investigate the effect of alpha-mangostin on the in vitro adhesion of C. albicans to denture acrylic and germ tube formation by C. albicans and to compare its activity with clotrimazole which is a topical antifungal agent commonly used for the treatment of Candida-associated denture stomatitis. Materials and Methodology: Alpha-mangostin was extracted by thin layer chromatography. The effect of alpha-mangostin on adhesion of C. albicans to denture acrylic was determined by using a colorimetric tetrazolium assay and germ tube formation by C. albicans was determined by using the counting chamber. Results: A significant reduction of C. albicans adhesion to denture acrylic was evident after exposure to 2,000 µg/ml of alpha-mangostin for only 15 min. In addition, the 2,000 µg/ml of the alpha-mangostin-treated C. albicans had a reduced ability for germ tube formation. These inhibitory effects of alpha-mangostin were as effective as clotrimazole. Conclusion: Alpha-mangostin has antifungal property against C. albicans by inhibiting the adhesion to denture acrylic and germ tube formation in vitro. These results suggest the potential application of alpha-mangostin as a topical medication or a natural oral hygiene product for treatment of Candida-associated denture stomatitis. PMID:26962371

  20. Flocculation Efficiency of Poly(Acrylamide-Co-Acrylic Acid) Obtained by Electron Beam Irradiation

    Gabriela Craciun; Elena Manaila; Maria-Daniela Stelescu

    2013-01-01

    A correlation between physicochemical characteristics of flocculants obtained by electron beam irradiation and their efficiency for wastewater treatment is presented. For real wastewater treatment, our interest was focused upon total suspended solids, fatty matter, and chemical oxygen demand. Flocculation studies were carried out using a standard jar test. A treatment option based on poly(acrylamide-co-acrylic acid) for wastewater taken from a slaughterhouse plant is presented.

  1. Use of an acrylic painting to increase the durability of reinforced concrete in a seawater environment

    Aguiar, J. L. Barroso de; Sousa, M.B.

    2000-01-01

    One of the most aggressive environments for reinforced concrete is the contact with seawater. The chlorides present in seawater penetrate into the concrete and the possibility to armatures corrosion increases significantly. In this study an acrylic painting was used to protect the concrete and decrease the diffusion of chlorides. We used two concretes with different compositions. One composition respects the exigencies of European standardisation for this environment and the other one no. The...

  2. The Effect of Reactives Diluents to the Physical Properties of Acrylated Palm Oil Based Polyurethane Coatings

    Onn Munirah; Mohd Ahmad Faiza; Yhaya Mohd Firdaus

    2016-01-01

    The development of polyurethane with hydroxyl access in a molecule leads to a new alternative of low toxicity green product. Palm oil is one of the major commodities in Malaysia. The potential of palm oil to be used as coatings raw material such as alkyd is limited due to low unsaturated side on fatty acid chains. To overcome this limitation, palm oil was modified through transesterification process to produce polyol. Acrylated isocyanate (urethane oligomer) was then grafted onto polyol to pr...

  3. Design and Characterization of Diclofenac Diethylamine Transdermal Patch using Silicone and Acrylic Adhesives Combination

    Panchaxari Dandigi M; Pampana Sowjanya; Pal Tapas; Devabhaktuni Bhavana; Aravapalli Anil Kumar

    2013-01-01

    Abstract Background and purpose of the study The objective of the study was to develop and characterize Diclofenac Diethylamine (DDEA) transdermal patch using Silicone and acrylic adhesives combination. Methods Modified solvent evaporation method was employed for casting of film over Fluoropolymer coated polyester release liner. Initial studies included solubilization of drug in the polymers using solubilizers. The formulations with combination of adhesives were attempted to combine the desir...

  4. Effect of different solutions on color stability of acrylic resin-based dentures

    Marcelo Coelho Goiato

    2014-01-01

    Full Text Available The aim of this study was to evaluate the effect of thermocycling and immersion in mouthwash or beverage solutions on the color stability of four different acrylic resin-based dentures (Onda Cryl, OC; QC20, QC; Classico, CL; and Lucitone, LU. The factors evaluated were type of acrylic resin, immersion time, and solution (mouthwash or beverage. A total of 224 denture samples were fabricated. For each type of resin, eight samples were immersed in mouthwashes (Plax-Colgate, PC; Listerine, LI; and Oral-B, OB, beverages (coffee, CP; cola, C; and wine, W, and artificial saliva (AS; control. The color change (DE was evaluated before (baseline and after thermocycling (T1, and after immersion in solution for 1 h (T2, 3 h (T3, 24 h (T4, 48 h (T5, and 96 h (T6. The CIE Lab system was used to determine the color changes. The thermocycling test was performed for 5000 cycles. Data were submitted to three-way repeated-measures analysis of variance and Tukey's test (p < 0.05. When the samples were immersed in each mouthwash, all assessed factors, associated or not, significantly influenced the color change values, except there was no association between the mouthwash and acrylic resin. Similarly, when the samples were immersed in each beverage, all studied factors influenced the color change values. In general, regardless of the solution, LU exhibited the greatest DE values in the period from T1 to T5; and QC presented the greatest DE values at T6. Thus, thermocycling and immersion in the various solutions influenced the color stability of acrylic resins and QC showed the greatest color alteration.

  5. Nanoparticles containing ketoprofen and acrylic polymers prepared by an aerosol flow reactor method

    Eerikäinen, Hannele; Peltonen, Leena; Raula, Janne; Hirvonen, Jouni; Kauppinen, Esko I

    2004-01-01

    The purpose of this study was to outline the effects of interactions between a model drug and various acrylic polymers on the physical properties of nanoparticles prepared by an aerosol flow reactor method. The amount of model drug, ketoprofen, in the nanoparticles was varied, and the nanoparticles were analyzed for particle size distribution, particle morphology, thermal properties, IR spectroscopy, and drug release. The nanoparticles produced were spherical, amorphous, and had a matrix-type...

  6. Radiation-initiated graft polymerization of methyl acrylate onto chrome-tanned sheepskin

    Radiation grafting method was applied to obtain leather-polymer composite. Grafting of methyl acrylate onto chrome-tanned, bluestock sheepskin was investigated under the initiatory effect of 60Co radiation of 0.20 11.50 Mrad. The percent of grafting was determined and water adsorption and shrinkage temperature measurements were carried out. It was shown that 2-4 Mrad is convenient to produce leather-polymer composite. (author)

  7. Permittivity and Electromagnetic Interference Shielding Investigations of Activated Charcoal Loaded Acrylic Coating Compositions

    Sharief ud Din Khan; Manju Arora; Wahab, M. A.; Parveen Saini

    2014-01-01

    Acrylic resin (AR) based electromagnetic interference (EMI) shielding composites have been prepared by incorporation of up to 30 wt% activated charcoal (AC) in AR matrix. These composites have been characterized by XRD, Raman spectroscopy, scanning electron microscopy, dielectric, and EMI shielding measurement techniques. XRD patterns and Raman studies confirm the incorporation of AC particles inside AR matrix and suggest possible interactions between phases. The SEM images show that incorpo...

  8. Ethyl 3-(4-hydroxyphenoxy)-2-(4-methoxyphenyl)acrylate

    Jin Hou

    2008-01-01

    In the title compound, C18H18O5, the dihedral angle between the two benzene rings is 55.2 (3)°. The ethyl acrylate linkage is planar and forms dihedral angles of 21.3 (3) and 41.0 (3)°, respectively, with the hydroxyphenyl and methoxyphenyl rings. In the crystal structure, molecules are linked into zigzag chains along the b axis by O—H...O hydrogen bonds.

  9. Adhesion and Proliferation of Human Periodontal Ligament Cells on Poly(2-methoxyethyl acrylate)

    Erika Kitakami; Makiko Aoki; Chikako Sato; Hiroshi Ishihata; Masaru Tanaka

    2014-01-01

    Human periodontal ligament (PDL) cells obtained from extracted teeth are a potential cell source for tissue engineering. We previously reported that poly(2-methoxyethyl acrylate) (PMEA) is highly biocompatible with human blood cells. In this study, we investigated the adhesion, morphology, and proliferation of PDL cells on PMEA and other types of polymers to design an appropriate scaffold for tissue engineering. PDL cells adhered and proliferated on all investigated polymer surfaces except fo...

  10. Microencapsulation of 2-octylcyanoacrylate tissue adhesive for self-healing acrylic bone cement

    Brochu, Alice B. W.; Chyan, William J.; Reichert, William M

    2012-01-01

    Here, we report the first phase of developing self-healing acrylic bone cement: the preparation and characterization of polyurethane (PUR) microcapsules containing a medical cyanoacrylate tissue adhesive. Capsules were prepared by interfacial polymerization of a toluene-2,4-diisocyanate-based polyurethane prepolymer with 1,4-butanediol to encapsulate 2-octylcyanoacrylate (OCA). Various capsule characteristics, including: resultant morphology, average size and size distribution, shell thicknes...

  11. The adsorption of an epoxy acrylate resin on aluminium alloy conversion coatings

    Grilli, R; Abel, ML; Baker, MA; Dunn, B.; Watts, JF

    2011-01-01

    A thermodynamic study of the adsorption of an epoxy acrylate resin used for UV-cured coatings on two different anticorrosion pretreatments on aluminium alloys relevant to aerospace industry has been undertaken. Aluminium alloy Al2219 specimens, treated with an inorganic chromate based conversion coating (Alodine 1200S) and an organic titanium based conversion coating (Nabutan STI/310), were immersed in solutions of different concentrations of the resin and adsorption isotherms were determined...

  12. New UV-curable acrylated polyester prepolymers from palm oil based products

    Acrylated polyester prepolymers (PEPP-1 and PEPP-2) were synthesized from palm oil and its products. UV-curing and characteristic properties of UV-cured films of synthesized polyester resins were studied. The characteristic properties studied include pendulum hardness, gel content, FT-IR analysis, tensile strength and elongation at break. The materials have good potential for the production of radiation curable coating applications

  13. Effect of curing on water diffusivities in acrylate free films as measured via a sorption technique

    Wurster, Dale Eric; Bhattacharjya, Sushmita; Flanagan, Douglas R.

    2007-01-01

    Studies were performed to investigate the effect of curing on the diffusion coefficients of water, as measured via the sorption technique, in acrylate polymeric films. The mathematical model selected for obtaining diffusion constants from the vapor-phase sorption studies was derived from the longtime Fourier equation used for diffusion into a planar sheet. For Eudragit NE films, the diffusion coefficients of water decreased continuously until a constant minimum value was reached. Diffusion co...

  14. Surgical treatment of neurological scoliosis using hybrid construct (lumbar transpedicular screws plus thoracic sublaminar acrylic loops)

    La Rosa, Guido; Giglio, Giancarlo; Oggiano, Leonardo

    2011-01-01

    In the nineties, most spinal surgeons supported the validity of segmental spine instrumentation, but this procedure has progressively been abandoned because difficult and with a high risk of neurological complications, in favor of the Cotrel-Dobousset (CD). The CD instrumentation is based on segmentation of curves, thus improving the angular correction and actuates sagittal profile. Sublaminar acrylic loops (Universal Clamp) shows the same resistance to stress as steel or titanium alloy subla...

  15. Modification of hydrophobic polypeptide-based film by blending with hydrophilic poly(acrylic acid)

    Guoquan Zhu; Fagang Wang; Qiaochun Gao; Yuying Liu

    2013-01-01

    In this study, a series of poly(γ-benzyl L-glutamate)/poly(acrylic acid) (PBLG/PAA) polymer blend films were prepared by casting the polymer blend solution in dimethylsulfoxide (DMSO). The structure and morphology of the polymer blend film were investigated by Fourier Transform Infrared Spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM). Thermal, mechanical, and chemical properties of PBLG/PAA polymer blend films were studied by Differential Scanning Calorimetry (DSC), Thermogra...

  16. Transformation of Nickelalactones to Methyl Acrylate: On the Way to a Catalytic Conversion of Carbon Dioxide

    Lee, S. Y. Tina

    2011-08-26

    Mu-nick: The methyl iodide-mediated ring opening of nickelalactones, which can be formed by oxidative coupling of carbon dioxide and ethylene at Ni 0 complexes, induces β-H elimination, producing methyl acrylate in yields of up to 56 %. This reaction is found to be very sensitive to the ligands coordinated to the central nickel atom. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Biodegradation kinetic of organic compounds of acrylic fiber wastewater in biofilm

    ZHANG Ya-lei; ZHAO Jian-fu; GU Guo-wei

    2003-01-01

    A group function relation curve between flux (J) and bulk phase concentration of substrate ( S ) was set up. The biodegradation kinetic of organic compounds of acrylic fiber wastewater in biofilm is studied ( the treatment technology is coagulation/sedimentation-anoxic/aerobic biofilm process), and the results showed that the concentration of non-degradation pollutants in effluent is 77 mg/L. In aerobic zone,corresponds to the fact that there are some biorefractory compounds in the wastewater.

  18. Synthesis and Application of a New Acrylic Ester Resin for Recycling SIPA from its Water Solution

    2005-01-01

    A new acrylic ester polymer YWB-7 resin was prepared and characterized. The properties of YWB-7 resin were compared with those of the commercial Amberlite XAD-7, Diaion HP2MG and hypercrosslinked macroporous polymer NDA-150 resins. Both surface area and micropore area of YWB-7 resin were bigger than those of XAD-7 resin and HP2MG resin. The YWB-7 resin was successfully employed to recycle 5-sodiosulfoisophthalic acids (SIPA) from its solutions with and without methanol.

  19. Transdermal Nitroglycerin Delivery Using Acrylic Matrices: Design, Formulation, and In Vitro Characterization

    Houman Savoji; Amir Mehdizadeh; Ahmad Ramazani Saadat Abadi

    2014-01-01

    Nitroglycerin (TNG) transdermal drug delivery systems (TDDSs) with different acrylic pressure-sensitive adhesives (PSAs) and chemical permeation enhancers (CPEs) were prepared. The effects of PSAs and CPEs types and concentrations on skin permeation and in vitro drug release from devices were evaluated using the dissolution method as well as the modified-jacketed Franz diffusion cells fitted with excised rat abdominal skin. It was demonstrated that the permeation rate or steady state flux (J ...

  20. Study of physico-chemical properties of the new film-type material based on ethyl acrylate and 2-hydroxyethyl acrylate

    Raykhan Rakhmetullaeva

    2015-03-01

    Full Text Available During recent years the complexes based on water swellable hydrophilic polymers with the drugs and preparation of the film materials used in medicine have attracted attention of researchers. Due to the controlled release of drugs and low toxicity, the polymeric film materials are used as drug delivery systems and dressings. Polymeric film materials for drug delivery were obtained first time by grafting 2-hydroxyethyl acrylate (HEA and ethyl acrylate (EA monomers onto polyvinyl alcohol (PVA. In this study, it was found that the films obtained without thermal treatment are soluble in an aqueous medium. Thus, they were heat treated in the range of 1-15 hours at 90-150ºC. Physico-chemical properties of the films have been studied depending on environmental effects as well as methods of obtaining films have been investigated. An increase of the thermal treatment time leads to a decrease in the degree of swelling and reduces the solubility properties of com­posite materials. The surface morphology and thermal properties of films based on HEA-EA were investigated by scanning electron microscopy, thermogravimet­ric analysis and differential scanning calorimetry. It was shown that the surface of obtained films were homogeneous without any bubbles.

  1. Effect of C-Tetramethyl Calix[4]resorcinarene Acrylate on Curing Behavior and Film Properties of Thiol-acrylate Coating System

    FU Qi; SHI Wen-fang

    2009-01-01

    An octa-fiinctional acrylate of C-tetramethyl calix[4]resorcinarene(CMC-4-RA) was facilely synthesized and characterized with ~1H NMR, ~(13)C NMR and FTIR spectroscopy. The CMC-4-RA was added to a thiol-acrylate system with different mass ratios, and exposed to a middle pressure mercury lamp. The maximum photopolymeriza-tion rate and final vinyl group conversion in the cured film increased greatly along with CMC-4-RA addition that was monitored with Photo-DSC. The tensile strength and pendulum hardness were improved significantly after the addition of CMC-4-RA. With increasing the content of CMC-4-RA to 60%(mass fraction), the glass transition temperature increased from 34.2℃ to 84.1℃; the cross-link density was calculated to be increased from 23.83 mmol/cm3 to 82.40 mmol/cm3 according to dynamic mechanical thermal analysis; the thermostability was greatly improved.

  2. Nanoparticles of Block Ionomer Complexes from Double Hydrophilic Poly(acrylic acid-b-poly(ethylene oxide-b-poly(acrylic acid Triblock Copolymer and Oppositely Charged Surfactant

    Sun Yuelong

    2009-01-01

    Full Text Available Abstract The novel water-dispersible nanoparticles from the double hydrophilic poly(acrylic acid-b-poly(ethylene oxide-b-poly(acrylic acid (PAA-b-PEO-b-PAA triblock copolymer and oppositely charged surfactant dodecyltrimethyl ammonium bromide (DTAB were prepared by mixing the individual aqueous solutions. The structure of the nanoparticles was investigated as a function of the degree of neutralization (DN by turbidimetry, dynamic light scattering (DSL,ζ-potential measurement, and atomic force microscope (AFM. The neutralization of the anionic PAA blocks with cationic DTAB accompanied with the hydrophobic interaction of alkyl tails of DTAB led to formation of core–shell nanoparticles with the core of the DTAB neutralized PAA blocks and the shell of the looped PEO blocks. The water-dispersible nanoparticles with negative ζ-potential were obtained over the DN range from 0.4 to 2.0 and their sizes depended on the DN. The looped PEO blocks hindered the further neutralization of the PAA blocks with cationic DTAB, resulting in existence of some negative charged PAA-b-PEO-b-PAA backbones even when DN > 1.0. The spherical and ellipsoidal nature of these nanoparticles was observed with AFM.

  3. Synthesis and characterization of kappaphycus seaweed-poly (acrylic) acid superabsorbent hydrogel for agricultural use

    The main objective of this research is to synthesize and characterize kappaphycus seaweed-poly (acrylic) acid superabsorbent hydrogel for agricultural use. The superabsorbent polymers (SAPs), KCSW: PAA hydrogels were synthesized by using gamma radiation technique from Cobalt-60 source at absorbed dose 0f 5, 10 and 15 kGy. The effect of absorbed dose, seaweed concentration, and concentration of acrylic acid on the degree of swelling was studied and optimum swelling conditions were established. Irradiated samples of 3% KCSW, 50% neutralized AAC at an absorbed dose of 10kGy gave the highest degree of swelling and gel fraction and were found to be suitable for application in the agriculture. Samples with different concentrations of acrylic acid were characterized using FTIR and TGA. The water retention experiment in sandy soil showed high water retention capacity of KCSW: PAA hydrogel at a value of 92% for a period of 7 days. Effect of the germination of mung bean showed very promising result of 78% germination.(author)

  4. Aluminum nanoparticle/acrylate copolymer nanocomposites for dielectric elastomers with high dielectric constants

    Hu, Wei; Zhang, Suki N.; Niu, Xiaofan; Liu, Chao; Pei, Qibing

    2014-03-01

    Dielectric elastomers are useful for large-strain actuation and energy harvesting. Their application has been limited by their low dielectric constants and consequently high driving voltage. Various fillers with high dielectric constants have been incorporated into different elastomer systems to improve the actuation strain, force output and energy density of the compliant actuators and generators. However, agglomeration may happen in these nanocomposites, resulting in a decrease of dielectric strength, an increase of leakage current, and in many instances the degree of enhancement of the dielectric constant. In this work, we investigated aluminum nanoparticles as nanofillers for acrylate copolymers. This metallic nanoparticle was chosen because the availability of free electrons could potentially provide an infinite value of dielectric constant as opposed to dielectric materials including ferroelectric nanocrystals. Moreover, aluminum nanoparticles have a self-passivated oxide shell effectively preventing the formation of conductive path. The surfaces of the aluminum nanoparticles were functionalized with methacrylate groups to assist the uniform dispersion in organic solutions and additionally enable copolymerization with acrylate copolymer matrix during bulk polymerization, and thus to suppress large range drifting of the nanoparticles. The resulting Al nanoparticle-acrylate copolymer nanocomposites were found to exhibit higher dielectric constant and increased stiffness. The leakage current under high electric fields were significantly lower than nanocomposites synthesized without proper nanoparticle surface modification. The dielectric strengths of the composites were comparable with the pristine polymers. In dielectric actuation evaluation, the actuation force output and energy specific work density were enhanced in the nanocomposites compared to the pristine copolymer.

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

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

  6. Effect of nanosilver on thermal and mechanical properties of acrylic base complete dentures.

    Fahimeh Hamedi-Rad

    2014-10-01

    Full Text Available Polymethyl methacrylate (PMMA, widely used as a prosthodontic base, has many disadvantages, including a high thermal expansion coefficient and low thermal conductivity, a low elasticity coefficient, low impact strength and low resistance to fatigue. This study aimed to make an in vitro comparison of the thermal conductivity, compressive strength, and tensile strength of the acrylic base of complete dentures with those of acrylic reinforced with nanosilver.For this study, 36 specimens were prepared. The specimens were divided into three groups of 12; which were further divided into two subgroups of control (unmodified PMMA and test (PMMA mixed with 5 weight% nanosilver.The results were analysed by Independent t-test.This study showed that the mean thermal conductivity and compressive strength of PMMA reinforced with nanosilver were significantly higher than the unmodified PMMA (P<0.05, while the tensile strength decreased significantly after the incorporation of nanosilver (P<0.05.Considering our results suggesting the favorable effect of silver nanoparticles on improving the thermal conductivity and compressive strength of PMMA, use of this material in the palatal area of maxillary acrylic resin dentures is recommended.

  7. Dimensional changes of acrylic resin denture bases: conventional versus injection-molding technique.

    Jafar Gharechahi

    2014-08-01

    Full Text Available Acrylic resin denture bases undergo dimensional changes during polymerization. Injection molding techniques are reported to reduce these changes and thereby improve physical properties of denture bases. The aim of this study was to compare dimensional changes of specimens processed by conventional and injection-molding techniques.SR-Ivocap Triplex Hot resin was used for conventional pressure-packed and SR-Ivocap High Impact was used for injection-molding techniques. After processing, all the specimens were stored in distilled water at room temperature until measured. For dimensional accuracy evaluation, measurements were recorded at 24-hour, 48-hour and 12-day intervals using a digital caliper with an accuracy of 0.01 mm. Statistical analysis was carried out by SPSS (SPSS Inc., Chicago, IL, USA using t-test and repeated-measures ANOVA. Statistical significance was defined at P<0.05.After each water storage period, the acrylic specimens produced by injection exhibited less dimensional changes compared to those produced by the conventional technique. Curing shrinkage was compensated by water sorption with an increase in water storage time decreasing dimensional changes.Within the limitations of this study, dimensional changes of acrylic resin specimens were influenced by the molding technique used and SR-Ivocap injection procedure exhibited higher dimensional accuracy compared to conventional molding.

  8. Mechanical and thermal properties of UV curable polyurethane acrylate composite coatings

    UV curable coating formulation comprises urethane acrylate resin and nano silica as filter were synthesized to develop UV curable inorganic hybrid composite (PUA). The surface of the nano silica was chemically modified to improve its chemical interaction within the urethane acrylate matrix. The modification had been undertaken by applying vinyltrymetoxysilane (VTMOS) that acted as a coupling agent to produce organophilic silica shell (SIMA). The shell is linked to the silica via reaction with the surface silanol group of the silica. The disappearance of methoxy groups in VTMOS was demonstrated by FTIR spectrum. The percentage of silica particles in UV curable hybrid formulation were varied on 5 %, 10 %, 15 %, 20 % and 25 wt % respectively. In this work, the formulation was applied on medium density fiber board (MDF) substrate and subsequent has been irradiated under UV light. Then, the coated MDF were characterized by several testing equipment (TGA, DSC, scratch tester, instron, SEM). From the result, we found that the addition of silica nanoparticles exhibit significant improvement in coating film properties as compared to film without silica nanoparticle includes significant improvement in its modulus and scratch resistance. This make them as promising coating candidate for MDF product. On the other hand, we also found that an increase of silica particle up to 25 wt %, the viscosity has increased rapidly indicates that it is not suitable for acrylate coating formulation due to disappearance of desired effect known as thixotropy. (Author)

  9. [Capability and microbial community analysis of a membrane bioreactor for acrylic fiber wastewater treatment].

    Wei, Jian; Song, Yong-Huil; Zhao, Le

    2014-12-01

    Sequencing batch membrane bioreactor (SBMBR) was used for the treatment of acrylic fiber polymerization wastewater and acrylonitrile wastewater. The operation efficiencies of SBMBR under different wastewater ratios and operation conditions were investigated, and the microbial community structure of the SBMBR system was analyzed by using PCR-DGGE technology. The results showed that SBMBR had a high removal efficiency on pollutants in acrylic fiber wastewater, and the lacking of carbon source and alkalinity were the main limiting factors for nitrogen removal. Under the designed operation conditions of 90 min anoxic/150 min aerobic cyclic operation and HRT of 24 h, the average COD, NH4(+) -N and TN removal efficiencies were 82.5%, 98.7% and 74.6%, respectively. The effluent of the SBMBR could steadily meet the Grade I standards of the Wastewater Comprehensive Discharge Standard of China (GB 8978-1996). The PCR-DGGE analyses showed that the microbial communities in SBMBR had a significant shift with the changes of influent characteristics and operation conditions. By cloning and sequencing analyses of selected dominant bacteria, 22 16S rDNA sequence were successfully identified from 9 sludge samples, from which 7 dominant functional microorganisms for the degradation of organic pollutants in acrylic fiber wastewater were screened out. PMID:25826932

  10. UV curable polyester polyol acrylate/bentonite nanocomposites: synthesis, characterization, and drug release.

    Thatiparti, Thimma Reddy; Tammishetti, Shekharam; Nivasu, Muram V

    2010-01-01

    Polyesterpolyolacrylate/bentonite nanocomposites, capable of in situ photo polymerization, were synthesized and characterized. The organically modified bentonite clay was prepared by an ion exchange process, in which sodium ions were replaced by alkyl ammonium ions. Organo modification of bentonite was confirmed from X-ray diffraction and fourier transform-infrared data. Microstructures were characterized by XRD data and transmission electron microscopy (TEM). Both XRD data and TEM images of polyester polyol acrylate/organo modified bentonite nanocomposites indicated that most of silicate layers were intercalated into the acrylate matrix. The resulting nanocomposites were characterized by gel content, water equilibrium swell, tensile strength, and in vitro degradation. The results showed that water equilibrium swell and in vitro degradation of these nanocomposites decreased with increase in the clay content. The tensile strength of these nanocomposites also increased with increase in the clay content. Release of two model drugs namely sulfamethoxazole and diclofenac sodium (DS) from these nanocomposites was studied in phosphate buffer saline pH = 7.4 at 37 degrees C. The drug release studies showed that sulfamethoxazole released slower than DS from polyester polyol acrylate nanocomposites. Therefore, these materials may be useful for mucoadhesive drug carriers and other biomedical applications. PMID:19904735

  11. A Potentiometric Formaldehyde Biosensor Based on Immobilization of Alcohol Oxidase on Acryloxysuccinimide-modified Acrylic Microspheres

    Lee Yook Heng

    2010-11-01

    Full Text Available A new alcohol oxidase (AOX enzyme-based formaldehyde biosensor based on acrylic microspheres has been developed. Hydrophobic poly(n-butyl acrylate-N-acryloxy-succinimide [poly(nBA-NAS] microspheres, an enzyme immobilization matrix, was synthesized using photopolymerization in an emulsion form. AOX-poly(nBA-NAS microspheres were deposited on a pH transducer made from a layer of photocured and self-plasticized polyacrylate membrane with an entrapped pH ionophore coated on a Ag/AgCl screen printed electrode (SPE. Oxidation of formaldehyde by the immobilized AOX resulted in the production of protons, which can be determined via the pH transducer. Effects of buffer concentrations, pH and different amount of immobilization matrix towards the biosensor’s analytical performance were investigated. The formaldehyde biosensor exhibited a dynamic linear response range to formaldehyde from 0.3–316.2 mM and a sensitivity of 59.41 ± 0.66 mV/decade (R2 = 0.9776, n = 3. The lower detection limit of the biosensor was 0.3 mM, while reproducibility and repeatability were 3.16% RSD (relative standard deviation and 1.11% RSD, respectively (n = 3. The use of acrylic microspheres in the potentiometric formaldehyde biosensor improved the biosensor’s performance in terms of response time, linear response range and long term stability when compared with thick film immobilization methods.

  12. Adsorption of surfactants onto acrylic ester resins with different pore size distribution

    YANG Weiben; LI Aimin; CAI Jianguo; MENG Guanhua; ZHANG Quanxing

    2006-01-01

    In this study, a series of acrylic ester resins with different pore size distribution were prepared successfully by varying the type and the amount of pore-forming agents. In order to investigate the adsorption behavior and mechanism of surfactants on acrylic ester resins, three kinds of surfactants were utilized as adsorbates that were sodium 6-dodecyl benzenesulfonate (6-NaDBS),sodium 1-dodecyl benzene sulfonate (1-NaDBS) and sodium 1-dodecyl sulfonate, respectively. It was observed that the surface area was available in a particular pore size and an appropriate pore size of resins appeared to be more important for the adsorption of surfactants. As compared to commercial acrylic ester resins XAD-7 and HP2MG, 50# and 38# resins exhibited more excellent adsorption properties toward 1-NaDBS and 6-NaDBS. The experimental equilibrium data were fitted to the Langmuir, and double-Langmuir models. Two models provided very good fittings for all resins over the temperature range studied. The investigation dicated that electrostatic attraction and hydrogen bond between resins and surfactants were the main forces and had an obvious effect on adsorption process.

  13. Swelling of Bacterial Cellulose-Acrylic Acid Hydrogels: Sensitivity Towards External Stimuli

    This study evaluated various environmental factors affecting the swelling degree of bacterial cellulose-acrylic acid hydrogels. Aqueous bacterial cellulose-acrylic acid (4:1) mixtures were prepared and subjected to electron beam irradiation at 30 and 50 kGy. Swelling rate under influenced of pH, temperature and ionic strength was investigated from 1 to 24 hours. Swelling degree of hydrogels was dependent on irradiation dose: those synthesized at 50 kGy exhibited significant higher swelling degree (p<0.0001) in methanol (619 %) compared to water (510 %) at room temperature after 24 hours. External ionic strength affected swelling, for example elevation in sodium chloride concentration decreased swelling degree. Hydrogels were also sensitive to pH: swelling increased with increasing pH and was optimal at pH 7. Swelling also increased with increasing temperature from 25 to 50 degree Celsius. In conclusion, the ability of electron irradiated bacterial cellulose-acrylic acid hydrogels to respond to various external environment make it a material to be developed as an active delivery system for drugs, proteins and hormones. (author)

  14. Effect of sodium bicarbonate on Candida albicans adherence to thermally activated acrylic resin

    Fernando Augusto Cervantes Garcia de Sousa

    2009-12-01

    Full Text Available The purpose of this study was to evaluate the effect of 5% sodium bicarbonate on the adherence of Candida albicans to thermally activated acrylic resin. Fifty 4 mm² specimens of acrylic resin were obtained using a metallic matrix. The specimens received chemical polishing, were sterilized and then immersed in Sabouraud broth, inoculated with Candida albicans standardized suspension. After 24 hours of incubation at 37ºC, the specimens were divided into four groups according to the substance used for disinfection (5% sodium bicarbonate, 0.12% digluconate chlorhexidine, vinegar and Corega Tabs. A control group was included, in which distilled water was used. The adhered microorganisms were dispersed, diluted and plated onto culture media to determine the number of colony-forming units (cfu/mL. The results were analyzed through the Mann-Whitney statistical test at the 5% level of significance. Only 0.12% digluconate chlorhexidine and 5% sodium bicarbonate presented a statistically significant difference (p = 0.0010 and p = 0.0156, respectively compared to the control group, decreasing the number of cfu/mL. However, when the different disinfecting solutions were compared with each other, only 0.12% digluconate chlorhexidine presented a statistically significant difference in the reduction of cfu/mL. It was concluded that although 0.12% digluconate chlorhexidine was more effective in the reduction of Candida albicans adherence values to thermally activated acrylic resin, 5% sodium bicarbonate also proved to be a viable alternative.

  15. Determination of acrylamide and acrylic acid by isocratic liquid chromatography with pulsed electrochemical detection.

    Casella, Innocenzo G; Pierri, Marianna; Contursi, Michela

    2006-02-24

    The electrochemical behaviour of the polycrystalline platinum electrode towards the oxidation/reduction of short-chain unsaturated aliphatic molecules such as acrylamide and acrylic acid was investigated in acidic solutions. Analytes were separated by reverse phase liquid chromatographic and quantified using a pulsed amperometric detection. A new two-step waveform, is introduced for detection of acrylamide and acrylic acid. Detection limits (LOD) of 20 nM (1. 4 microg/kg) and 45 nM (3.2 microg/kg) were determined in water solutions containing acrylamide and acrylic acid, respectively. Compared to the classical three-step waveform, the proposed two-step waveform shows favourable analytical performance in terms of LOD, linear range, precision and improved long-term reproducibility. The proposed analytical method combined with clean-up procedure accomplished by Carrez clearing reagent and subsequent extraction with a strong cation exchanger cartridges (SPE), was successfully used for the quantification of low concentrations of acrylamide in foodstuffs such as coffee and potato fries. PMID:16426623

  16. SYNTHESIS OF ACRYLIC ESTERS IN PHASE TRANSFER CATALYSIS: KINETICS AND ECOLOGICAL ASPECTS

    GAGIK TOROSYAN

    2012-06-01

    Full Text Available Phase-Transfer Catalysis (PTC technology is used in the commercial manufacture and also in pollution mitigation treatment processes. In the paper is demonstrated the synthesis of esters of acrylic and metacrylic acids, which have wide applications in the industry for the synthesis of unique polymeric materials, by phase transfer catalysis method. It is necessary to notice that the synthesis of acrylic acids in PTC medium is more important because that compounds are more sensitive at acidic and basic conditions. Here is shown that the offered method has more advantages in comparison with the traditional methods. PTC is characterized by a higher degree of conversion of raw materials into useful products, smaller material and power resources consumption. The offered method for acrylic ester synthesis in comparison with the traditional methods has more advantages: higher process rates, mild reaction conditions, allowing lower energy costs, the complete elimination of hazardous and dangerous organic solvents, all leading to a sharp reduction of air pollution, and volume of generated wastewaters.

  17. Transdermal thiol-acrylate polyethylene glycol hydrogel synthesis using near infrared light.

    Chung, Solchan; Lee, Hwangjae; Kim, Hyung-Seok; Kim, Min-Gon; Lee, Luke P; Lee, Jae Young

    2016-08-01

    Light-induced polymerization has been widely applied for hydrogel synthesis, which conventionally involves the use of ultraviolet or visible light to activate a photoinitiator for polymerization. However, with these light sources, transdermal gelation is not efficient and feasible due to their substantial interactions with biological systems, and thus a high power is required. In this study, we used biocompatible and tissue-penetrating near infrared (NIR) light to remotely trigger a thiol-acrylate reaction for efficient in vivo gelation with good controllability. Our gelation system includes gold nanorods as a photothermal agent, a thermal initiator, diacrylate polyethylene glycol (PEG), and thiolated PEG. Irradiation with a low-power NIR laser (0.3 W cm(-2)) could induce gelation via a mixed-mode reaction with a small increase in temperature (∼5 °C) under the optimized conditions. We also achieved successful transdermal gelation via the NIR-assisted photothermal thiol-acryl reactions. This new type of NIR-assisted thiol-acrylate polymerization provides new opportunities for in situ hydrogel formation for injectable hydrogels and delivery of drugs/cells for various biomedical applications. PMID:27389611

  18. Synthesis, characterization, swelling and dye adsorption properties of starch incorporated acrylic gels.

    Mandal, Bidyadhar; Ray, Samit Kumar

    2015-11-01

    Several hydrogels were prepared by a free radical polymerization of acrylic acid (AA), sodium acrylate (SA) and AA/hydroxy ethyl methacrylate (HEMA) in the presence of starch in water. These starch incorporated acrylic gels were prepared by varying the concentration of the initiator, monomer, crosslinker and the starch. The resulting gels were characterized by FTIR, SEM, XRD, DTA-TGA, pH at point zero charge (PZC), swelling and the diffusion in water. The gels showed high adsorption and removal% of Safranine T (ST) and Brilliant Cresyl Blue (BCB) dyes from water. The swelling and the adsorption data were fitted to different kinetic models and isotherms. Amongst the three kinds of gels, the starch incorporated sodium polyacrylate gel showed the highest adsorption of 9.7-85.3mg/L (97-61% removal) of BCB dye and 9.1-83mg/L (91-60% removal) of ST dye for a feed dye concentration of 10-140mg/L. PMID:26318665

  19. Effect of Antiadherents on the Physical and Drug Release Properties of Acrylic Polymeric Films.

    Ammar, Hussein O; Ghorab, Mamdouh M; Felton, Linda A; Gad, Shadeed; Fouly, Aya A

    2016-06-01

    Antiadherents are used to decrease tackiness of a polymer coating during both processing and subsequent storage. Despite being a common excipient in coating formulae, antiadherents may affect mechanical properties of the coating film as well as drug release from film-coated tablets, but how could addition of antiadherents affect these properties and to what extent and is there a relation between the physical characteristics of the tablet coat and the drug release mechanisms? The aim of this study was to evaluate physical characteristics of films containing different amounts of the antiadherents talc, glyceryl monostearate, and PlasACRYL(TM) T20. Eudragit RL30D and Eudragit RS30D as sustained release polymers and Eudragit FS30D as a delayed release material were used. Polymer films were characterized by tensile testing, differential scanning calorimetry (DSC), microscopic examination, and water content as calculated from loss on drying. The effect of antiadherents on in vitro drug release for the model acetylsalicylic acid tablets coated with Eudragit FS30D was also determined. Increasing talc concentration was found to decrease the ability of the polymer films to resist mechanical stress. In contrast, glyceryl monostearate (GMS) and PlasACRYL produced more elastic films. Talc at concentrations higher than 25% caused negative effects, which make 25% concentration recommended to be used with acrylic polymers. All antiadherents delayed the drug release at all coating levels; hence, different tailoring of drug release may be achieved by adjusting antiadherent concentration with coating level. PMID:26314244

  20. Transdermal nitroglycerin delivery using acrylic matrices: design, formulation, and in vitro characterization.

    Savoji, Houman; Mehdizadeh, Amir; Ramazani Saadat Abadi, Ahmad

    2014-01-01

    Nitroglycerin (TNG) transdermal drug delivery systems (TDDSs) with different acrylic pressure-sensitive adhesives (PSAs) and chemical permeation enhancers (CPEs) were prepared. The effects of PSAs and CPEs types and concentrations on skin permeation and in vitro drug release from devices were evaluated using the dissolution method as well as the modified-jacketed Franz diffusion cells fitted with excised rat abdominal skin. It was demonstrated that the permeation rate or steady state flux (J ss) of the drug through the excised rat skin was dependent on the viscosity and type of acrylic PSA as well as the type of CPE. Among different acrylic PSAs, Duro-Tak 2516 and Duro-Tak 2054 showed the highest and Duro-Tak 2051 showed the lowest J ss. Among the various CPEs, propylene glycol and cetyl alcohol showed the highest and the lowest enhancement of the skin permeation of TNG, respectively. The adhesion properties of devices such as 180° peel strength and probe tack values were obtained. It was shown that increasing the concentration of CPE led to reduction in the adhesion property of PSA. Moreover, after optimization of the formulation, it was found that the use of 10% PG as a CPE and 25% nitroglycerin loading in Duro-Tak 2054 is an effective monolithic DIAP for the development of a transdermal therapeutic system for nitroglycerin. PMID:24511396

  1. Preparation and characterization of high salts polymer electrolyte based on poly(lithium acrylate)

    TANG Ai-dong; HUANG Ke-long; PAN Chun-yue; LU Cui-hong

    2005-01-01

    Novel polymer electrolytes were prepared by highly mixing poly(lithium acrylate)(PPALi) with eutectic lithium salts of lithium acetate and lithium nitrate.Poly(lithium acrylate) was preparaed by inverse emulsion polymerization from crylic acid and LiOH.Phase transition temperatures were measured for all the eutectic lithium of binary system samples as a function of the concentration of Li(CH3 COO),and the mixtures exhibit the lowest phase transition temperatures of (448±2) K at about 50% (mass fraction) Li(CH3 COO).Thermogravimetry(TG)and X-ray diffraction(XRD) analysis indicate the formation of a novel polymer-salt complex.The highest conductivity(approximately 4.97 ×10-5S·cm-1) is found at room temperature with the electrolyte composition of eutectic mixture of about 80% (mass fraction),poly(lithium acrylate) 20% under quickly cooling condition,which is 150%higher than that under natural cooling condition.

  2. Preparation and reactivity of metal-containing monomers. Communication 3. Radiation graft polymerization of Co(II), Ni(II), and Cu(II) acrylates on polyethylene

    Graft polymerization of Co(II), Ni(II), and Cu(II) acrylates was carried out on polyethylene powder subjected to prior irradiation in the air and graft copolymers were obtained with up to 1.4 mass % metal content. The graft polymerization of metal acrylates on polyethylene proceeds 10 times more slowly than in the case of acrylic acid with virtually the complete absence of thermal homopolymerization. The graft rate is independent of the concentration of the metal-containing monomer in the range from 1 to 10 mass %. The graft polymerization of acrylates is initiated by radicals formed as a result of the decomposition of the hydroperoxide groups with subsequent predominantly bimolecular termination of the growing polymer chains in the case of Co(II) and Ni(II) acrylates and monomolecular termination in the case of Cu(II) acrylate. The effective activation energies for the graft polymerization reactions were determined

  3. Thermodynamic Interactions between Polystyrene and Long-Chain Poly(n-Alkyl Acrylates) Derived from Plant Oils.

    Wang, Shu; Robertson, Megan L

    2015-06-10

    Vegetable oils and their fatty acids are promising sources for the derivation of polymers. Long-chain poly(n-alkyl acrylates) and poly(n-alkyl methacrylates) are readily derived from fatty acids through conversion of the carboxylic acid end-group to an acrylate or methacrylate group. The resulting polymers contain long alkyl side-chains with around 10-22 carbon atoms. Regardless of the monomer source, the presence of alkyl side-chains in poly(n-alkyl acrylates) and poly(n-alkyl methacrylates) provides a convenient mechanism for tuning their physical properties. The development of structured multicomponent materials, including block copolymers and blends, containing poly(n-alkyl acrylates) and poly(n-alkyl methacrylates) requires knowledge of the thermodynamic interactions governing their self-assembly, typically described by the Flory-Huggins interaction parameter χ. We have investigated the χ parameter between polystyrene and long-chain poly(n-alkyl acrylate) homopolymers and copolymers: specifically we have included poly(stearyl acrylate), poly(lauryl acrylate), and their random copolymers. Lauryl and stearyl acrylate were chosen as model alkyl acrylates derived from vegetable oils and have alkyl side-chain lengths of 12 and 18 carbon atoms, respectively. Polystyrene is included in this study as a model petroleum-sourced polymer, which has wide applicability in commercially relevant multicomponent polymeric materials. Two independent methods were employed to measure the χ parameter: cloud point measurements on binary blends and characterization of the order-disorder transition of triblock copolymers, which were in relatively good agreement with one another. The χ parameter was found to be independent of the alkyl side-chain length (n) for large values of n (i.e., n > 10). This behavior is in stark contrast to the n-dependence of the χ parameter predicted from solubility parameter theory. Our study complements prior work investigating the interactions between

  4. Synthesis and Thermal Properties of Acrylonitrile/Butyl Acrylate/Fumaronitrile and Acrylonitrile/Ethyl Hexyl Acrylate/Fumaronitrile Terpolymers as a Potential Precursor for Carbon Fiber

    Siti Nurul Ain Md Jamil

    2014-09-01

    Full Text Available A synthesis of acrylonitrile (AN/butyl acrylate (BA/fumaronitrile (FN and AN/EHA (ethyl hexyl acrylate/FN terpolymers was carried out by redox polymerization using sodium bisulfite (SBS and potassium persulphate (KPS as initiator at 40 °C. The effect of comonomers, BA and EHA and termonomer, FN on the glass transition temperature (Tg and stabilization temperature was studied using Differential Scanning Calorimetry (DSC. The degradation behavior and char yield were obtained by Thermogravimetric Analysis. The conversions of AN, comonomers (BA and EHA and FN were 55%–71%, 85%–91% and 76%–79%, respectively. It was found that with the same comonomer feed (10%, the Tg of AN/EHA copolymer was lower at 63 °C compared to AN/BA copolymer (70 °C. AN/EHA/FN terpolymer also exhibited a lower Tg at 63 °C when compared to that of the AN/BA/FN terpolymer (67 °C. By incorporating BA and EHA into a PAN system, the char yield was reduced to ~38.0% compared to that of AN (~47.7%. It was found that FN reduced the initial cyclization temperature of AN/BA/FN and AN/EHA/FN terpolymers to 228 and 221 °C, respectively, in comparison to that of AN/BA and AN/EHA copolymers (~260 °C. In addition, FN reduced the heat liberation per unit time during the stabilization process that consequently reduced the emission of volatile group during this process. As a result, the char yields of AN/BA/FN and AN/EHA/FN terpolymers are higher at ~45.1% and ~43.9%, respectively, as compared to those of AN/BA copolymer (37.1% and AN/EHA copolymer (38.0%.

  5. Surface properties of ionomers based on styrene-b-acrylic acid copolymers obtained by copolymerization in emulsion

    Surface properties of styrene-b-acrylic acid copolymers obtained in emulsion and suitable ionomers before and after UV-irradiation were studied by measurements of contact angles and FTIR-ATR spectroscopy. The research focused on the influence of different content of carboxylic acid groups in copolymers, of various types and contents of alkali metal salts in ionomers and of cesium acrylate or methacrylate in ionomers on hydrophilicity of the surfaces of these samples and the course of photodegradation in them. Hydrophilicity of initial copolymer surfaces was higher than this of polystyrene as a result of presence of carboxylic acid groups, which also made the surfaces of these copolymers more sensitive to UV-irradiation. Hydrophilicity of the surfaces of ionomers containing cesium acrylates depended on the content of cesium salt in the samples. The course of ionomer photooxidation was also dependent on the content of this salt. The surface of ionomer containing cesium methacrylate was more polar than this of ionomer containing cesium acrylate. Styrene-based ionomers containing 3.7 mol% of various alkali metal acrylates had less polar surfaces than initial copolymer and they were also more resistant to UV-irradiation in comparison to the initial copolymer. Copolymers obtained in emulsion and suitable ionomers had more polar surfaces and they were more sensitive to UV-light compared to copolymers obtained in bulk and their ionomers.

  6. Synthesis of superabsorbent hydrogel by radiation crosslinking of acrylic acid, semi-refined kappa-carrageenan and sugarcane bagasse blend

    Superabsorbent hydrogels have three-dimensional networks that enable it to exhibit great water absorption capacity leading to its promising applications. However, existing commercial hydrogels are mainly acrylic acid which causes environmental problems. In this study, the incorporation of agricultural waste as filler and polysaccharide from natural sources as binder for the production of superabsorbent hydrogel was done to reduce the use of acrylic acid as well as its environmental impact while adding value to the incorporated materials. A series of superabsorbent hydrogel with the blend of acrylic acid, semi-refined kappa carrageenan and sugarcane bagasse were synthesized by radiation crosslinking. The gel fraction and swelling capacity of the hydrogels were determined and studied. The characterizations were facilitated by Fourier transform infrared spectroscopy technique (FTIR) and Thermogravimetric Analysis (TGA). In the results obtained from analyses, the characteristic peaks of acrylic acid and sugarcane bagasse were observed in the FTIR spectra and the three step peaks if synthesized hydrogel in its TGA implies an improvement in thermal stability of the product. The synthesized superabsorbent hydrogel blends had exhibited comparable gel fraction to that of the polyacrylic acid hydrogel, had great swelling capacity, and achieved equilibrium degree of swelling within 72-96 hours. The optimum synthesized superabsorbent hydrogel is 3% semi-refined kappa-carrageenan, 3% sugarcane bagasse, 15% acrylic acid neutralize up to 50% and irradiated at 15kGy dose which exhibited a swelling of 599.53 and gel fraction of 39.73. (author)

  7. Designing Visible Light-Cured Thiol-Acrylate Hydrogels for Studying the HIPPO Pathway Activation in Hepatocellular Carcinoma Cells.

    Lin, Tsai-Yu; Bragg, John C; Lin, Chien-Chi

    2016-04-01

    Various polymerization mechanisms have been developed to prepare peptide-immobilized poly(ethylene glycol) (PEG) hydrogels, a class of biomaterials suitable for studying cell biology in vitro. Here, a visible light mediated thiol-acrylate photopolymerization scheme is reported to synthesize dually degradable PEG-peptide hydrogels with controllable crosslinking and degradability. The influence of immobilized monothiol pendant peptide is systematically evaluated on the crosslinking of these hydrogels. Further, methods are proposed to modulate hydrogel crosslinking, including adjusting concentration of comonomer or altering the design of multifunctional peptide crosslinker. Due to the formation of thioether ester bonds, these hydrogels are hydrolytically degradable. If the dithiol peptide linkers used are susceptible to protease cleavage, these thiol-acrylate hydrogels can be designed to undergo partial proteolysis. The differences between linear and multiarm PEG-acrylate (i.e., PEGDA vs PEG4A) are also evaluated. Finally, the use of the mixed-mode thiol-acrylate PEG4A-peptide hydrogels is explored for in situ encapsulation of hepatocellular carcinoma cells (Huh7). The effects of matrix stiffness and integrin binding motif (e.g., RGDS) on Huh7 cell growth and HIPPO pathway activation are studied using PEG4A-peptide hydrogels. This visible light poly-merized thiol-acrylate hydrogel system represents an alternative to existing light-cured hydrogel platforms and shall be useful in many biomedical applications. PMID:26709469

  8. Crystal structures of (E)-3-(furan-2-yl)-2-phenyl-N-tosyl­acryl­amide and (E)-3-phenyl-2-(m-tol­yl)-N-tosyl­acryl­amide

    Cheng, Dong; Meng, Xiangzhen; Sheng, Zeyuan; Wang, Shuangming; Duan, Yuanyuan; Li, Ziqian

    2016-01-01

    In the title N-tosyl­acryl­amide compounds, C20H17NO4S, (I), and C23H21NO3S, (II), the conformation about the C=C bond is E. The acryl­amide groups, [–NH—C(=O)—C=C–], are almost planar, with the N—C—C=C torsion angle being −170.18 (14)° in (I) and −168.01 (17)° in (II). In (I), the furan, phenyl and 4-methyl­benzene rings are inclined to the acryl­amide mean plane by 26.47 (11), 69.01 (8) and 82.49 (9)°, respectively. In (II), the phenyl, 3-methyl­benzene and 4-methyl­benzene rings are inclin...

  9. Property Research of Instant Polymerization Acrylate Size Mixture%瞬时聚合丙烯酸酯浆料的性能研究

    吴长春; 武海良; 沈艳琴; 杨微

    2011-01-01

    探讨在采用瞬时聚合法直接合成固体丙烯酸酯浆料的过程中,疏水性单体丙烯酸丁酯用量对所生成丙烯酸酯浆料性能的影响.测试了不同丙烯酸丁酯用量下反应生成物的水溶性、水溶液黏度及对涤棉粗纱黏附性,并对合成的固体丙烯酸浆料进行红外表征.结果表明:在丙烯酸的中和度为50%、氧化还原引发体系中引发剂为单体量的6%时,丙烯酸丁酯为单体量的25%时合成的浆料性能最好,所生产的浆料为丙烯酸-丙烯酸钠盐-丙烯酸丁酯共聚物.%Effect of hydrophobic monomer butyl acrylate amount on acrylate size mixture property in the process of compounding solid acrylate size mixture directly by instant polymerization was discussed. Water-soluble, solution viscosity and adhesion to polyester cotton roving of polymer were tested in condition of different butyl acrylate amount. Infrared spectroscopy was done on solid acrylate size mixture. The result shows that property of the acrylate size mixture is the best,the size mixture is acrylate,acrylic acid,butyl acrylate copolymer when acrylic acid neutralization degree is 50% ,initiator content in redox initiation system is 6% ,butyl acrylate is 25%.

  10. In vitro antifungal action of different substances over microwaved-cured acrylic resins

    Henrique Montagner

    2009-10-01

    Full Text Available OBJECTIVE: The presence of Candida albicans on the surfaces of denture-base acrylic resins is strongly related to the development of oral stomatitis. This study evaluated the antifungal action of different agents over microwave-cured acrylic resin without polishing specimens previously contaminated with Candida albicans. MATERIAL AND METHODS: Sixty specimens were immersed in BHI broth previously inoculated with the yeast and stored for 3 h at 37ºC. They were divided into 5 experimental groups (n=10: G1: 2% chlorhexidine solution (10 min; G2: 0.5% sodium hypochlorite (10 min; G3: modified sodium hypochlorite (10 min; G4: effervescent agent (5 min; G5: hydrogen peroxide 10v (30 min. The specimens of the control group 1 (C1 were not disinfected. Ten additional specimens of the control group 2 (C2 were not infected with the yeast, aiming to check the asepsis during the experiment. The disinfection agents were neutralized and the acrylic resin specimens were immersed in BHI Broth for 24 h. Culture media turbidity was evaluated spectrophotometrically according to the transmittance degree, i.e. the higher the transmittance the stronger the antimicrobial action. Statistical analysis was performed (Kruskal-Wallis Test, p<0.05. RESULTS: The results, represented by the medians, were: G1 = 40; G2 = 100; G3 = 100; G4 = 90; G5 = 100; C1 = 40; C2 = 100. CONCLUSIONS: This in vitro study suggested that sodium hypochlorite-based substances and hydrogen peroxide are more efficient disinfectants against C. albicans than 2% chlorhexidine solution and the effervescent agent.

  11. Antibacterial activity of chitosan and the interpolyelectrolyte complexes of poly(acrylic acid-chitosan

    Hortensia Ortega-Ortiz

    2010-06-01

    Full Text Available The antimicrobial activity of chitosan and water soluble interpolyelectrolyte complexes of poly(acrylic acid-chitosan was studied. Chitosans of two different molecular weights were tested at different concentration for 0.5 to 5 g·L-1 as antimicrobial agents against P. aeruginosa and P. oleovorans. In both cases, the best microbial inhibition was obtained with the concentration of 5 g·L-1. However, the interpolyelectrolyte complexes of poly(acrylic acid-chitosan with composition φ =2 produced higher antibacterial activity than the two chitosans at the concentration of 0.5 g·L-1. The NPEC2 complex was more effective than chitosans. This could be attributed to the number of moles of the amino groups of chitosan and the carboxylic acid groups of the interpolyelectrolyte complexes poly(acrylic acid.A atividade antimicrobiana de quitosana e complexos interpolieletrolíticos hidrossoluvéis de poli(ácido acrílico-quitosana foi estudada. Quitosanas de dois diferentes pesos moleculares foram testados em diferentes concentrações, 0,5 a 5 g • L-1, como agentes antimicrobianos nas P. aeruginosa e P. oleovorans. Em ambos os casos, obteu-se a melhor inibição microbiana com a concentração de 5 g • L-1, no entanto os complexos interpolieletrolíticos de poli (ácido acrílico-quitosana com composição φ = 2 apresentaram maior atividade antibacteriana do que os dois quitosans na concentração de 0,5 g • L-1. O complexo NPEC2 foi mais eficaz do que as quitosanas, sendo que o resultado pode ser atribuído ao número de moles dos grupos aminos da quitosana e aos grupos carboxílicos dos complexos de poli(ácido acrílico.

  12. Partial oxidation of D-xylose to maleic anhydride and acrylic acid over vanadyl pyrophosphate

    Xylose is the second most abundant sugar after glucose. Despite its tremendous potential to serve as a renewable feedstock, few commercial processes exploit this resource. Here, we report a new technology in which a two-fluid nozzle atomizes a xylose-water solution into a capillary fluidized bed operating above 300 °C. Xylose-water droplets form at the tip of the injector, vaporize then react with a heterogeneous mixed oxide catalyst. A syringe pump metered the solution to the reactor charged with 1 g of catalyst. Product yield over vanadyl pyrophosphate was higher compared to molybdenum trioxide-cobalt oxide and iron molybdate; it reached 25% for maleic anhydride, 17% for acrylic acid and 11% for acrolein. Gas residence time was 0.2 s. The catalyst was free of coke even after operating for 4 h – based on a thermogravimetric analysis of catalyst withdrawn from the reactor. Below 300 °C, powder agglomerated at the tip of the injector at 300 °C; it also agglomerated with a xylose mass fraction of 7% in water. - Highlights: • D-xylose reacts to form maleic anhydride and acrylic acid above 250 °C. • Vanadyl pyrophosphate is both active and selective for maleic and acrylic acid. • Acid and acrolein yield approaches 50% for a xylose mass fraction of 3% in water. • Catalyst agglomerates at low temperatures and high xylose aqueous mass fraction. • Atomization quality is a determining factor to minimize agglomeration

  13. Effect of an acrylic resin combined with an antimicrobial polymer on biofilm formation

    Juliê Marra

    2012-12-01

    Full Text Available OBJECTIVES: The purpose of this study was to evaluate the antimicrobial activity of an acrylic resin combined with an antimicrobial polymer poly (2-tert-butylaminoethyl methacrylate (PTBAEMA to inhibit Staphylococcus aureus, Streptococcus mutans and Candida albicans biofilm formation. MATERIAL AND METHODS: Discs of a heat-polymerized acrylic resin were produced and divided according to PTBAEMA concentration: 0 (control, 10 and 25%. The specimens were inoculated (10(7 CFU/mL and incubated at 37ºC for 48 h. After incubation, the wells were washed and each specimen was sonicated for 20 min. Replicate aliquots of resultant suspensions were plated at dilutions at 37ºC for 48 h. The number of colony-forming units (CFU was counted and expressed as log (CFU+1/mL and analyzed statistically with α=.05. RESULTS: The results showed that 25% PTBAEMA completely inhibited S. aureus and S. mutans biofilm formation. A significant reduction of log (CFU+1/mL in count of S. aureus (control: 7.9±0.8A; 10%: 3.8±3.3B and S. mutans (control: 7.5±0.7A; 10%: 5.1±2.7B was observed for the group containing 10% PTBAEMA (Mann-Whitney, p0.05, P=0.079. CONCLUSIONS: Acrylic resin combined with 10 and 25% of PTBAEMA showed significant antimicrobial activity against S. aureus and S. mutans biofilm, but it was inactive against the C. albicans biofilm.

  14. An Electrochemical DNA Microbiosensor Based on Succinimide-Modified Acrylic Microspheres

    Sharina Abu Hanifah

    2012-04-01

    Full Text Available An electrochemical microbiosensor for DNA has been fabricated based on new acrylic microspheres modified with reactive N-acryloxysuccinimide (NAS functional groups. Hydrophobic poly(n-butylacrylate-N-acryloxysuccinimide microspheres were synthesized in an emulsion form with a simple one-step photopolymerization technique. Aminated DNA probe was attached to the succinimde functional group of the acrylic microspheres via covalent bonding. The hybridization of the immobilized DNA probe with the complementary DNA was studied by differential pulse voltametry using anthraquninone-2-sulfonic acid monohydrate sodium salt (AQMS as the electroactive hybridization label. The influences of many factors such as duration of DNA probe immobilization and hybridization, pH, type of ions, buffer concentrations, ionic strength, operational temperature and non-complementary DNA on the biosensor performance were evaluated. Under optimized conditions, the DNA microbiosensor demonstrated a linear response range to target DNA over a wide concentration range of 1.0 × 10−16 and 1.0 ´ 10−8 M with a lower limit of detection (LOD of 9.46 ´ 10−17 M (R2 = 0.97. This DNA microbiosensor showed good reproducibility with 2.84% RSD (relative standard deviation (n = 3. Application of the NAS-modified acrylic microspheres in the construction of DNA microbiosensor had improved the overall analytical performance of the resultant DNA microbiosensor when compared with other reported DNA biosensors using other nano-materials for membranes and microspheres as DNA immobilization matrices.

  15. Behaviour of alkaline cement mortars reinforced with acrylic and polypropylene fibres

    Puertas, P.; Amat, T.; Vázquez, T.

    2000-01-01

    In the present work, the behaviour of alkaline cement mortars reinforced with fibres of different nature (acrylic and polypropylene fibres) is studied. Also the chemical stability of those fibres in strong alkaline medium has been investigated. Three different matrixes have been used: glass blast furnace slag activated with NaOH 2M (room temperature, 22 ºC); fly ash activated with NaOH 8M, cured at 85ºC during 24 hours and 50% fly ash / 50% slag activated with NaOH 8M, room temperature. The f...

  16. A Simple Method for Making Diagnostic Casts for Dental Implants Using Acrylic Abutments

    H. Siadat

    2007-06-01

    Full Text Available The use of multiple implants in the same jaw requires a detailed knowledge of abutment angulation. The position and angulation of the abutments play an important role in treatment planning and fabrication of the custom tray. Therefore diagnostic casts thatcontain cover screws may cause problems during implant therapy.The current article describes a technique for making a preliminary cast with acrylic custom abutments in order to help the clinician select an appropriate impression technique and evaluate the location and angulations of the implant bodies. This method can also aid the technician to provide adequate and proper space for the fabrication of an open custom tray.

  17. Acidic polyanion poly(acrylic acid) prevents calcium oxalate crystal deposition

    Kleinman, Jack G.; Alatalo, Laura J.; Beshensky, Ann M.; Wesson, Jeffrey A.

    2008-01-01

    Acidic macromolecules inhibit calcium oxalate nucleation, growth, aggregation and attachment to cells in vitro. To test for such an effect in vivo we used osmotic minipumps to continuously infuse several doses of the 5.1 kDa poly(acrylic acid) (pAA5.1) into rats fed a diet which causes renal calcium oxalate crystal deposition. Although kidneys of rats receiving the saline control contained calcium oxalate crystals, measured by polarized light microscopy, those of animals given pAA5.1 had sign...

  18. Radiation Induced Formation of Acrylated Palm Oil Nanoparticles using Cetyltrimethylammonium Bromide Microemulsion System

    In this study, we report the preparation of Acrylated Palm Oil (APO) nanoparticles using aqueous Cetyltrimethylammonium bromide (CTAB) microemulsion system. This microemulsion system which contains the dispersed APO nano droplets was subjected to the gamma irradiation to induce the formation of the crosslinked APO nanoparticle. After irradiation at higher doses, the size of APO nanoparticles was transformed from a submicron-sized to a nano-sized of the particles. Size decreasing might be due to the intermolecular and the intramolecular crosslinking reactions of the APO nanoparticles during the irradiation process. (author)

  19. Towards control of viscous effects in acrylic-based actuator applications

    Thylander, S.; Menzel, A.; Ristinmaa, M.

    2016-09-01

    Dielectric elastomers offer clear advantages over more traditional and conventional materials when soft, lightweight, noiseless actuator applications with large deformations are considered. However, the viscous time-dependent behaviour associated with most elastomers limit the number of possible applications. For this purpose, the possibility of controlling the viscous response by regulating the applied electric potential is explored. The constitutive model chosen is calibrated to fit the electro-viscoelastic response of an acrylic elastomer often used in dielectric elastomer actuators. The response of both homogeneous deformation examples and inhomogeneous finite element boundary value problems, chosen to mimic existing applications, are presented. Control of both force and displacement quantities are successfully achieved.

  20. Adsorption properties of leather modified by radiation induced grafting with methyl methacrylate and butyl acrylate

    Adsorption properties of leathers modified by radiation induced grafting with butyl acrylate and methyl methacrylate have been investigated by the McBain method. Isotherms of adsorption and desorption of water vapour have been obtained and the specific surface for various leathers calculated. No change in the adsorption properties of modified leather was noticed up to 25% content of grafted polymer. At higher polymer content deterioration of hygienic properties of modified leather was observed. From the adsorption measurements it has been concluded that the size of millipores undergoes random distribution and no specific group of pores prevails. Explanation of the observed phenomena is proposed. (author)

  1. Incorporating functional groups on the structure of Acrylic fibers for adsorption of metal ionic compounds

    Common commercial acrylic fibers were modified by incorporating different suitable ion adsorbing functional groups into their structures. To study the ion adsorption ability of modified fibers against ionic compounds, the raw fibers were treated with hydroxylamine, hydrazine and urea. The new incorporated functional groups were characterized and appropriate formula for each reaction was suggested. In order to evaluate the ion adsorption capacity of the system, the modified fibers were immersed in separated metal salt solutions. The results show that the samples modified by hydroxylamine, have higher adsorption capacity than others, however, by pretreatment with hydrazine or urea not only the functional groups were increased but also the efficiency of the adsorption was improved

  2. The active component of vanadium-molybdenum catalysts for the oxidation of acrolein to acrylic acid

    The catalytic properties of the vanadium-molybdenum oxide system were investigated in the oxidation of acrolein to acrylic acid. The active component of the catalyst is the compound VMo3O11, the maximum amount of which is observed at a content of 7-15 mole% V2O4. The compound VMo3O11 is formed in the thermodecomposition of silicomolybdovanadium heteropoly acids or isopoly compounds, reduced with respect to vanadium, and contains V4+ and Mo6+. The optimum treatment for the formation of this compound is treatment in the reaction mixture at 400 degrees C

  3. ESTERIFICATION OF ACRYLIC ACID WITH 1-BUTANOL IN LIQUID PHASE CATALYZED WITH AL-MCM-41

    Edson Avellaneda Maytán; Gustavo Paim Valença

    2010-01-01

    This work studies the esterification of acrylic acid with 1-butanol using Al-MCM-41 as catalyst with different degrees of acidity at different temperatures. Al-MCM-41 synthesis was made from bromate Cetyl trimethyl ammonium using as router agent, NH4OH (25%), deionized H2O and Al2(SO4)3. Catalytic tests were carried out by groups and worked with temperature ranges among (333 to 348) K and a small sample was collected at predetermined intervals of time for subsequent gas chromatography analysi...

  4. (E)-Methyl 3-(10-bromo­anthracen-9-yl)acrylate

    Bernhard Bugenhagen; Yosef Al Jasem; Bassam al Hindawi; Nathir Al Rawashdeh; Thies Thiemann

    2013-01-01

    In the title molecule, C18H13BrO2, the anthracene unit forms an angle of 46.91 (2)° with the mean plane of the methyl acrylate moiety. In the crystal, the molecules arrange themselves into strands parallel to [010] and, due to the crystal symmetry, there are eight strands crossing the unit cell. In each strand, molecules form short C—H...O and C—H...π contacts and have their anthracene groups parallel to each other. Neighboring strands, related by a c-glide operati...

  5. Ultra-Thin Films of Poly(acrylic acid)/Silver Nanocomposite Coatings for Antimicrobial Applications

    Alaa Fahmy; Eisa, Wael H.; Mohamed Yosef; Ali Hassan

    2016-01-01

    In this work not only colloids of poly(acrylic acid) (PAA) embedded with silver nanoparticles (Ag-NPs) but thin films (10 nm) also were deposited using electrospray deposition technique (ESD). A mixture of sodium borohydride (NaBH4) and ascorbic acid (AA) were utilized to reduce the silver ions to generate Ag-NPs in the PAA matrix. Moreover, sodium tricitrate was used to stabilize the prepared colloids. The obtained colloids and films were characterized using UV-visible, transmission electron...

  6. Synthesis of hemicellulose-acrylic acid graft copolymer super water absorbent resin by ultrasonic irradiation technology

    Liu, Fangfang; Conghui DU; Linya ZHANG

    2015-01-01

    The hemicellulose super water absorbent resin is prepared by using ultrasonic irradiation technology, with the waste liquid produced during the preparation of viscose fiber which contains a large amount of hemicellulose as raw material, acrylic acid as graft monomer, N,N’-methylene bis acrylamide (NMBA) as cross linking agent, and (NH4)2S2O8-NaHSO3 as the redox initiation system. The synthesis conditions, structure and water absorption ability of resin are discussed. The results indicate that...

  7. Immobilization of penicillin acylase on copolymer of butyl acrylate and ethylene glycol dimethacrylate.

    Bryjak, J; Noworyta, A

    1993-01-01

    The effects of glutaraldehyde, enzyme concentrations and reactants volumes, ionic strength, pH value and carrier particle diameter on immobilization of penicillin acylase onto acrylic carriers were studied. The activity of immobilized enzyme preparations was also studied over a range of pH values and temperatures and thermal and pH stabilities were determined. The use of the immobilized preparation for penicillin G hydrolysis in a batch reactor was investigated. The immobilized enzyme gave a significant reduction in hydrolysis time compared to hydrolysis by the native enzyme. PMID:7763686

  8. Ethyl 3-(4-hydroxy-phen-oxy)-2-(4-methoxy-phen-yl)acrylate.

    Hou, Jin

    2008-01-01

    In the title compound, C(18)H(18)O(5), the dihedral angle between the two benzene rings is 55.2 (3)°. The ethyl acrylate linkage is planar and forms dihedral angles of 21.3 (3) and 41.0 (3)°, respectively, with the hydroxy-phenyl and methoxy-phenyl rings. In the crystal structure, mol-ecules are linked into zigzag chains along the b axis by O-H⋯O hydrogen bonds. PMID:21581271

  9. The Relationship Between Water Structure and Blood Compatibility in Poly(2-methoxyethyl Acrylate) (PMEA) Analogues.

    Sato, Kazuhiro; Kobayashi, Shingo; Kusakari, Miho; Watahiki, Shogo; Oikawa, Masahiko; Hoshiba, Takashi; Tanaka, Masaru

    2015-09-01

    Six types of poly(2-methoxyethyl acrylate) (PMEA) analogues were synthesized and the water structure in the hydrated polymers was characterized using differential scanning calorimetry (DSC). The hydrated PMEA analogues exhibited the different amounts of intermediate water. Non-thrombogenicity evaluation was performed on PMEA analogues for platelet adhesion and protein adsorption. Platelet adhesion was suppressed on PMEA analogues. In addition, the protein adsorption and deformation were suppressed by increasing the amount of intermediate water. This study demonstrates that the amount of intermediate water might play a key role in expressing the blood compatibility of polymeric materials. PMID:26017931

  10. Influence of an Acrylic Polymer Blend on the Physical Stability of Film-Coated Theophylline Pellets

    Kucera, Shawn; Shah, Navnit H.; Malick, A. Waseem; Infeld, Martin H.; McGinity, James W.

    2009-01-01

    The purpose of this study was to investigate the physical stability of a coating system consisting of a blend of two sustained release acrylic polymers and its influence on the drug release rate of theophylline from coated pellets. The properties of both free films and theophylline pellets coated with the polymer blend were investigated, and the miscibility was determined via differential scanning calorimetry. Eudragit® RS 30 D was plasticized by the addition of Eudragit® NE 30 D, and the pre...

  11. Modification of hydrophobic polypeptide-based film by blending with hydrophilic poly(acrylic acid

    Guoquan Zhu

    2013-01-01

    Full Text Available In this study, a series of poly(γ-benzyl L-glutamate/poly(acrylic acid (PBLG/PAA polymer blend films were prepared by casting the polymer blend solution in dimethylsulfoxide (DMSO. The structure and morphology of the polymer blend film were investigated by Fourier Transform Infrared Spectroscopy (FT-IR and Scanning Electron Microscopy (SEM. Thermal, mechanical, and chemical properties of PBLG/PAA polymer blend films were studied by Differential Scanning Calorimetry (DSC, Thermogravimetric (TG Analysis, Tensile Tests, and measurements of Surface Contact Angles. The results revealed that the introduction of PAA could exert great effects on the structure and properties of the polypeptide films.

  12. Structure and Proton Conductivity in Mixtures of Poly(acrylic acid) and Imidazole

    Yang, Han-Chang; Griffin, Philip J.; Winey, Karen I.; University of Pennsylvania Team

    2015-03-01

    Proton conductivity in polymer electrolyte membranes (PEMs) typically involves water, which requires that during operation the humidity of the PEM be carefully controlled. In contrast, anhydrous protic polymer membranes promote proton transport by incorporating heterocyclic molecules, such as imidazole and its derivatives, into acid-containing polymers. In this work, we explore the interplay between nanoscale-structure and proton conduction of poly(acrylic acid) (PAA) blended at varying compositions with 2-ethyl-4-methylimidazole (EMI). We present the glass transition temperature from differential scanning calorimetry, morphology characterization from X-ray scattering, and proton conductivity from electrical impedance spectroscopy.

  13. Properties of Low Surface Energy Fluorocarbon Polymers with Fluoro-acrylic Resins

    LIU Xiusheng; WANG Can; LIU Lanxuan; LI Jian; GAO Wanzhen

    2008-01-01

    The low surface energy fluorocarbon polymer from the synthesized fluoro-acrylic resins was developed. Then the molecule orientation principle of nonpolar and polar functional groups in the polymers was analyzed. And the contact angles of pure water drops on the surfaces of various fluoro-monomer homopolymers and interpolymers were measured. So the relation of polymers' fluoro-content with the surface energy was determined. The distribution of fluoric functional groups in the polymers was investigated. And the test results show that though the total fluorine content of the fluorocarbon polymers is relative few, their surface energy is really low due to the enrichment of fluoro-chains on the polymers surface.

  14. Effects of Sonication Conditions on Ultrasonic Dispersion of Inorganic Particles in Acrylic Resin

    Tuziuti, Toru; Yasui, Kyuichi; Towata, Atsuya; Kato, Kazumi

    2011-07-01

    The effects of sonication conditions on the ultrasonic dispersion of titanium dioxide particles in acrylic resin are investigated. Pulsing operation at appropriate on-off duty cycles enables us to attain a particle size smaller than that at a continuous wave (CW) at the same net time of sonication between operations. It is useful that frequency-sweep operation attains almost the same particle size as that at CW, which can provide a constant dispersion of particles even if the resonant frequency used to effectively drive an ultrasonic transducer changes with liquid conditions, such as the temperature and acoustic impedance of a liquid.

  15. Bioinspired bioadhesive polymers: dopa-modified poly(acrylic acid) derivatives.

    Laulicht, Bryan; Mancini, Alexis; Geman, Nathanael; Cho, Daniel; Estrellas, Kenneth; Furtado, Stacia; Hopson, Russell; Tripathi, Anubhav; Mathiowitz, Edith

    2012-11-01

    The one-step synthesis and characterization of novel bioinspired bioadhesive polymers that contain Dopa, implicated in the extremely adhesive byssal fibers of certain gastropods, is reported. The novel polymers consist of combinations of either of two polyanhydride backbones and one of three amino acids, phenylalanine, tyrosine, or Dopa, grafted as side chains. Dopa-grafted hydrophobic backbone polymers exhibit as much as 2.5 × the fracture strength and 2.8 × the tensile work of bioadhesion of a commercially available poly(acrylic acid) derivative as tested on live, excised, rat intestinal tissue. PMID:23008096

  16. Modification of magnetite coating formation in presence of alkaline acrylic acid

    In Indian PHWR's, the hot conditioning of primary heat transport system is carried out to form a protective magnetite coating on the inner surface of PHT system at the start up of the reactor and also after decontamination of PHT system to minimize the release of loose crud particulates and corrosion of the PHT system. An attempt has been made to modify the chemistry conditions for the formation of protective magnetite coating on CS coupons in a static autoclave at 523K to view its impact on the nature of the protectivity. In continuation of our efforts to modify the film with various organic additives like Glycerol, Ethylene glycol, PEG, in this paper the effect of acrylic acid on magnetite coating formation is discussed. The metal oxide powders synthesized by polymer combustion route in PVA, PEG and PAA resulted in nano crystallites. To see the effect of theses organics in reducing the crystallite sizes and improving the corrosion resistance behaviour in hydrothermal conditions the experiments are carried out. In presence of Acrylic acid (AA) at different concentrations (50, 100, 500ppm) at alkaline pH (LiOH -10.4 ) in static autoclave, magnetite coating is formed on CS coupons. The coupons were characterized by XRD, SEM, Raman and Electrochemical impedance and Potentiodynamic Anodic Polarization (PDAP) studies. The addition of acrylic acid results in smaller crystallite sizes and the crystallites look like thread bundles for 50ppm concentration of AA. PDAP studies indicate better film protectivity for magnetite coating formed in 50 ppm AA. Corrosion rate is observed to be less for CS coupons in presence of 50 and 100 ppm AA. The tendency for the film formed to dissolve is less for both 50 and 100 ppm AA developed coating in comparison to coating developed in LiOH alone. The impedance studies indicated the pore resistance of the film increased two fold and seven fold for 50 and 100 ppm acrylic acid case in comparison to simple LiOH case where as the charge

  17. Decolourization performance in C. I. Vat Yellow 1 aqueous suspension using hydrophobically modified poly(acrylic acid).

    Chen, J; Chen, M C

    2011-01-01

    A series of hydrophobically modified poly(acrylic acid) (PAA), poly(2-phenoxyethyl acrylate-co-acrylic acid) (poly(PHEA-co-AA)), have been synthesized and characterized by Ubbelohde type viscometry, Nuclear Magnetic Resonance (1H NMR) spectrometry and Differential Scanning Calorimetry (DSC). The shear thinning Non-Newtonian fluid behavior of their aqueous solution and the dependence on pH and hydrophobic group contents were found through apparent viscosity and rheological property investigating. Decolourization performance in C. I. Vat Yellow 1 aqueous suspension was evaluated through visible absorbance data. Decolourization performance of hydrophobically associated polymer indicates two times better than that of PAA. The quantitative relationship was mainly studied. PMID:21866762

  18. Corrosion Inhibitive Evaluation of an Environmentally Friendly Water-Base Acrylic Terpolymer on Mild Steel in Hydrochloric Acid Media

    Azghandi, Mojtaba Vakili; Davoodi, Ali; Farzi, Gholam Ali; Kosari, Ali

    2013-12-01

    The corrosion inhibitive performance of an environmentally friendly water-base acrylic terpolymer [methyl methacrylate/Butyl Acrylate/Acrylic acid (ATP)] on mild steel in 1 M HCl was investigated by alternating current and direct current electrochemical techniques and the quantum chemical method. An efficiency of more than 97 pct was obtained with 0.8 mmol/L ATP. The increase in inhibitor concentration and immersion time has a positive effect, while the temperature influence is negligible on the inhibitor efficiency. The present terpolymer obeys the Langmuir isotherm, and thermodynamic calculation reveals a chemisorption type on the surface. Density functional calculations showed that the lone pairs of electrons of oxygen in the structure of three monomers are suitable sites to adsorb onto the metal surface. Finally, in the presence of ATP, a decrease in surface roughness and corrosion attacks was demonstrated by atomic force microscopy and optical microscopy examinations, respectively.

  19. Radiation-curing of acrylate composites including carbon fibres: A customized surface modification for improving mechanical performances

    Martin, Arnaud; Pietras-Ozga, Dorota; Ponsaud, Philippe; Kowandy, Christelle; Barczak, Mariusz; Defoort, Brigitte; Coqueret, Xavier

    2014-12-01

    The lower transverse mechanical properties of radiation-cured acrylate-based composites reinforced with carbon-fibre with respect to the thermosettable analogues was investigated from the viewpoint of chemical interactions at the interface between the matrix and the carbon material. XPS analysis of representative commercial carbon fibres revealed the presence of a significant amount of chemical functions potentially exerting an adverse effect on the initiation and propagation of the free radical polymerization initiated under high energy radiation. The EB-induced polymerization of n-butyl acrylate as a simple model monomer was conducted in the presence of various aromatic additives exhibiting a strong inhibiting effect, whereas thiols efficiently sensitize the initiation mechanism and undergo transfer reactions. A method based on the surface modification of sized fibres by thiomalic acid is proposed for overcoming the localized inhibition phenomenon and for improving the mechanical properties of the resulting acrylate-based composites.

  20. Characterization of acrylic resins used for restoration of artworks by pyrolysis-silylation-gas chromatography/mass spectrometry with hexamethyldisilazane.

    Osete-Cortina, Laura; Doménech-Carbó, María Teresa

    2006-09-15

    A procedure based on the technique of the pyrolysis-GC/MS has been applied, in this work, in order to determine the composition of synthetic acrylic resins employed in artworks. The method is based on the on line derivatization of these resins using hexamethyldisilazane (HMDS). Results obtained have been compared with those others from direct pyrolysis and in situ thermally assisted hydrolysis and methylation with tetramethylammonium hydroxide (TMAH). Sensitivity using HMDS as derivatising reagent is found similar to that from direct pyrolysis and methylation with TMAH. Better resolution of the most representative peaks has been also obtained. Additionally, this method reduces the formation of free acrylic acid molecules during the pyrolysis process and, in consequence, more simplified and well-resolved chromatograms are obtained. Finally, the reported procedure has been successfully used for characterizing several acrylic-based varnishes and binding media currently used in Fine Arts and real pictorial samples from graffiti performed on a Middle Ages bridge. PMID:16797558

  1. A silver bullet: elemental silver as an efficient reducing agent for atom transfer radical polymerization of acrylates.

    Williams, Valerie A; Ribelli, Thomas G; Chmielarz, Pawel; Park, Sangwoo; Matyjaszewski, Krzysztof

    2015-02-01

    Elemental silver was used as a reducing agent in the atom transfer radical polymerization (ATRP) of acrylates. Silver wire, in conjunction with a CuBr(2)/TPMA catalyst, enabled the controlled, rapid preparation of polyacrylates with dispersity values down to Đ = 1.03. The silver wire in these reactions was reused several times in sequential reactions without a decline in performance, and the amount of copper catalyst used was reduced to 10 ppm without a large decrease in control. A poly(n-butyl acrylate)-block-poly(tert-butyl acrylate) diblock copolymer was synthesized with a molecular weight of 91 400 and Đ = 1.04, demonstrating good retention of chain-end functionality and a high degree of livingness in this ATRP system. PMID:25599253

  2. Physicochemical and electrochemical characterization of battery separator prepared by radiation induced grafting of acrylic acid onto microporous polypropylene membranes

    2009-05-01

    Full Text Available Mutual radiation grafting technique was used to graft acrylic acid on micrometer thick micro-porous polypropylene membrane using high-energy gamma radiation. Grafting could not be achieved in aqueous acrylic acid solution. The presence of Mohr’s salt effectively retarded the homopolymerization of acrylic acid but did not lead to grafting enhancement. Mohr’s salt in presence of acids was found to be effective in enhancing the grafting yield. Contact angle measurement studies of the grafted and radiation treated polypropylene showed that initial grafting as well as radiation treatment of poly(propylene in aqueous medium and in presence of Mohr’s salt enhances its affinity towards the grafting solution. The enhancement in the polar component of surface energy of treated polypropylene membrane is the primary cause of grafting enhancement. The membranes grafted to an extent of ~20% were found to perform comparably with the battery separator presently being used by battery industry.

  3. Poly(acrylic acid) to induce competitive crystallization of a theophylline/oxalic acid cocrystal and a theophylline polymorph

    Jang, Jisun; Kim, Il Won

    2016-01-01

    Polymeric additives to induce competitive crystallization of pharmaceutical compounds were explored. A cocrystal of theophylline and oxalic acid was used as a model system, and poly(acrylic acid), poly(caprolactone), and poly(ethylene glycol) were the additives. The cocrystal formation was selectively hindered with addition of poly(acrylic acid). First the size of the cocrystals were reduced, and eventually the cocrystallization was inhibited to generate neat theophylline crystals. The theophylline crystals were of a distinctively different crystal structure from known polymorphs, based on powder X-ray diffraction. They were also obtained in nanoscale size, when millimeter-scale crystals formed without poly(acrylic acid). Polymeric additives that could form specific interactions with crystallizing compounds seem to be useful tools for the phase and size control of pharmaceutical crystals.

  4. Perubahan warna lempeng resin akrilik yang direndam dalam larutan desinfektan sodium hipoklorit dan klorhexidin (The color changes of acrylic resins denture base material which are immersed in Sodium hypochlorite and chlorhexidine)

    David David; Elly Munadziroh

    2006-01-01

    One of the acrylic resins properties is the water absorption including color fluids and chemically fluids that affect on the color changes of the acrylic resins. This laboratory experiments studied sodium hypochlorite and chlorhexidine effect on the color changes of acrylic denture base resins material. The study was conducted by immersing heat cured acrylic plate samples of 26 mm of diameter and 0.4 mm of thickness in sodium hypochlorite for 10; 70 and 140 minutes and chlorhexidine for 15; 1...

  5. Perubahan suhu transisi kaca dan massa resin akrilik heat cured akibat kelembaban dan lama penyimpanan (Changes in glass transition temperature and heat cured acrylic resin mass due to moisture and storage time)

    Sherman Salim

    2014-01-01

    Background: Acrylic resins, especially poly methyl methacrylate (PMMA) was introduced in 1937. Acrylic resin has favorable properties, among others, aesthetic, color and texture similar to that of the gingival aesthetic in the mouth, relatively low water absorption and dimensional changes. However, some studies suggest that the duration of storage of acrylic resin will affect the changes in the glass transition temperature and the mass of acrylic resin. Purpose: The objective of this research...

  6. Acrylic and Methacrylic Acids Obtaining by Gas-Phase Aldol Condensation of Carbonyl Compounds on B2O3?P2O5?WO3?V2O5/SiO2 Catalysts

    Nebesnyi, Roman; Petelka, Oksana; Shpyrka, Iryna

    2013-01-01

    Prospects of acrylic acid obtaining by acetic acid aldol condensation with formaldehyde are considered. Complex oxide catalysts of the process have been developed. It is shown that raw materials costs in case of acrylic acid production by the condensation method are commeasurable with those in case of its production by oxidation method (main industrial method of acrylic acid production).This method of acrylic acid obtaining may be used as an alternative and enables diversifying the raw materi...

  7. Acrylate metathesis via the second-generation Grubbs catalyst: unexpected pathways enabled by a PCy3-generated enolate.

    Bailey, Gwendolyn A; Fogg, Deryn E

    2015-06-17

    The diverse applications of acrylate metathesis range from synthesis of high-value α,β-unsaturated esters to depolymerization of unsaturated polymers. Examined here are unexpected side reactions promoted by the important Grubbs catalyst GII. Evidence is presented for attack of PCy3 on the acrylate olefin to generate a reactive carbanion, which participates in multiple pathways, including further Michael addition, proton abstraction, and catalyst deactivation. Related chemistry may be anticipated whenever labile metal-phosphine complexes are used to catalyze reactions of substrates bearing an electron-deficient olefin. PMID:26030596

  8. Synthesis and characterization of organometallic copolymers of acrylic acid g-polyethylene, with Mo, Fe, Co, Zn and Ni

    In this study, the preparation of a series of low density polyethylenes grafted with acrylic acid is presented. The grafting reactions were initiated by different doses of γ radiation; it was observed that grafting increased with the doses of radiation. The prepared copolymers were coordinated with different metals, as Mo, Fe, Co, Zn and Ni. The amount of metal supported on the polymer was determined by atomic absorption. Infrared spectroscopy and thermogravimetric analysis confirmed the metal chelation on the graft copolymer. The film surfaces were observed by scanning electron microscopy. positron annihilation spectroscopy revealed a decrease on the free volume in the low density polyethylene after the grafting with acrylic acid. (Author)

  9. HYDROLYSIS TRANSFORMATION OF A POLYSTYRENE-b-POLY(tert-BUTYL ACRYLATE)COPOLYMER AND MICELLIZATION PROPERTIES OF THE HYDROLYZED COPOLYMER

    2001-01-01

    A very mild and extremely efficient hydrolysis method for transformation of polystyrene-b-poly(tert-butyl acrylate) (PS-b-PtBA) to polystyrene-b-poly(acrylic acid) (PS-b-PAA)was designed and carried out using more convenient and inexpensive chlorotrimethylsilane/sodium iodide as reagents. The hydrolysis product can self-assemble in aqueous media to give regular micelles with PS block forming the core and PAL4 block forming the corona, or in tetrahydrofuran (THF) to give reverse micelles with the hydrophilic block in the core.

  10. Novel Routes for the Design of Poly((meth)acrylic acid) Containing Polymer Structures by Controlled Radical Polymerization

    Van Camp, W

    2007-01-01

    Easy preparation of specialty polymers containing poly((meth)acrylic acid) Poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMAA) are well-known polymers in a high number of applications because of their pH-responsive nature, their hydrophylic characteristics and for their interaction with metal ions. PAA, high tech material An increasing part of high tech polymer materials introduce P(M)AA as segments in well-defined polymer structures. These can be block copolymers, polymer brushes, sta...

  11. Poly (acrylic acid sodium) grafted carboxymethyl cellulose as a high performance polymer binder for silicon anode in lithium ion batteries

    Liangming Wei; Changxin Chen; Zhongyu Hou; Hao Wei

    2016-01-01

    The design of novel binder systems is required for the high capacity silicon (Si) anodes which usually undergo huge volume change during the charge/discharge cycling. Here, we introduce a poly (acrylic acid sodium)-grafted-carboxymethyl cellulose (NaPAA-g-CMC) copolymer as an excellent binder for Si anode in lithium ion batteries (LIBs). The NaPAA-g-CMC copolymer was prepared via a free radical graft polymerization method by using CMC and acrylic acid as precursors. Unlike the linear, one-dim...

  12. Use of a continuous-flow microreactor for thiol-ene functionalization of RAFT-derived poly(butyl acrylate)

    Vandenbergh, Joke; Junkers, Thomas

    2012-01-01

    This study describes the synthesis of functionalized RAFT-derived poly(n-butyl acrylate) polymers via the use of a continuous-flow microreactor, in which aminolysis as well as thiol-ene reactions are executed in reaction times of just 20 minutes. Poly(n-butyl acrylate) (M-n = 3800 g mol(-1), PDI = 1.10) with a trithiocarbonate end group was prepared via a conventional RAFT process. The polymer was then functionalized via aminolysis/thiol-ene reactions in the micro-flow reactor with isobornyl ...

  13. Synthesis of Graft Copolymers Based on Poly(2‐Methoxyethyl Acrylate) and Investigation of the Associated Water Structure

    Javakhishvili, Irakli; Tanaka, Masaru; Ogura, Keiko; Jankova Atanasova, Katja; Hvilsted, Søren

    2012-01-01

    Graft copolymers composed of poly(2‐methoxyethyl acrylate) are prepared employing controlled radical polymerization techniques. Linear backbones bearing atom transfer radical polymerization (ATRP) initiating sites are obtained by reversible addition–fragmentation chain transfer copolymerization of...... 2‐methoxyethyl acrylate (MEA) and 2‐(bromoisobutyryloxy)ethyl methacrylate (BriBuEMA) as well as 2‐hydroxyethyl methacrylate and BriBuEMA in a controlled manner . MEA is then grafted from the linear macroinitiators by Cu (I)‐mediated ATRP. Fairly high molecular weights (>120 000 Da) and low...

  14. The pH-responsive behaviour of poly(acrylic acid) in aqueous solution is dependent on molar mass.

    Swift, T; Swanson, L.; Geoghegan, M; Rimmer, S.

    2016-01-01

    Fluorescence spectroscopy on a series of aqueous solutions of poly(acrylic acid) containing a luminescent label showed that polymers with molar mass, Mn < 16.5 kDa did not exhibit a pH responsive conformational change, which is typical of higher molar mass poly(acrylic acid). Below this molar mass, polymers remained in an extended conformation, regardless of pH. Above this molar mass, a pH-dependent conformational change was observed. Diffusion-ordered nuclear magnetic resonance spectroscopy ...

  15. Evaluation of shrinkage polymerization and temperature of different acrylic resins used to splinting transfer copings in indirect impression technique

    Franco, Ana Paula G. O.; Karam, Leandro Z.; Galvão, José R.; Kalinowski, Hypolito J.

    2015-09-01

    The aim of the present study was evaluate the shrinkage polymerization and temperature of different acrylic resins used to splinting transfer copings in indirect impression technique. Two implants were placed in an artificial bone, with the two transfer copings joined with dental floss and acrylic resins; two dental resins are used. Measurements of deformation and temperature were performed with Fiber Braggs grating sensor for 17 minutes. The results revealed that one type of resin shows greater values of polymerization shrinkage than the other. Pattern resins did not present lower values of shrinkage, as usually reported by the manufacturer.

  16. Biocompatible Metal-Oxide Nanoparticles: Nanotechnology Improvement of Conventional Prosthetic Acrylic Resins

    Nowadays, most products for dental restoration are produced from acrylic resins based on heat-cured Poly(Methyl Methacrylate) (PMMA). The addition of metal nanoparticles to organic materials is known to increase the surface hydrophobicity and to reduce adherence to biomolecules. This paper describes the use of nano structured materials, TiO2 and Fe2O3, for simultaneously coloring and/or improving the antimicrobial properties of PMMA resins. Nanoparticles of metal oxides were included during suspension polymerization to produce hybrid metal oxides-alginate-containing PMMA. Metal oxide nanoparticles were characterized by dynamic light scattering, and X-ray diffraction. Physicochemical characterization of synthesized resins was assessed by a combination of spectroscopy, scanning electron microscopy, viscometry, porosity, and mechanical tests. Adherence of Candida albicans cells and cellular compatibility assays were performed to explore biocompatibility and microbial adhesion of standard and novel materials. Our results show that introduction of biocompatible metal nanoparticles is a suitable means for the improvement of conventional acrylic dental resins.

  17. A Hydrogen Ion-Selective Sensor Based on Non-Plasticised Methacrylic-acrylic Membranes

    Musa Ahmad

    2002-08-01

    Full Text Available A methacrylic-acrylic polymer was synthesised for use as a non-plasticised membrane for hydrogen ion-selective sensor incorporating tridodecylamine as an ionophore. The copolymer consisted of methyl methacrylate and n-butyl acrylate monomers in a ratio of 2:8. Characterisation of the copolymer using FTNMR demonstrated that the amount of each monomer incorporated during solution polymerisation was found to be similar to the amount used in the feed before polymerisation. The glass transition temperature of the copolymer determined by differential scanning calorimetry was -30.9 ºC. Potentiometric measurements conducted showed a linear pH response range of 4.3 – 9.6 with the response slope of 56.7 mV/decade. The selectivity of the sensors towards hydrogen ions was similar to other plasticiser based membrane electrodes and the logarithmic selectivity coefficients for discrimination against interference cations is close to –9.7. However, the incorporation of a lipophilic anion as membrane additive is essential in ensuring optimum performance of the hydrogen ion sensor.

  18. Spectroscopic and density functional theory studies of trans-3-(trans-4-imidazolyl)acrylic acid

    Arjunan, V.; Remya, P.; Sathish, U.; Rani, T.; Mohan, S.

    2014-08-01

    The structural parameters, thermodynamic properties and vibrational frequencies of the optimised geometry of trans-3-(trans-4-imidazolyl)acrylic acid have been determined from B3LYP methods with 6-311++G** and cc-pVTZ basis sets. The effects of substituents (acrylyl group) on the imidazole vibrational frequencies are analysed. The vibrational frequencies of the fundamental modes of trans-3-(trans-4-imidazolyl)acrylic acid have been precisely assigned and analysed and the theoretical results are compared with the experimental vibrations. 1H and 13C NMR isotropic chemical shifts are calculated and the assignments made are compared with the experimental values. The energies of important MO’s of the compound are also determined from DFT method. The total electron density and electrostatic potential of the compound are determined by natural bond orbital analysis. Various reactivity and selectivity descriptors such as chemical hardness, chemical potential, softness, electrophilicity, nucleophilicity and the appropriate local quantities employing natural population analysis (NPA) are calculated.

  19. Synthesis and characterization of super absorbent poly (acrylamide-co-potassium acrylate) hydrogels by radiation technique

    A series of super absorbent hydrogels were prepared from acrylamide (AAm) and potassium acrylate (KA) by gamma irradiation technique at room temperature. The solution containing potassium acrylate 15% and different concentrations of AAm (10-16%) were irradiated by gamma rays (20-40 kGy). The hydrogels produced by irradiation were characterized by fourier transform infra red spectroscopy (FT-IR). The gel fraction, kinetics of swelling and the equilibrium degree of swelling (EDS) were studied. Under irradiation dose of 20 kGy and concentration of AAM 10 %), poly(AAm-co-KA) hydrogel with high gel fraction (99.08%) and very high EDS (420 g/g) were obtained. The capacity of hydrogel to adsorb metal ion Cu2+and Fe3+were investigated. It is shown than 10 minutes the hydrogel could adsorb Cu2+ ion up to 95 %, and Fe3+ ion up to 55 % in 80 minutes. This hydrogel has a potential to be used for soil conditioning and ion metal absorbent. (author)

  20. Impact of Acrylic Acid on ASP Flooding Performance: Interfacial Tension Behaviour

    Shuaib Ahmed Kalwar

    2014-01-01

    Full Text Available In chemical EOR, interfacial tension plays one of the important roles in carbonate reservoirs. Carbonate reservoirs are composed of calcium and magnesium minerals which affect the performance of alkali and surfactants to reduce interfacial tension. In this study, acrylic acid was used to inhibit precipitation and to create a compatible solution without any precipitations. The impact of acrylic acid on interfacial tension was investigated using various inhibitor concentrations with a hard brine composition of 59, 940 TDS. Sodium metaborate, alpha olefin sulfonate and internal olefin sulfonate were screened as promising chemicals for interfacial tension. Various fluid-fluid compatibility tests were first performed to find the optimum acid-alkali ratio to prevent any precipitations. The optimum acid-alkali ratio was found to be 0.6:1.0. This ratio was then used to keep all solution without any precipitations for 30 days at 80°C. It was also observed that the increase in acid-alkali concentrations can significantly reduce the interfacial tension. Using the optimum concentration for acid, alkali and surfactant, the interfacial tension reduced from 14.9-0.401 mN m-1.

  1. A Biosensor for Urea from Succinimide-Modified Acrylic Microspheres Based on Reflectance Transduction

    Musa Ahmad

    2011-08-01

    Full Text Available New acrylic microspheres were synthesised by photopolymerisation where the succinimide functional group was incorporated during the microsphere preparation. An optical biosensor for urea based on reflectance transduction with a large linear response range to urea was successfully developed using this material. The biosensor utilized succinimide-modified acrylic microspheres immobilized with a Nile blue chromoionophore (ETH 5294 for optical detection and urease enzyme was immobilized on the surface of the microspheres via the succinimide groups. No leaching of the enzyme or chromoionophore was observed. Hydrolysis of the urea by urease changes the pH and leads to a color change of the immobilized chromoionophore. When the color change was monitored by reflectance spectrophotometry, the linear response range of the biosensor to urea was from 0.01 to 1,000 mM (R2 = 0.97 with a limit of detection of 9.97 mM. The biosensor response showed good reproducibility (relative standard deviation = 1.43%, n = 5 with no interference by major cations such as Na+, K+, NH4+ and Mg2+. The use of reflectance as a transduction method led to a large linear response range that is better than that of many urea biosensors based on other optical transduction methods.

  2. Influencing solvent miscibility and aqueous stability of aluminum nanoparticles through surface functionalization with acrylic monomers.

    Crouse, Christopher A; Pierce, Christian J; Spowart, Jonathan E

    2010-09-01

    With growing interest in the development of new composite systems for a variety of applications that require easily processable materials and adequate structural properties with high energy densities, we have pursued the chemical functionalization of oxide-passivated aluminum nanoparticles (nAl) using three acrylic monomers, 3-methacryloxypropyltrimethoxysilane (MPS), 2-carboxyethyl acrylate (CEA), and phosphonic acid 2-hydroxyethyl methacrylate ester (PAM), to provide chemical compatibility within various solvent and polymeric systems. Fourier transform infrared and X-ray photoelectron spectroscopy suggest that attachment of MPS and PAM monomers occurs through the formation of bonds directly to the passivated oxide surface upon reaction with surface hydroxyls, whereas CEA monomers interact through the formation of ionic carboxylate binding to aluminum atoms within the oxide. The coated particles demonstrate enhanced miscibility in common organic solvents and monomers; MPS and PAM coatings are additionally shown to inhibit oxidation of the aluminum particles when exposed to aqueous environments at room temperature, and PAM coatings are stable at even elevated temperatures. PMID:20795650

  3. Microbubble enhanced ozonation process for advanced treatment of wastewater produced in acrylic fiber manufacturing industry

    Zheng, Tianlong

    2015-02-02

    This work investigated microbubble-ozonation for the treatment of a refractory wet-spun acrylic fiber wastewater in comparison to macrobubble-ozonation. CODcr, NH3-N, and UV254 of the wastewater were removed by 42%, 21%, and 42%, respectively in the microbubble-ozonation, being 25%, 9%, and 35% higher than the removal rates achieved by macrobubble-ozonation at the same ozone dose. The microbubbles (with average diameter of 45μm) had a high concentration of 3.9×105 counts/mL at a gas flow rate of 0.5L/min. The gas holdup, total ozone mass-transfer coefficient, and average ozone utilization efficiency in the microbubble-ozonation were 6.6, 2.2, and 1.5 times higher than those of the macrobubble-ozonation. Greater generation of hydroxyl radicals and a higher zeta potential of the bubbles were also observed in the microbubble ozonation process. The biodegradability of the wastewater was also significantly improved by microbubble-ozonation, which was ascribed to the enhanced degradation of alkanes, aromatic compounds, and the many other bio-refractory organic compounds in the wastewater. Microbubble-ozonation can thus be a more effective treatment process than traditional macrobubble-ozonation for refractory wastewater produced by the acrylic fiber manufacturing industry.

  4. 4D printing smart biomedical scaffolds with novel soybean oil epoxidized acrylate.

    Miao, Shida; Zhu, Wei; Castro, Nathan J; Nowicki, Margaret; Zhou, Xuan; Cui, Haitao; Fisher, John P; Zhang, Lijie Grace

    2016-01-01

    Photocurable, biocompatible liquid resins are highly desired for 3D stereolithography based bioprinting. Here we solidified a novel renewable soybean oil epoxidized acrylate, using a 3D laser printing technique, into smart and highly biocompatible scaffolds capable of supporting growth of multipotent human bone marrow mesenchymal stem cells (hMSCs). Porous scaffolds were readily fabricated by simply adjusting the printer infill density; superficial structures of the polymerized soybean oil epoxidized acrylate were significantly affected by laser frequency and printing speed. Shape memory tests confirmed that the scaffold fixed a temporary shape at -18 °C and fully recovered its original shape at human body temperature (37 °C), which indicated the great potential for 4D printing applications. Cytotoxicity analysis proved that the printed scaffolds had significant higher hMSC adhesion and proliferation than traditional polyethylene glycol diacrylate (PEGDA), and had no statistical difference from poly lactic acid (PLA) and polycaprolactone (PCL). This research is believed to significantly advance the development of biomedical scaffolds with renewable plant oils and advanced 3D fabrication techniques. PMID:27251982

  5. Antimicrobial and Thermal Properties of Metal Complexes of Grafted Fabrics with Acrylic Acid by Gamma Irradiation

    Cotton, cotton/PET blend and PET fabrics were treated against microbial effect by radiation - induced grafting of acrylic acid followed by metal complexation with some divalent transition metal ions Co (II), Ni (II) and Cu (II). The microbial resistance was evaluated by testing the mechanical properties of the treated fabrics after burring for one and two weeks in a moist soil reach with microorganisms. Also, the growth of microorganisms was examined by scanning electron microscope (SEM). Moreover, the effect of this treatment on the thermal decomposition behavior was investigated by thermogravimetric analysis (TGA). On the basis of microbial studies, it was found that the metal complexation of the grafted fabrics with acrylic acid enhanced the antimicrobial resistance of the fabrics and the antimicrobial resistance could be arranged according to the metal ions as follows: copper> nickel> cobalt. Also, the thermal stability of different fabrics could be arranged as follow: grafted fabrics complexed with Cu (II) > grafted fabrics complexed with Ni (II) > grafted fabrics complexed with Co (II)

  6. Surface and interfacial properties of PVDF/acrylic copolymer blends before and after UV exposure

    Morphological and chemical properties of both the surface and interface of poly(vinylidene fluoride)/poly(methyl methacrylate)-co-poly(ethyl acrylate) (PVDF/PMMA-co-PEA) blend films have been investigated before and after the samples were exposed to ultraviolet (UV) irradiation using a xenon arc lamp at 50 deg. Cand 9% relative humidity (RH) for 7 months. Surface and interfacial morphologies were studied by atomic force microscopy (AFM). Chemical composition information was obtained by confocal Raman microscopy, attenuated total reflection-FTIR spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and contact angle measurements. Results show an enrichment of the PVDF material at the air surface, while the acrylic copolymer enriches the interface. Blends having greater than 50% mass fraction of PVDF show little change in the surface morphology after UV exposure for 7 months. However, for a lower PVDF content, blends exhibit significant degradation of PMMA-co-PEA copolymer and a much rougher surface after UV exposure. Microstructural changes in the PVDF spherulites are also observed after UV degradation. It is found that the surface and interfacial morphologies are correlated with the chemical properties

  7. Synthesis and properties of collagen-g-poly(sodium acrylate-co-2-hydroxyethylacrylate superabsorbent hydrogels

    M. Sadeghi

    2013-06-01

    Full Text Available Novel biopolymer-based superabsorbent hydrogels were prepared by grafting crosslinked poly(acrylic acid-co-2-hydroxyethyl acrylate (PAA-co-PHEA chains onto collagen backbones through a free radical polymerization method. The graft copolymerization reaction was carried out in a homogeneous medium and in the presence of ammonium persulfate (APS as initiator and N,N '-methylene bisacrylamide (MBA as crosslinker. A proposed mechanism for collagen-g-(PAA-co-PHEA formation was suggested and the hydrogel structure was confirmed using FTIR spectroscopy and TGA thermal analysis. Moreover, the morphology of the samples was examined by scanning electron microscopy (SEM. The effect of concentration of MBA as well as AA/HEA weight ratio on the swelling capacity of the hydrogel was also studied. Furthermore, the water absorbency of hydrogels was measured in solutions with pH ranging 1 to 13. The collagen-based hydrogel exhibited a pH-responsive character, so that a swelling-deswelling pulsatile behavior was recorded at pHs 2 and 8. Preliminary swelling and deswelling behaviors of the hydrogels were also studied. Additionally, the hydrogels exhibited salt-sensitivity and cation exchange properties.

  8. Controlled release of anti-diabetic drug Gliclazide from poly(caprolactone)/poly(acrylic acid) hydrogels.

    Bajpai, S K; Chand, Navin; Soni, Shweta

    2015-01-01

    Drug Gliclazide (Glz) has limited solubility and low bioavailability. In order to obtain a controlled release of this drug and to improve its bioavailability, the drug has been loaded into poly(caprolactone) (PCL)/poly(acrylic acid) (PAAc) hydrogels, prepared by free radical polymerization of acrylic acid in the presence of poly(caprolactone) in acetone medium using azo-isobutyronitrile as initiator and N,N' methylene bisacrylamide as cross-linking agent. The swelling behaviour of these hydrogels has been investigated in the physiological gastric and intestinal fluids to obtain an optimum composition suitable for delivery of a biologically active compound. The gels were loaded with anti-diabetic drug Glz and a detailed investigation of release of drug has been carried out. Various kinetic models have been applied on the release data. Finally, the Albino wistar rats were treated for Streptozotocin plus nicotinamide - induced diabetes using a Glz-loaded PCL/PAAc hydrogel. The results indicated a fair reduction in the glucose level of rats. PMID:26135033

  9. Clinical properties of a novel, glistening-free, single-piece, hydrophobic acrylic IOL

    Packer M

    2014-02-01

    Full Text Available Mark Packer,1 Mohan Rajan,2 Edoardo Ligabue,3 Peter Heiner4 1Oregon Health and Science University, Portland, OR, USA; 2Rajan Eye Care Hospital Pvt Ltd, Chennai, India; 3Ophthalmology Department, Centro Diagnostico Italiano, Milan, Italy; 4Bond University Medical School, Robina, QLD, Australia Abstract: A new, single-piece, hydrophobic acrylic lens – the first constructed with a lens optic and haptics comprised of a hydroxyethyl methacrylate-polyethylene glycol phenyl ether acrylate–styrene copolymer, cross-linked with ethylene glycol dimethacrylate, and labeled as "glistening-free" – was recently introduced globally. Glistenings have been a significant source of clinical concern with previous hydrophobic lens designs. This new monofocal lens provides enhanced, clear optics for lens-based surgery. The superior optical clarity of this lens is achieved through the elimination of glistenings, enhanced surface durability, high refractive index, a high Abbe number, and an aspheric design. Additionally, the lens design reduces the risk of developing posterior capsule opacification. Keywords: glistenings, monofocal hydrophobic acrylic, IOL, aspheric

  10. Use of acrylic acid in the synthesis of molecularly imprinted polymers for the analysis of cyproheptadine

    The synthesis and comparative characterization of molecularly imprinted polymers (MIPs) with cyproheptadine (CYP), using two different monomers, acrylic acid (AA) and methacrylic acid (MAA), are described. Polyacids (PA) [poly(methacrylic acid) (PMAA) and poly(acrylic acid) (PAA)] were obtained by the radical polymerization of MAA and AA, respectively, in dichloromethane as the porogen solvent-imprinted medium. The non-covalent imprinting process was performed via thermal decomposition of an azo-initiator at 60 deg. C, using ethylene glycol dimethacrylate as the cross-linker and 2,2'-azobis(2-methylpropionitrile) as the initiator. The selectivities of MIPs and NIPs particles were evaluated in binding experiments of the four synthesized polymeric materials (MIPaa, MIPmaa, NIPmaa and NIPaa) with CYP. The effects of monomers on: a) the surface morphology, b) the binding capacity and c) the swelling properties of imprinted and non-imprinted polymers were studied and are presented here. Polymer material morphology was assessed with scanning electron microscopy (SEM). This revealed differences in monomer function, depending on which one was employed, as well as differences in function when polymerization occurred in the presence of template or without it. Non-specific retention of the template to NIPs was higher for NIPs-PAA polymers than for NIPs-PMAA materials. In terms of specific binding (ΔQ = QMIP - QNIP), MIPmaa showed the greatest value (53.47%) in comparison with MIPaa (50.07%)

  11. Radiation synthesis of chitosan beads grafted with acrylic acid for metal ions sorption

    Benamer, S., E-mail: benamers@yahoo.fr [Division of Nuclear Applications, Centre de Recherche Nucleaire d' Alger, BP-399 Alger-Gare (Algeria); Mahlous, M.; Tahtat, D.; Nacer-Khodja, A.; Arabi, M. [Division of Nuclear Applications, Centre de Recherche Nucleaire d' Alger, BP-399 Alger-Gare (Algeria); Lounici, H.; Mameri, N. [Ecole Nationale Polytechnique d' El-Harrach Alger (Algeria)

    2011-12-15

    Radiation-induced grafting of acrylic acid onto chitosan beads was performed in solution at a dose rate of 20.6 Gy/min of cobalt-60 gamma rays. The effect of absorbed dose on grafting yield was investigated. The characterization of the grafted material was performed by FTIR spectroscopy and the swelling measurements at different pHs. The grafting yield increased with the increase in dose, it reached 80% at 40 kGy irradiation dose. The removal of Pb and Cd ions from aqueous solutions was investigated with both ungrafted and grafted chitosan beads. The sorption behavior of the sorbents was examined through pH, kinetics and equilibrium measurements. Grafted chitosan beads presented higher sorption capacity for both metal ions than unmodified chitosan beads. - Highlights: > Pb and Cd ions are removed from aqueous solution by adsorption on chitosan beads. > Crosslinking process improves chemical stability of chitosan beads. > Radiation grafting of acrylic acid onto chitosan improves its metal adsorption capacity. > Increase in grafting degree enhances the adsorption capacity of the material. > Gamma radiation is a powerful tool for an accurate control of the grafting yield.

  12. Detection of Defects in Acrylic and Steel Inclusions in Gypsum Using Compton Backscattered Gamma Rays

    Boldo, Emerson M.; Appoloni, Carlos R.

    2011-08-01

    Compton scattering of gamma radiation is a nondestructive technique used for the detection of defects and inclusions in materials. The methodology allows one-side inspection of large structures, is relatively inexpensive and can be portable. The number of photons inelastically scattered within a well-defined volume element is linearly proportional to the electron density of the material. Targeting a sample with a collimated beam of gamma rays, the energy spectrum of backscattered photons can be used to determine local density perturbations. In this work we used the Compton backscattering technique to detection of small collinear defects in acrylic blocks and steel rods inclusions in gypsum blocks samples. The samples were irradiated with gamma rays from a O/2 mm collimated 241Am (100 mCi) source and the inelastically scattered photons were collected at an angle of 135° by a CdTe detector with a O/7 mm×30 mm collimation. Scanning was achieved by lateral movement of the sample blocks across the source and detector field of view in steps of 1 mm. The results showed that defects in the acrylic samples as small as 3 mm in size were visible in the intensity versus energy spectrum. The tests on gypsum blocks with steel rods inclusions suggest that, for a low energy and activity source, the effects of beam attenuation are more decisive to the scattered intensity than increasing of material density. An analysis of the density contrast is also presented.

  13. Characterization of bioactive RGD peptide immobilized onto poly(acrylic acid) thin films by plasma polymerization

    Seo, Hyun Suk; Ko, Yeong Mu; Shim, Jae Won [Department of Dental Materials, School of Dentistry, MRC Center, Chosun University, Gwangju (Korea, Republic of); Lim, Yun Kyong; Kook, Joong-Ki [Department of Oral Biochemistry, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Cho, Dong-Lyun [School of Applied Chemical Engineering and Center for Functional Nano Fine Chemicals, Chonnam National University, Gwangju (Korea, Republic of); Kim, Byung Hoon, E-mail: kim5055@chosun.ac.kr [Department of Dental Materials, School of Dentistry, MRC Center, Chosun University, Gwangju (Korea, Republic of)

    2010-11-01

    Plasma surface modification can be used to improve the surface properties of commercial pure Ti by creating functional groups to produce bioactive materials with different surface topography. In this study, a titanium surface was modified with acrylic acid (AA) using a plasma treatment and immobilized with bioactive arginine-glycine-aspartic acid (RGD) peptide, which may accelerate the tissue integration of bone implants. Both terminals containing the -NH{sub 2} of RGD peptide sequence and -COOH of poly(acrylic acid) (PAA) thin film were combined with a covalent bond in the presence of 1-ethyl-3-3-dimethylaminopropyl carbodiimide (EDC). The chemical structure and morphology of AA film and RGD immobilized surface were investigated by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR), atomic force microscopy (AFM), and scanning electron microscopy (SEM). All chemical analysis showed full coverage of the Ti substrate with the PAA thin film containing COOH groups and the RGD peptide. The MC3T3-E1 cells were cultured on each specimen, and the cell alkaline phosphatase (ALP) activity were examined. The surface-immobilized RGD peptide has a significantly increased the ALP activity of MC3T3-E1 cells. These results suggest that the RGD peptide immobilization on the titanium surface has an effect on osteoblastic differentiation of MC3T3-E1 cells and potential use in osteo-conductive bone implants.

  14. Characterization of bioactive RGD peptide immobilized onto poly(acrylic acid) thin films by plasma polymerization

    Plasma surface modification can be used to improve the surface properties of commercial pure Ti by creating functional groups to produce bioactive materials with different surface topography. In this study, a titanium surface was modified with acrylic acid (AA) using a plasma treatment and immobilized with bioactive arginine-glycine-aspartic acid (RGD) peptide, which may accelerate the tissue integration of bone implants. Both terminals containing the -NH2 of RGD peptide sequence and -COOH of poly(acrylic acid) (PAA) thin film were combined with a covalent bond in the presence of 1-ethyl-3-3-dimethylaminopropyl carbodiimide (EDC). The chemical structure and morphology of AA film and RGD immobilized surface were investigated by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR), atomic force microscopy (AFM), and scanning electron microscopy (SEM). All chemical analysis showed full coverage of the Ti substrate with the PAA thin film containing COOH groups and the RGD peptide. The MC3T3-E1 cells were cultured on each specimen, and the cell alkaline phosphatase (ALP) activity were examined. The surface-immobilized RGD peptide has a significantly increased the ALP activity of MC3T3-E1 cells. These results suggest that the RGD peptide immobilization on the titanium surface has an effect on osteoblastic differentiation of MC3T3-E1 cells and potential use in osteo-conductive bone implants.

  15. Synthesis of ion exchange membrane by radiation grafting of acrylic acid onto polyethylene

    Radiation grafting of vinyl monomers onto polymer films has been extensively studied by many workers. In the preirradiation method of grafting a polymer substrate is activated by irradiation (either in the presence or absence of oxygen) and subsequently allowed to react with a monomer. The preirradiation method was utilized in this study to synthesize an ion exchange membrane useful for a battery separator by grafting acrylic acid onto polyethylene film. The battery separator should be chemically and thermally stable, sufficiently durable in electrolyte as well as highly electrically conductive. Membranes made from regenerated cellulose, e.g., cellophane, have long been used as a separator in the batteries with alkaline electrolyte, such as silver oxide primary cell. However, it has poor durability, as short as one year, due to breakdown of the membrane during operation or storing. The acrylic acid-grafted polyethylene film was found to be quite useful for a separator in the alkaline batteries. This membrane has a high electric conductivity and an excellent durability. (author)

  16. Multi-walled carbon nanotubes/polymer composites in absence and presence of acrylic elastomer (ACM).

    Kumar, S; Rath, T; Mahaling, R N; Mukherjee, M; Khatua, B B; Das, C K

    2009-05-01

    Polyetherimide/Multiwall carbon nanotube (MWNTs) nanocomposites containing as-received and modified (COOH-MWNT) carbon nanotubes were prepared through melt process in extruder and then compression molded. Thermal properties of the composites were characterized by thermo-gravimetric analysis (TGA). Field emission scanning electron microscopy (FESEM) images showed that the MWNTs were well dispersed and formed an intimate contact with the polymer matrix without any agglomeration. However the incorporation of modified carbon nanotubes formed fascinating, highly crosslinked, and compact network structure throughout the polymer matrix. This showed the increased adhesion of PEI with modified MWNTs. Scanning electron microscopy (SEM) also showed high degree of dispersion of modified MWNTs along with broken ends. Dynamic mechanical analysis (DMA) results showed a marginal increase in storage modulus (E') and glass transition temperature (T(g)) with the addition of MWNTs. Increase in tensile strength and impact strength of composites confirmed the use the MWNTs as possible reinforcement agent. Both thermal and electrical conductivity of composites increased, but effect is more pronounced on modification due to formation of network of carbon nanotubes. Addition of acrylic elastomer to developed PEI/MWNTs (modified) nanocomposites resulted in the further increase in thermal and electrical properties due to the formation of additional bond between MWNTs and acrylic elastomers at the interface. All the results presented are well corroborated by SEM and FESEM studies. PMID:19452959

  17. Development of UV Curable Overprint Varnishes (OPV) Formulation from Epoxidized Palm Olein Acrylated (EPOLA)

    The synthesis procedure of Epoxidized Palm Olein Acrylated (EPOLA) has been established by Radiation Curing and Synthesis Group. The quality control test such as acid value, oxirane oxygen content and Fourier- Transform Infra Red (FTIR) were done to monitor the synthesis process. The completion of synthesis process was observed via FTIR with the presence of hydroxyl (-OH) absorption between 3440-3480 cm-1 and an absorption of acrylate groups at 819 cm-1. The EPOLA was then coated on glass plate and irradiated with UV light. It was found that EPOLA is curable under exposure of UV light and has potential in the application of Overprint Varnishes (OPV). Several formulations have been developed which basically consist of oligomer, monomer, photo initiator EPOLA and additives. The formulations were then coated on black and white paper and irradiated under UV light. The speed of the conveyer was set at 5 m/ min and 20 m/ min during irradiation and the number of passes for the coated substrate to be cured is recorded. The physical characterization such as adhesion and curing rate were observed compared with desirable finished products. (author)

  18. Enhancing dry adhesives and replica molding with ethyl cyano-acrylate

    The use of cyano-acrylate to improve the performance of dry adhesives and their method of fabrication is investigated. Specifically, the contributions of this work are: (1) a new adhesion method to adhere to a large variety of surfaces, (2) a strategy to increase the compliance of dry adhesives, and (3) an improved fabrication process for micro-structured dry adhesives based on replica molding. For the first contribution, the adhesion method consists of anchoring a micro-structured dry adhesive to a surface through a layer of hardened ethyl cyano-acrylate (ECA). This method increases the adhesion of the orders of magnitude at the expense of leaving residue after detachment. However, this method preserves reusability. For the second contribution, a double-sided dry adhesive is obtained by introducing a substrate with a millimeter-sized pillar structure, which enabled further increasing adhesion. For the third contribution, an ECA layer is used as a mold for the fabrication of new adhesives. These new types of molds proved able to produce dry adhesives with high reproducibility and low degradation. (paper)

  19. Effect of ionizing radiation on properties of acrylic pressure sensitive adhesives

    Pressure-sensitive adhesives for technical application are widely produced. The biological properties of adhesives depend on the type of monomers used. The available literature data as experience of the authors of this study in the area of pressure-sensitive acrylic adhesive, polymers used in medicine, polymerisation in aqueous media, radiation sterilization, permit to make an assumption that it is possible to elaborate the technology of production of pressure-sensitive adhesives in aqueous emulsion for medical applications. Identification of phenomena influencing the adhesive properties, especially its adhesion, cohesion, tack and durability is of great importance. The control of polymer structure is performed by means of adequate selection of conditions of synthesis and parameters of radiation processing. The authors investigate the influence on the final products of such factors as the type and amount of monomers used, their mutual ratio, as well as the ratio monomers and the dose of ionising radiation. There is no available literature information concerning the investigation of resistance of acrylic emulsion adhesive to sterilisation by electron beam. It is known from unpublished research that some adhesives are resistant to radiation, while others undergo destruction. It probably depends on the composition of emulsion, specifically on the additives which modify adhesives. Simultaneous achievement of good cohesion and adhesion in the case of such types of pressure sensitive adhesives is very difficult pressure sensitive adhesives is very difficult

  20. The Effect of Reactives Diluents to the Physical Properties of Acrylated Palm Oil Based Polyurethane Coatings

    Onn Munirah

    2016-01-01

    Full Text Available The development of polyurethane with hydroxyl access in a molecule leads to a new alternative of low toxicity green product. Palm oil is one of the major commodities in Malaysia. The potential of palm oil to be used as coatings raw material such as alkyd is limited due to low unsaturated side on fatty acid chains. To overcome this limitation, palm oil was modified through transesterification process to produce polyol. Acrylated isocyanate (urethane oligomer was then grafted onto polyol to produce polyurethane with vinylic ends. The polyurethane was formulated with different cross-linkers (reactive diluents and cured under UV radiation. The effect of three different diluents; monoacrylate, diacrylate and triacrylate on the properties of cured polymer were studied in this research. Fourier Transform Infrared (FTIR, Hydroxyl Value Titration, Gel Content, and Volatile Organic Compound (VOC were used for characterization. Physical testing performed were Pencil Hardness and Pull-Off Adhesion test. Novel palm oil-based polyurethane coatings have been found to have good properties with mono acrylate functionality.

  1. Radiation synthesis of chitosan beads grafted with acrylic acid for metal ions sorption

    Radiation-induced grafting of acrylic acid onto chitosan beads was performed in solution at a dose rate of 20.6 Gy/min of cobalt-60 gamma rays. The effect of absorbed dose on grafting yield was investigated. The characterization of the grafted material was performed by FTIR spectroscopy and the swelling measurements at different pHs. The grafting yield increased with the increase in dose, it reached 80% at 40 kGy irradiation dose. The removal of Pb and Cd ions from aqueous solutions was investigated with both ungrafted and grafted chitosan beads. The sorption behavior of the sorbents was examined through pH, kinetics and equilibrium measurements. Grafted chitosan beads presented higher sorption capacity for both metal ions than unmodified chitosan beads. - Highlights: → Pb and Cd ions are removed from aqueous solution by adsorption on chitosan beads. → Crosslinking process improves chemical stability of chitosan beads. → Radiation grafting of acrylic acid onto chitosan improves its metal adsorption capacity. → Increase in grafting degree enhances the adsorption capacity of the material. → Gamma radiation is a powerful tool for an accurate control of the grafting yield.

  2. Characterization of bioactive RGD peptide immobilized onto poly(acrylic acid) thin films by plasma polymerization

    Seo, Hyun Suk; Ko, Yeong Mu; Shim, Jae Won; Lim, Yun Kyong; Kook, Joong-Ki; Cho, Dong-Lyun; Kim, Byung Hoon

    2010-11-01

    Plasma surface modification can be used to improve the surface properties of commercial pure Ti by creating functional groups to produce bioactive materials with different surface topography. In this study, a titanium surface was modified with acrylic acid (AA) using a plasma treatment and immobilized with bioactive arginine-glycine-aspartic acid (RGD) peptide, which may accelerate the tissue integration of bone implants. Both terminals containing the -NH2 of RGD peptide sequence and -COOH of poly(acrylic acid) (PAA) thin film were combined with a covalent bond in the presence of 1-ethyl-3-3-dimethylaminopropyl carbodiimide (EDC). The chemical structure and morphology of AA film and RGD immobilized surface were investigated by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR), atomic force microscopy (AFM), and scanning electron microscopy (SEM). All chemical analysis showed full coverage of the Ti substrate with the PAA thin film containing COOH groups and the RGD peptide. The MC3T3-E1 cells were cultured on each specimen, and the cell alkaline phosphatase (ALP) activity were examined. The surface-immobilized RGD peptide has a significantly increased the ALP activity of MC3T3-E1 cells. These results suggest that the RGD peptide immobilization on the titanium surface has an effect on osteoblastic differentiation of MC3T3-E1 cells and potential use in osteo-conductive bone implants.

  3. Preparation of metal adsorbent from poly(methyl acrylate)-grafted-cassava starch via gamma irradiation

    Metal adsorbent containing hydroxamic acid groups was successfully synthesized by radiation-induced graft copolymerization of methyl acrylate (MA) onto cassava starch. The optimum conditions for grafting were studied in terms of % degree of grafting (Dg). Conversion of the ester groups present in poly(methyl acrylate)-grafted-cassava starch copolymer into hydroxamic acid was carried out by treatment with hydroxylamine (HA) in the presence of alkaline solution. The maximum percentage conversion of the ester groups of the grafted copolymer, % Dg=191 (7.63 mmol/g of MA), into the hydroxamic groups was 70% (5.35 mmol/g of MA) at the optimum condition. The adsorbent of 191%Dg had total adsorption capacities of 2.6, 1.46, 1.36, 1.15 and 1.6 mmol/g-adsorbent for Cd2+, Al3+, UO22+, V5+ and Pb2+, respectively, in the batch mode adsorption. - Highlights: ► Adsorbent containing hydroxamic acid group was prepared by radiation-induced grafting. ► The adsorbent exhibited a remarkable % adsorption for Cd2+, Al3+, UO22+, V5+ and Pb2+. ► The selectivity of adsorbent towards metal ions used is in this order: Cd2+>Pb2+> Al3+> UO22+ > V5+.

  4. Protein absorption and fouling on poly(acrylic acid)-graft-polypropylene microfiltration membrane

    Liu, Yanjun; Ma, Huiying; Lv, Chunying; Yang, Jia; Fu, Xueqi

    2009-07-01

    A series of pH-sensitive poly (acrylic acid)-graft-polypropylene hollow fiber microfiltration membranes were prepared by UV-photo-irradiation. Bovine serum albumin (BSA) was chosen as the model protein to investigate its absorption and fouling behaviors on membranes. The results showed that the hydrophilicity of grafted membrane was improved by poly(acrylic acid) chains with parts of membrane pores blocked. The grafted membranes were markedly pH-dependent on the water permeability as pH was altered from 1 to 11. The zeta potential of grafted membranes calculated by streaming potential was negative in most pH range. Electrostatic interaction energy calculated by DLVO theory showed the electric interaction force between grafted membrane and BSA was attractive. With the rise of grafting degree, the electric attractive force between grafted membrane and BSA increased as pH=3 and decreased as pH=8, while it kept basically unchanged as pH=4.7. As a result, most serious fouling was observed as pH=4.7. Grafted membranes had a lower BSA absorption and better antifouling behavior as pH=8, while the opposite result was revealed as pH=3. In conclusion, the absorption and fouling behavior of BSA on membranes was pH-dependent due to the pH-dependence of membrane charge, and the conformation of BSA and grafting chains.

  5. Investigation of small molecular weight poly(acrylic acid) adsorption on γ-alumina

    Liu, Lei; Luo, Shi-Zhong [College of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065 (China); Wang, Bin, E-mail: bin_wang@scu.edu.cn [College of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065 (China); Guo, ZhanHu [Chemical and Biomolecular Engineering Department, University of Tennessee, Knoxville, TN 37996 (United States)

    2015-08-01

    Highlights: • Small molecular weight poly(acrylic acid) incorporated on γ-alumina. • PAA adsorbed primarily on outer surface of alumina at low pH. • PAA infiltrated inside alumina pore at high pH. • Polymer chain reptation motion during the infiltration. - Abstract: The interactions between poly(acrylic acid) (PAA) and alumina have been widely investigated. In this study, the pattern of small molecular weight PAA (M{sub W} 3000) interaction with γ-alumina has been dissected. The alumina/PAA hybrids were prepared at pH 4.0, 5.5, and 7.0, respectively. Nitrogen absorption–desorption analysis, Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and elemental analysis were conducted to illustrate the characteristics of the hybrids. At pH 4.0, the coiled PAA conformation yielded polymer adsorption primarily on alumina outer surface. At higher pH values, the more stretched PAA molecules were able to infiltrate inside the alumina pores. The phenomenon is explained by the polymer chain reptation motion model. Coiled polymer chains are not oriented enough to penetrate the oxide pore channels. In contrary, stretched polymer chains are more likely to move along the pore channels.

  6. Studies on the kinetics of gel formation in polyurethane acrylate cured by UV-radiation

    In this paper, the kinetics of gel formation in polyurethane acrylate initiated by UV-radiation was investigated with the help of IR spectra, in which benzophenone/benzoic ethyl ether was a mixed photo sensitizer. The reaction degrees of double-bonds changing at 1408 cm-1 of acrylates in IR were detected in the different UV exposure time. The relationship between reaction degree Pc-c = 0.325 t0.135. After a critical geloint, the reaction degrees of double-bonds existed: Pc=c (gel) > Pc=c > Pc=c(sol) and besides there was a distributional relation between gel and sol fractions in the whole processing. The critical gel point was obtained with the extrapolation method, and its experimental gel point and the theoretical modeling one were quite close to each other. The experimental curves of Pc=c, Pc=c(gel) and Pc=c(sol) functions related to gel fractions were in fairly good agreement with their theoretical modeling ones in both shape and tendency

  7. Investigation of small molecular weight poly(acrylic acid) adsorption on γ-alumina

    Highlights: • Small molecular weight poly(acrylic acid) incorporated on γ-alumina. • PAA adsorbed primarily on outer surface of alumina at low pH. • PAA infiltrated inside alumina pore at high pH. • Polymer chain reptation motion during the infiltration. - Abstract: The interactions between poly(acrylic acid) (PAA) and alumina have been widely investigated. In this study, the pattern of small molecular weight PAA (MW 3000) interaction with γ-alumina has been dissected. The alumina/PAA hybrids were prepared at pH 4.0, 5.5, and 7.0, respectively. Nitrogen absorption–desorption analysis, Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and elemental analysis were conducted to illustrate the characteristics of the hybrids. At pH 4.0, the coiled PAA conformation yielded polymer adsorption primarily on alumina outer surface. At higher pH values, the more stretched PAA molecules were able to infiltrate inside the alumina pores. The phenomenon is explained by the polymer chain reptation motion model. Coiled polymer chains are not oriented enough to penetrate the oxide pore channels. In contrary, stretched polymer chains are more likely to move along the pore channels

  8. Effects of gas atmospheres on poly(lactic acid) film in acrylic acid plasma treatment

    Plasma polymerized acrylic acid (AA) coatings were deposited on poly(lactic acid) (PLA) films in various gas atmospheres during the pre-treatment of PLA and the deposition of AA, respectively. Therefore, this work was twofold: the argon pretreated PLA films followed by a deposition in argon were investigated against the mixture of argon and oxygen pretreated ones under the same deposition conditions; the plasma deposition of AA operating in different atmospheres (argon, oxygen and nitrogen) was employed to modify the pretreated PLA in oxygen. Chemical and physical changes on the plasma-treated surfaces were examined using contact angle, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM) and attenuated total reflection infrared (ATR-FTIR) analysis. The results showed that the discharge gas can have a significant influence on the chemical composition of the PLA surfaces: oxygen plasmas introduced oxygen-containing groups in company with surface etching in pretreatment and deposition, while argon discharges was able to achieve much better hydrophilic behavior and high retention ratio of poly(acrylic acid) (PAA) coating before and after washing in water.

  9. Influence of Initiator on Synthesis and Properties of Polyurethane-acrylate Hybrid Emulsion

    HU Guowen; SHEN Huifang; FIU Heqing; CHEN Huanqin

    2008-01-01

    The prepolymer polyurethanes(PUs)based on isophorone diisocyanate(IPDI),poly(propylene glycol)(PPG),1,4-butanedioi(BDO)and dimethylopropionic acid(DMPA)were synthesized at 75-80℃ for 7-8 hours,using dibutyltin dilauate(DBTDL)as catalyzer,and polyturethane-acrylate hybrid emulsion was prepared after methyl methacrylate(MMA)was polymerized,using potassium persulfate and azobisisobutyronitrile(AIBN)as initiator,respectively.The influences of these factors such as the kind of initiator,the feed method of initiator and the addition of initiator on properties of polyurethane-acrylate were studied.The FTIR and GPC of aqueous polyurethane were analyzed.The FTIR spectra show that the degree of microphase-separate between the soft segments and rigid segments is high.The analysis of molecular weights stated that molecular weights increased most significantly after amine was added.The experimental results reveal that the appearance of emulsion is excellent,the film is harder and the water absorption radio of the film is less when oil-solubility AIBN is used as initiator.The semi-continuous can increase the molecular weight of polymer and the optimum amount of the initiator was 3% for MMA.

  10. Effects of gas atmospheres on poly(lactic acid) film in acrylic acid plasma treatment

    Zhao, Yun, E-mail: yun.zhaotju@yahoo.com [Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Turin (Italy); Fina, Alberto [Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino – sede di Alessandria, V. T. Michel 5, 15121 Alessandria (Italy); Venturello, Alberto; Geobaldo, Francesco [Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Turin (Italy)

    2013-10-15

    Plasma polymerized acrylic acid (AA) coatings were deposited on poly(lactic acid) (PLA) films in various gas atmospheres during the pre-treatment of PLA and the deposition of AA, respectively. Therefore, this work was twofold: the argon pretreated PLA films followed by a deposition in argon were investigated against the mixture of argon and oxygen pretreated ones under the same deposition conditions; the plasma deposition of AA operating in different atmospheres (argon, oxygen and nitrogen) was employed to modify the pretreated PLA in oxygen. Chemical and physical changes on the plasma-treated surfaces were examined using contact angle, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM) and attenuated total reflection infrared (ATR-FTIR) analysis. The results showed that the discharge gas can have a significant influence on the chemical composition of the PLA surfaces: oxygen plasmas introduced oxygen-containing groups in company with surface etching in pretreatment and deposition, while argon discharges was able to achieve much better hydrophilic behavior and high retention ratio of poly(acrylic acid) (PAA) coating before and after washing in water.

  11. The Reinforcement Effect of Nano-Zirconia on the Transverse Strength of Repaired Acrylic Denture Base

    ArRejaie, Aws S.; Abdel-Halim, Mohamed Saber; Rahoma, Ahmed

    2016-01-01

    Objective. The aim of this study was to evaluate the effect of incorporation of glass fiber, zirconia, and nano-zirconia on the transverse strength of repaired denture base. Materials and Methods. Eighty specimens of heat polymerized acrylic resin were prepared and randomly divided into eight groups (n = 10): one intact group (control) and seven repaired groups. One group was repaired with autopolymerized resin while the other six groups were repaired using autopolymerized resin reinforced with 2 wt% or 5 wt% glass fiber, zirconia, or nano-zirconia particles. A three-point bending test was used to measure the transverse strength. The results were analyzed using SPSS and repeated measure ANOVA and post hoc least significance (LSD) test (P ≤ 0.05). Results. Among repaired groups it was found that autopolymerized resin reinforced with 2 or 5 wt% nano-zirconia showed the highest transverse strength (P ≤ 0.05). Repairs with autopolymerized acrylic resin reinforced with 5 wt% zirconia showed the lowest transverse strength value. There was no significant difference between the groups repaired with repair resin without reinforcement, 2 wt% zirconia, and glass fiber reinforced resin. Conclusion. Reinforcing of repair material with nano-zirconia may significantly improve the transverse strength of some fractured denture base polymers. PMID:27366150

  12. Acrylic coatings exhibiting improved hardness, solvent resistance and glossiness by using silica nano-composites

    Dashtizadeh, Ahmad; Abdouss, Majid; Mahdavi, Hossein; Khorassani, Manuchehr

    2011-01-01

    To prepare nano-composite emulsion acrylic resins with improved surface hardness and solvent resistance, nano-silica particles were treated with surfactants. The monomers of methyl methacrylate/butylacrylate were co-polymerized on the surface of dispersed silica particles. Several emulsions with different silica contents and copolymer mole fractions were prepared. Finally the emulsions were modified to water-based acrylic coatings and improved properties such as surface hardness, solvent resistance and glossiness were determined. The study of coatings was directed to find the improved resin by optimum surface properties. Size distribution and morphology of latexes were characterized by Fourier transform infrared spectroscopy, dynamic light scattering, transmission electron microscopy and scanning electron microscopy. The glass transition temperature of nano-composites was measured and discussed its relation with silica contents, monomer mole fractions and improved properties of coatings. The optimum pendulum hardness of coatings was on 0.46 methyl methacrylate mole fraction and 120 g silica content. An increase in pendulum hardness of nano-composites with the addition of modified silica was observed. DLS and TEM studies indicate that silica particles were dispersed homogenously through the polymer matrix.

  13. 4D printing smart biomedical scaffolds with novel soybean oil epoxidized acrylate

    Miao, Shida; Zhu, Wei; Castro, Nathan J.; Nowicki, Margaret; Zhou, Xuan; Cui, Haitao; Fisher, John P.; Zhang, Lijie Grace

    2016-01-01

    Photocurable, biocompatible liquid resins are highly desired for 3D stereolithography based bioprinting. Here we solidified a novel renewable soybean oil epoxidized acrylate, using a 3D laser printing technique, into smart and highly biocompatible scaffolds capable of supporting growth of multipotent human bone marrow mesenchymal stem cells (hMSCs). Porous scaffolds were readily fabricated by simply adjusting the printer infill density; superficial structures of the polymerized soybean oil epoxidized acrylate were significantly affected by laser frequency and printing speed. Shape memory tests confirmed that the scaffold fixed a temporary shape at −18 °C and fully recovered its original shape at human body temperature (37 °C), which indicated the great potential for 4D printing applications. Cytotoxicity analysis proved that the printed scaffolds had significant higher hMSC adhesion and proliferation than traditional polyethylene glycol diacrylate (PEGDA), and had no statistical difference from poly lactic acid (PLA) and polycaprolactone (PCL). This research is believed to significantly advance the development of biomedical scaffolds with renewable plant oils and advanced 3D fabrication techniques. PMID:27251982

  14. Solid phase graft copolymerization of acrylic monomers onto thermoplastics and their use as blend compatibilizers

    Subramanian, Srinivas

    This research work is an extension of some of the earlier work done on the development of solid phase grafting technique to graft various monomers onto polymers as well as postulation of the usefulness of the graft copolymers thus synthesized. Polystyrene grafted with acrylic acid, previously developed in bench scale, was synthesized in pilot-plant scale batches. Process parameter studies on the grafting of acrylic acid onto polypropylene and developmental studies on the grafting of maleic anhydride onto polystyrene were also done. Polymers grafted with polar molecules such as maleic anhydride and acrylic acid have been used to compatibilize immiscible blends of polar and non-polar polymers. On the same note, the applicability of the solid phase graft copolymers as blend compatibilizers were investigated and their performance was compared to commercially available compatibilizers. Solid phase graft copolymerization process is a technique to synthesize graft copolymers. Some of its salient features are use of minimal solvent to conduct the reaction and easy equipment modification. It is a low pressure and low temperature process. This technique provides a viable alternative to the environmentally hazardous, and time consuming conventional process currently in use. Hence, development of this technique could be beneficial not only to the plastics industry, but also to mankind. Also, this technique provides a low-cost and extremely easy method to develop graft copolymers such as acrylic acid functionalized polymers that are rapidly gaining popularity as blend compatibilizers and polymer reinforcing agents. A study that proves the potential of these solid phase graft copolymers as good blend compatibilizers for industrially important immiscible polymers will develop interest in the industries about this grafting process. The free radical solid phase graft copolymerization process was carried in a modified Brabender-type mixer fitted with specially designed blades to

  15. Ethyl 3-[2-(3,4-dimethoxybenzyl-1-phenylsulfonyl-1H-indol-3-yl]acrylate chloroform hemisolvate

    M. Thenmozhi

    2011-06-01

    Full Text Available In the title compound, C28H27NO6S·0.5CHCl3, the ethyl acrylate substituent adopts an extented conformation with all torsion angles close to 180°. The chloroform solvent molecule is disordered across an inversion centre and is therefore half occupied. The molecular packing is controlled by intermolecular C—H...O interactions.

  16. Preparation and application of crosslinked poly(sodium acrylate)--coated magnetite nanoparticles as corrosion inhibitors for carbon steel alloy.

    Atta, Ayman M; El-Mahdy, Gamal A; Al-Lohedan, Hamad A; El-Saeed, Ashraf M

    2015-01-01

    This work presents a new method to prepare poly(sodium acrylate) magnetite composite nanoparticles. Core/shell type magnetite nanocomposites were synthesized using sodium acrylate as monomer and N,N-methylenebisacrylamide (MBA) as crosslinker. Microemulsion polymerization was used for constructing core/shell structures with magnetite nanoparticles as core and poly(sodium acrylate) as shell. Fourier transform infrared spectroscopy (FTIR) was employed to characterize the nanocomposite chemical structure. Transmittance electron microscopy (TEM) was used to examine the morphology of the modified poly(sodium acrylate) magnetite composite nanoparticles. These particle will be evaluated for effective anticorrosion behavior as a hydrophobic surface on stainless steel. The composite nanoparticles has been designed by dispersing nanocomposites which act as a corrosion inhibitor. The inhibition effect of AA-Na/magnetite composites on steel corrosion in 1 M HCl solution was investigated using potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). Polarization measurements indicated that the studied inhibitor acts as mixed type corrosion inhibitor. EIS spectra exhibit one capacitive loop. The different techniques confirmed that the inhibition efficiency reaches 99% at 50 ppm concentration. This study has led to a better understanding of active anticorrosive magnetite nanoparticles with embedded nanocomposites and the factors influencing their anticorrosion performance. PMID:25594340

  17. Preparation and Application of Crosslinked Poly(sodium acrylate-Coated Magnetite Nanoparticles as Corrosion Inhibitors for Carbon Steel Alloy

    Ayman M. Atta

    2015-01-01

    Full Text Available This work presents a new method to prepare poly(sodium acrylate magnetite composite nanoparticles. Core/shell type magnetite nanocomposites were synthesized using sodium acrylate as monomer and N,N-methylenebisacrylamide (MBA as crosslinker. Microemulsion polymerization was used for constructing core/shell structures with magnetite nanoparticles as core and poly(sodium acrylate as shell. Fourier transform infrared spectroscopy (FTIR was employed to characterize the nanocomposite chemical structure. Transmittance electron microscopy (TEM was used to examine the morphology of the modified poly(sodium acrylate magnetite composite nanoparticles. These particle will be evaluated for effective anticorrosion behavior as a hydrophobic surface on stainless steel. The composite nanoparticles has been designed by dispersing nanocomposites which act as a corrosion inhibitor. The inhibition effect of AA-Na/magnetite composites on steel corrosion in 1 M HCl solution was investigated using potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS. Polarization measurements indicated that the studied inhibitor acts as mixed type corrosion inhibitor. EIS spectra exhibit one capacitive loop. The different techniques confirmed that the inhibition efficiency reaches 99% at 50 ppm concentration. This study has led to a better understanding of active anticorrosive magnetite nanoparticles with embedded nanocomposites and the factors influencing their anticorrosion performance.

  18. All-acrylic film-forming colloidal polymer/silica nanocomposite particles prepared by aqueous emulsion polymerization.

    Fielding, Lee A; Tonnar, Jeff; Armes, Steven P

    2011-09-01

    The efficient synthesis of all-acrylic, film-forming, core-shell colloidal nanocomposite particles via in situ aqueous emulsion copolymerization of methyl methacrylate with n-butyl acrylate in the presence of a glycerol-functionalized ultrafine silica sol using a cationic azo initiator at 60 °C is reported. It is shown that relatively monodisperse nanocomposite particles can be produced with typical mean weight-average diameters of 140-330 nm and silica contents of up to 39 wt %. The importance of surface functionalization of the silica sol is highlighted, and it is demonstrated that systematic variation of parameters such as the initial silica sol concentration and initiator concentration affect both the mean particle diameter and the silica aggregation efficiency. The nanocomposite morphology comprises a copolymer core and a particulate silica shell, as determined by aqueous electrophoresis, X-ray photoelectron spectroscopy, and electron microscopy. Moreover, it is shown that films cast from n-butyl acrylate-rich copolymer/silica nanocomposite dispersions are significantly more transparent than those prepared from the poly(styrene-co-n-butyl acrylate)/silica nanocomposite particles reported previously. In the case of the aqueous emulsion homopolymerization of methyl methacrylate in the presence of ultrafine silica, a particle formation mechanism is proposed to account for the various experimental observations made when periodically sampling such nanocomposite syntheses at intermediate comonomer conversions. PMID:21776995

  19. (E)-Ethyl 3-(3-bromo­phen­yl)-2-cyano­acrylate

    Yin Ye; Wei-Li Shen; Xian-Wen Wei

    2009-01-01

    The title molecule, C12H10BrNO2, adopts an E configuration with respect to the C=C bond of the acrylate unit. In the crystal structure, molecules are connected by a pair of intermolecular C—H...O hydrogen bonds, forming a centrosymmetric dimer.

  20. A facile one pot strategy for the synthesis of well-defined polyacrylates from acrylic acid via RAFT polymerization.

    Li, Qianbiao; Wang, Taisheng; Dai, Jingwen; Ma, Chao; Jin, Bangkun; Bai, Ruke

    2014-03-28

    A facile one pot strategy for the preparation of linear and hyperbranched polyacrylates has been successfully developed by the combination of in situ esterification of acrylic acid with halogenated compounds promoted by 1,1,3,3-tetramethylguanidine (TMG) and RAFT polymerization. PMID:24534953