bluuebunny/crossref_metadata_2025_split huggingface dataset:
Curing of mixtures of epoxy resins and 4‐methyl‐1,3‐dioxolan‐2‐one with several initiators
Authors: Cervellera Roser , Ramis Xavier , Salla Josep Maria , Mantecón Ana , Serra Angels 
Published: August 2006

AbstractDiglycidyl ether of bisphenol A or 3,4‐epoxycyclohexylmethyl 3,4‐epoxycyclohexane carboxylate were mixed with different proportions of 4‐methyl‐1,3‐dioxolan‐2‐one and cured using lanthanide triflates as initiators. In order to compare the materials obtained, conventional initiators such as boron trifluoride complexes andN,N‐dimethylaminopyridine were also tested. The curing process was followed by differential scanning calorimetry (DSC) and Fourier transform IR in attenuated total reflectance mode. This technique proved that the carbonate accelerates the curing process because it helps to form the active initiating species, although it was not chemically incorporated into the network and remained entrapped in the material. The DSC kinetic study was also reported. © 2006 Wiley Periodicals Inc. J Appl Polym Sci 102: 2086–2093, 2006
Retention properties of arsenate anions of water‐soluble polymers by a liquid‐phase polymer‐based retention technique
Authors: Rivas Bernabé L. , Aguirre María del Carmen , Pereira Eduardo 
Published: August 2006

AbstractThe retention properties of arsenic ions from an aqueous solution by water‐soluble cationic polymers and cationic–anionic copolymers were investigated. Poly[(3‐methacryloylamine)propyl]trimethylammonium chloride [P(ClMPTA)] and poly[(3‐methacryloylamine)propyl]trimethylammonium chloride–co–acrylic acid [P(ClMPTA‐co‐AA] were synthesized by radical polymerization. The copolymers were prepared with feed mole ratios of ClMPTA to AA of 1 : 1, 1 : 2, and 2 : 1. The copolymer compositions were evaluated by FTIR spectroscopy, TG‐DSC, and elemental analysis. The liquid‐phase polymer‐based retention (LPR) technique was used. This technique consists of retention of arsenate anions by the quaternary ammonium salt of a water‐soluble polymer in a filtration membrane cell. It was shown that the polymers could bind H2AsO species from an aqueous solution more selectively at pHs of 6 and 8, than at a pH of 4. An increase in the polymer concentration was associated with increased retention capacity but not linearly. At the highest concentration the influence of pH was better observed. Investigation of copolymers showed the concerted action of polycations and polyanions on the ability to retain arsenic. At the lowest pH, the role of ionic strength of the media had a remarkable effect on the retention ability, independently of copolymer composition. At a pH of 6 a copolymer polycation/polyanion composition of 2 : 1 had the highest selective effect. At a pH of 8, a nonequimolar copolymer composition showed the same efficiency for the retention of arsenate species. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2677–2684, 2006
Properties of polyurethane coatings containing additives of phenolic compounds
Authors: Yokoyama Naoki 
Published: August 2006

AbstractThe properties of polyurethane containing five kinds of model phenolic additives were investigated. The IR spectra of polyurethane containing phenolic additives indicated that the phenolic additives reacted with isocyanate groups in a polyisocyanate compound. For an index of anticorrosion, the tensile adhesion strength was measured for polyurethane coatings with phenolic additives on steel plates treated with the salt‐water spraying test for 3000 h. It was found that there was a relationship between the tensile adhesion strength of polyurethane and the density. We considered the reason to be that the increase in density (i.e., a reduction in free volume) should provide a route to reduce salt‐water access to an adhesive bond. The increase in density was explained by the term antiplasticizers, which means that the phenolic additives reduce the free volume that is available for molecular motion in the stiff chain of polyurethane. In the polyurethanes with every phenolic additive, the elongation was increased, the moduli were decreased, the storage modulus was decreased, and the coefficient of thermal expansion was increased. These phenomena are the characteristics of plasticizers. Thus, the phenolic additives have both the character of antiplasticizers and plasticizers, but the polyurethane with phenolic additives had more characteristics of plasticizers than those of antiplasticizers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2099–2106, 2006
Polyaniline/FE3O4 magnetic nanocomposite prepared by ultrasonic irradiation
Authors: Qiu Guihua , Wang Qi , Nie Min 
Published: August 2006

AbstractUltrasonic irradiation is employed to assist the chemical oxidative polymerization of aniline in the presence of Fe3O4 nanoparticles in order to prepare a polyaniline (PANI)/Fe3O4 magnetic nanocomposite. In the chemical oxidative polymerization of aniline in the initially neutral medium, the optimum molar ratio of the oxidant ammonium persulfate to the monomer aniline is 2 : 1. The prepared PANI is in the emeraldine form and is doped by sulfate anions. Fe3O4 particles are encapsulated by PANI and dispersed well in PANI. Fe3O4 increases the doping level and decreases the crystallinity of PANI. The PANI/Fe3O4 nanocomposite possesses conductivity and magnetic properties. Increasing the Fe3O4 content increases the magnetization of the PANI/Fe3O4 composite but decreases its conductivity. © 2006 Wiley Periodicals Inc. J Appl Polym Sci 102: 2107–2111, 2006
Low temperature solid‐state extrusion of recycled poly(ethylene terephthalate) bottle scraps
Authors: Guo Weihong , Tang Xianwen , Yin Guorong , Gao Yuanji , Wu Chifei 
Published: August 2006

AbstractThe processing of poly(ethylene terephthalate) (PET) involves thermal and hydrolytic degradation of the polymer chain, which reduces not only the intrinsic viscosity and molecular weight, but also the mechanical properties of recycled materials. A novel PET/bisphenol A polycarbonate/styrene–ethylene–butylene–styrene alloy based on recycled PET scraps is prepared by low temperature solid‐state extrusion. Hydrolysis and thermal degradation of PET can be greatly reduced by low temperature solid‐state extrusion because the extrusion temperature is between the glass‐transition temperature and cold‐crystallization temperature of PET. Modification of recycled PET by low temperature solid‐state extrusion is an interesting method; it not only provides an easy method to recycle PET scraps by blend processing, but it can also form novel structures such as orientation, crystallization, and networks in the alloy. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2692–2699, 2006
Redox initiation system of ceric salt and α,ω‐dihydroxy poly(dimethylsiloxane)s for vinyl polymerization
Authors: Öz Nesrin , Akar Ahmet 
Published: August 2006

AbstractThe redox system of ceric salt and α,ω‐dihydroxy poly(dimethylsiloxane) is used to polymerize vinyl monomers such as acrylonitrile and styrene to produce block copolymers. The concentration and type of α,ω‐dihydroxy poly(dimethylsiloxane) affects the yield and the molecular weight of the copolymers. The copolymers have about 20°C lower glass‐transition temperatures and much higher contact angle values than of the corresponding homopolymer of vinyl monomers, although the weight percent of α,ω‐dihydroxy poly(dimethylsiloxane) of the copolymers is in the range of 1–2%. © 2006 Wiley Periodicals Inc. J Appl Polym Sci 102: 2112–2116, 2006
Polypropylene–nanosilica‐filled composites: Effects of epoxy‐resin‐grafted nanosilica on the structural, thermal, and dynamic mechanical properties
Authors: Srinivasa Reddy Chaganti , Kumar Das Chapal 
Published: August 2006

AbstractThis article reports a comparative study of polypropylene (PP) nanocomposites synthesized with nanosilica (NS) and diglycidyl ether of bisphenol A, an epoxy‐resin‐grafted nanosilica (ENS), as nanofillers. These nanocomposites were prepared with the melt‐mixing method at a constant loading level of 2.5 wt %; this loading level was much lower than that used for fillers in conventional composites. The effects of pure NS and ENS on the thermal, structural, mechanical, and dynamic mechanical properties of PP were analyzed with wide‐angle X‐ray diffraction, transmission electron microscopy, thermogravimetric analysis, differential scanning calorimetry, dynamic mechanical analysis, and scanning electron microscopy. The transmission electron microscopy studies showed a better dispersion of ENS in the PP matrix, that is, in the polypropylene‐epoxy‐resin‐grafted nanosilica (PP–ENS) nanocomposite, in comparison with NS in the PP matrix, that is, in the polypropylene–nanosilica (PP–NS) nanocomposite. Also, the thermogravimetric analysis results showed a higher thermal stability for PP–ENS than PP–NS. Furthermore, the dynamic mechanical analysis studies showed an increase in the elastic modulus and glass‐transition temperature for PP–ENS with respect to PP–NS. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2117–2124, 2006
Spectroscopic, thermal, and electrical investigations of PVDF films filled with BiCl3
Authors: Hakeem N. A. , Abdelkader H. I. , El‐sheshtawi N. A. , Eleshmawi I. S. 
Published: August 2006

AbstractPoly(vinylidene fluoride) (PVDF) films filled with BiCl3 in the mass fraction range of 0.1 ≤ W ≤ 10 were prepared. α‐ and β‐Crystalline PVDF phases were detected and characterized by spectroscopic analysis. Fourier transform infrared analysis detected the presence of α‐ and β‐phase head‐to‐head and tail‐to‐tail polymer chain defects. The band detected at 1670 cm−1 was assigned to CC, indicating polarons in the polymeric matrix. The degree of crystallinity increased by increasing the filling level (FL), and the maximum relative β‐phase content was found at w = 5% FL. This result was confirmed by X‐ray diffraction (XRD) and differential scanning calorimetry (DSC) analysis. The X‐ray analysis confirmed the presence of α and β phases, and no peaks corresponding to pure BiCl3 were found. DSC therograms showed a sharp endothermic peak at T1 = 444 K for different FLs because of the melting. This peak was used to calculate the activation energy and the order of the reaction. The DC electrical resistivity was attributed to the one‐dimensional interpolaron hopping mechanism. The FL dependence of log ρ and hopping distance (Ro) at 373 K was observed, indicating the FL affected the distribution of the hopping sites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2125–2131, 2006
Viscoelasticity and morphology of poly(ethylene‐co‐vinyl acetate)/polyisobutylene blends
Authors: Shumsky V. F. , Lipatov Y. , Getmanchuk I. , Usenko A. , Cassagnau P. , Boiteux G. , Melis F. , Lucas J.‐M. 
Published: August 2006

AbstractBlends of an ethylene/vinyl acetate copolymer (EVA) and polyisobutylene of various compositions were prepared by mechanical mixing at a temperature above the melting point of EVA (TmEVA) but below the upper critical solution temperature of 170°C for given blends. The rheological properties of the components and blends were studied in the region of small‐amplitude oscillating deformation at temperatures above and below TmEVA in the frequency range of 0.01–100 rad/s. At temperatures lower than TmEVA, the rheological properties were determined by the existence of the yield stress. With diminishing frequency, the viscosity increased, and the plateau in the relaxation spectrum at low frequencies broadened. The morphology of the blends depended on the conditions of sample heating. The introduction of a finely dispersed filler into the blends led to an anomalous drop in the viscosity. The morphology of the systems that arose by mechanical blending of the molten components was the important factor in the rheological behavior. The observed effects were examined in the framework of the concept of structural networks formed in melts by nonmelted crystallites of EVA. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2700–2707, 2006
Use of nylon 6/polyethylene blends in the preparation of textile yarns
Authors: de Rezende Camila Alves , Schuchardt Ulf Friedrich , Gonçalves Maria do Carmo 
Published: August 2006

AbstractNylon 6 fibers are extensively used by the textile industry because of their excellent properties for yarn manufacturing. In this work, we show that it is possible to prepare yarns of reduced cost with blends of nylon 6 and polyethylene (PE), a lower priced polymer. Blends of nylon 6 and PE (nylon 6/PE) were tested in different compositions. Field emission scanning electron microscopy analyses and tensile tests showed better compatibilization in blends whose components had similar melt flow indices. Without adding compatibilizing agents, we incorporated up to 5 wt % PE into the nylon 6 matrix and successfully prepared yarns of nylon 6/PE blends on an industrial scale. Characterizing the yarns prepared from the blends by conventional techniques employed by the textile industry, we observed values very close to those presented by pure nylon 6 yarns, which indicated that the addition of small amounts of PE to the nylon 6 matrix could reduce the cost of the final yarns without changing significantly the properties of nylon 6. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2142–2148, 2006
Impact of melt impregnation on the color of wood–plastic composites
Authors: Zhang Yaolin , Zhang S. Y. , Chui Ying Hei 
Published: August 2006

AbstractThe aesthetics of wood–plastic composites (WPCs) can affect the acceptance of the products by consumers. This study was aimed at providing a better understanding of how impregnation variables affect color changes, thereby allowing for the development of an optimal process for WPCs. The effects of impregnation parameters and impregnants on the WPC color were investigated in this study via a screening design. Sixteen runs of resolution IV design for seven factors at two levels were conducted. The seven factors were the ratio of maleated polyethylene in the formulations, the ratio of polyethylenes with different molecular weights, four process factors (vacuum, pressure, time, and temperature), and wood species (red maple and aspen). The studied color parameters included the lightness change, chroma change, hue angle change, saturation change, and total color change. All treatments darkened the wood and increased the chroma values and the saturation. Even though all treatments had an impact on the hue angle, the changes were very small. The wood species, impregnants, impregnation time, and temperature played significant roles in the color change and chroma coordinates. However, no parameter dominated the hue angle change and saturation. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2149–2157, 2006
Reflective and electrically conductive palladium surface‐metallized polyimide nanocomposite membranes
Authors: Davis Luke M. , Compton J. M. , Kranbuehl D. E. , Thompson D. W. , Southward R. E. 
Published: August 2006

AbstractA previous article (Southward and Thompson, Chem Mater 2004, 16, 2091) focused on the characterization of surface metallized palladium‐BTDA/4,4′‐ODA (3,3′,4,4′‐benzophenone tetracarboxylic dianhydride‐4,4′‐oxydianiline) hybrid membranes formed by in situ reduction of Pd2+ to Pd○ during thermal imidization of the poly(amic acid) via the protocol of St. Clair et al. (J Am Chem Soc 1980, 102, 876). The present work extended the Pd‐polyimide metallization synthesis to the BPDA/4,4′‐ODA (3,3′,4,4′‐biphenyltetracarboxylic dianhydride‐4,4′‐ODA) polymer. The effects of the Pd2+ ligand on the reductive metallization of BTDA/4,4′‐ODA were also examined for the PdCl2(SMe2)2, PdBr2(SMe2)2, and Pd(CF3COO)2 complexes. The hybrid films were characterized by specular and diffuse reflectivity and by conductivity measurement. Maximum specular reflectivity was in the range of 35%–55%, and conductivity was in the range of 1–10 Ω/square. Scanning electron microscopy and transmission electron microscopy revealed that the initial Pd metal particles formed within the films were in the 3–8 nm range in size. These particles increased in size with irregular shapes at the surface as the metallic exterior emerged. A fraction of the nanometer‐sized Pd particles remained uniformly distributed throughout the bulk of the film. The mechanism for the formation of a metallic surface required selective oxidative degradation of the polyimide at the polyimide–air interface. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2708–2716, 2006
Inhibitive properties of cationic polymers in a borehole environment
Authors: Souza C. E. C. , Fonseca M. V. , Sá C. H. , Nascimento R. S. V. 
Published: August 2006

AbstractThe adsorption behavior of poly(diallyldimethylammonium chloride) (PDADMAC) and of a copolymer with acrylamide on a native clay was studied as a function of the molecular weight of homopolymers, the ionic strength of the medium, and the ionic nature of the constituent blocks of the polymers. The clay was used without further purification or treatment in order to simulate a borehole environment. The properties of the clay–polymer systems studied were evaluated through total organic carbon analysis, thermogravimetric analysis (TGA), and X‐ray diffraction analysis. The adsorption isotherms showed that all cationic polymers had high affinity for the clay, even in a highly saline medium and that the amount of polymer adsorbed strictly depended on the length of the macromolecular chain. The TGA results showed that polymer adsorption was able to reduce the water content of the clay surfaces, independently of the molecular weight of the homopolymer. The inhibitive properties of the polycations were measured by conventional oilfield cuttings rolling tests, which showed that these polymers were able to reduce the dispersion and disintegration of the clay cuttings. The results also showed that inhibition was directly related to the clay–polymer interactions and, therefore, to the polymer structure. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2158–2163, 2006.
Thermally bonded nonwoven filters composed of bi‐component polypropylene/polyester fiber. II. Relationships between fabric area density, air permeability, and pore size distribution
Authors: Wang X. Y. , Gong R. H. 
Published: August 2006

AbstractThe relationships between the pore size, fabric area density, and air permeability of the three‐dimensional (3D) nonwoven filter samples produced using a new 3D forming process has been studied. Results indicate that the thermally bonded nonwoven filter samples consist of multiple filtration layers of interconnected pores and tortuous pore paths through the fabric thickness. Both the bubble point pore diameter and the mean flow pore diameter of the produced filter samples increase linearly with increase in the reciprocal of the fabric area density. The air permeability of the nonwoven filter samples decreases significantly to a certain value with increasing fabric area density, and then becomes almost stable with further increasing of fabric area density. The measured pore size data in the thermally bonded nonwoven samples were found to follow all the bi‐normal, bi‐lognormal, and bi‐Weibull distributions. Taken into account together the pore structure, pore size distribution, air permeability, and fabric area density, the new 3D forming system can substitute most of the commercial polyester filter media with significantly reduced costs. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2264–2275, 2006
Interpolymer interactions and miscibility in poly(n‐butyl methacrylate‐co‐methacrylic acid)/poly(styrene‐co‐N,N‐dimethyl acrylamide) blends
Authors: Hadj‐Hamou Assia Siham , Djadoun Said 
Published: August 2006

AbstractThe miscibility of poly(n‐butyl methacrylate‐co‐methacrylic acid) containing 18 mol % methacrylic acid (BMAM‐18) and poly(styrene‐co‐N,N‐dimethyl acrylamide) containing 17 mol % N,N‐dimethyl acrylamide (SAD‐17) was investigated with viscometry, differential scanning calorimetry (DSC), and Fourier transform infrared (FTIR) spectroscopy. The DSC analysis showed a single glass‐transition temperature for all the blends, indicating that these copolymers were miscible over the entire composition range. The glass‐transition temperatures of these blends were higher than those calculated with the additivity rule. This was characteristic of the presence of specific interactions. The interactions between BMAM‐18 and the tertiary amide of SAD‐17 were studied with FTIR spectroscopy, which revealed that hydrogen‐bonding interactions occurred between the hydroxyl groups of BMAM‐18 and the carbonyl amide of SAD‐17. A new band characterizing these interactions appeared around 1613 cm−1. The quantitative results showed that the fraction of the associated amide increased with an increase in the amount of the acidic BMAM‐18 copolymer. Although BMAM‐18 and SAD‐17 led to homogeneous solutions in butan‐2‐one, as the concentration of N,N‐dimethyl acrylamide increased to 32 mol % [as within the poly(styrene‐co‐N,N‐dimethyl acrylamide) containing 32 mol % N,N‐dimethyl acrylamide], complexation occurred when this latter compound was mixed with BMAM‐18 in butan‐2‐one. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2717–2724, 2006
High‐performance filaments from compatibilized polypropylene/clay nanocomposites
Authors: Joshi M. , Viswanathan V. 
Published: August 2006

AbstractPolypropylene (PP)/nanoclay composite filaments were produced by melt spinning and characterized to study the effect of the compatibilizer and the role of the nanoclay in improving the physical properties. The compatibilizer was maleic anhydride grafted PP. Clay loadings up to 1 wt % with up to 3 wt % compatibilizer were explored. There was a significant improvement in the tensile, thermal, and dynamic mechanical properties and creep resistance of PP/nanoclay composite filaments over neat PP filaments at very low clay loadings of 0.25–0.5 wt % and a compatibilizer/clay ratio of 2:1. The properties were correlated to the morphology of the nanocomposite filaments, which was investigated with differential scanning calorimetry, X‐ray diffraction, and transmission electron microscopy. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2164–2174, 2006.
A high‐performance positive‐working photosensitive polyimide: Effects of reactive end groups on the physical properties of the films
Authors: Jung Myung‐Sup , Joo Won‐Jae , Kwon Ohyun , Sohn Byung H. , Jung Hee‐Tae 
Published: August 2006

AbstractTo investigate the effects of reactive end‐cappers on the performance of PI precursors and the resulting polyimide (PI) films, poly(amic acid)s (PAAs) as a base polymer of the positive‐working photosensitive polyimides (PSPIs) were synthesized via ring‐opening polymerization of 4,4′‐oxydiphthalic anhydride and 4,4′‐oxydianiline with four different reactive end‐cappers [maleic anhydride, citraconic anhydride, 2,3‐dimethylmaleic anhydride (DMA), and 5‐norbornene‐2,3‐dicarboxylic anhydride (NDA)]. During imidization of these end‐capped PAAs to form the corresponding PI films, chain extension and crosslinking reactions of the respective end groups occurred, resulting in an improvement in the mechanical and thermal properties despite the low molecular weight of the precursors. However, the UV transmittance at ˜365 nm, an important property of PSPIs for thick‐film applications, such as stress buffer layers, was strongly influenced by the type of end‐capper used. These behaviors were understood in terms of the optimized geometries and the simulated UV–vis spectra of modeled end groups determined from density functional theory calculations. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:2180–2188, 2006