bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ozone‐induced grafting of a sulfoammonium zwitterionic polymer onto low‐density polyethylene film for improving hemocompatibility
Authors: Shan Bing , Yan Han , Shen Jian , Lin Sicong 
Published: June 2006

AbstractOzone‐induced grafting was developed to improve the hemocompatibility of biomaterials based on low‐density polyethylene (LDPE). An LDPE film was activated with ozone and graft‐polymerized with N,N′‐dimethyl(methacryloylethyl)ammonium propane sulfonate (DMAPS). The existence of sulfobetaine structures on the grafted film was confirmed by X‐ray photoelectron spectroscopy and attenuated total reflection/Fourier transform infrared (ATR–FTIR). More DMAPS was grafted onto the LDPE film as the DMAPS concentration increased, as determined by ATR–FTIR. Static contact‐angle measurements indicated that the DMAPS‐grafted LDPE film had a significant increase in hydrophilicity. The blood compatibility of the grafted film was preliminarily evaluated with a platelet‐rich‐plasma (PRP) adhesion study. No platelet adhesion was observed on the grafted film incubated with PRP at 37°C for 180 min. This new sulfoammonium zwitterionic‐structure‐grafted biomaterial might have potential for biomedical applications. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3697–3703, 2006
Nonisothermal crystallization kinetics of poly(ethylene terephthalate) and poly(methyl methacrylate) blends
Authors: Bishara Ahmed , Shaban Habib I. 
Published: June 2006

AbstractThe nonisothermal crystallization kinetics of poly(ethylene terephthalate) (PET) and poly(methyl methacrylate) (PMMA) blends were studied. Four compositions of the blends [PET 25/PMMA 75, PET 50/PMMA 50, PET 75/PMMA 25, and PET 90/PMMA 10 (w/w)] were melt‐blended for 1 h in a batch reactor at 275°C. Crystallization peaks of virgin PET and the four blends were obtained at cooling rates of 1°C, 2.5°C, 5°C, 10°C, 20°C, and 30°C/min, using a differential scanning calorimeter (DSC). A modified Avrami equation was used to analyze the nonisothermal data obtained. The Avrami parameters n, which denotes the nature of the crystal growth, and Zt, which represents the rate of crystallization, were evaluated for the four blends. The crystallization half‐life (t½) and maximum crystallization (tmax) times also were evaluated. The four blends and virgin polymers were characterized using a thermogravimetric analyzer (TGA), a wide‐angle X‐ray diffraction unit (WAXD), and a scanning electron microscope (SEM). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3565–3571, 2006
Living cationic polymerization of isobutyl vinyl ether (II): Photoinduced living cationic polymerization in a mixed solvent of toluene and diethyl ether
Authors: Kwon Soonhong , Lee Younsung , Jeon Hyunjeong , Han Kyuchan , Mah Soukil 
Published: June 2006

AbstractA new method of preparation of living cationic polymer of isobutyl vinyl ether via photoinduced polymerization in the presence of diphenyliodonium iodide (DPII, initiator) and zinc iodide in a mixed solvent of toluene/diethyl ether, which was irradiated at −78°C for short period, was completed within 15 min. The reaction was allowed for further reaction in the dark until monomer was fully consumed. It was found that increase in the conversion of monomer to polymer during the irradiation is very limited. Confirmation of the linear dependence of number‐average molar mass of resulting polymer on % conversion together with the fact that polymerization proceeds until monomer consumption, and controllability of number‐average molar mass of resulting polymer, depending on the molar ratio of monomer and initiator, strongly suggests the living nature of this polymerization, unless reaction temperature becomes higher than 0°C, i.e., the absence of chain breaking process. The narrow molar mass distribution, whose polydispersity index values are less than 1.2, reveals that the rate of initiation where irradiation is usually completed within 15 min is much faster than that of propagation in cationic nature in this system. Effect of some major factors, such as solvent polarity and temperature, on the living nature of the polymerization was also investigated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3581–3586, 2006
Composites of poly(lactic acid) with flax fibers modified by interstitial polymerization
Authors: Shanks R. A. , Hodzic A. , Ridderhof D. 
Published: June 2006

AbstractNatural fiber composites were designed and optimized to achieve good mechanical properties and resistance to growth of living organisms. Composite materials were prepared from poly(lactic acid) (PLA) with flax fibers, which had been subjected to interstitial polymerization to replace the water in the cellulose fibers. Prior to the polymerization, the flax fibers were extracted with sodium hydroxide and acetone to remove lignin, pectin, and waxes from the cellulose. Differential scanning calorimetry was used to study the crystallization and melting of the composites compared to pure PLA. The surface wetting of the fibers and morphology of the composites were studied by scanning electron microscopy and optical microscopy. Mechanical properties were studied using dynamic mechanical analysis. The influence of the interstitial polymerization on the dynamic storage modulus was found to be significant. The composites of polymerization treated flax with acetone washed fibers had higher storage moduli than the unwashed fiber composites, which suggested that the adhesion between the flax fibers and the matrix was improved by the treatments. The composites were subjected to moist environmental conditions in order to test for development of mold and fungi, and the acetone washed polymerization treated flax composites were resistant to these growths. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3620–3629, 2006
Poly(vinyl chloride)–green coconut fiber composites and their nonlinear viscoelastic behavior as examined with fourier transform rheometry
Authors: Leblanc Jean L. 
Published: June 2006

AbstractUsing a purposely modified torsional dynamic rheometer with a closed cavity, I investigated composites of poly(vinyl chloride) (PVC) and green coconut fibers (GCFs) with Fourier transform (FT) rheometry, a new dynamic test technique that resolves the complex dynamic response of materials submitted to harmonic strain into their main and harmonic components. Because of instrument limitations in the low‐strain region, torque signal harmonic components had to be corrected to yield results that suited established theoretical considerations. The preparation method of the composites had major effects on their linear and nonlinear viscoelastic responses; essentially, no homogeneous material could be prepared by dry blending plus extrusion, in contrast to dry blending plus mixing, which is the recommended technique; this was likely because PVC plasticization was then achieved. One of the most important rheological characteristics of the PVC–GCF composites was the quasidisappearance of the linear viscoelastic behavior. Nevertheless, an easy extrapolation technique was used to extract linear modulus data from the FT results, which led me to the conclusion that the reinforcing effect of the GCFs was essentially hydrodynamic with little, if any, interfacial interaction between the polymer matrix and the fibers. The results gathered from nonlinear viscoelastic properties, as obtained through FT rheometry, supplement this conclusion. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3638–3651, 2006
Evaluation of the shrinking‐core model for examining the kinetics of film formation in a reactive latex blend
Authors: Boyars Brian , Daniels Eric S. , Klein Andrew 
Published: June 2006

AbstractWe prepared reactive latex blends from two copolymer latices comprised of n‐butyl methacrylate (n‐BMA) with acetoacetoxyethyl methacrylate and n‐BMA/dimethylaminoethyl methacrylate to study the kinetics of film formation. We generated thin films by blending equal weights of the two latices. The films were then cured at temperatures ranging from 50 to 90°C. The extent of the crosslinking reaction was calculated from the crosslink density, which was determined from swelling measurements of the films in toluene. The shrinking‐core model, a diffusion/reaction model, which was originally derived for combustion reactions of coal particles, was adopted to calculate the diffusion coefficient (De) and reaction rate constants from the extent of the reaction with time data. This model system exhibited a diffusion‐controlled regime above 70°C and a reaction‐controlled regime at temperatures below 70°C. In the reaction‐controlled regime, the shrinking‐core model predicted De for the system, which was in agreement with literature values for n‐BMA. In the diffusion‐controlled regime, the model predicted a lower apparent value for De but with an activation energy that was close to that obtained for n‐BMA. The model was also used to examine the kinetics of the crosslinking reaction. The kinetic rate constants for the crosslinking reaction were also determined. The activation energy for the crosslinking reaction was 18.8 kcal/mol, which compared reasonably with the activation energy of 22.8 kcal/mol determined for the reaction between the functional monomers as small molecules. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3659–3665, 2006
Use of trifluoromethanesulfonic acid as catalyst for the cyclization of polyisoprene
Authors: Chan Cheng‐Kuang , Lin Chia‐Ying 
Published: June 2006

AbstractIn this study, trifluoromethanesulfonic acid was employed as catalyst for the cyclization of polyisoprene. From 1H nuclear magnetic resonance spectroscopy and gel permeation chromatography investigations, cyclization was confirmed, and the molecular structure variation of polyisoprene during cyclization reaction was determined. With the comparison to that catalyzed by other strong acids (methanesulfonic acid), polyisoprene was cyclized with much higher efficiency, using trifluoromethanesulfonic acid as catalyst. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3666–3669, 2006
Stabilization of polymers of vinylchloride with sulfur
Authors: Akhmetkhanov Rinat M. , Kabalnova Natalya N. , Akhmetkhanov Ruslan R. , Kolesov Sergey V. , Zaikov Gennadi E. 
Published: June 2006

AbstractThe high stabilizing efficiency of element sulfur was revealed by the thermooxidative destruction of polymers of vinylchloride (VC). It was shown that the stabilizing efficiency of sulfur in compositions of polymers of VC is comparable with the efficiency of phenolic antioxidants. Element sulfur inhibits process of autooxidation of esters‐plastifiers of polymers of VC, apparently, because of destruction of formed hydroperoxides. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4538–4542, 2006
Study of nucleation activity and application of a nucleating agent to copolypropylene
Authors: Tu Zhigang , Mai Kancheng , Wu Zengqing 
Published: June 2006

AbstractThe influences of nucleating agent content on crystallization peak temperature, crystallization curve shape, crystallization onset temperature, and crystallinity of a copolypropylene were studied in detail by differential scanning calorimetry. The results showed that crystallization onset temperature and crystallization peak temperature increased 17°C–22°C and 15°C–19°C, respectively, with increasing nucleating agent content. The behavior of the nucleating agent showed excellent efficiency. But the shape of the crystallization curve broadened with increasing nucleating agent content, and the crystallinity came to an extremum when the nucleating agent content was 0.2%. These results generally differed from those for crystallization of i‐PP by a nucleating agent. Modification of copolypropylene was studied by use of a nucleating agent, and the characteristics of the effects of the nucleating agent on copolypropylene were mastered. The results showed that the hardness of a copolypropylene improved observably. So the abrasion resistance of biaxially oriented polypropylene (BOPP) film for cigarette packaging was improved by adopting the modified copolypropylene as the skin‐layer heat‐seal material of BOPP film. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101:3915–3919, 2006
Hybrid acrylic–polyurethane latexes: Emulsion versus miniemulsion polymerization
Authors: Wang Chunpeng , Chu Fuxiang , Guyot Alain , Gauthier Catherine , Boisson Fernande 
Published: June 2006

AbstractTwo kinds of hybrid acrylic–polyurethane (PUA) latexes are compared according to their synthesis and properties. The acrylic part is a copolymer of styrene, methyl methacrylate, and butyl acrylate. The PUAs are based on the polycondensation of isophorone diisocyanate and poly(propylene glycol) using butanediol and ethylene diamine as chain extenders. The first class result from the polymerization of miniemulsions of solutions of PU in the mixture of monomers using benzoyl peroxide as an initiator at 80°C. In the second class PUs modified by neutralized dimethylolpropionic acid are used as seeds and emulsifiers for emulsion polymerization of the monomer mixtures initiated with azobisisobutyronitrile at 75°C. The polymerization kinetics are compared, as well as the morphology of the latex particles. Films are obtained upon coalescence of these latexes, and the surface composition of these films and their tensile properties are studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3927–3941, 2006
A thermodynamic study of the binding of human serum albumin onto N,N′‐diethylaminoethyl dextran microbeads
Authors: Kaplan Can Hatice , Güner Ali 
Published: June 2006

AbstractAdsorption of proteins on solid surfaces is widely studied because of its importance in various biotechnological, medical, and technical applications, e.g., biosensors, cardiovascular implants, and chromatography. Adsorption thermodynamics has been studied on the microbeads of N,N′‐diethylaminoethyl (DEAE) Dextran anion exchanger for the human serum albumin (HSA) at 25, 30, 35, 40, and 45°C. As a result, some thermodynamic parameters like Freundlich constants, thermodynamic equilibrium constant (KD), standard free energy changes (ΔGassoc), standard entropy changes (ΔSassoc), and standard enthalpy change (ΔHassoc) have been evaluated. Using the linear Van't Hoff plot, ΔHassoc value of the system for the interaction of bovine serum albumin (BSA)‐adsorbed crosslinked DEAE dextran microbeads was determined as 20.650 kJ/mol. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3942–3947, 2006
Antimicrobial, mechanical, barrier, and thermal properties of starch–casein based, neem (Melia azardirachta) extract containing film
Authors: Jagannath J. H. , Radhika M. , Nanjappa C. , Murali H. S. , Bawa A. S. 
Published: June 2006

AbstractThe Starch–Casein‐based edible films containing with or without neem (Melia azadirachta) extract was prepared. The neem based free films were also heat pressed and all of them were assessed for inhibition of pathogenic organisms namely E. coli, Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, Pseudomonas spp., and Salmonella, using disc diffusion assay. The Glass‐transition temperature (Tg) and thermal properties of the films were determined with the help of DSC and DMA. Tensile strength (TS), elongation at break (EAB), water vapor transmission rate (WVTR), and oxygen transmission rate (OTR) of the films were also determined. Incorporation of neem extract to edible film did not affect any of the physical properties except microbial, and the films were effective in inhibiting the growth of pathogens, since the inhibition zones varied from 15 mm as large as 24 mm. However, the heat‐pressed films containing neem extract led higher the Tg, TS, and modulus, while the EAB was marginally affected, indicating the toughening of the film and as expected, the heat pressing of films decreased the WVTR and marginally affected OTR. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3948–3954, 2006
Effect of various environmental conditions on the swelling property of PAAm/PAAcK superabsorbent hydrogel prepared by ionizing radiation
Authors: Abd El‐Rehim H. A. , Hegazy El‐Sayed A. , Abd El‐Mohdy H. L. 
Published: June 2006

AbstractPolyacrylamide/potassium polyacrylate (PAAm/PAAcK) superabsorbent hydrogels were prepared by using ionizing radiation for possible use in agricultural purposes. The influence of environmental conditions such as water quality, fertilizer salts, soil pH, and surrounding temperature on PAAm/PAAcK water absorbency and retention was investigated. The water absorbency apparently decreased with an increase in the valence and ionic strength of the salt solutions. The swelling of PAAm/PAAcK immersed in the solutions containing fertilizer of different nitrogen sources followed the order: Urea > NH4NO3 > (NH4)2SO4. The PAAm/PAAcK water absorbency in solutions containing different types of phosphate sources was in the order: H3PO4 > KH2PO4 > K2HPO4. However, the water absorbency of PAAm/PAAcK in the solution of different types of potassium salts followed the order: KCl > K2SO4 > K2HPO4. PAAm/PAAcK hydrogel is fully swollen at pH 6. The relation between the ability of PAAm/PAAcK to retain water against time at different temperatures was studied. As the environmental temperature increases, the water retention of PAAm/PAAcK decreases. Potential application of PAAm/PAAcK in agriculture was evaluated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3955–3962, 2006
Study on the morphology of the novel hydrophobically associative acrylamide‐based terpolymer in aqueous solution by AFM measurements
Authors: Zhong Chuanrong , Huang Ronghua , Ye Lin , Dai Hua 
Published: June 2006

AbstractThe synthesized hydrophobically associating water‐soluble polymer P(AM‐BST‐NaAMPS) (PASA) exhibits good viscosification properties in the aqueous and brine solution. To study the viscosifying mechanisms of the polymer in the aqueous solution and brine solution, atomic force microscope (AFM) was applied to observe the micromorphology of the polymer solution. The AFM measurements show that continuous network structures have been formed in the aqueous solution of 0.05 g dL−1 PASA, and with the increase in PASA concentration, the network structures become much bigger and more condensed. The network structures of PASA are collapsed by the addition of salt, and tree‐like crystals are formed, leading to the decrease in the apparent viscosity of PASA solution. However, by increasing the NaCl concentration or the polymer concentration in the brine solution, the sizes of crystals increase. These results are consistent with the ESEM and viscosity study results. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3996–4002, 2006
Transformation of vulcanized natural rubber into lower molecular weight polymers and their application to grafted copolymer synthesis with some vinyl monomers
Authors: Yamazaki Hiroki , Nagasawa Tomomi , Choi Wonmun , Endo Takeshi 
Published: June 2006

AbstractGraft copolymerization of several vinyl monomers onto polyisoprene was carried out to explore the possibility to recycle waste rubber to useful functional materials. Synthetic polyisoprene, vulcanized natural rubber, and vulcanized natural rubber with carbon black were converted to lower molecular weight polymers at 300°C, under air or nitrogen atmosphere. The obtained low molecular weight natural rubber and polyisoprene were soluble in organic solvents, such as hexane, toluene, tetrahydrofuran (THF), chloroform, and monochlorobenzene. Radical copolymerization of styrene with a thermally fragmented natural rubber was carried out at 80°C in bulk for 2 h in the presence of 2,2′‐azobis(isobutyronitrile) (AIBN) under air atmosphere to give the corresponding grafted copolymer. The obtained polymer was a beige powdery copolymer at room temperature and consisted of isoprene (38 mol %) and styrene (62 mol %) units, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4003–4010, 2006
Curing of epoxy resin with poly(m‐phenylene methylphosphonate)
Authors: Wu Tao , Piotrowski Andrew M. , Yao Qiang , Levchik Sergei V. 
Published: June 2006

AbstractThe mechanism and kinetics of curing of epoxy resin with poly(m‐phenylene methylphosphonate) (PMP) was studied by extraction and swelling experiments, DSC, 31P NMR, and FTIR. It was shown that at linear heating of 20°C/min PMP cures bisphenol A type epoxy resin at 230–300°C, whereas in the presence of catalytic amount of 2‐methyl imidazole the curing occurs at 200–230°C. Under isothermal conditions, epoxy resin was cured with PMP after 40–70 min at 150°C. An unusual mechanism of curing due to opening and insertion of epoxy into the phosphonate bond was suggested. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4011–4022, 2006
Study on the synthesis of thiirane
Authors: Li Yafeng , Cheng Jue , Zhang Junying 
Published: June 2006

AbstractIn this study, a thiirane resin was synthesized by the reaction of corresponding epoxy resin with KSCN. The synthetic conditions influencing the conversion of epoxy group were systematically investigated, such as the reaction temperature, reaction media, reaction time and the ratio of KSCN to epoxy group. It was found that the conversion of epoxy group increased with the increasing reaction temperature, improving the solubility of the mediate, extending reaction time, and the enhancing ratio of salt (KSCN) to epoxy group. Wherein, the reaction temperature and the ratio of the KSCN to epoxy group were more effective. For example, when the molar ratio of KSCN to epoxy group was equal to 2.0, the conversion of epoxy group got the maximum value, 0.65. In addition, the hot plate method was used to measure the gelling time of the resultant thiirane resin at different temperatures. It was found that the gelling time was reduced to 47–85% times as the corresponding epoxy resin depending on the conversion of the epoxy group, and the curing activation energy was diminished from 39 kJ/mol of epoxy resin to 17 kJ/mol. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4023–4027, 2006
Surface characterization of hollow fiber membranes used in artificial kidney
Authors: Rafat Mehrdad , De Dibyendu , Khulbe K. C. , Nguyen Thanh , Matsuura Takeshi 
Published: June 2006

AbstractThe internal and external curved surfaces of polysulfone hollow fiber membranes were characterized by atomic force microscopy (AFM), contact angle measurement (CAM), and scanning electron microscopy (SEM) with the aim of improving the membrane surface properties for blood compatibility. Novel approaches were applied to evaluate a number of properties, including the roughness, pore size, nodule size, and wettability of the surfaces of the hollow fibers. CAM studies were carried out by directly observing the liquid meniscus at the surfaces of hollow fibers. Observation of the meniscus and measurement of the contact angle became possible by using an imaging system developed in our laboratory. AFM and SEM studies were also conducted on the surfaces of the hollow fiber membranes by cutting them at an inclined angle. The effect of the molecular weight of poly(ethylene glycol) (PEG) in the polymer blend on the surface properties of the hollow fibers was studied. Increasing the PEG molecular weight increased the average pore size whereas it decreased the contact angle. The contact angle depended on the microscopic surface morphology, including nodule size and roughness parameters. The theoretical prediction along with the experimental data showed that the measured contact angle would be greater than the value intrinsic to the membrane material because of the formation of composite surface structures. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4386–4400, 2006