bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and characterization of the copolymers obtained by grafting of monoacryloxyethyl phosphate onto polytetrafluoroethylene membranes and poly(tetrafluoroethylene‐co‐hexafluoropropylene) films
Authors: Grøndahl Lisbeth , Cardona Francisco , Chiem Khang , Wentrup‐Byrne Edeline 
Published: October 2002

AbstractTwo fully fluorinated polymers, poly(tetrafluoroethylene) (PTFE) membranes and poly(tetrafluoroethylene‐co‐hexafluoropropylene) (FEP) films, were modified by graft copolymerization with monoacryloxyethyl phosphate (MAEP) in an aqueous solution at ambient temperature using gamma irradiation. The modified membranes were characterized by XPS, FTIR, and phosphate analysis. A correlation between peak heights in the FTIR PAS spectra and the overall grafting yield was found. Neither the surface coverage (as obtained from XPS multiplex scans) nor the overall grafting yield (as obtained from phosphate analysis) showed simple correlations on the monomer concentrations (20–40%) or the irradiation doses (25–150 kGy) within the ranges investigated. Similar surface coverage was achieved on the PTFE membranes and on the FEP films. In contrast, the overall grafting yields were significantly higher for the PTFE membranes than for the FEP films. The high porosity of the PTFE membranes is the most likely explanation for these differences in grafting. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2550–2556, 2002
Pervaporative separation of a 1‐methoxy propanol and water mixture
Authors: Mandal Sangita , Pangarkar Vishwas G. 
Published: October 2002

AbstractThe pervaporative dehydration of ether derivatives of alcohol, such as 1‐methoxy propanol (MP) and water mixtures, was studied with polyimide (PI), cellophane, poly(vinyl alcohol) (PVA), cellulose diacetate (CDA), cellulose triacetate, two separate blends of cellulose acetate and CDA with cellulose acetate propionate, and PVA crosslinked with multifunctional crosslinkers. The effects of different substitution derivatives of cellulosic materials were investigated. Membranes of PVA and citric acid and of PVA and maleic anhydride were studied with respect to the effect of the crosslinker and its loading. Among all the hydrophilic membranes, PI gave the best selectivity but poor flux. Poly(dimethylsiloxane) (PDMS) and linear low‐density polyethylene (LLDPE) membranes were invoked for the selective permeation of comparatively weaker hydrophilic components. PDMS showed acceptable results for MP separation in terms of both flux and selectivity. LLDPE yielded better selectivity but very poor MP flux. All these membranes were stable, and no changes in their properties were observed over the entire range of concentration at 30°C. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2194–2210, 2002
Selective separation of water from aqueous alcohol mixtures through functionalized syndiotactic poly(styrene‐co‐4‐methylstyrene) membranes by pervaporation
Authors: Li Chi‐Lan , Wang Yi‐Chieh , Kao Se‐Tsung , Fan Shu‐Chin , Lee Kueir‐Rarn , Lai Juin‐Yih 
Published: October 2002

AbstractThe pervaporation performances of a series of functionalized syndiotactic poly(styrene‐co‐4‐methylstyrene) (SPSM) membranes for various alcohol mixtures were investigated. The syndiotactic polystyrene copolymers, poly(styrene‐co‐4‐methylstyrene) (SPSM), were prepared by styrene with 4‐methylstyrene using a Cp*Ti(OCH3)3/methyl aluminoxane (metallocene/MAO) catalyst. The effect of functionalization on the thermal properties and polymer structure of the SPSM membranes were also investigated. The crystallinity of the functionalized SPSM membrane is lower than that of the unfunctionalized SPSM membranes. The water molecules preferentially permeate through the SPSM membranes. Compared with unfunctionalized SPSM membranes, the functionalized SPSM membrane effectively increases the membrane formation performances and the pervaporation performances. The optimun pervaporation performance (a separation factor of 510 and permeation rate of 220 g/m2h) was obtained by the bromination of SPSM (SPSMBr) membrane with a 90 wt % aqueous ethanol solution. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2247–2254, 2002
Low‐temperature hygrothermal degradation of ambient cured E‐glass/vinylester composites
Authors: Karbhari V. M. , Rivera J. , Zhang J. 
Published: October 2002

AbstractFreeze and freeze‐thaw durability characteristics of fiber reinforced polymer (FRP) composites, especially in the presence of moisture, need to be investigated prior to the widespread implementation of these materials in civil, polar, and offshore structural components and systems. The hygrothermal degradation characteristics of an ambient cure E‐glass/vinylester system due to exposure to −10°C conditions and conditions of freeze‐thaw, including in the presence of water and seawater, was investigated. Changes in mechanical characteristics such as strength and modulus, and thermo‐mechanical dynamic characteristics such as storage and loss moduli, and glass‐transition temperature were measured, and short‐term effects of environmental exposure were assessed. It is seen that the presence of moisture/solution has a significant effect; both in terms of physical and chemical aging, and in terms of microcracking and fiber–matrix debond initiation. Results indicate the critical importance of cure characteristics and diffusion related phenomena. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2255–2260, 2002
Electric stimuli responses to poly(vinyl alcohol)/chitosan interpenetrating polymer network hydrogel in NaCl solutions
Authors: Kim Seon Jeong , Park Sang Jun , Kim In Young , Shin Mi‐Seon , Kim Sun I. 
Published: October 2002

AbstractAn interpenetrating polymer network (IPN) hydrogel composed of poly(vinyl alcohol) (PVA) and chitosan exhibited electric‐sensitive behavior. The PVA/chitosan IPN hydrogel was synthesized by an ultraviolet (UV) irradiation method that is used in several biomedical and industrial fields. The swelling behavior of the PVA/chitosan IPN hydrogel was studied by immersion of the gel in NaCl aqueous solutions at various concentrations. The swelling ratio decreased with increasing concentration of NaCl solution. The stimuli response of the IPN hydrogel in electric fields was also investigated. When a swollen PVA/chitosan IPN was placed between a pair of electrodes, the IPN exhibited bending behavior in response to the applied electric field. The bending angle and the bending speed of the PVA/chitosan IPN increased with increasing applied voltage and concentration of NaCl aqueous solution. The PVA/chitosan IPN also showed stepwise bending behavior depending on the electric stimulus. In addition, thermal properties of PVA/chitosan IPN were investigated by differential scanning calorimetry (DSC) and dielectric analysis (DEA). © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2285–2289, 2002
Diffusion and sorption behavior of glycidyl methacrylate in styrene butadiene rubber
Authors: Hwang Kum Kang , Ryu Sung Hun , Hong Seong Uk 
Published: October 2002

AbstractIn this study, the diffusion and sorption behavior of glycidyl methacrylate in styrene butadiene rubber (SBR) was investigated as a function of waste tire powder content, sulfur content (i.e., the crosslink density), and temperature by using the gravimetric sorption method. The results indicate that penetrant solubility increases as sulfur and waste tire powder contents decrease, whereas the temperature affects the solubility favorably. The results also indicate that mutual diffusion coefficients decrease as the sulfur and waste tire powder contents increase. This behavior was interpreted in terms of free volume of the polymer and tortuosity. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2701–2706, 2002
Mixed radiation field effects from a nuclear reactor on poly(aryl ether ether ketone): A melt viscosity study
Authors: Pagé D. J. Y. S. , Bonin H. W. , Bui V. T. , Bates P. J. 
Published: October 2002

AbstractPoly(aryl ether ether ketone) (PEEK) is a high‐temperature engineering thermoplastic used in the aerospace industry. To assess its suitability for nuclear industry applications, the effects of mixed field radiation from a nuclear reactor were investigated on two industrial semicrystalline PEEK grades (VICTREX 150P and 450P). Specimens were first processed on an ENGEL55 injection molder and then irradiated in the pool of a SLOWPOKE‐2 nuclear research reactor. Specimens were thus exposed to a mixed field of radiation including gamma, electrons, protons, and neutrons, for exposures resulting in doses ranging from 0.15 to 15 MGy. Irradiated samples were characterized by viscosity measurements in the melt, differential scanning calorimetry (DSC), and density measurements. Melt viscosity of irradiated samples proved to be significant in detecting early molecular weight changes in PEEK and helped explain the interaction of competing chain scission and crosslinking reactions at various stages of the radiolysis. All results pointed toward the following transformation of the resin with increased dosage: chain scission of the tie‐molecules between the amorphous and crystalline phases, crosslinking in the amorphous phase, followed by a general degradation of the molecular weight dominated by chain‐scission. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2713–2719, 2002
Biodegradation of nylon4 and its blend with nylon6
Authors: Hashimoto Kazuhiko , Sudo Mie , Ohta Kazumi , Sugimura Takayuki , Yamada Hiroyuki , Aoki Takayuki 
Published: October 2002

AbstractThe nylon4 portion in the blend films composed of nylon4 and nylon6 was degraded and completely disappeared within 4 months in two kinds of composted soils gathered from different university farms as well as pure nylon4 film reported previously, while the nylon6 portion remained even after the burial test for 15 months. Nylon4 powder was also degraded to carbon dioxide in the degradation test in an activated sludge obtained from a sewage disposal institution in Kogakuin University. Three species of microoganisms (i.e., ascomytous fungi) were isolated through the inoculation from the nylon4 film partially degraded in the soil on a medium containing nylon4 powder as a carbon source. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2307–2311, 2002
Synthesis and characterization of chitosan alkyl carbamates
Authors: Cárdenas Galo , Paredes Juan C. , Cabrera Gustavo , Casals Pedro 
Published: October 2002

AbstractThe synthesis of chitosan methylcarbamate (ChMC) and ethylcarbamate (ChEC) is described by using a new methodology. Polymers with substitution degrees up to 63% for ChEC and 68.5% for ChMC were obtained. Derivatives with lower substitutions were acid soluble but those with higher ones were completely insoluble. This could be due to the loss in hydrophilic sites when the substitution degree increases. The reaction conditions and degree of substitution obtained for both derivatives were also described. A complete chemical characterization was carried out by spectroscopic techniques. The thermal degradation of chitosan and derivatives were studied in the range 25–500°C and both derivatives were shown to be thermally less stable than chitosan. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2742–2747, 2002
Factors affecting the interfacial polymerization of polyamide active layers for the formation of polyamide composite membranes
Authors: Jegal Jonggeon , Min Sung Gyu , Lee Kew‐Ho 
Published: October 2002

AbstractPolyamide (PA) composite membranes were prepared by interfacial polymerization with piperazine, m‐phenylene diamine, and trimesoyl chloride as monomers and polysulfone ultrafiltration membranes as supports. Factors affecting the performances of the composite membranes by changing the characteristics of the PA active layers were studied. First, the monomer compositions were varied, and organic solvents (benzene and 1,2‐dichloroethane) with better solubility for PA than hexane were used for the interfacial polymerization. As chemical additives capable of changing the property of the interface formed between water and organic phases, n‐propanol and i‐propanol were used, and phase‐transfer catalysts such as triethyl benzyl ammonium bromide were used to improve the polymerization efficiency of the PA active layers. The characteristics of the PA composite membranes prepared, including their permeation properties and morphology, were carefully studied with various analytical methods, such as field emission scanning microscopy, atomic force microscopy, differential scanning calorimetry, and permeation testing. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2781–2787, 2002
Effects of molecular architecture on two‐step, melt‐spun poly(lactic acid) fibers
Authors: Cicero John A. , Dorgan John R. , Garrett James , Runt James , Lin J. S. 
Published: October 2002

AbstractFibers of poly(lactic acid) (PLA) produced by two‐step melt spinning have been studied. The PLA resins used contain a 96:04 ratio of L:D stereochemical centers; however, one of the materials is branched by a peroxide treatment. The thermal, mechanical, and morphological properties of the fibers are compared for the two different molecular architectures. In the branched material, at least some of the branches exceed the entanglement molecular weight. The branched material is accordingly characterized by greater shear and extensional viscosity than the linear material. Fiber properties are highly influenced by the draw ratio; both branched and linear materials reach a plateau of about 35% crystallinity. The branched polymer reaches the plateau at a lower draw ratio, and this is indicative of faster crystallization kinetics. Both materials shrink in boiling water, and the amount of shrinkage decreases with increasing draw ratio. At an intermediate draw ratio of 6, the branched material is characterized by significantly larger shrinkage. With small‐angle X‐ray scattering and atomic force microscopy, the morphology is found to be fibrillar. Microfibril diameters range from approximately 20 to 30 nm and are almost identical for the two molecular architectures studied. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2839–2846, 2002
Novel polyisobutylene stars. XXIII. Thermal, mechanical, and processing characteristics of poly(phenylene ether)/polydivinylbenzene(polyisobutylene‐b‐polystyrene)37 blends
Authors: Asthana S. , Kennedy J. P. 
Published: October 2002

AbstractThe objective of these investigations was to increase the use temperature of novel star‐block polymers consisting of a crosslinked polydivinylbenzene (PDVB) core from which radiate multiple poly(isobutylene‐b‐polystyrene) (PIB‐b‐PSt) arms, abbreviated by PDVB(PIB‐b‐PSt)n. We achieved this objective by blending star‐blocks with poly(phenylene oxide) (PPO) that is miscible with PSt. Thus, various PPO/PDVB(PIB‐b‐PSt)n blends were prepared, and their thermal, mechanical, and processing properties were investigated. The hard‐phase glass‐transition temperature of the blends could be controlled by the amount (wt %) of PPO. The blends displayed superior retention of tensile strengths at high temperatures as compared to star blocks. The melt viscosities of blends with low weight percentages of PPO were lower than those of star blocks. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2866–2872, 2002
Tensile properties, morphology, and biodegradability of blends of starch with various thermoplastics
Authors: Park Hwan‐Man , Lee Sang‐Rock , Chowdhury Subhendu R. , Kang Tae‐Kyu , Kim Hak‐Kil , Park Seung‐Hoon , Ha Chang‐Sik 
Published: October 2002

AbstractIn the present study, blends of starch with different thermoplastics were prepared by a melt blending technique. The tensile properties and morphology of the blends were measured. It was found that with increasing starch content in starch/ionomer blends, the tensile strength and modulus increase. But for starch/low‐density polyethylene (LDPE) and starch/aliphatic polyester (APES) blends, tensile strength and modulus decrease with increasing the starch loading. Elongation at break values of all the blend systems decrease with increasing starch loading. The scanning electron micrographs (SEM) support the findings of tensile properties. Better homogeneity is observed in starch/ionomer systems compared with that in starch/APES and starch/LDPE systems. Up to 50% starch content, the starch/ionomer blends appear as a single phase. The extent of phase interactions of starch/APES system lies in between the starch/LDPE and starch/ionomer systems. From the biodegradability studies of the blends it was found that, although the pure LDPE and ionomer are not biodegradable, the starch/LDPE and starch/ionomer blends are biodegradable with an appreciable rate. The rate of biodegradation of the starch/APES is very high as both the components are biodegradable. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2907–2915, 2002
Antiinflammatory effect of retrovirally transfected interleukin‐10 on monosodium urate monohydrate crystal–induced acute inflammation in murine air pouches
Authors: Murakami Yousuke , Akahoshi Tohru , Kawai Shinichi , Inoue Matsuhisa , Kitasato Hidero 
Published: October 2002

AbstractObjectiveTo investigate the role of interleukin‐10 (IL‐10) in the inflammatory response, the antiinflammatory effect of retrovirally transfected IL‐10 was evaluated both in vitro and in vivo.MethodsA recombinant retrovirus containing the murine IL‐10 gene was constructed using the pLXSN vector and was designated as LXSN‐IL‐10. Murine IL‐10 was introduced into embryonic C57BL/6J fibroblast cells using LXSN‐IL‐10 to create C57‐IL‐10 cells. The effect of IL‐10 in the culture supernatant of these cells was then evaluated by determining changes in the production of tumor necrosis factor α (TNFα), macrophage inflammatory protein 1α (MIP‐1α), and MIP‐1β by macrophages. The antiinflammatory effect of C57‐IL‐10 cells was also investigated using an in vivo model of monosodium urate monohydrate (MSU) crystal–induced acute inflammation.ResultsThe IL‐10 gene transcript and its product were detected by reverse transcriptase–polymerase chain reaction and enzyme‐linked immunosorbent assay, respectively. The level of IL‐10 in the culture supernatant of C57‐IL‐10 cells was estimated to be 50 ng/ml. The culture supernatant of these cells exerted the biologic activity of IL‐10, showing inhibition of TNFα, MIP‐1α, and MIP‐1β production by macrophages. Injection of C57‐IL‐10 cells into murine air pouches significantly inhibited MSU crystal–induced cellular infiltration (P < 0.01) and production of the mouse CXC chemokine KC (P < 0.05). These findings were consistent with the results obtained by the injection of recombinant human IL‐10 into air pouches.ConclusionIn this murine air pouch model of MSU crystal–induced inflammation, IL‐10 seemed to inhibit the recruitment of neutrophils at least partly by suppressing KC production. These findings seem to suggest that IL‐10 gene therapy may be useful for inflammatory diseases.
Modeling the progression of rheumatoid arthritis: A two‐country model to estimate costs and consequences of rheumatoid arthritis
Authors: Kobelt Gisela , Jönsson Linus , Lindgren Peter , Young Adam , Eberhardt Kerstin 
Published: October 2002

AbstractObjectiveTwo simulation models were developed to analyze the cost‐effectiveness of new treatments that affect the progression of rheumatoid arthritis (RA).MethodsWe used data from 2 cohorts of patients with early RA who had been followed up since disease onset (up to 15 years). In the Swedish study, 183 patients were followed up for a mean of 11.3 years. In the UK study, 916 patients were followed up for a mean of 7.8 years. Disease progression over 10 years was modeled as annual transitions between disease states, defined by Health Assessment Questionnaire (HAQ) scores. A regression model was used to estimate transition probabilities conditional on age, sex, and time since onset of disease, in order to allow simulation of different patient cohorts. Costs and utilities associated with different HAQ levels were based on data from the cohort studies and cross‐sectional surveys.ResultsCosts increase and quality of life decreases as RA progresses. In Sweden, total annual costs range from $4,900 to $33,000 per patient, compared with $4,900 to $14,600 in the UK. Cumulative costs over 10 years for patients starting in disease state 1 (HAQ < 0.6) are $54,600 in Sweden and $26,600 in the UK. The cumulative numbers of quality‐adjusted life‐years (QALYs) are 5.5 and 5.6, respectively. Both costs and QALYs were discounted at 3%.ConclusionThe 2 models, which were based on different patient cohorts, reach a similar conclusion in terms of the effect of RA over 10 years. They appear to accurately capture disease progression and its effects and can therefore be useful in estimating the cost‐effectiveness of new treatments in RA.
A pilot randomized trial comparing CD34‐selected versus unmanipulated hemopoietic stem cell transplantation for severe, refractory rheumatoid arthritis
Authors: Moore John , Brooks Peter , Milliken Sam , Biggs Jim , Ma David , Handel Malcolm , Cannell Paul , Will Rob , Rule Simon , Joske David , Langlands Bob , Taylor Kerry , O'Callaghan Joe , Szer Jeff , Wicks Ian , McColl Geoff , Passeullo Frances , Snowden John 
Published: October 2002

AbstractObjectiveEvidence from animal studies, case reports, and phase I studies suggests that hemopoietic stem cell transplantation (HSCT) can be effective in the treatment of rheumatoid arthritis (RA). It is unclear, however, if depletion of T cells in the stem cell product infused after high‐dose chemotherapy is beneficial in prolonging responses by reducing the number of infused autoreactive T cells. This pilot multicenter, randomized trial was undertaken to obtain feasibility data on whether CD34 selection (as a form of T cell depletion) of an autologous stem cell graft is of benefit in the HSCT procedure in patients with severe, refractory RA.MethodsThirty‐three patients with severe RA who had been treated unsuccessfully with methotrexate and at least 1 other disease‐modifying agent were enrolled in the trial. The patients received high‐dose immunosuppressive treatment with 200 mg/kg cyclophosphamide followed by an infusion of autologous stem cells that were CD34 selected or unmanipulated. Safety, efficacy (based on American College of Rheumatology [ACR] response criteria), and time to recurrence of disease were assessed on a monthly basis for up to 12 months.ResultsAll patients were living at the end of the study, with no major unexpected toxicities. Overall, on an intent‐to‐treat basis, ACR 20% response (ACR20) was achieved in 70% of the patients. An ACR70 response was attained in 27.7% of the 18 patients who had received CD34‐selected cells and 53.3% of the 15 who had received unmanipulated cells (P = 0.20). The median time to disease recurrence was 147 days in the CD34‐selected cell group and 201 days in the unmanipulated cell group (P = 0.28). There was no relationship between CD4 lymphopenia and response, but 72% of rheumatoid factor (RF)–positive patients had an increase in RF titer prior to recurrence of disease.ConclusionHSCT can be performed safely in patients with RA, and initial results indicate significant responses in patients with severe, treatment‐resistant disease. Similar outcomes were observed in patients undergoing HSCT with unmanipulated cells and those receiving CD34‐selected cells. Larger studies are needed to confirm these findings.