bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surface modification of poly(vinyl chloride) for antithrombogenicity study
Authors: Xie Yunchuan , Yang Qingfang 
Published: August 2002

AbstractA process was established to conduct heparinization on the surface of poly(vinyl chloride) for antithrombogenicity utilization. A bifunctional monomer, glycidyl methacrylate (GMA), was grafted onto the surface of PVC by gas‐phase photografting polymerization without degassing first; then heparin was immobilized onto the poly(glycidyl methacrylate) segments. The branch structure of GMA and heparin were characterized by Fourier transfer infrared (FTIR) spectroscopy and electron spectroscopy (ESCA). It was confirmed that the bifunctional monomer GMA and heparin were grafted successfully onto the surface of PVC. The antithrombogenicity of the samples was tested both in vitro and in vivo, respectively. Results indicated that the blood compatibility of those products was improved greatly. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1013–1018, 2002
Thermal behavior and morphology of polyamide 6 based multicomponent blends
Authors: Jafari S. H. , Pötschke P. , Stephan M. , Pompe G. , Warth H. , Alberts H. 
Published: August 2002

AbstractThe thermal behavior and morphology of multicomponent blends based on PA6, polyamide 6 (PA6)/styrene–acrylonitirle copolymer (SAN), PA6/acrylonitrile–butadiene–styrene terpolymer (ABS), and their compatibilized blends with styrene–acrylonitrile–maleic anhydride copolymer (SANMA) were studied using DSC and SEM. The blends were prepared in a twin‐screw extruder under similar processing conditions, keeping the PA6 content fixed at 50 wt %. It was found that, in all the blends, the second component had a nucleating effect and improved the overall degree and rate of crystallization of PA6, whereas addition of a compatibilizer slightly diminished these effects and resulted in significant changes in the blend morphology. The nucleating effect and consequent changes in the crystallization behavior was attributed to the presence of SAN, which is a common component in all the blends. The Tg of PA6 in the blends with a cocontinuous morphology, due to the connectivity between the phases, is higher than in the blends with a disperse‐type morphology. The compatibilized blends have a lower crystallization rate and nucleation ability with a cocontinuous morphology, whereas the uncompatibilized blends have a higher crystallization rate with a higher nucleation ability and a disperse and/or a coarse cocontinuous morphology. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2753–2759, 2002
Dielectric investigation of some normal alcohols and diols dispersed in some polymeric matrices
Authors: Abd‐El‐Messieh S. L. , Mohamed M. G. , Mazrouaa A. M. , Soliman A. 
Published: August 2002

AbstractA series of diols and normal alcohols were dispersed in some polymeric matrices, namely, polystyrene (PS), polyethylene (PE), and poly(methyl methacrylate) (PMMA). The dielectric properties of these systems were investigated in the frequency range of 102–105 Hz at a room temperature of 25°C. The experimental data were analyzed according to the Fröhlich equation into two relaxation processes: The first relaxation in the lower‐frequency range could be attributed to the Maxwell–Wagner effect as a result of the difference in permittivities and conductivities of the investigated systems. The second relaxation in the higher‐frequency range could be attributed to an intramolecular motion involving the rotation of various segments of the chain about the CC bond accompanied by movement of the main dipoles for either diols or alcohols. The presence of the phenyl ring in the PS matrix may hinder such rotation when compared with the other matrices. The dielectric properties were also investigated for PMMA blended with either PS or PE at different ratios before and after the addition of small quantities of ethanediol. The interaction that might be expected between PMMA and PS in the blend may affect the rotation of the ethanediol chain in the blend matrix. The dielectric data as well as the data obtained from the calculated heat of mixing show that the investigated blends are incompatible. The addition of ethanediol to such blends gives the possibility that a large number of dipoles can be impregnated into the blend matrix and the problem of phase separation could be solved.© 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 271–281, 2002
Effect of different polymers on the efficiency of water‐borne methyl amine adduct as corrosion inhibitor for surface coatings
Authors: Badran Badran M. , Mohammed Heba A. , Aglan Heshmat A. 
Published: August 2002

AbstractStyrene/acrylic emulsion copolymer and water‐based short oil urethane alkyd resin were used as binders to prepare water‐based, environmentally friendly paints by using 0.5% emulsified methylamine adduct as corrosion inhibitor. The choice of the two above‐mentioned binders was based on the fact that styrene/acrylic emulsion copolymer is a nonconvertible binder, whereas short oil urethane alkyd resin is a convertible binder. The physical, chemical, mechanical, and corrosion properties of the paint films were evaluated and compared with a commercially known anticorrosive water‐based paint. It was found that the prepared paints have unique desirable properties such as the following: they do not contain anticorrosive pigments (which contain heavy metals in their main chemical structure); they are solvent‐free; and they can be produced to match any color. Corrosion tests on the films of the formulated paints revealed that the short oil urethane alkyd resin is superior to the styrene/acrylic copolymer. Moreover, the corrosion inhibition properties of the paint films prepared from both binders are comparable with the commercially available paints containing anticorrosive pigments. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 879–885, 2002
Effect of GMA on monodisperse epoxy‐functionalized polymer microsphere particles by dispersion copolymerization of styrene with glycidyl methacrylate
Authors: Lee Sung‐Soo , Park Kang‐Yeol , Kim Ju‐Young , Suh Kyung‐Do 
Published: August 2002

AbstractMonodisperse poly[styrene‐co‐glycidyl methacrylate (GMA)] microparticles were synthesized by dispersion copolymerization in a water–ethanol medium. The effects of various polymerization parameters on the particle size and size distribution of the dispersion copolymerization were investigated. The dispersion of polymer particles decreased when the GMA was added if the polystyrene homopolymer particles were polydispersed. The GMA acted as a comonomer as well as a costabilizer in the dispersion copolymerization of styrene with GMA. The solvency of the monomer increased with the concentration of GMA in the polymerization medium because GMA has a greater hydrophilicity than styrene, resulting in a large particle size and a slow polymerization rate. From an HCl–dioxane analysis of the poly(styrene‐co‐GMA) microparticles, great amounts of epoxy groups were detected after the completion of dispersion copolymerization. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1206–1212, 2001
Biodegradable polylactide/poly(ethylene glycol)/polylactide triblock copolymer micelles as anticancer drug carriers
Authors: Liu Li , Li Chenxi , Li Xuechen , Yuan Zhi , An Yingli , He Binglin 
Published: August 2002

AbstractAdriamycin (ADR) was selected as a model drug to evaluate the potential applications of polylactide/poly(ethylene glycol)/polylactide (PLA/PEG/PLA) micelles as drug carriers in parenteral delivery systems. The PLA/PEG/PLA triblock copolymer micelles were characterized by dynamic light scattering and transmission electron microscopy. It was found that the micelle size increased with the increasing of the PLA chain length. The average size of ADR‐loaded micelles was 143.2 nm. The histogram analysis showed that the ADR‐loaded micelles possessed a narrow unimodal size distribution. The ADR loading contents of the micelles and ADR entrapment efficiency were dependent on the PLA chain length and PEG chain length in the copolymer. They increased with the increase of the PLA chain length, but the PEG chain length was identical and decreased with the increase of the PEG chain length; the length of the PLA block was similar. The initial amount of ADR also influenced the drug contents and entrapment efficiency (i.e., the more the initial amount added, the more the drug contents and the higher encapsulation efficiency). The drug release experiments indicated that the ADR‐loaded micelles possessed sustained release characteristics. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1976–1982, 2001
A study on HDPE/sulfonated EPDM‐treated CaCO3 blends
Authors: Li Huilin , Zheng Mingjia , Xu Xi 
Published: August 2002

AbstractIn this article, sulfonated ethylene‐propylene‐diene monomer terpolymer (H–SEPDM) was used to treat CaCO3 particles. CaCO3 particles are encapsulated by H–SEPDM through the reaction of sulfonic acid group (SO3H) in H–SEPDM with CaCO3 to improve the interface adhesion of CaCO3 with HDPE. In case the treated CaCO3 is blended with HDPE, a brittle–ductile transition occurs. The impact strength of the blend rises sharply at 25–30 wt % CaCO3, and amounts to more than 700 J/m, four times as high as that of HDPE at 30 wt % CaCO3, without much loss of its yield strength and modulus. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2140–2144, 2001
FTIR studies of the curing reactions of palm oil alkyd–melamine enamels
Authors: Gan Seng‐Neon , Tan Boon‐Yeow 
Published: August 2002

AbstractThree alkyds of high hydroxyl numbers with oil lengths of 21, 30, and 41 were prepared from crude palm oil. The excess hydroxyl groups provided good compatibility with melamine resins, and also served as sites for crosslinking reactions. They were made into baking enamels by blending with 20% of a commercial melamine resin. All of them could be cured at temperatures below 200°C although thermodecomposition might occur above 290°C. The dry‐hard time of these enamels cured at temperatures between 140–180°C ranged from 10 to 180 min. Fourier transform infrared spectroscopy could be used to follow the major curing reactions. The absorbance of OH and NCH2OCH3 groups showed significant reduction. The changes in the absorbance of these peaks with time and temperature were investigated. The predominant reaction was identified as the formation of methylene ether linkages. However, the self‐condensation reactions of the amino resin and ester linkages did not occur to any noticeable extent. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2309–2315, 2001
Synthesis of tung oil–diacrylate copolymers via the Diels‐Alder reaction and properties of films from the copolymers
Authors: Trumbo D. L. , Mote B. E. 
Published: August 2002

AbstractCopolymers were synthesized from tung oil and 1,6 hexanediol diacrylate or 1,4‐butanediol diacrylate via the Diels‐Alder reaction. The copolymers were completely soluble in common laboratory solvents, and had very broad molecular weight distributions. The residual double bonds in the copolymers were used to cure films by oxidative means. The films had good solvent resistance, good gloss, and a reasonable hardness–flexibility balance. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2369–2375, 2001
Preparation and characterization of nanofiltration composite membranes using polyacrylonitrile (PAN). II. Preparation and characterization of polyamide composite membranes
Authors: Oh Nam‐Wun , Jegal Jonggeon , Lee Kew‐Ho 
Published: August 2002

AbstractPolyamide (PA) composite membranes in which PA active layers were interconnected with support layers via the formation of ionic bonds were prepared by the interfacial polymerization of piperazine (PIP) with trimesoyl chloride (TMC) on the surfaces of microporous polyacrylonitrile (PAN) supports containing carboxylic acid groups. Formation of the ionic bonds through an acid‐base reaction between NH group of PIP and COOH of the support was studied using FTIR‐ATR spectroscopy. Variation of the surface morphologies of the composite membranes that was induced by the presence of the ionic bonds was observed with a FESEM and an AFM. Permeation tests with various feed solutions such as PEG 600, Na2SO4, MgSO4, MgCl2, and NaCl solutions were carried out to see how the characteristics of the PAN supports affected on the flux and rejection of the corresponding PA composite membranes. Chemical stabilities of the composite membranes with the ionic bonds were studied and compared with that of a conventional PA composite membrane, using alcohol solutions. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2729–2736, 2001
Characterization of poly(L‐lactic acid) fibers produced by melt spinning
Authors: Yuan Xiaoyan , Mak Arthur F. T. , Kwok K. W. , Yung Brian K. O. , Yao Kangde 
Published: August 2002

AbstractBiodegradable poly(L‐lactic acid) (PLLA) fibers were processed by a two‐step melt‐spinning method (melt extrusion and hot draw) from PLLA with three different viscosity‐average molecular weights (494,600, 304,700, and 262,800). Before spinning, the polymer flakes were first milled into powders and dried under vacuum. Viscosity‐average molecular weight of PLLA following the fabrication process was monitored. Tensile properties of as‐spun and hot‐drawn fibers were investigated. Morphology of the PLLA fibers was viewed under a scanning electron microscope. Crystallinity of these fibers was assessed by thermogram analysis of differential scanning calorimetry. Results showed that the extent of decrease in the viscosity‐average molecular weight of PLLA dropped sharply by 13.1–19.5% during pulverization and by 39.0–69.0% during melt‐extrusion. The hot‐draw process in this study had a little effect on the viscosity‐average molecular weight of PLLA. Smoother fibers could be obtained for the die temperature at least 230°C for raw materials with higher crystallinity (more than 75%) and at least 220°C for raw materials with lower crystallinity (about 60%). The as‐spun fibers showed crystallinity of 16.5–22.8% and the value increased to 50.3–63.7% after hot draw. Tensile moduli of the as‐spun fibers were in the range of 1.2–2.4 GPa, which were raised to 3.6–5.4 GPa after hot draw. The final PLLA fibers with 110–160 μm diameters showed tensile strengths of 300–600 MPa. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 251–260, 2001
Miscibility and crystallization behavior of the solution‐blended sulfonated poly(phenylene oxide)/ poly(styrene‐co‐4‐vinyl pyridine) blend
Authors: Pan Yan , Fu Weiwen , Xue Feng , Luo Yuanfang , Gu Ju 
Published: August 2002

AbstractThe miscibility and crystallization behavior of the solution‐blended lightly sulfonated poly(phenylene oxide) (SPPO)/poly(styrene‐co‐4‐vinylpyridine) (PSVP) blend were investigated by conventional and modulated differential scanning calorimetry (MDSC). It was found that the original blend film is actually composed of a crystalline SPPO phase and a noncrystalline compatible SPPO–PSVP phase. The original phase‐segregated structure will evolve to a noncrystalline homogenous structure by subsequent high temperature annealing. The resulting good miscibility was attributed to two aspects: one is that the SPPO crystalline structure could be destroyed as annealing temperature is high enough; the other is that the acid–base interaction between the sulfonic group of SPPO and the pyridine ring of PSVP could promote mixing of different components effectively. And such acid–base interaction was demonstrated by 1C NMR spectra. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2843–2848, 2001
Preparation of epoxidized rubber using a reactive processing technique. I. Synthesis and characterization of epoxidized polybutadiene rubber
Authors: Zhang Ying , Chen Xin‐Zhong , Zhang Yong , Zhang Yin‐Xi 
Published: August 2002

AbstractThe epoxidation of high cis‐butadiene rubbers (BR) with monoperoxy phthalic acid was successfully performed in reactive processing equipment of the HAKKE mixer at room temperature. The effects of such reaction conditions as the concentration of peroxy acid and reaction time on the epoxidation level and the efficiency of monoperoxy phthalic acid were investigated. The structure of epoxidized BR was characterized by 1H NMR and Fourier transform infrared spectrometer. Differential scanning calorimeter analysis revealed that the glass transition temperature of epoxidized BR had a progressive increase with epoxidation level. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2987–2992, 2001
Analysis of the phase partitioning of additives in rubber‐modified plastics
Authors: Smith Patrick B. , Buzanowski Walter C. , Gunderson Judy J. , Priddy Duane B. , Pfenninger Lance 
Published: August 2002

AbstractThe phase partitioning of additives in polymer blends has a large impact on the performance of the blend. Therefore, it is necessary to be able to quantify the level of the additives in each phase. A 1H–NMR method is presented to determine the partitioning of additives between the rubber and rigid phases of a high‐impact polystyrene (HIPS) material. In one case, a HIPS material was modified with 2,6‐di‐tert‐butyl‐4‐methyl‐phenol (Ionol, CAS# 128‐37‐OMF) as a stabilizer for both phases. HIPS materials with varying levels of Ionol were melt‐blended by extrusion and the total level of additives was determined analytically for these standard materials. The 1H–NMR method was used to determine the level of Ionol in the poly(butadiene) rubber phase. The Ionol was found to preferentially partition into the rubber phase with a partition coefficient of about 2. A second example of the same concept, instead utilizing 13C–NMR, involved the analysis of the partition coefficient for both Tinuvin P and Tinuvin 770 (CAS# 2440‐22‐4 and 52829‐07‐9), partitioning between the rigid and rubber phases of an ethylene–propylene–diene‐modified (EPDM) toughened styrene–ran–acrylonitrile (SAN) copolymer. The partition coefficient was determined to be 0.5 for Tinuvin P and 1.3 for Tinuvin 770. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1963–1970, 2001
Succinoylation of wheat straw hemicelluloses with a low degree of substitution in aqueous systems
Authors: Sun Runcang , Sun X. F. , Bing X. 
Published: August 2002

AbstractThe reaction of wheat straw hemicelluloses with succinic anhydride in aqueous alkaline systems was studied. The products showed a rather low degree of substitution, ranging from 0.017 to 0.21. The effects of reaction times of 0.5–16 h, temperatures of 25–45°C, and molar ratios of succinic anhydride to anhydroxylose units in hemicelluloses of 1:5–1:1 on the succinoylation yield and degree of substitution were examined. With the reaction kept within a pH range of 8.5–9.0, a temperature range of 25–28°C, a reaction duration of 1–2 h, and a 1:1 molar ratio of succinic anhydride to hemicelluloses were preferred. The structure of the resulting polymers was determined with Fourier transform infrared and1H‐ and13C‐NMR spectroscopy, which indicated monoester substitution. The thermal stability of the esterified polymer increased with chemical modification. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 757–766, 2002
Effect of styrene‐butadiene‐styrene addition on polystyrene/high‐density polyethylene blends
Authors: Taşdemi̇r Münir , Yildirim Hüseyin 
Published: August 2002

AbstractIn order to prepare an ideal mixture, the physical and chemical properties of the constituent polymers must be known in detail. Thus, selection of the polymers that will constitute the mixture and a thorough study of the mixing methods and the economic factors become important. A rigid plastic is toughened by dispersing a small amount of rubbery material (generally 5–20%) in the rigid plastic matrix. Such a mixture of plastics is characterized by its impact resistance. Among thermoplastics toughened in this way are polystyrene (PS), poly(vinyl chloride), poly(methyl methacrylate), polypropylene, polycarbonate, and nylons, and recently thermoset resins such as epoxies, unsaturated polyester resins, and polyamids. In this study PS and high‐density polyethylene polymers were mixed in various ratios. In order to increase the compatibility of the mixtures, 5, 7.5, and 10% SBS copolymer was also added. The mixing operation was conducted by using a twin‐screw extruder. The morphology and the compatibility of the mixtures were examined by using SEM and DSC techniques. Furthermore, the elastic modulus, yield and tensile strengths, percent elongation, Izod impact resistance, hardness, and melt flow index values of the polymer alloys of various ratios were determined. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2967–2975, 2002; DOI 10.1002/app.2325
Impact of hydropattern disturbance on crayfish population dynamics in the seasonal wetlands of Everglades National Park, USA
Authors: Acosta Charles A. , Perry Sue A. 
Published: August 2002

Abstract1. The natural hydropattern in the seasonally‐flooded marl prairie wetlands of Everglades National Park has been severely disrupted by human water control activities, seriously impacting higher trophic organisms, e.g. wading birds, that depend on these wetlands. Less is known about the impacts on key aquatic fauna, such as crayfish Procambarus alleni, or how these populations might respond to proposed habitat restoration strategies. 2. Under severe environmental stress, populations of burrowing crayfish are predicted to have skewed size structure, low reproductive success, low survival, and widespread dispersal. As predicted for populations in stressed habitats, crayfish density was low, small dispersing adults were dominant, juvenile abundance was low, and survival was low in habitats where the hydroperiod (duration of flooding) was short and groundwater level was lowest.3. Crayfish dispersed during flooding, but during the drydown, they burrowed rather than sought deeper water. This dispersal strategy may be adaptive for surviving in seasonal wetlands, but this had severe consequences on survival in disturbed habitats with shortened hydroperiods. Survival in burrows during the dry season was high in the longer‐hydroperiod habitats but was zero in the short‐hydroperiod habitat where the groundwater level fell more than 1 m.4. Long‐hydroperiod marl prairie may function as sources, whereas short‐hydroperiod habitats act as population sinks. Our study suggests that the threshold conditions for preventing mass mortality of crayfish in these wetlands are hydroperiods >7 months and groundwater levels <0.5 m below the surface during the dry season.5. Historical (pre‐drainage) hydroperiods appear to be restricted to the longest hydroperiod areas of the marl prairie. This indicates that much of the marl prairie wetlands now function as population sinks for crayfish and other invertebrates. The historical hydropatterns need to be re‐established throughout the marl prairie wetlands to achieve the restoration goal of increasing productivity in the aquatic faunal community.Copyright © 2001 John Wiley & Sons, Ltd.