bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of molecular structure of star S‐SBR on its properties
Authors: Zhao S. , Zhang X. , Jin G. 
Published: June 2003

AbstractStar S‐SBR can be produced in one step by a kind of new anion polymerization technology in which modified naphthalene lithium acted as the initiator and SnCl4 acted as the coupling agent. The influence of the molecular structure of star S‐SBR on its mechanical and dynamic properties was studied. The results showed that Star S‐SBR, with styrene (St) content of 20–25% and vinyl (Bv) content of 45%, and molecular weight for one arm (MW/arm) of 8 ten thousand, has good mechanical properties, low rolling resistance and high wet grip. The end of the S‐SBR molecular chain was coupled by a coupling agent, which resulted in low internal friction loss. The bound rubber content of star S‐SBR‐carbon black compound was larger than that of linear S‐SBR compound. Experiments showed that the Sn—C key in star S‐SBR broke easily under shear action and formed a free group, and the free group bonded immediately with the active group on the surface of a carbon black particle. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2311–2315, 2003
Effects of thermal ageing treatment and antioxidants on the positive temperature coefficient characteristics of carbon black/polyethylene conductive composites
Authors: Seok Park Jong , Hyun Kang Phil , Chang Nho Young , Hack Suh Dong 
Published: June 2003

AbstractPolyethylene (PE)‐filled with carbon black (CB) is a prototypical composite that displays resistance switching. These materials can exhibit either a positive temperature coefficient (PTC) or negative temperature coefficient (NTC). The CB‐filled semicrystalline polymer composites ideally need antioxidants, which stabilize the composites against thermooxidative degradation, because they should be resistant to the severe conditions of high temperature. The characterization of PTC materials is affected by the crystallinity of the polymer, and the crystallinity of the polymer is changed with thermal ageing treatment. Thermal ageing of PTC samples was conducted in an oven in the range 50–140°C, in air. The composites, containing 0.5–3% (by weight) Irganox 1076 (Ciba‐Geigy), were irradiated under nitrogen at room temperature with different doses of gamma rays from a 60Co source. The resulting composites were analyzed by differential scanning calorimetry, gel fractionation, X‐ray diffraction, and dynamic mechanical analysis. The conductivity of the composites depended on the amounts of antioxidants and the duration of the thermal ageing treatment. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2316–2322, 2003
Preparation of polyethylene–clay nanocomposites directly from Na+ montmorillonite by a melt intercalation method
Authors: Wang Shaofeng , Hu Yuan , Tang Yong , Wang Zhengzhou , Chen Zuyao , Fan Weicheng 
Published: June 2003

AbstractPolyethylene (PE)/clay nanocomposites were prepared directly from Na+ montmorillonite by a melt intercalation technique, using hexadecyl trimethyl ammonium bromide (C16) as a reactive compatibilizer. Three other polymer–clay nanocomposites were also prepared by this new technique. Their structures were characterized by X‐ray diffraction and transmission electron microscopy. The mechanism of this new method was studied. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2583–2585, 2003
Enzyme‐catalyzed hydrolysis of poly(ethylene terephthalate) cyclic trimer
Authors: Hooker Jacob , Hinks David , Montero Gerardo , Icherenska Magdelena 
Published: June 2003

AbstractOligoesters present in poly(ethylene terephthalate) fibers are commonly extracted from the fiber during processing, such as aqueous‐based dyeing. Aqueous, insoluble oligoesters, particularly cyclic trimers that precipitate on processing machinery and on the fiber surface are difficult to remove under benign conditions. Reported is a new method for the efficient removal of cyclic trimer by enzyme‐catalyzed hydrolysis. Almost complete hydrolysis of trimer was accomplished at pH 8 and 60°C. Effects of time, agitation, surfactant, and enzyme and trimer concentrations on the efficiency of hydrolysis are reported. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2545–2552, 2003
Synthesis and asymmetric nanofiltration membrane performance of heterogeneously sulfonated aromatic polyimides
Authors: Kim In‐Chul , Lee Kew‐Ho , Tak Tae‐Moon 
Published: June 2003

AbstractSoluble sulfonated polyimides (PI) were heterogeneously synthesized by reacting soluble PIs with sulfur trioxide and dichloromethane solvent. The sulfonated PIs were soluble in polar solvents like N‐methyl‐2‐pyrrolidone (NMP) and N,N'‐dimethylformamide. The sulfonated PIs were characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, differential scanning calorimetry, thermogravimetric analysis, triangular phase diagram, and back titration. Asymmetric nanofiltration membranes were prepared by the phase inversion method from the casting solution containing NMP and diethyleneglycol dimethylether (DGDE). Introducing DGDE as an additive in the casting solution decreased pore size. The rejection rates of organic molecules and salts were investigated. The observed salt rejection of the membrane was of the order R(Na2SO4) > R(NaCl) > R(CaCl2). The membrane morphology was investigated by scanning electron microscopy. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2483–2489, 2003
Microhardness of ternary blends of polyolefins with recycled polymer components
Authors: Berdjane K. , Berdjane Z. , Rueda D.R. , Bénachour D. , Baltá‐Calleja F.J. 
Published: June 2003

AbstractMicrohardness tests, Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC) measurements were performed on melt‐pressed films of multicomponent blends based on low‐density polyethylene (LDPE), linear LDPE (LLDPE), high‐density polyethylene (HDPE), and polypropylene (PP), and their recycled homologues. Some of the PE blends also contained ethylene‐propylene‐diene monomer (EPDM) as compatibilizer. In all cases, the variation of microhardness as a function of content of the recycled component follows the additivity law of components. Thus, the range of hardness values of polyolefin blends can be controlled by choice of both components and their relative content in the blend. The hardness of the components increases from LDPE, to LLDPE, to HDPE, to PP and increases from 20 to 84 MPa. For recycled components, the hardness values are reduced by ∼15%. According to DSC results, all the blends are immiscible. Results are discussed in terms of the levels of crystallinity reached for the different blends. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2046–2050, 2003
Probe selection and description in IGC: A nontrivial factor
Authors: Schreiber H. P. 
Published: June 2003

AbstractInverse gas chromatography (IGC) has found many uses in the characterization of polymer surfaces and their interaction capabilities. The IGC method relies on the selection of vapors with which to probe polymer surfaces. Problems attached to the volatile phase in IGC are considered. One of these is the temperature dependence of the probe molecule dimensions. Experimental work shows that correcting for this temperature dependence is recommended when IGC work is carried out at temperatures removed from the ambient by more than 30°C. A second problem area is a possible variation in the orientation of adsorbed probe molecules. The variable orientation of linear alkane probe molecules on a polystyrene substrate is demonstrated, as is an orientational degree of freedom when diols of varying chain lengths are adsorbed on polymeric as well as on inorganic substrates. A conclusion reached from the experiments of this work is that acid–base parameters generated by the IGC method have relative but not necessarily absolute significance. Further, the orientation of polar probe molecules is dependent on the force field generated by the underlying substrate, which may be characterized by its total surface free energy. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2323–2330, 2003
Effect of various additives on pore size of polysulfone membrane by phase‐inversion process
Authors: Kim In‐Chul , Lee Kew‐Ho 
Published: June 2003

AbstractThe phase‐inversion process was used to prepare integrally skinned asymmetric polysulfone (PSf) membranes with different pore sizes. Membranes were prepared from a casting solution of PSf; N‐methyl‐2‐pyrrolidone (NMP) as solvent; and 1,4‐dioxane, diethylene glycol dimethyl ether (DGDE), acetone, and γ‐butyrolactone (GBL) as additives by immersing them in water as a coagulant. The effect of the additives on membrane performance and structure was investigated. The low miscibility of 1,4‐dioxane, DGDE, and acetone with the coagulant resulted in reduced membrane pore size. However, by using GBL as additive pore size of the membrane was slightly increased because of its higher miscibility with the coagulant than NMP. Changing the amount of additives in the casting solution could control the molecular‐weight cutoff values of asymmetric membranes. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2562–2566, 2003
Toughening of trifunctional epoxy using an epoxy‐functionalized hyperbranched polymer
Authors: Ratna D. , Varley R. , Simon G. P. 
Published: June 2003

AbstractChemorheology of curing as well as the phase separation behavior of an epoxy‐functionalized hyperbranched polymer (HBP)‐modified triglycidyl p‐amino phenol (TGAP) epoxy mixtures has been studied by several techniques. There was little change in gel time as a result of addition of HBP up to 10% of HBP, even though the HBP reacts at a slower rate with amine hardeners compared to the TGAP alone. The thermal and dynamic viscoelastic behavior of the modified matrices have been examined and compared with the unmodified TGAP matrix. Finally, impact properties have been discussed in terms of the morphological behavior for a TGAP matrix modified with various amounts of HBP. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2339–2345, 2003
Study on 1‐4 cycloaddition reaction. I. Synthesis and optimization of new adduct using Diels–Alder reaction
Authors: Mazroua Azza M. , Youssif M. A. 
Published: June 2003

AbstractThe present investigation has been achieved in accordance with the Diels–Alder reaction (1,4 cycloaddition) to produce a new halogenated bicyclic adduct. ortho‐Bromoallylbenzoate is a new dienophile that was prepared in a pure form, and its structure was confirmed. The Diels–Alder syntheses of hexachlorocyclopentadiene and the new dienophile were studied to determine the optimum condensation reaction conditions under a temperature range of 90–160°C, reaction times of 1–8 h, and molar diene/dienophile ratios from 1:1 to 5:1 as a consequence. The optimum conditions reached were a temperature of 140°C, an initial diene/dienophile molar ratio of 3:1, and a duration time of 6 h. The maximum stoichometric yield under these optimum conditions (82.5%) was obtained. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2331–2338, 2003
High‐resolution thermogravimetry/coupled mass spectrometry analysis of flame‐retardant rubber
Authors: Gupta Y. N. , Chakraborty Amitabh , Pandey G. D. , Setua D. K. 
Published: June 2003

AbstractA bromobutyl rubber composition containing a variety of conventional flame retardants, such as Saytex (decabromodiphenyl oxide), Sb2O3, chlorinated paraffin wax, and polychloroprene rubber, was prepared and used to coat nylon 6 fabric in a laboratory‐coating device. An attempt was made to evaluate the decomposition profile, the evolved gases, and the kinetics of the decomposition process at a dynamic heating rate with high‐resolution thermogravimetric analysis (HR‐TGA). HR‐TGA was used with mass spectrometry for evolved gas analysis (EGA). The HR‐TGA results were compared with results from conventional thermogravimetric analysis (TGA) at a constant heating rate; the former offered sharp transitions, an economic timescale, and an accurate activation energy. The resolution optimization for stability analysis and the effect of its variation on the kinetic parameters offered better results for HR‐TGA than conventional TGA. A lifetime and temperature relationship was evaluated in HR‐TGA with Toop's method, and it was observed that the shelf life decreased sharply with temperature. The effluents HBr, HCl, Br ·, and Cl ·, generated between 210 and 496°C during EGA, were correlated with the thermal stability and fire‐retardancy behavior of the material. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2051–2057, 2003
Thermal degradation of electron beam crosslinked polyethylene and (ethylene–vinylacetate) blends in hot water
Authors: Hassanpour S. , Khoylou F. , Jabbarzadeh E. 
Published: June 2003

AbstractLow‐density polyethylene and (ethylene–vinylacetate) blends in pure form were exposed to electron beam radiation at doses between (80–150) kGy, at room temperature, in air. Postirradiation thermal aging was done through immersing the samples in hot water at 95°C. Mechanical properties and changes in chemical structure were determined after 1500 h. Accelerated oven aging test was carried out on thin films after immersing them in hot water for 1000 h. Heat aging treatment showed that the blends have a convenient thermal stability compared to polyethylene. Although elongation at break and tensile strength decreased after heat aging procedure, obviously, this reduction was lower in blended samples than that of pure PE. In all samples, hydroxyl and transvinylene unsaturated end groups were formed during heat aging in hot water. Formation of these groups was less in blends at doses between 80–100 kGy, but was higher at 150 kGy than pure polyethylene. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2346–2352, 2003
Thermal and thermomechanical properties of biocomposites made from modified recycled cellulose and recycled polypropylene
Authors: Espert Ana , Camacho Walker , Karlson Sigbritt 
Published: June 2003

AbstractResidual cellulose fibers from the paper industry have been used as reinforcements in recycled polypropylene (PP) composites. The main obstacle to obtaining good properties with this biocomposite is deficiencies in the compatibility between the nonpolar matrices and the polar cellulose fibers used as reinforcements. The aim of this work was to improve the compatibilization between these cellulose fibers and the PP matrix with four different methods: modification by the addition of polypropylene–maleic anhydride copolymer (PPgMA) during the process of blending, preblending modification of the cellulose with a solution of PPgMA, modification of cellulose by silanes (vinyltrimethoxysilane), and acetylation of cellulose. Blends with all of the differently modified celluloses were prepared with the cellulose content varied up to 40%, and then all of the blends were subjected to thermal (differential scanning calorimetry and thermogravimetric analysis) and thermomechanical (dynamic mechanical thermal analysis) analyses. The results showed that the addition of cellulose fibers improved the thermomechanical behavior of the PP, increasing the value of the log of the dynamic modulus, and affected the thermal and thermooxidative behavior. Moreover, an advantage of the use of a recycled PP containing a small quantity of ethyl vinyl acetate (EVA) as a prime material in the composition was the enhancement of mechanical properties. The use of these methods for the modification of cellulose led to more desirable thermal and thermooxidative stabilities. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2353–2360, 2003
Graft copolymerizaztion of methyl acrylate onto chitosan initiated by potassium diperiodatocuprate (III)
Authors: Liu Yinghai , Liu Zhenghao , Zhang Yanzhe , Deng Kuilin 
Published: June 2003

AbstractA novel redox system, potassium diperiodatocuprate [Cu (III)–chitosan], was employed to initiate the graft copolymerization of methyl acrylate (MA) onto chitosan in alkali aqueous solution. The effects of reaction variables such as monomer concentration, initiator concentration, pH and temperature were investigated. By means of a series of copolymerization reactions, the grafting conditions were optimized. Cu (III)–chitosan system was found to be an efficient redox initiator for this graft copolymerization. The structures and the thermal stability of chitosan and chitosan‐g‐poly(methyl acrylate) (PMA) were characterized by infrared spectroscopy (IR) and thermogravimetric analysis (TGA). In this article, a mechanism is proposed to explain the formation of radicals and the initiation. Finally, the graft copolymer was used as the compatibilizer in blends of poly(vinyl chloride) (PVC) and chitosan. The scanning electron microscope (SEM) photographs and differential scanning calorimetry (DSC) thermograms indicate that the graft copolymer improved the compatibility of the blend. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2283–2289, 2003
Synthesis and characterization of methyl methacrylate/styrene hyperbranched copolymers via living radical mechanism
Authors: Ishizu Koji , Park Jaebum , Ohta Yoshihiro , Shibuya Takeshi 
Published: June 2003

AbstractFree‐radical copolymerizations of N,N‐diethylaminodithiocarbamoylmethylstyrene (inimer: DTCS) with a methyl methacrylate (MMA)/zinc chloride (ZnCl2) complex were carried out under UV light irradiation. DTCS monomers play an important role in this copolymerization system as an inimer that is capable of initiating living radical polymerization of the vinyl group. The reactivity ratios (r1 = 0.56 and r2 = 0.52: DTCS [M1]; MMA [M2]) obtained for this copolymerization system were different from a corresponding model system (alternating copolymer) of a styrene and MMA/ZnCl2 complex (r1 = 0.25 and r2 = 0.056). It was found that the hyperbranched copolymers produced exhibited a random branching structure. It was found that the Lewis acid ZnCl2 formed the complex not only with MMA but also with the carbamate group of inimer. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2490–2495, 2003
Study on thermoplastic polyurethane/polypropylene (TPU/PP) blend as a blood bag material
Authors: Ajili Shadi H. , Ebrahimi Nadereh G. , Khorasani Mohammad T. 
Published: June 2003

AbstractBlends with different ratios of thermoplastic polyurethane/polypropylene (TPU/PP) were prepared by melt mixing using an internal Haake mixer. Properties of the blends were investigated using SEM micrographs of cryofractures and measurement of the mechanical strength, water absorption, cell culture, and platelet adhesion in vitro tests, which were compared with those of PVC blood bags. The effect of the addition of the ethylene–vinyl acetate (EVA) copolymer on the TPU/PP blend properties was investigated. The results indicated that a TPU/PP/EVA = 80/20/5 blend can be used as a new blood bag material. It was observed that the blend is homogeneous with higher mechanical strength than that of the commercial PVC blood bag. This blend also showed a compatible cell response in contact with L929 fibroblast cells and fewer tendencies to interaction with platelets compared to the PVC blood bag. Although the blends were immissible and no chemical reaction at the interface could be found, the blood compatibility of the blends were improved. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2496–2501, 2003
Viscosity behavior and surface and interfacial activities of hydrophobically modified water‐soluble acrylamide/N‐phenyl acrylamide block copolymers
Authors: Abu‐Sharkh B. F. , Yahaya G. O. , Ali S. A. , Hamad E. Z. , Abu‐Reesh I. M. 
Published: June 2003

AbstractIn this study, the viscosity behavior and surface and interfacial activities of associative water‐soluble polymers, which were prepared by an aqueous micellar copolymerization technique from acrylamide and small amounts of N‐phenyl acrylamide (1.5 and 5 mol %), were investigated under various conditions, including the polymer concentration, shear rate, temperature, and salinity. The copolymer solutions exhibited increased viscosity due to intermolecular hydrophobic associations, as the solution viscosity of the copolymers increased sharply with increasing polymer concentration, especially above a critical overlap concentration. An almost shear‐rate‐independent viscosity (Newtonian plateau) was also displayed at high shear rates, and typical non‐Newtonian shear‐thinning behavior was exhibited at low shear rates and high temperatures. Furthermore, the copolymers exhibited high air–water and oil–water interfacial activities, as the surface and interfacial tensions decreased with increasing polymer concentration and salinity. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2290–2300, 2003
Pervaporation membranes based on imide‐containing poly(amic acid) and poly(phenylene oxide)
Authors: Polotskaya G. A. , Kuznetsov Y. P. , Goikhman M. Y. , Podeshvo I. V. , Maricheva T. A. , Kudryavtsev V. V. 
Published: June 2003

AbstractThree imide‐containing poly(amic acids) were synthesized and used for homogeneous and composite membrane preparation. The transport properties of composite membranes consisting of an imide‐containing poly(amic acid) top layer on an asymmetric porous poly(phenylene oxide) support were studied in the pervaporation of aqueous solutions of organic liquids (ethanol, isopropanol, acetone, and ethylacetate) and organic/organic mixtures (ethylacetate/ethanol, methanol/cyclohexane). For most of the aqueous/organic mixtures, the composite membranes exhibited dehydration properties. Dilute aqueous solutions of ethylacetate were an exception. In these solutions, the composite membranes exhibited organophilic properties, high permeability, and selectivity with respect to ethylacetate. In the pervaporation of methanol/cyclohexane mixtures, methanol was removed with very high selectivity. To account for specific features of pervaporation on the composite membranes, the sorption and transport properties of homogeneous membranes prepared from polymers comprising the composite membrane [imide‐containing poly(amic acids) and poly(phenylene oxide)] were studied. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2361–2368, 2003
Effects of maleated syndiotactic polystyrene on the morphology, mechanical properties, and crystallization behavior of syndiotactic polystyrene/polyamide 6 blends
Authors: Quan Zhang Xue , Son Younggon 
Published: June 2003

AbstractThe compatibilization of syndiotactic polystyrene (sPS)/polyamide 6 (PA‐6) blends with maleic anhydride grafted syndiotactic polystyrene (sPS‐g‐MA) as a reactive compatibilizer was investigated. The sPS/PA‐6 blends were in situ compatibilized by a reaction between the maleic anhydride (MA) of sPS‐g‐MA and the amine end group of PA‐6. The occurrence of the chemical reaction was substantiated by the disappearance of a characteristic MA peak from the Fourier transform infrared spectrum. Morphology observations showed that the size of the dispersed PA‐6 domains was significantly reduced and that the interfacial adhesion was much improved by the addition of sPS‐g‐MA. As a result of reactive compatibilization, the impact strengths of the sPS/PA‐6 blends increased with an increase in the sPS‐g‐MA content. The crystallization behaviors of the blends were affected by the compatibilization effect of sPS‐g‐MA. A single melting peak of sPS in the noncompatibilized blend was gradually split into two peaks as the amount of the compatibilizer increased. A single crystallization peak of PA‐6 in the noncompatibilized blend became two peaks with the addition of 3 wt % sPS‐g‐MA. The new peak was a result of the fractionation crystallization. As the amount of sPS‐g‐MA increased, the intensity of the new peak increased, and the original peak nearly disappeared. Finally, the crystallization peak of PA‐6 disappeared with 20 wt % sPS‐g‐MA in the blend. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2502–2506, 2003