bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of the composition on the phase size in immiscible blends with the viscosity ratio close to unity
Authors: Zeng Jijun , Aoyama Masatoshi , Takahashi Hiroshi 
Published: May 2003

AbstractThe influence of the composition and interfacial tension on the phase size in immiscible polymer blends with a viscosity ratio close to unity has been investigated with poly(methyl methacrylate)/poly(ethylene terephthalate) blends and data from various works. For all the blends considered, the dispersed particle diameter (d) is proportional to the interfacial tension of the system. When the dispersed‐phase content (ϕ) is below 1%, there is minimal change of d with increasing ϕ. When ϕ is between 1 and 20%, d is proportional to ϕ0.4. It seems that the processing conditions do not influence the morphology significantly for blend systems with a viscosity ratio close to unity.© 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1791–1799, 2003
Synthesis of a high‐trans 1,4‐butadiene/isoprene copolymers with supported titanium catalysts
Authors: He Aihua , Huang Baochen , Jiao Shuke , Hu Youliang 
Published: May 2003

AbstractThe copolymerization of butadiene (Bd) and isoprene (Ip) with a supported titanium‐triisobutyl aluminum catalyst system was studied. An analysis using differential scanning calorimetry, X‐ray diffraction, and13C‐NMR spectra indicated that products with 25–60 mol % Bd units were random copolymers and that the melting temperatures and glass‐transition temperatures (Tg) were 30–40 and −74°C (or thereabout), respectively, which were very similar to those of natural rubber. The chemical structure of these copolymers was characterized by a high‐trans 1,4‐configuration: the trans 1,4‐content of Ip units was greater than 98%, and the trans 1,4‐content of Bd units was greater than 90%. The reactivity ratio of Bd was greater than that of Ip (rBd= 5.7 andrIp= 0.17). The sequence distribution of the monomer units of the copolymers followed a first‐order Markov statistical model. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1800–1807, 2003
Synthesis and kinetic analysis of 1,4‐naphthalene‐di(carboxylic acid) and hydroquinone diacetate based homopolyesters
Authors: Al‐Adwani H. , Bishara A. , Shaban H. 
Published: May 2003

AbstractA variety of high temperature liquid crystalline polymers can be developed using the homopolyester of 1,4‐naphthalene di(carboxylic acid) (1,4‐NDCA) and hydroquinone diacetate (HQDA) as a spacer. In such cases the monomer 1,4 NDCA acts as a kink. Kinetic studies of the synthesis of homopolyesters by melt polymerization using 1,4‐NDCA and hydroquinone diacetate (HQDA) are reported. The performance of two transesterification catalysts are estimated for this system. In this study, initial stage polymerization kinetics of the homopolyesters were examined. The side product, acetic acid, evolved in the homopolymerization of 1,4‐NDCA and HQDA, was used to estimate the progress of the reaction. The polycondensations were found to obey second order kinetics, regardless of whether the reaction was catalyzed or uncatalyzed.A set of twelve differential equations containing four different rate constants, k1, k2, k3 and k4 has been developed and computed, to study the initial stage kinetics. The computed values of acetic acid are compared with the experimentally collected amounts, and the four rate constants are optimized using a differential algebraic optimization technique. The present model represents the data with an acceptable accuracy and with an average percentage error of less than 5% for the entire experimental range. The correlation coefficient values range from 0.95 to 0.99 for all experimental data. The kinetic constants and activation energy values are reported.Differential scanning calorimetric (DSC) analysis of the homopolyesters indicate that 1,4 NDCA–HQDA had the highest melting temperature, around 350°C. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1808–1817, 2003
Polyimide asymmetric membranes: Elaboration, morphology, and gas permeation performance
Authors: Leblanc N. , Le Cerf D. , Chappey C. , Langevin D. , Métayer M. , Muller G. 
Published: May 2003

AbstractAsymmetric 2,2‐bis‐(3,4‐dicarboxyphenyl) hexafluoropropane dianhydride (6FDA)‐2‐methyl‐1,3‐phenylenediamine (mPDA) polyimide membranes were prepared according to a phase‐inversion mechanism by using different solvent/nonsolvent blends. The membrane formation mechanism and the final performances of the asymmetric membranes have been found both nonsolvent and solvent nature dependent. From the visualization of cross sections of asymmetric membranes by scanning electron microscopy and the study of the permeation of two gases (N2, CO2) through asymmetric membranes, a relationship between elaboration conditions and asymmetric membranes characteristics could be drawn. The organization of polymer chains in solution strongly affects the final polymer arrangement and thus the final performances of the membrane. The influence of preliminary solvent evaporation before immersion has been shown to be dependent on the structure of the asymmetric membrane: finger‐like or sponge‐like structures. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1838–1848, 2003
Gas transport properties of poly(ethylene‐2,6‐naphtalene dicarboxylate) films: Influence of crystallinity and orientation
Authors: Hardy L. , Espuche E. , Seytre G. , Stevenson I. 
Published: May 2003

AbstractH2 and CO2 transport properties were investigated on semicrystalline poly(ethylene‐2,6‐dicarboxylate naphtalene) (PEN) films and biaxially stretched films and analyzed in terms of solubility and diffusion. The decrease of the permeability observed on the thermally crystallized samples has been described by Maxwell's law. No change of the sorption properties of the amorphous phase has been noticed as a function of the thermal treatment and the evolution of the diffusion coefficient has been related to a tortuosity effect. The low permeability measured on the biaxially stretched film is related to both a change of the free volume sizes distribution and a tortuosity effect. The interesting barrier properties of the biaxially stretched film are kept even after annealing the film at 250°C. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1849–1857, 2003
Pseudo‐interpenetrating polymer networks based on tetrafunctional epoxy resins and poly(methyl methacrylate)
Authors: Alcântara Robério Marcos , Pires Alfredo Tibúrcio Nunes , De Barros Glaucione Gomes , Belfiore Laurence A. 
Published: May 2003

AbstractPseudo‐interpenetrating polymer networks (p‐IPNs) of an epoxy resin and poly(methyl methacrylate) (PMMA) were synthesized simultaneously. Methyl methacrylate (MMA) was polymerized with benzoyl peroxide in the presence of an oligomeric epoxy resin, which contained stoichiometric amounts of either a tetrafunctional [i.e., ethylenediamine (EDA)] or hexafunctional [i.e., triethylenetetramine (TETA)] crosslinking agent. The resulting materials would be useful for aerospace, automotive, medical, and dental applications. The structure of the epoxy resin (i.e., tetraglycidyl 4,4′‐diamine diphenyl methane) was confirmed by elemental analysis and IR and NMR spectroscopies. The thermal, mechanical, and kinetic behaviors of the polymeric networks produced from this oligomeric epoxy resin and the p‐IPNs of this crosslinked epoxy with linear PMMA were compared. Time‐resolved IR spectroscopy of the cyclic ether group in the epoxy at 906 cm−1 revealed kinetic information between 40 and 80°C for a complex reaction scheme. In the absence of MMA, the asymptotic final conversion of epoxide groups was achieved after (1) 60 min of chemical crosslinking at 50°C and (2) 30 min of crosslinking at 80°C with tetrafunctional EDA. In the presence of 10 wt % MMA, asymptotic final conversions of the epoxide group were achieved after (1) 150 min at 40°C, (2) 80 min at 50°C, and (3) 30 min at 80°C. In agreement with other kinetic studies based on the same epoxy resin but different crosslinking agents, these solvent‐free polymerizations were diffusion‐controlled during the later stages of chemical crosslinking because the apparent reaction order was very close to unity, via an unsteady state batch reactor model with lumped‐parameter kinetics. The thermal expansion coefficients of the crosslinked epoxy resin increased at higher concentrations of PMMA, but hexafunctional TETA produced a higher crosslink density and reduced the thermal expansion relative to the same networks and p‐IPNs prepared with tetrafunctional EDA. Elastic modulus, fracture stress, and toughness increased synergistically when the epoxy resin was crosslinked with EDA at 40°C in the presence of 10 wt % MMA. This p‐IPN exhibited minimal shrinkage, on the order of 0.15%, during the actual polymerization. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1858–1868, 2003
Brominated phenol–formaldehyde resin as an adhesive for plywood
Authors: Petsom Amorn , Roengsumran Sophon , Hanphichanchai Supattra , Sangvanich Polkit 
Published: May 2003

AbstractA brominated phenol–formaldehyde resin was investigated as a plywood adhesive to study the effect of bromine on the physical and flammability properties of this resin. The results of these studies showed that brominated phenol–formaldehyde resin of 10% bromine content by weight of the phenol–formaldehyde resin was suitable to be used as a plywood adhesive. The optimal compressing temperature and compressing time were 110°C and 30 min, respectively. The prepared plywood obtained from the optimal condition gave a high shear strength, good flame retardancy, and good resistance to both hot and cold water. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1918–1924, 2003
Poly(sulfobetaine)s and corresponding cationic polymers. IX. Synthesis and aqueous solution properties of zwitterionic poly(sulfobetaine) derived from a styrene–N,N‐dimethylaminopropyl maleamidic acid copolymer
Authors: Lee Wen‐Fu , Chen Yan‐Ming 
Published: May 2003

AbstractA styrene–N,N‐dimethyl(maleamidic acid)propyl ammonium propane sulfonate (SDMMAAPS) copolymer was synthesized through an amidoacidation reaction of a styrene–maleic anhydride alternating copolymer with N,N‐dimethylaminopropylamine (ring‐opening reaction) and then reacted with propane sultone. The cloud point and minimum salt concentration (msc) of this ampholytic SDMMAAPS copolymer were determined in aqueous salt solutions. The effects of counterions on the cloud point and msc of SDMMAAPS were not entirely the same as those of other zwitterionic poly(sulfobetaine)s. The greatest difference from other poly(sulfobetaine)s, such as styrene–N,N‐dimethyl(maleimido propyl)ammonium propane sulfonate copolymers, was the carboxylic group on the polymer chain unit of SDMMAAPS. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1884–1889, 2003
Synthesis of polyurethane/polyethylene grafted polymers using cyclotriphosphazene as a coupling agent
Authors: Dez Isabelle , De Jaeger Roger 
Published: May 2003

AbstractThe reaction between a dihydroxyphenoxycyclotriphosphazene containing allylic functions, 3, and hexamethylene‐1,6‐diisocyanate (HDI) leads to a new cyclotriphosphazene‐substituted polyurethane 4. The structures of both classes of compounds involved in that synthesis were investigated by 31P‐, 13C‐, and 1H‐NMR, infrared, and mass spectrometries, size‐exclusion chromatography, and elemental analysis. The thermal behavior of 4 was investigated and compared to that of hexaphenoxycyclotriphosphazene, N3P3(OC6H5)6, and of a polyurethane synthesized from 1,3‐bis(hydroxy)benzene and HDI. The free‐radical‐promoted grafting of 4 onto the polyethylene surface is described. The resultant surface was studied by ATR–IR, XPS, and contact‐angle techniques. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1925–1934, 2003
Synthesis and properties of the semi‐interpenetrating polymer network–like, thermosensitive poly(N‐isopropylacrylamide) hydrogel
Authors: Zhang Xian‐Zheng , Chu Chih‐Chang 
Published: May 2003

AbstractA new strategy was used to prepare a semi‐interpenetrating polymer network (semi‐IPN)–like poly(N‐isopropylacrylamide) (PNIPAAm) polymeric hydrogel, consisting of either low (2300) or high (33,000) molecular weight linear PNIPAAm chains and the crosslinked PNIPAAm network. The properties of the resulting PNIPAAm hydrogels were characterized by DSC and SEM as well as their swelling ratios at various temperatures, the deswelling in hot water (48°C), and the oscillating shrinking–swelling properties within small temperature cycles. It was found that the deswelling rate of these semi‐IPN–like PNIPAAm hydrogels was improved if the molecular weight and/or composition of the linear PNIPAAm chains within the semi‐IPN–like PNIPAAm hydrogels were increased. This improved deswelling rate was attributed to the fast response nature of the linear PNIPAAm chains and the increased pore number in the matrix network, which provided numerous water channels for the water to diffuse out during the deswelling process at a temperature above the lower critical solution temperature. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1935–1941, 2003
Ce(IV)‐initiated graft polymerization of acrylic acid onto poly(ethylene terephthalate) fiber
Authors: Chansook N. , Kiatkamjornwong S. 
Published: May 2003

AbstractGraft copolymerization of acrylic acid onto poly(ethylene terephthalate) (PET) fiber by a redox system using ceric (IV) initiator was studied with regard to various parameters of importance: acrylic acid concentration, ceric (IV) concentration, nitric acid concentration, reaction temperature, and reaction time. Based on the morphology of the PET fiber, it could be concluded that ceric (IV) in dilute nitric acid is a redox initiator for the surface graft copolymerization of the acrylic acid/PET system. The grafted PET fiber showed an increase in improved moisture regain to reach 900% at 39.5% graft yield. The dyeability with the basic dye and disperse dye significantly increased by 100 and 22%, respectively, as a result of the grafting onto PET fiber. Both tenacity and elongation gradually decreased by 51.2 and 28.9%, respectively, with increasing graft yield, which reduced the fiber service lifespan. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1952–1958, 2003
Cashew nut shell liquid–based tailor‐made novolac resins: Polymer morphology quantitation by 1‐D and 2‐D NMR techniques and performance evaluation
Authors: Roy Debmalya , Basu P. K. , Raghunathan P. , Eswaran S. V. 
Published: May 2003

AbstractThe application of cashew nut shell liquid (CNSL) and CNSL‐based polymers in the burgeoning microelectronics industry is rare. “High ortho” alternating and semialternating tailor‐made novolac copolymers based on CNSL and m‐cresol and/or p‐cresol and have been made and successfully used as photoresists for microlithography. The microstructure of one of the representative m‐cresol copolymer is exhaustively elucidated based on 1‐D and 2‐D NMR techniques. Incorporation of different monomers in the resin backbone has been quantitatively estimated based on an improved NMR methodology. The lithographic performance of photoresists using novolac resins based on cardanol (fractionated CNSL) and diazonaphthoquinone ester was also evaluated. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1959–1965, 2003
Effect of the copolycondensation temperature on the reactivities of bis(3‐hydroxypropyl)terephthalate and bis(2‐hydroxyethyl)terephthalate
Authors: Sik Yoon Won , Seok Lyoo Won , Do Ghim Han , Lee Jinwon , Ho Kim Joon , Soo Kim Sam 
Published: May 2003

AbstractThe rate constants of cross reactions in the copolycondensation of bis(3‐hydroxypropyl)terephthalate (BHPT) and bis(2‐hydroxyethyl)terephthalate (BHET), k12 and k21, were determined with the results obtained from 1H NMR spectroscopy analysis. BHPT and BHET were polymerized and copolymerized at 260, 270, and 280°C with titanium tetrabutoxide as a catalyst. With the adoption of second‐order kinetics to the polycondensation, k11 and k22 were calculated. The monomer reactivity ratios of BHPT were much larger than those of BHET, indicating the block nature of the copolycondensation, but the difference between the reactivity ratios was lowest at the highest polycondensation temperature of 280°C. This indicated that the probability of randomization was increased. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1890–1895, 2003
Membrane properties of microporous structures prepared from polyethylene/polymethacrylate IPN
Authors: Pionteck Jürgen , Hu Jianjiang , Schulze Ulrich 
Published: May 2003

AbstractPolyethylene/polymethacrylate interpenetrating polymer networks (PE/PMA IPN) form a matrix–particle or a co‐continuous morphology that can be adjusted by the composition and synthesis conditions. Based on the fact that PMA degrades whereas PE crosslinks when they are exposed to energetic irradiation, we developed a new approach to create a porous structure by electron beam irradiation. IPN systems that differ in the methacrylate components and composition were studied. One system contains poly(butyl methacrylate‐co‐methyl methacrylate) (BMA‐co‐MMA) and the other contains poly(dodecyl methacrylate‐co‐ethyl methacrylate) (DMA‐co‐EMA) as the PMA phase. After electron beam irradiation followed by extraction with xylene, both IPN systems have a porous structure that is permeable to water. However, the structure and size of the pores depend on the PMA components and the synthesis conditions. PMAs with long aliphatic side chains degrade less than PMAs containing only short aliphatic pendant groups. Therefore, the PE/BMA‐co‐MMA IPN forms bigger pores than PE/DMA‐co‐EMA, resulting in a higher water flux. The molecular cutoffs of the IPN are characteristic for microfiltration or ultrafiltration.© 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1976–1982, 2003
Preparation of high capacity weak base poly(methyl methacrylate)–ethylene glycol dimethylacrylate copolymer anion exchange resin by modification using NOx
Authors: Sinha Shishir , Jayaswal Namita , Kumar Anil 
Published: May 2003

AbstractMacroporous poly(methyl methacrylate)–ethylene glycol dimethylacrylate (PMMA–EGDM) resin (resin 1) was prepared by suspension polymerization and gelatin was found to be the key component deciding the size of particles. To prepare aminated macroporous weak base PMMA–EGDM exchanger, resin 1 was nitrated using NO2 gas with a minor amount of NO (termed NOx). The modified PMMA–EGDM resin (resin 2) was reduced to NH2 groups and the exchange capacity of the weak base anion exchange resin (resin 3) was determined. Regression analysis of NOx consumption versus time and the exchange capacity Q versus time data suggested a second‐order kinetics for the modification reaction and these are reported. We examined the effect of duration of nitration on the exchange capacity of resin 3. It was found that it first increased with the increase in the extent of nitration, reaching a broad maximum of 4.8 meq/g of wet resin with 78% moisture for about 8 h of nitration, and decreasing for longer nitration times as a result of polymer degradation. These results were compared with commercial resin, which had an exchange capacity of 1.68 meq/wet g with 43% moisture content. To assess the salvation ability of the modified PMMA–EGDM resin, consistent with the literature, we devised three stages of removing moisture. Experiments suggest that the high capacity of the modified PMMA–EGDM resin may be attributed to this increased salvation ability. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1991–1999, 2003
Cloud‐point measurements for salt + poly(ethylene glycol) + water systems by viscometry and laser beam scattering methods
Authors: Nozary S. , Modarress H. , Eliassi A. 
Published: May 2003

AbstractThe phase separation of salt + poly(ethylene glycol) + water systems was studied by cloud‐point measurements using viscometry and laser beam scattering methods. The Flory–Huggins model was applied to determinate the condition for salt‐induced liquid–liquid phase separation in the system. A temperature‐ and concentration‐dependent interaction parameter was employed to fit the phase diagrams for the systems. The temperature and concentration functionality of the interaction parameter was determined and used to predict cloud‐point curves for the systems. The cloud‐point curves were found to be in quantitative agreement with experimental data. Also, the effect of various salts on the measured cloud points was studied. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1983–1990, 2003
Effect of nitrogen and oxygen incorporated into TMSAA plasma coating on surface‐bound heparin activity
Authors: Chen Meng , Osaki Shigemasa (Gem) , Zamora Paul O. , Potekhin Mila 
Published: May 2003

AbstractTo investigate the influence of nitrogen and oxygen incorporated into N‐trimethylsilylallyamine (TMSAA) plasma coating on heparin binding to the surfaces, four types of monomer combinations were utilized. Those combinations include TMSAA alone, TMSAA mixed with nitrogen (TMSAA + N2), with air (TMSAA + air), and with oxygen (TMSAA + O2). Fourier transform infrared (FTIR) spectroscopy was employed to study the coating of the bulk structure. The thickness and surface morphology of the coatings were measured using atomic force microscopy (AFM). Electron spectroscopy for chemical analysis (ESCA) and the contact angle were used to investigate the surface elemental composition and hydrophilicity, respectively. It was found that the incorporation of oxygen into the coating formation significantly increased the deposition rate of the TMSAA + O2 coating, but the heparin activity was the least even though it made the coating surface more hydrophilic. This is considered to have resulted from the loss of nitrogen in the coating structure due to the oxygen replacement to nitrogen. The nitrogen incorporated into the coating had no noticeable effect on the heparin surface‐binding ability. The TMSAA + air plasma grafting process exhibited the best heparin attachment to the surface, which could be largely attributed to its highest surface roughness, although the nitrogen composition was decreased to some extent compared to the pure TMSAA plasma coating. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1875–1883, 2003
Pharmacokinetics and bioequivalence evaluation of two simvastatin 40 mg tablets (Simvast & Zocor) in healthy human volunteers
Authors: Najib Naji M. , Idkaidek Nasir , Adel Ayman , Admour Isra' , Astigarraga Rafel E. B. , Nucci Gliberto De , Alam S. Mahmood , Dham Ruwayda , Qumaruzaman  
Published: May 2003

AbstractThe pharmacokinetics of two brands of simvastatin 40 mg tablets were compared in 24 healthy human volunteers after a single oral dose in a randomized cross‐over study, conducted at IPRC, Amman, Jordan. Reference (Zocor, MSD, Netherlands) and test (Simvast, Julphar, UAE) products were administered to fasted volunteers; blood samples were collected at specified time intervals, plasma separated and analyzed for simvastatin and its active metabolite (β‐hydoxy acid) using a validated LC–MS/MS method at Cartesius Analytical Unit, Institute of Biomedical Sciences – USP, Sao Paulo, Brazil. The pharmacokinetic parameters AUC0−t, AUC0−∝, CMAX, TMAX, T1/2 and elimination rate constant were determined from plasma concentration–time profile for both formulations and were compared statistically to evaluate bioequivalence between the two brands, using the statistical modules recommended by FDA. The analysis of variance (ANOVA) did not show any significant difference between the two formulations and 90% confidence intervals fell within the acceptable range for bioequivalence. Based on these statistical inferences it was concluded that the two brands exhibited comparable pharmacokinetic profiles and that Julphar's Simvast is bioequivalent to Zocor of MSD, Netherlands. Copyright © 2003 John Wiley & Sons, Ltd.