bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermal and mechanical properties of poly(ethylene terephthalate)/lamellar zirconium phosphate nanocomposites
Authors: Brandão Lilian S. , Mendes Luís C. , Medeiros Marta E. , Sirelli Lys , Dias Marcos L. 
Published: August 2006

AbstractThe preparation of nanocomposites of poly (ethylene terephthalate) (PET) and lamellar zirconium phosphorous compounds by melt extrusion was investigated. Two types of zirconium phosphorous compounds were synthesized by the direct precipitation reaction method: α‐zirconium bis(monohydrogen orthophosphate) monohydrate (ZrP) and organic–inorganic hybrid layered zirconium phenylphosphonate (ZrPP). Composites containing 2 and 5 wt % ZrP and ZrPP were prepared in a twin‐screw extruder and specimens were obtained by injection molding. The extent of dispersion of the layered filler in the composite matrix was investigated by X‐ray diffraction and transmission electron microscopy (TEM). The crystallization and thermal properties were analyzed by differential scanning calorimetry and thermogravimetry, and the mechanical properties were evaluated by tensile tests. Whereas ZrP‐containing composites showe characteristic diffraction peaks at 2θ 11.7° (d = 7.54 Å), indicative of no delamination, ZrPP showed practically no low‐angle diffraction peak at 2θ 5.5° (d = 15.24 Å), indicating loss of the layered order. TEM images of ZrPP particles indicated the formation of an intercalated/partially delaminated nanocomposite. The behavior was attributed to the higher affinity of the polyester with phenyl groups on the platelet surface of ZrPP. In both cases, the addition of the fillers increased the crystallization rate and the modulus. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3868–3876, 2006
Removal of endocrine disruptors in milk by circulation through polydimethylsiloxane tubing
Authors: Higuchi Akon , Takayama Emi , Hirai Kazunari , Ishikawa Takako , Takizawa Nobuko , Sakurai Masaru , Egashira Satsuki , Matsuoka Yuki , Natori Shizue Hayashi 
Published: August 2006

AbstractA simple circulating system was developed, in which an aqueous solution, cow milk, or human milk was circulated through hydrophobic polymeric tubing to remove the endocrine disruptors from the solution by sorption into the tubing. The effect of circulating parameters, such as tube length, circulating time, and flow rate, against the removal ratio (R) of endocrine disruptors was investigated. R of 1,2,3,4,5,6‐hexachlorocyclohexane (γ‐HCH, lindane) increased with the length of the hydrophobic polymeric tubing, circulating time, and flow rate when cow milk containing 1 ppm γ‐HCH was circulated through polydimethylsiloxane tubing. The R values of several endocrine disruptors with different octanol–water distribution coefficients (log Pow) was investigated for γ‐HCH and dichlorodiphenyltrichloroethane in an aqueous solution, cow milk, and human milk. A similar trend for R versus log Pow of the human milk to that of the aqueous solution and cow milk was observed. The R values of the endocrine disruptors decreased in the following order: Aqueous solution > Human milk > Cow milk. Stable micelles in cow milk disturbed the shift of the endocrine disruptors from the milk micelles into the hydrophobic tubing. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:3634–3640, 2006
Synthesis and properties of fluorinated aromatic poly(amide imide)s based on 4,4′‐bis(4‐amino‐2‐trifluoromethylphenoxy)benzophenone and various bis(trimellitimide)s
Authors: Su Yu‐Yang , Yang Chin‐Ping 
Published: August 2006

AbstractA CF3‐containing diamine, 4,4′‐bis(4‐amino‐2‐trifluoromethylphenoxy)benzophenone (2), was synthesized from 4,4′‐dihydroxybenzophenone and 2‐chloro‐5‐nitrobenzotrifluoride. Imide‐containing diacids (3 and 5Ba–5Bg) were prepared by the condensation reaction of aromatic diamines and trimellitic anhydride. Then, two series of novel soluble aromatic poly(amide imide)s (PAIs; 6Aa–6Ak and 6Ba–6Bg) were synthesized from a diamine (4Aa–4Ak or 2) with the imide‐containing diacids (3 and 5Ba–5Bg) via direct polycondensation with triphenyl phosphate and pyridine. The aromatic PAIs had inherent viscosities of 0.74–1.76 dL/g. All of the synthesized polymers showed excellent solubility in amide‐type solvents, such as N‐methyl‐2‐pyrrolidone and N,N‐dimethylacetamide (DMAc), and afforded transparent and tough films by DMAc solvent casting. These polymer films had tensile strengths of 90–113 MPa, elongations at break of 8–15%, and initial moduli of 2.0–2.9 GPa. The glass‐transition temperatures of the aromatic PAIs were in the range 242–279°C. They had 10% weight losses at temperatures above 500°C and showed excellent thermal stabilities. The 6B series exhibited less coloring and showed lower yellowness index values than the corresponding 6A series. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:3641–3653, 2006
Experimental and theoretical approaches to investigating the miscibility of anhydride‐containing copolymers and dextran
Authors: Can Hatice Kaplan , Barsbay Murat , Güner Ali , Rzaev Zakir M. O. 
Published: August 2006

AbstractThe miscibility behavior of dextran (Dx) with synthesized functional binary poly(citraconic anhydride‐acrylamide) (poly(CA‐alt‐AAm) and ternary poly(citraconic anhydride‐acrylamide‐vinyl acetate) (poly(CA‐co‐AAm‐co‐VA) copolymers was investigated in dilute aqueous solutions by viscometry and in a solid state by Fourier transform infrared (FTIR) spectroscopy. The relative viscosities of each polymer and their blends with Dx/related copolymer ratios of 20 : 80, 50 : 50, and 80 : 20 were measured at body temperature, 37°C, in bidistilled and deionized water. Starting with the classical Huggins equation, results of the viscosity measurements of each parent polymer and their blends were interpreted in terms of miscibility parameters: Δk, Δb, α, β, ΔB, and μ. Based on the sign convention used with these criteria, the miscibility between Dx and related copolymers was found to increase with the weight fraction of Dx in the blends and with the number of AAm units in the copolymer composition. From FTIR spectral analysis, supporting results were achieved that explained the interactions between Dx and the copolymers. Miscibility behavior was also investigated theoretically with Askadskii's miscibility criterion, and the theoretical calculations provided strong evidence supporting the experimental results. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2132–2141, 2006
Surface functionalization of polyolefin films via the ultraviolet‐induced photografting of acrylic acid: Topographical characterization and ability for binding antifungal agents
Authors: Costamagna Vanina , Wunderlin Daniel , Larrañaga Maider , Mondragon Iñaki , Strumia Miriam 
Published: August 2006

AbstractThe photoinduced graft copolymerization of acrylic acid with ultraviolet radiation onto films of poly(vinyl chloride), polypropylene, and polyethylene was studied. Benzophenone was used as the initiator for most of the experiments performed. The percentage of grafting was determined by gravimetric measurements, and the characterization of the grafted films was carried out by chemical analysis (Fourier transform infrared spectroscopy, volumetric titration, and dye adsorption). In all samples, the grafted yield increased with the ultraviolet exposure time. High levels of grafting were obtained at room temperature. In addition, optical and atomic force microscopy allowed the topography of the modified films to be studied as a function of the reaction time. The pendant functional groups that were grafted were then used to bind antifungal agents, such as natamycin and crystal violet, and the antifungal properties of the films were demonstrated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:2254–2263, 2006
Synthesis of a thioether modified hyperbranched polyglycerol and its template effect on fabrication of CdS and CdSe nanoparticles
Authors: Wan Decheng , Fu Qiang , Huang Junlian 
Published: August 2006

AbstractA thioether‐containing hyperbranched polyglycerol (PG) was synthesized by a simple and effective two‐step reaction; first a part of the hydroxyls of PG was transformed to carbamates by the reaction with the highly reactive 2‐chloroethyl isocyanate, and then the chlorine group was S‐alkylated with HS(CH2)nOH (n = 2, 6, 11). The resulting PGs with various molecular weights were successfully used as template for synthesis of nanoscale cadmium chalcogenide quantum dots (QDs). It was found that the size of these QDs was dependent on the polymer template. Moreover, after solvent evaporation, the polymer was assembled into large cluster, and a variety of morphologies were formed by the cluster inside the QDs. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3679–3684, 2006
Development of dispersion in rubber‐particle compounds in internal and continuous mixers
Authors: White James L. , Liu Dan , Bumm Sug Hun 
Published: August 2006

AbstractExperiments of mixing silica, carbon black, and CaCO3 into various elastomers (EPDM, NBR, and SBR) were carried out in this paper. We have investigated the breakup of filler agglomerates in the mixing process and compared the mixing results between the internal mixer and the NEX‐T continuous mixer. We have evaluated the impact of the elastomer type, filler type, filler loading, and mixing time on the breakup of filler agglomerates. When the filler agglomerates break up, the agglomerate size was reduced to a steady state size. The steady state size primarily depends on the type and primary particle size of the filler. A model was developed for the rate of agglomerate breakup. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3940–3943, 2006
Modification of polyacrylonitrile precursors for carbon fiber via copolymerization of acrylonitrile with ammonium itaconate
Authors: Liu Jian‐Junn , Ge Heyi , Wang Cheng‐Guo 
Published: August 2006

AbstractAmmonium‐modified polyacrylonitrile was prepared by free‐radical solution copolymerization of acrylonitrile (AN) with ammonium itaconate (AIA), and then it was spun into precursor fibers in this study. Effects of AIA and itaconic acid on the characteristics of the copolymers and precursor fibers were studied in contrast. It has been found that the ammonium modification could obviously increase the hydrophilicity of the copolymer. And in the spinning processes, modified copolymer can withstand higher total draw‐ratio of 12.6 folds, while unmodified copolymer only 8.5 folds. The void volume, fineness, tenacity, and elongation at‐break of the ammonium‐modified precursors are all improved and enhanced. WAXD test manifested that the modified precursors had higher degree of orientation. DSC test showed that the thermal properties of the modified and unmodified precursor fibers were almost the same. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 102: 2175–2179, 2006
Modified sulfonated poly(phthalazinone ether ketone) membranes with inorganic particles for potential applications in PEMFCs
Authors: Hongwei Zhang , Baoku Zhu , Youyi Xu 
Published: August 2006

AbstractComposite membranes of sulfonated poly (phthalazinone ether ketone)s (SPPEK)s and Zirconium hy drogen phosphate (ZrP) or 12‐phosphotungstic acid (PWA) were prepared by direct blending method. The physicochemical properties of these composite membranes were studied through Fourier transform infrared attenuated total reflection (FTIR‐ATR) spectroscopy, field‐emission scan ning electron microscope (FSEM), X‐ray diffraction (XRD) and thermogravimetry analysis (TGA). The SPPEK/PWA composite membranes showed better properties, whose highest proton conductivity could reach 0.17 S/cm at 80°C under 100% relative humidity (R.H.). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3972–3977, 2006
Synthesis of poly(epichlorohydrin‐g‐methyl methacrylate) graft copolymers by the combination of cationic and atom transfer radical polymerization
Authors: Cakmak Ismail , Baykara Haci 
Published: August 2006

AbstractPoly(epichlorohydrin) possessing chloromethyl side groups in the main chain was used in the atom transfer radical polymerization of methyl methacrylate and styrene to yield poly(epichlorohydrin‐g‐methyl methacrylate) and poly(epichlorohydrin‐g‐styrene graft copolymers. The polymers were characterized by 1H NMR spectroscopy, gel permeation chromatography, differential scanning calorimetry, and fractional precipitation method. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2725–2729, 2006
Preparation and evaluation of floating‐bioadhesive microparticles containing clarithromycin for the eradication of Helicobacter pylori
Authors: Zheng Jianhua , Liu Chaowu , Bao Decai , Zhao Yanjun , Ma Xiaojun 
Published: August 2006

AbstractThe development of a gastric floating‐bioadhesive drug delivery system to increase the efficacy of clarithromycin against Helicobacter pylori is described. Floating‐bioadhesive microparticles containing clarithromycin were prepared by a combined method of emulsification/evaporation and internal/ion gelation for the treatment of H. pylori infection. Ethylcellulose microspheres (EMs) were prepared by the dispersion of clarithromycin, ethylcellulose, and chitosan in dichloromethane and subsequent solvent evaporation. EMs were coated with alginate by the internal gelation process to obtain alginate–ethylcellulose microparticles (AEMs); then, AEMs were dispersed in a chitosan solution, and chitosan–alginate–ethylcellulose microparticles (CAEMs) were obtained by ion gelation to enhance the bioadhesive properties. The morphologies of EMs and CAEMs were investigated under optical and scanning electron microscopes. In vitro buoyancy and drug‐release testing confirmed the good floating and sustained‐release properties of CAEMs. About 74% of the CAEMs floated in an acetate buffer solution for 8 h, and 90% of the clarithromycin contained in the CAEMs was released within 8 h in a sustained manner. In vivo mucoadhesive testing showed that 61% of the CAEMs could be retained in the stomach for 4 h. Under a pretreatment with omeprazole, the clarithromycin concentration in gastric mucosa of the CAEM group was higher than that of the clarithromycin solution group. These results suggest that CAEMs might be a promising drug delivery system for the treatment of H. pylori infection. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2226–2232, 2006
Monomer apparent reactivity ratios for acrylonitrile/methyl vinyl ketone copolymerization system
Authors: Hou Chen , Liu Junshen , Ji Chunnuan , Ying Liang , Sun Hongbin , Wang Chengguo 
Published: August 2006

AbstractMethyl vinyl ketone was firstly used to successfully copolymerize with acrylonitrile. This was achieved by using azobisisobutyronitrile as the initiator, and dimethyl sulfoxide as the solvent. Effect of copolymerization systems on monomer apparent reactivity ratios for copolymer of acrylonitrile with methyl vinyl ketone was studied for contrast. Values of monomer apparent reactivity ratios were calculated by Kelen–Tudos method. It has been found that the apparent reactivity ratios in aqueous suspension polymerization system were similar to those in solution polymerization system at polymerization conversion less than 20%. Beyond 50% of conversion, the changes of monomer apparent reactivity ratios become less prominent. In water‐rich reaction medium [(H2O/dimethylsulfoxide (DMSO)>80/20), monomer apparent reactivity ratios were approximately equivalent to those in aqueous suspension polymerization system. In DMSO‐rich reaction medium (DMSO/H2O > 80/20), apparent reactivity ratios were similar to those in solution polymerization system. Values of apparent reaction ratios both decreased when AN/MVK copolymer was synthesized in DMF and DMAc. The values of apparent reaction ratios gradually tend to 1 with increasing the copolymerization temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4045–4048, 2006
Rheological behavior and microstructure of bimodal suspensions of core‐shell structured swollen particles
Authors: Nakamura Hiroshi , Tachi Kazuyuki 
Published: August 2006

AbstractThe rheological behavior and microstructure of bimodal suspensions of core‐shell structured swollen particles have been examined with changing volume ratio of two different sized particles. As the volume fraction of large particles increases, the viscosity, degree of shear‐thinning, and the critical shear stress σc decreases, while the interparticle distance ξ of the microstructure increases. The suspensions exhibit single mode rheological behavior and have a single diffraction peak in the SAXS profiles. These results suggest that the bimodal suspensions of the core‐shell structured swollen particles behave likely to unimodal suspensions of hard spheres with alloy like single mode microstructure composed of hypothetical intermediate size particle. The relationship between σc and ξ can be represented as σc = 3kT/4πξ3, which corresponds to the dynamics of the Brownian hard sphere model with ξ being the particle diameter. These findings indicate that the shear‐thinning of the suspensions can be attributed to dynamical competition between the thermal motion and the hydrodynamic motion under shear flow and that the mechanism can be applied to bimodal suspensions of the swollen particles as well as unimodal suspensions of hard spheres. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 102: 2212–2217, 2006
Effects of hygrothermal ageing on mechanical properties of flax pulps and their polypropylene matrix composites
Authors: Retegi A. , Arbelaiz A. , Alvarez P. , Llano‐Ponte R. , Labidi J. , Mondragon I. 
Published: August 2006

AbstractThe aim of this work was to study the kinetics of water uptake and its influence on mechanical behavior of both flax pulps and their composites with a maleic anhydride polypropylene copolymer (MAPP) modified polypropylene (PP) matrix by immersion in distilled water at 30, 50, 70, and 100°C. Both the influence of two different MAPP compatibilizers and the optimum doses of each ones were analyzed. The kinetics of water uptake was studied from weight measurements at regular interval times. The diffusion coefficient was dependent on the immersion temperature and MAPP content. Tensile modulus and strength of single flax fiber decreased by water immersion. Both flexural strength and modulus of composites decreased as a result of the combined effect of thermal ageing and moisture absorption. MAPP coupling agent increases moisture resistance and mechanical properties for MAPP‐modified systems with respect to the unmodified ones. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3438–3445, 2006
Effect of ionic strength on the temperature‐dependent behavior of hydroxypropyl methylcellulose solution and matrix tablet
Authors: Xu Xiao Ming , Song Yun Mei , Ping Qi Neng , Wang Yan , Liu Xian Yang 
Published: August 2006

AbstractThe focus of the present study is on the temperature‐dependent behavior of hydroxypropyl methylcellulose (HPMC) solutions at various ionic strength levels. Such behavior is then introduced into the study of tablet dissolution with the aim of explaining why ionic strength could vary the dissolution rate or cause the tablets to disintegrate. The results show that increasing the concentration of solute in the dissolution media will affect the thermal property of hydrated HPMC and then have an effect on the matrix tablets dissolution process. Of the thermal property, reduction of the cloud point is believed to have some relationship with the decrease of the dissolution rate, and decline of the thermal gelation temperature (TGT) might be responsible for the disintegration of the matrix tablets. A “gel out” process concerning the mechanism of the disintegration has been put forward, and a rheological method to test the lower critical solution temperature (LCST) is also presented. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4066–4074, 2006
Properties of calcium carbonate filled and unfilled polystyrene foams prepared using supercritical carbon dioxide
Authors: Chiu Fang‐Chyou , Lai Sun‐Mou , Wong Chang‐Ming , Hui Chang Chaio 
Published: August 2006

AbstractFoaming behaviors of four polystyrenes (PSs) filled and unfilled with various amounts of CaCO3using supercritical carbon dioxide were investigated. The PSs include three general purpose grades with different molecular weights (different melt index) and one high impact grade. By adjusting foaming conditions, foam density was determined for each investigated sample. In general, the sample with a lower molecular weight (i.e. higher melt index) yielded a lower foam density for the three general purpose PSs. With the addition of CaCO3filler, foam density would increase. The inclusion of rubber in high impact PS was found to complicate its foaming behavior. A qualitative correlation between various types of filled/unfilled PSs and foam density was found in a certain range. An optimum foaming temperature range was required to obtain low foam density for each sample. The corresponding change in matrix modulus by employing various PSs and various filler contents apparently affected the resulting foam density. Although several factors were involved in foaming conditions, the addition of CaCO3filler played a significant role in reducing cell size and increasing cell density of the PSs foams investigated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2276–2284, 2006
Preparation of phenol–urea–formaldehyde copolymer adhesives under heterogeneous catalysis
Authors: Schmidt Kerstin , Grunwald Dirk , Pasch Harald 
Published: August 2006

AbstractA new synthetic strategy for PUF copolymers based on three steps was developed. In the first step, two precondensates of phenol with formaldehyde and urea with formaldehyde, respectively, were produced. In the second step, the two precondensates were mixed and condensed using a heterogeneous catalyst in a tube reactor at 90°C. The last step is a vacuum distillation to reach the final copolymer compositions. With regard to the properties, the products can be used as adhesive. The copolymers were analysed by gel permeation chromatography (GPC), 13C‐NMR‐spectroscopy, and MALDI‐TOF mass spectrometry. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2946–2952, 2006
Phase morphology control of immiscible polymer blends under vibration force field
Authors: Du Yao‐Xue , Qu Jin‐Ping 
Published: August 2006

AbstractThe formulas of polymer melt velocity, shearing rate, and shearing stress under vibration force field are established through simplifying coaxial cylinder circular flow into plane motional flow. On the basis of the concept of energy ratio model, the rate of energy dissipation and the energy ratio about blending systems are expressed, and the affected factors on phase morphology are studied theoretically. The calculated and analytical results of dynamic flow field and energy ratio show that with the increasing of vibration strength, the fluctuating shearing force field exerted on polymer melt and the negative pressure diffusion behavior of instantaneous impulse strengthen. The energy consumption for phase inversion of immiscible polymer blends under vibration force field is less than that of steady state. The parameter controllability of vibration force field provides a more effective method for realizing phase inversion of immiscible polymer blends. The analysis of transmission electron microcopy micrographs of ethylene–propylene–diene terpolymer/polypropylene blends verifies that the energy ratio model and its phase morphology controlling theory have a good coincidence in comparison with experimental results. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2299–2307, 2006