bluuebunny/crossref_metadata_2025_split huggingface dataset:
Film formation from pigmented latex systems: Mechanical and surface properties of ground calcium carbonate/functionalized poly(n‐butyl methacrylate‐co‐n‐butyl acrylate) latex blend films
Authors: Ding Tianhua , Daniels Eric S. , El‐Aasser Mohamed S. , Klein Andrew 
Published: March 2006

AbstractThe mechanical and surface properties of films prepared from model latex/pigment blends were studied using tensile tests, surface gloss measurements, and atomic force microscopy. Functionalized poly(n‐butyl methacrylate‐co‐n‐butyl acrylate) [P(BMA/BA)] and ground calcium carbonate (GCC) were used as latex and extender pigment particles, respectively. The critical pigment volume concentration of this pigment/latex blend system was found to be between 50 and 60 vol % as determined by surface gloss measurement and tensile testing of the blend films. As the pigment volume concentration increased in the blends, the Young's modulus of the films increased. Nielsen's equations were found to fit the experimental data very well. When the surface coverage of carboxyl groups on the latex particles was increased, the yield strength and Young's modulus of the films both increased, indicating better adhesion at the interfaces between the GCC and latex particles. When the carboxyl groups were neutralized during the film formation process, regions with reduced chain mobility were formed. These regions acted as a filler to improve the modulus of the copolymer matrix and the modulus of the resulting films. The carboxyl groups on the latex particle surfaces increased the surface smoothness of the films as determined by surface gloss measurement. When the initial stabilizer coverage of the latex particles was increased, the mechanical strength of the resulting films increased. At the same time, rougher film surfaces also were observed because of the migration of the stabilizer to the surface during film formation. With smaller‐sized latex particles, the pigment/latex blends had higher yield strength and Young's modulus. Higher film formation temperatures strengthen the resulting films and also influence their surface morphology. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4550–4560, 2006
Structural modification of expandable polystyrene. III. Copolymerization with siloxane‐based macroinitiator
Authors: Taşkıran Isa 
Published: March 2006

AbstractConventional expandable polystyrene (EPS) was chemically modified by preparing copolymers containing 0.1%, 0.2%, and 0.5% siloxane‐based macroinitiator. This was used to enhance the surface and thermal properties of EPS particles. Copolymeric expandable polystyrene samples were characterized with various techniques including 1H‐NMR, gel permeation chromatography, differential scanning calorimetry, scanning electron microscopy, and contact angle measurement. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4826–4831, 2006
Effect of crosslinkers on the preparation and properties of ETFE‐based radiation‐grafted polymer electrolyte membranes
Authors: Chen Jinhua , Asano Masaharu , Yamaki Tetsuya , Yoshida Masaru 
Published: March 2006

AbstractThis study concerns a comparative study of three crosslinkers, divinylbenzene (DVB), 1,2‐bis(p,p‐vinylphenyl)ethane (BVPE), and triallyl cyanurate (TAC) crosslinked poly(ethylene‐co‐tetrafluoroethylene) (ETFE)‐based radiation‐grafted membranes, which were prepared by radiation grafting of p‐methylstyrene onto ETFE films and subsequent sulfonation. The effect of the different types and contents of the crosslinkers on the grafting and sulfonation, and the properties such as water uptake, proton conductivity, and thermal/chemical stability of the resulting polymer electrolyte membranes were investigated in detail. Introducing crosslink structure into the radiation‐grafted membranes leads to a decrease in proton conductivity due to the decrease in water uptake. The thermal stability of the crosslinked radiation‐grafted membranes is also somewhat lower than that of the noncrosslinked one. However, the crosslinked radiation‐grafted membranes show significantly higher chemical stability characterized in the 3% H2O2 at 50°C. Among the three crosslinkers, the DVB shows a most pronounced efficiency on the crosslinking of the radiation‐grafted membranes, while the TAC has no significant influence; the BVPE is a mild and effective crosslinker, showing the moderate influence between the DVB and TAC crosslinkers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4565–4574, 2006
In situ Fourier transform infrared spectroscopic study of the conformational changes of high‐density poly(ethylene) during the melting and crystallization processes
Authors: Xiao Yan , Yan Liangyu , Zhang Puming , Zhu Na , Chen Liang , He Peng , Wang Yanping , Shen Xinyuan , Zhu Xinyuan , Yan Deyue 
Published: March 2006

AbstractThe conformational analysis of high‐density poly(ethylene) (HDPE) during the melting and crystallization processes has been performed by the aid of the time‐reserved Fourier transform infrared spectroscopy and multivariate analysis technique. Upon heating, the conformational transition of HDPE takes place, gradually, due to the restraint of crystal lattice, and various conformational transformations can be discerned clearly. However, during the cooling process, HDPE crystallizes very quickly and only one major conformational transition occurs in the crystallization process. The comparison of conformational changes during the melting and crystallization processes exhibits that although the polymer crystallization is the reverse process of polymer melting, there still exist some obvious differences in the conformational transformation between them. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4835–4841, 2006
Determination of the degradation apparent activation energy of acrylonitrile/acrylic acid copolymers
Authors: Hou Chen , Liu Junshen , Ji Chunnuan , Wang Chengguo 
Published: March 2006

AbstractAcrylonitrile/acrylic acid copolymers were prepared by H2O/dimethyl formamide suspension polymerization technique. Differential scanning calorimetry was used to investigate the degradation of acrylonitrile/acrylic acid copolymers in air. The apparent activation energy of degradation of the copolymer was calculated with the Kissinger method. Effects of copolymerization conditions on the apparent activation energy of copolymer were studied. It has been found that increasing the dimethyl formamide concentration in the solvent mixture led to a gradual increase (97.3–149.4 kJ mol−1) in the apparent activation energy of degradation of the acrylonitrile/acrylic acid copolymers. The apparent activation energy decreases with increase in acrylic acid concentration, and this change became less prominent as the acrylic acid/acrylonitrile weight ratio is more than 5/95. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4668–4671, 2006
Synthesis and characterization of polystyrene‐supported glucosamine resin and its adsorption behavior for Au(III)
Authors: Sun Changmei , Qu Rongjun , Wang Qun , Ji Chunnuan , Wang Chunhua , Xu Qiang , Fang Xiaofu , Cheng Guoxiang 
Published: March 2006

AbstractA novel chelating resin, crosslinking polystyrene‐supported glucosamine (PS‐GA), was prepared and its structure was confirmed by FTIR, elemental analysis, and X‐ray photoelectron spectroscopy. The adsorption properties of PS‐GA for Au(III) were investigated. PS‐GA resin possessed excellent enriching property to Au(III) ions and adsorption proportion E% could reach to about 90 shortly after 3 h. The adsorption dynamics of Au(III) showed that the adsorption was controlled by liquid film diffusion and the apparent activation energy Ea was 12.91 kJ mol−1. Both Langmuir model and Freundlich model could describe the isothermal process of Au(III), and ΔG, ΔH, ΔS values were calculated. The mechanism of adsorption for Au(III) was confirmed by FTIR, SEM, and XPS. The results showed that redox reaction occurred and both coordination and ion‐exchange existed simultaneously in the adsorption. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4581–4586, 2006
Miscibility of dextran and poly(ethylene glycol) in dilute aqueous solutions. II. Effect of temperature and composition
Authors: Barsbay Murat , Güner Ali 
Published: March 2006

AbstractThe miscibility of dextran (Dx) with poly(ethylene glycol) (PEG) was investigated in dilute aqueous solutions by viscometry. Homopolymers of Dx and PEG and their blends with Dx/PEG ratios of 10/90, 25/75, 50/50, 75/25, and 90/10 were studied at 25, 30, 35, 40, and 45°C in bidistilled and deionized water. Starting with the classical Huggins equation, the results of the viscosity behavior of each parent polymer and their blends were interpreted in terms of miscibility parameters, Δk, Δb, α, β, ΔB, and μ. On the basis of the sign convention involved in these criteria, miscibility between Dx and PEG was found to increase with the weight fraction of PEG in the blend composition and temperature. The fourier transform infrared (FTIR) analysis is also used to investigate the miscibility of the polymer pairs. The existence of specific interactions between Dx and PEG was demonstrated by FTIR spectroscopy. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4587–4594, 2006
Synthesis and characterization of 3,3′‐disulfonated‐4,4′‐dichlorodiphenyl sulfone (SDCDPS) monomer for proton exchange membranes (PEM) in fuel cell applications
Authors: Sankir M. , Bhanu V. A. , Harrison W. L. , Ghassemi H. , Wiles K. B. , Glass T. E. , Brink A. E. , Brink M. H. , McGrath J. E. 
Published: March 2006

AbstractA systematic study of the synthesis and characterization of 3,3′‐disulfonated‐4,4′‐dichlorodiphenyl sulfone (SDCDPS) monomer was conducted by varying reactant stoichiometries (molar ratios of 4,4′‐dichlorodiphenyl sulfone (DCDPS) to SO3 1 : 2.2, 1 : 2.9, and 1 : 3.3), reaction temperature (90–120°C), and reaction time (4–6 h). The optimum synthesis batch process variables were 1 : 3.3 reactant molar ratio (DCDPS : SO3) at 110°C for 6 h. In earlier studies, recrystallization of the “crude” disulfonated monomer from alcohol–water mixture was necessary to remove the monosulfonated and DCDPS impurities that lowered yield. However, in the current research, SDCDPS was successfully synthesized at nearly 100% conversion, which effectively eliminated the need for recrystallization. Recrystallization of SDCDPS from several alcohol–water mixtures (methanol–, ethanol–, and isoproponal–water mixtures) was investigated to compare product purities. Several characterization methods including proton NMR, HPLC, UV–visible, and fast atom bombardment mass spectroscopy confirmed that the crude SDCDPS was completely disulfonated and identical to recrystallized SDCDPS, without having any monosulfonated or starting material DCDPS impurities. Hence, it was demonstrated that the crude SDCDPS monomer by the current one‐step process and the recrystallized SDCDPS monomer were identical. This optimized monomer synthesis has been used to scale up the SDCDPS and poly(arylene ether sulfone) random and statistical copolymers at controlled disulfonation (35 and 45 mol %) levels, which were then used to fabricate proton exchange membranes for fuel cell applications. The intrinsic viscosity data confirmed that high molecular weight film forming copolymers were synthesized. The calculated degree of disulfonations by proton NMR was in close agreement with target disulfonations. It may be concluded that this optimized SDCDPS synthesis eliminates the need for recrystallization, which would be expected to improve process economics. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4595–4602, 2006
Kinetic study of copolymerization of acrylonitrile with ammonium acrylate
Authors: Hou Chen , Liu Junshen , Ying Liang 
Published: March 2006

AbstractAmmonium acrylate was first used to successfully copolymerize with acrylonitrile. Kinetics of copolymerization of acrylonitrile with ammonium acrylate was investigated in a H2O/dimethylsulfoxide (DMSO) mixture. The rate of copolymerization and particle size were measured. Kinetic equation of the copolymerization was obtained. Effect of copolymerization systems on monomer apparent reactivity ratios for acrylonitrile/ammonium acrylate copolymers was studied in comparison. Values of monomer apparent reactivity ratios were calculated by Kelen‐Tudos method. It has been found that monomer apparent reactivity ratios in water‐rich reaction medium [H2O/DMSO>80/20] are approximately equivalent to those in aqueous suspension polymerization system. In DMSO‐rich reaction medium (DMSO/H2O > 80/20), apparent reactivity ratios are similar to those in solution polymerization system. With an increase in polarity of solvent, values of apparent reaction ratios both decrease. The values of apparent reaction ratios gradually tend to 1 with increase in the copolymerization temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4679–4683, 2006
Polyelectrolyte complex beads composed of water‐soluble chitosan/alginate: Characterization and their protein release behavior
Authors: Shi Xiaowen , Du Yumin , Sun Liping , Zhang Baozhong , Dou Abo 
Published: March 2006

AbstractPolyelectrolyte complex (PEC) beads were prepared from water‐soluble chitosan (WSC) and alginate complex solution with different ratios by dropping method, and all procedures used were performed in aqueous medium at neutral environment. The structure and morphology of the beads were characterized by IR spectroscopy and scanning electron microscopy (SEM). IR spectroscopy confirmed the electrostatic interactions between amino groups of WSC and carboxyl groups of alginate. SEM showed internal section of the PEC bead, which had porous structure compared with compact structure of alginate beads. The swelling behavior, encapsulation efficiency, and release behavior of bovine serum albumin (BSA) from the beads at different pHs were investigated. PEC beads demonstrated different responses to pH from alginate beads. The ratio of WSC to alginate influenced the encapsulation and release of BSA. At pH 1.2, small amount (< 15%) of BSA was released from the PEC beads except AC12. However, at pH 7.4, a large amount (> 80%) of BSA was released from AL in the first 3 h due to the rapid disintegration of the beads, whereas BSA release was retarded from complex beads due to the forming of PEC. The results suggested that the WSC/alginate beads could be a suitable polymeric carrier for site‐specific protein drug delivery in the intestine. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4614–4622, 2006
Preparation and mechanical properties of natural rubber powder modified by carbon nanotubes
Authors: Wang J. D. , Zhu Y. F. , Zhou X. W. , Sui G. , Liang J. 
Published: March 2006

AbstractA suspension of carbon nanotubes in natural latex was obtained by liquid mixing and then was used to prepare powder natural rubber composites modified with carbon nanotubes by means of spray drying process. The composite powders were round‐like and fine, with an average diameter of less than about 5 μm. The dispersion of carbon nanotubes in the rubber matrix was improved remarkably compared with that obtained by the mechanical mixing method. By means of vulcanization tests, it was found that the addition of vulcanizing agent necessary for the powder rubber containing carbon nanotubes should be evidently greater than that in rubber prepared by mechanical mixing, there evidently existed vulcanization reversions for the natural rubber prepared by mechanical mixing, which disappeared in the powder rubber containing carbon nanotubes prepared by the spray drying process. The mechanical properties of the powder natural rubber containing carbon nanotubes were much improved because of the modification effect of carbon nanotubes in rubber. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4697–4702, 2006
Suppression of metallocene catalyst leaching by the removal of free trimethylaluminum from methylaluminoxane
Authors: Turunen Jani P. J. , Pakkanen Tuula T. 
Published: March 2006

AbstractThe leaching of the catalyst zirconocene dichloride (Cp2ZrCl2) from an SBA‐15 silica support during ethylene polymerization was studied; severe leaching was observed when commercial methylaluminoxane (MAO) was used as the cocatalyst. However, the removal of free trimethylaluminum (TMA) from an MAO solution with a sterically hindered phenol reduced the catalyst leaching by 97–100%. The results obtained from the leaching experiments with TMA‐free MAO suggested that the major reason for catalyst leaching was the free TMA in the commercial MAO solution, not the pure MAO itself. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4632–4635, 2006
Characteristics of poly(AAc5‐co‐HPMA3‐cl‐EGDMA15) hydrogel‐immobilized lipase of Pseudomonas aeruginosa MTCC‐4713
Authors: Kanwar S. S. , Pathak S. , Verma H. K. , Kumar S. , Gupta R. , Chimni S. S. , Chauhan G. S. 
Published: March 2006

AbstractFour series of noble networks were synthesized with acrylic acid (AAc) copolymerized with varying amount of 2‐hydroxy propyl methacrylate or dodecyl methacrylate (AAc/HPMA or AAc/DMA; 5:1 to 5:5, w/w) in the presence of ethylene glycol dimethacrylate (EGDMA; 1, 5, 10, 15, and 20%, w/w) as a crosslinker and ammonium per sulfate (APS) as an initiator. Each of the networks was used to immobilize a purified lipase from Pseudomonas aeruginosa MTCC‐4713. The lipase was purified by successive salting out with (NH4)2SO4, dialysis, and DEAE anion exchange chromatography. Two of the matrices, E15a, i.e. [poly (AAc5‐co‐DMA1‐cl‐EGDMA15)] and I15c, i.e. [poly (AAc5‐co‐HPMA3‐cl‐EGDMA15)], that showed relatively higher binding efficiency for lipase were selected for further studies. I15c‐hydrogel retained 58.3% of its initial activity after 10th cycle of repetitive hydrolysis of p‐NPP, and I15c was thus catalytically more stable and efficient than the other matrix. The I15c‐hydrogel‐immobilized enzyme showed maximum activity at 65°C and pH 9.5. The hydrolytic activity of free and I15c‐hydrogel‐immobilized enzyme increased profoundly in the presence of 5 mM chloride salts of Hg2+, NH4+, Al3+, K+, and Fe3+. The immobilized lipase was preferentially active on medium chain length p‐nitrophenyl acyl ester (C:8, p‐nitrophenyl caprylate). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4636–4644, 2006
PPO–PC block‐copolymers used as compatibilizers in PS/PC blends
Authors: Sartore Luciana , Penco Maurizio , Della Sciucca Stefania , Mendichi Raniero , Di Landro Luca , D'Antone Salvatore 
Published: March 2006

AbstractBlock‐copolymers containing poly(2,6‐dimethyl‐1,4‐phenylene oxide) (PPO) and polycarbonate of bisphenol A (PC) segments were employed as compatibilizers in polystyrene (PS)/PC blends. Block‐copolymers were prepared starting from oligomeric diols‐terminated PPO and PC. The poly(phenylene ethers) was obtained by oxidative coupling of 2,6‐dimethyl‐phenol in presence of tetramethyl bisphenol A. The copolymers were obtained with a chain extension reaction between the starting oligomers using bischloroformate of bisphenol A or phosgene as coupling agent. PS/PC blends, cast from chloroform solutions or mixed by melt, were studied by differential scanning calorimeter (DSC), dynamic‐mechanical thermal analysis (DMTA), and optical microscopy (OP). The thermal and morphological analyses showed a clear compatibilization effect between PS and PC, if PPO–PC copolymer is added when blending is performed in the melt; in addition, also mechanical properties are increased when compared with blends without PPO–PC. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4654–4660, 2006
Preparation of nanocomposites of thermosetting resin from benzoxazine and bisoxazoline with montmorillonite
Authors: Chen Qiao , Xu Riwei , Yu Dingsheng 
Published: March 2006

AbstractThe thermosetting resin from 2,2′‐(1,3‐phenylene)‐bis(4,5‐dihydro‐oxazoles) (PBO) and bis(3‐phenyl‐3,4‐dihydro‐2H‐1,3‐benzoxazine)isopropane (BZ) was prepared, and it was found that the thermal property of the final resin was affected greatly by the content of PBO. The nanocomposite from the thermosetting resin from BZ and PBO (molar ratio of PBO to BZ, 0.8 : 1) (PBZ–PBO) and organically modified montmorillonite (OMMT) was prepared by melt method. Differential scanning calorimetry showed that on the introduction of OMMT, the onset curing temperature of the copolymerization of BZ and PBO decreased. The X‐ray diffractometer and transmission electron micrograph characterization of the dispersion of OMMT in the PBZ–PBO matrix suggested that exfoliation structure of OMMT was achieved. Dynamic mechanical analyses indicated that the nanocomposites exhibited much higher Tg values than the PBZ–PBO resin and pristine polybenzoxazine, and storage modulus of the nanocomposites was maintained up to higher temperature with the increasing OMMT content. Dynamic thermogravimetric analysis showed that the dispersion of clay nanolayers in the PBZ–PBO copolymer gave better thermal stability. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4741–4747, 2006
Effect of some compatibilizing agents on clay dispersion of polypropylene‐clay nanocomposites
Authors: López‐Quintanilla M. L. , Sánchez‐Valdés S. , Ramos de Valle L. F. , Medellín‐Rodríguez F. J. 
Published: March 2006

AbstractPolypropylene (PP)‐clay nanocomposites were obtained and studied by using three different coupling agents, glycidyl methacrylate (GMA), acrylic acid (AA), and maleic anhydride (MA). Three different clays, natural montmorillonite (Cloisite Na+) and chemically modified clays Cloisite 20A and Cloisite 30B, have also been used. Nanocomposites were prepared by melt‐blending in a twin‐screw extruder using two mixing methods: two‐step mixing and one‐step mixing. The relative influence of each factor was observed from structural analysis by WAXD, POM, TEM, and mechanical properties. The results were analyzed in terms of the effect of each compatibilizing agent and incorporation method in the clay dispersion and mechanical properties of the nanocomposite. Experimental results showed that clay dispersion and interfacial adhesion are greatly affected by the kind of matrix modification. The polarity and reactivity of polar groups give as a result better interfacial adhesion and subsequent mechanical performance. PP‐g‐GMA and PP‐g‐MA were better compatibilizing agents than PP‐g‐AA. Better dispersion and exfoliation for the nanoclays were obtained when using two‐step mixing than one‐step mixing conditions. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4748–4756, 2006
Preparation and adsorption selectivity for Hg(II) and Ag(I) of chelating resin immobilizing benzothiazolyl group on crosslinked polystyrene via hydrophilic sulfur‐containing PEG spacer
Authors: Ji Chunnuan , Qu Rongjun , Sun Changmei , Wang Chunhua , Sun Yanzhi , Zhao Na , Xie Hongming 
Published: March 2006

AbstractA new chelating resin incorporating 2‐mercaptobenzothiazole (MBZ) into macroporous chloromethylated polystyrene via hydrophilic spacer of polyethylene glycol containing sulfur was synthesized. The resin was characterized by elementary analysis and infrared spectra. The adsorption capacity of the resin for Ag+, Hg2+, Cu2+, Zn2+, and Pb2+ as a function of pH was determined. The effects of interference ions, such as Na+, Mg2+, Ca2+, Ba2+, Cu2+, Zn2+, and Pb2+, on percent recovery were also investigated. The results showed that the resin could effectively remove Hg2+ and Ag+ from solutions containing a large excess of Na+, Mg2+, Ca2+, Ba2+, Cu2+, Zn2+, and Pb2+. In column operation, it was observed that Hg2+ and Ag+ in trace quantities were effectively removed from binary metal ions. The percent recovery of the resin for Hg2+ and Ag+ was >98.6% and >97.5%, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 5034–5038, 2006