bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular transport of esters, aldehydes, aromatic liquids, and a ketone into fluoroelastomer membrane at 30, 40, and 50°C
Authors: Kariduraganavar Mahadevappa Y. , Kulkarni Sangeeta B. , Aminabhavi Tejraj M. 
Published: February 2003

AbstractMolecular transport of esters, aldehydes, substituted aromatic liquids, and a ketone through a fluoroelastomer (FC‐2120) membrane sample was studied at 30, 40, and 50°C. Sorption results were obtained by using a gravimetric method and concentration‐independent diffusion coefficients were calculated using Fick's diffusion equation. Permeability coefficients were calculated from sorption and diffusion data. Concentration profiles of the liquid penetrants were calculated by solving the Fick's equation under appropriate initial and boundary conditions and these plots are displayed to show the variations in liquid concentrations with reference to the nature of liquids chosen, membrane thickness, as well as the time of polymer immersion in the liquids. Arrhenius activation parameters were also estimated from a temperature dependence of diffusion and sorption coefficients. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 840–847, 2003
Immobilization of lipase on a polymeric microsphere with an epoxy group prepared by radiation‐induced polymerization
Authors: Choi Seong‐Ho , Lee Kwang‐Pill , Kang Hee‐Dong 
Published: February 2003

AbstractA polymeric microsphere (PM) with an epoxy group was prepared by the radiation‐induced polymerization of glycidyl methacrylate and diethylene glycol dimethacrylate in reaction conditions with variations in solvents, irradiation dose, and monomer composition. The epoxy group of the PM was analyzed by solid‐state 13C‐NMR, Fourier transform infrared spectroscopy (FTIR), Fourier transform Raman spectroscopy, and elemental analysis (EA) after amination. In EA after amination, the epoxy group content was in the range 0.20–0.50 mmol/g. The lipase was immobilized to the epoxy group of the PM in experimental conditions with variations in the pH and the epoxy group content. The activity of the lipase‐immobilized PM was in the range 148–342 unit/mg min. The activity of lipase‐immobilized PM increased in accordance with the epoxy group content. The lipase‐immobilized PM was also characterized by FTIR and EA. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1153–1161, 2003
Recycling of unfilled polyurethane rubber using high‐power ultrasound
Authors: Ghose Sayata , Isayev A. I. 
Published: February 2003

AbstractThis investigation deals with the recycling of polyurethane rubber by the application of high‐power ultrasound in a continuous ultrasonic coaxial reactor. The cured rubber has been devulcanized at various feed rates and various gap sizes and then revulcanized again with certain adjustments in the curing recipe. The die pressure and the total power consumption have been recorded as a function of the processing conditions. The rheological and mechanical properties, hardness, gel fraction, and crosslink density of the original, devulcanized, and revulcanized samples have been measured and compared in an attempt to determine the optimum condition for devulcanization. Gel permeation chromatography (GPC) has been carried out with the sol part of the devulcanized samples to study the devulcanization and degradation. The results show that at low flow rates and narrow gaps, the material is degraded very quickly and, therefore, exhibits very poor mechanical properties. However, increasing the feed rate results in an improvement of the mechanical properties. Measured values of the crosslink densities and gel fractions indicate the processing conditions under which greater devulcanization and degradation of the samples take place. The lower molecular weights of the sol, extracted from the devulcanized samples, obtained in the GPC experiments in comparison with polyurethane gum indicate a breakdown of the polymeric chains as a result of devulcanization. The devulcanized samples show a higher activation energy of viscous flow, possibly because of the formation of branched structures. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 980–989, 2003
Use of silica from rice husk ash as an antiblocking agent in low‐density polyethylene film
Authors: Chuayjuljit S. , Kunsawat C. , Potiyaraj P. 
Published: February 2003

AbstractIn packaging applications, blocking is always found in low‐density polyethylene (LDPE) films. Practically, such problems can be solved by incorporation of antiblocking agents, for example, silica and talc. The objective of this research was to explore the possibility of using silica from rice husk ash (RHA silica) as an antiblocking agent in LDPE film. Properties of RHA silica were compared with commercial silica, Sylo‐1. The appropriate amount of silica to be used as an antiblocking agent in LDPE film was also investigated. The results indicate that RHA silica has a smaller particle size and a higher specific surface area but a higher bulk density than those of Sylo‐1 silica. In the plastic film industry, 500–1000 ppm of silica is added in LDPE films as an antiblocking agent. It was also found that LDPE film with 2000–3000 ppm RHA silica showed similar properties to LDPE film filled with commercial silica in terms of its blocking behavior, mechanical strength, and film clarity. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 848–852, 2003
Morphology and electrical properties of carbon‐black‐filled poly(ϵ‐caprolactone)/poly(vinyl butyral) nanocomposites
Authors: Wu Tzong‐Ming , Cheng Jen‐Chih 
Published: February 2003

AbstractThe morphology of poly(ε‐caprolactone) (PCL)/poly(vinyl butyral) (PVB)/clay nanocomposites was studied as a function of a small amount of amorphous PVB by polarized optical microscopy. The band spacings of PCL spherulites in PCL/PVB/clay nanocomposites decreased with increasing PVB content, and this indicated that increasing the PVB content shortened the period of lamellar twisting. The electrical properties of PCL/PVB/clay nanocomposites containing carbon black (CB) were also measured as a function of the PVB content. For samples with the same CB content, the intensity of the positive temperature coefficient (defined as the ratio of the peak resistivity to the resistivity at room temperature) of the nanocomposites increased as the PVB content increased. The change in the positive temperature coefficient was related to the morphological differences (i.e., the period of lamellar twisting) in the nanocomposites. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1022–1031, 2003
Synthesis and characterization of maleated poly(3‐hydroxybutyrate)
Authors: Chen Cheng , Peng Shuwen , Fei Bin , Zhuang Yugang , Dong Lisong , Feng Zhiliu , Chen Shan , Xia Hongmei 
Published: February 2003

AbstractGraft copolymerization of maleic anhydride (MA) onto poly(3‐hydroxybutyrate) (PHB) was carried out by use of benzoyl peroxide as initiator. The effects of various polymerization conditions on graft degree were investigated, including solvents, monomer and initiator concentrations, reaction temperature, and time. The monomer and initiator concentrations played an important role in graft copolymerization, and graft degree could be controlled in the range from 0.2 to 0.85% by changing the reaction conditions. The crystallization behavior and the thermal stability of PHB and maleated PHB were studied by DSC, WAXD, optical microscopy, and TGA. The results showed that, after grafting MA, the crystallization behavior of PHB was obviously changed. The cold crystallization temperature from the glass state increased, the crystallization temperature from the melted state decreased, and the growth rate of spherulite decreased. With the increase in graft degree, the banding texture of spherulites became more distinct and orderly. Moreover, the thermal stability of maleated PHB was obviously improved, compared with that of pure PHB. Its thermal decomposition temperature was enhanced by about 20°C. In addition, the introduction of the MA group promoted the biodegradability of PHB. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 659–668, 2003
Photoinitiation systems and thermal decomposition of photodefinable sacrificial materials
Authors: Wu Xiaoqun , Reed Hollie A. , Rhodes Larry F. , Elce Ed , Ravikiran R. , Shick Robert A. , Henderson Clifford L. , Allen Sue Ann Bidstrup , Kohl Paul A. 
Published: February 2003

AbstractThe exposure characteristics of norbornene‐based photosensitive sacrificial materials as functions of the photoinitiator have been investigated. The results show that the initiator, bis(2,4,6‐trimethylbenzoyl)‐phenylphosphine oxide, provides high photosensitivity and an adjustable contrast factor. The kinetics of the thermal decomposition of the polymers have been investigated with dynamic and isothermal thermogravimetric analysis to determine the most appropriate conditions for the thermal decomposition of the sacrificial polymers. The reaction is slightly higher than first‐order, and a single mechanism can account for the decomposition throughout the process. The dependence of the kinetic parameters on the composition of the copolymers has been studied, and the reaction order remains unchanged; however, the activation energy is lower when the alkenyl‐substituted norbornene content is increased in the copolymers. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1186–1195, 2003
Mechanical properties of a cryogenically mechanically alloyed polycarbonate–poly(aryl ether ether ketone) system
Authors: Martin Julie P. , Kander Ronald G. 
Published: February 2003

AbstractThe processing–property relationship of a model cryogenically mechanically alloyed polymer–polymer system [polycarbonate (PC) and poly(aryl ether ether ketone) (PEEK)] was investigated. PC and PEEK powders were cryogenically mechanically alloyed for 10 h, and the resulting two‐phase powder particles were processed into testable coupons with a miniature ram‐injection molder. The bulk mechanical properties of the coupons made from the mechanically alloyed powders and nonmechanically alloyed powders were investigated as a function of mechanical alloying and injection‐molding parameters. The injection‐molded coupons were mechanically tested in the three‐point‐bending mode. The results demonstrated that no measurable improvement was achieved in the energy to break, strain at failure, or failure strength in the coupons made from the mechanically alloyed materials in comparison with those of the coupons made from the nonmechanically alloyed powders. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1196–1202, 2003
Synthesis and properties of new polyurethane ionomers. I. Photosensitive cationomers with triazene units
Authors: Buruiana Emil C. , Niculescu Violeta , Buruiana Tinca 
Published: February 2003

AbstractNew bifunctional triazene compounds 1‐(m‐ hydroxymethyl)phenyl‐3‐(2‐hydroxyethyl)‐3‐methyltriaz(1)ene and l‐p‐nitrophenyl‐3,3‐di(2‐hydroxyethyl)triaz(1)ene as intermediates in polyurethane synthesis were prepared. Photosensitive polyetherurethane cationomers based on poly(tetramethylene oxide) diol of 2,000 average molecular weight, tolylene‐2,4‐diisocyanate, and N‐methyldiethanolamine/triazene diols, as cochain extender, followed by a quaternization with benzyl chloride, were synthesized and characterized. Upon UV irradiation, feniltriazene chromophore in monomer and both polymers (ionomeric or nonionomeric type) is irreversibly cleaved, as evidenced in photolytic and kinetic studies. The rate constant of photolysis in ionomer film was lower than for the corresponding nonionic film. A positive pattern can then be developed by treatment with CHCl3 that dissolves the exposed zone, while the unexposed area remains resistant and insoluble. By incorporating side nitrofeniltriazene groups, photostable polyurethanes were obtained. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1203–1210, 2003
Structural investigations of acrylonitrile–vinyl acid copolymers by NMR spectroscopy
Authors: Bajaj Pushpa , Sreekumar T. V. , Sen Kushal , Kumar Rajeev , Brar Ajaib Singh 
Published: February 2003

Abstract1H, 13C [1H]‐, and 2D HETCOR NMR spectroscopy have been employed to characterize polyacrylonitrile (PAN) homopolymer and copolymers of methacrylic acid (MAA) and itaconic acid (IA) prepared by solvent–water suspension polymerization technique in a mixture containing DMF (solvent) and water. The chemical composition of P(AN–MAA) copolymers was determined using 1H‐NMR and that of P(AN–IA) using quantitative 13C[1H]‐NMR spectra. P(AN–IA) copolymers show two separate signals due to two carboxylic groups in different magnetic environments of IA, whereas P(AN–MAA) shows only one in the region of δ 6.32–7.60 ppm in 1H‐NMR and δ 171.0–176.0 ppm in 13C[1H]‐NMR spectra. Evidence of acrylamide formation by the partial hydrolysis of AN groups is obtained by the small broad signal at δ 7.9 ppm in 1H‐NMR spectra. No carboxylic proton signal was observed in copolymers containing 12 mol % of comonomer, which indicates the formation of anhydride. The microstructure was obtained in terms of the A‐ and M‐centered triad sequences from 13C[1H]‐and 1H‐NMR spectra of the copolymers, which showed configurational and compositional sequences. For example, at higher comonomer content, the concentration of AAM and AAI sequencing increases. This is confirmed by 2D HETCOR NMR spectra also. The distribution of AN sequences is found to be random (n0 ∼ nm ≃ 2.0). The tacticity values are not affected by the comonomer content. The isotacticity remained almost same at 27% (mm, 26.5–29.3) in all acrylonitrile polymers irrespective of the nature of the comonomer and polymerization medium, that is, DMF/H2O ratio. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1211–1217, 2003
Electrochemical polymerization of azure A and properties of poly(azure A)
Authors: Chen Chuanxiang , Mu Shaolin 
Published: February 2003

AbstractThe electrochemical polymerization of azure A has been carried out using repeated potential cycling. The scan potential is set between −0.2 and 1.3 V (vs. Ag/AgCl). The electrolytic solution consisted of 5 mmol dm−3 azure A and 0.5 mol dm−3 Na2SO4 with pH 6.0. The temperature for polymerization was controlled at 50°C. An anodic peak and a cathodic peak appear at 0.38 and 0.23 V, respectively, on the cyclic voltammogram of poly(azure A) in 0.5 mol dm−3 Na2SO4 solution of pH 1.0. Their peak potentials shift toward the negative direction as pH value increases from 1.0 to 4.0. Poly(azure A) has good electrochemical activity and stability in the aqueous solution at the above pH range. The UV‐visible spectrum and FTIR spectrum of poly(azure A) are different from those of azure A. The FTIR spectrum of poly(azure A) indicates that no anions were doped into the oxidation form of poly(azure A). © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1218–1224, 2003
Preparation and properties of water‐soluble polyester surfactants. III. Preparation and wetting properties of polyethylene glycol–polydimethylsiloxane polyester surfactants
Authors: Liu Hsin‐Jiant , Lin Li‐Huei , Chen Keng‐Ming 
Published: February 2003

AbstractA novel series of water‐soluble polyethylene glycol–polydimethylsiloxane (PEG–Silicone) polyesters was prepared by reacting organopolysiloxane with hydroxyl‐terminated polyester. The polyesters are obtained by the polymerization of maleic anhydride (MA) and PEGs (number‐average molecular weights Mn = 2000–10,000). FTIR, 1H‐NMR, and elemental analysis were employed to characterized the structures of these compounds. These compounds exhibit good surface activities such as surface tension and low foaming. The influence of the PEG–Silicone polyester surfactants introduced at various concentrations (0.1–2 wt %) was examined by the contact angle method. The measurements performed with various solid substrates indicated that, at comparable concentrations, the PEG–Silicone polyester surfactants were shown to be more efficient for wetting PET and glass. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1236–1241, 2003
New process for the production of dry hexamethylenediammonium adipate
Authors: Papaspyrides C. D. , Vouyiouka S. N. , Bletsos I. V. 
Published: February 2003

AbstractA simple and easy technique is proposed for the preparation of dry hexamethylenediammonium adipate (HMA salt), using conventional dry‐blending equipment. The process includes contacting adipic acid and hexamethylenediamine, in the presence of a cryogenic medium, which is used to depress the exothermic of the salt formation. The purpose is the formation of free‐flowing HMA salt with good homogeneity and balanced end groups, which can be used as a starting intermediate in the polyamide industry. Critical parameters were studied, such as the nature and amount of cryogenic agent and the presence of water traces in the reacting mixture. Application in an industrial scale seems feasible so that all advantages of handling dry HMA salt instead of its components (adipic acid powder and hexamethylenediamine liquid) can be utilized. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1252–1257, 2003
Enhancement of the high‐temperature utility of a polystyrene‐b‐poly(ethylene‐co‐butylene)‐b‐polystyrene block copolymer by friedel–crafts naphthoylation
Authors: Jones Allan S. , Wright Timothy , Smook Malcolm A. , Harwood H. James 
Published: February 2003

AbstractA procedure was developed for the Friedel–Crafts naphthoylation of the polystyrene segments of a polystyrene‐b‐poly(ethylene‐co‐butene)‐b‐polystyrene (SEBS) triblock copolymer. It was possible to obtain up to 72% 1‐naphthoylation or 100% 2‐naphthoylation of the polystyrene segments in the copolymer. Naphthoylation could also be accomplished using trifluoromethanesulfonic acid as a catalyst. The naphthoylated products were characterized by 1H‐NMR spectroscopy, size‐exclusion chromatography, and dynamic mechanical thermal analysis. The mechanical properties of the original and naphthoylated polymers were measured from 25 to 125°C. The results obtained indicate that naphthoylation enhances the tensile properties of the polymers at elevated temperatures. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1289–1295, 2003
Size control of poly(2‐oxy‐6‐naphthoyl) whiskers by the addition of oligomers during polymerization
Authors: Sarker Ashim Kumar , Kimura Kunio , Yamashita Yuhiko 
Published: February 2003

AbstractThe method of controlling the size of a poly(2‐oxy‐6‐naphthoyl) (PON) whisker was examined with a focus on lengthening the whisker. PON whiskers were prepared by the polymerization of 2‐acetoxy‐6‐naphthoic acid in liquid paraffin at 330°C. The whiskers were very symmetrical. and both tips were very sharp. Growth of the whiskers along the length took place by which oligomer lamellae piled up along the long axis of the needlelike crystals with spiral growth. During steady growth until 8 min, the tip angle of the whiskers was constant at 80°. However, it became significantly sharper (22°) at 30 min, and later the trunk part of the whiskers stopped increasing. To depress the sharpening of the tips and to extend the steady‐growth period for longer whiskers, oligomers were added to the polymerization system after 8 min, just before the tip angle became sharper, to keep the concentration of the oligomers in the polymerization system constant. The addition of the oligomers extended the steady‐growth period, and the length increased from 12.5 to 17.3 μm. Although the width of the whiskers increased very slightly with the addition of the oligomers, the axial ratio of the whiskers increased from 19.4 to 24.7. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1320–1327, 2003
Reinforcement of polypropylene using sisal fibers grafted with poly(methyl methacrylate)
Authors: Zhou X. P. , Li R. K. Y. , Xie X. L. , Tjong S. C. 
Published: February 2003

AbstractSisal fiber (SF) surface modification was carried out by grafting with methyl methacrylate (MMA) using cerium and ammonium nitrate as initiator. The effects of reaction time, monomer, and initiator concentration on the grafting parameters were systematically investigated. The results showed that MMA was successfully grafted onto the sisal fiber surface. The PMMA‐grafted sisal fibers were melt blended with polypropylene (PP) and then injection molded. The PP/SF composites were characterized by means of thermal analysis, mechanical testing, wide‐angle X‐ray diffraction, and SEM examination. PMMA grafted onto the surface of SF enhanced the intermolecular interaction between the reinforcing SF and PP matrix, improved the dispersion of SF in the PP matrix, and promoted the formation of β‐crystalline PP. These enhanced the thermal stability and mechanical properties of PP/SF composites. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1055–1064, 2003
Surface morphology and nodule formation mechanism of cellulose acetate membranes by atomic force microscopy
Authors: Zeng Yiming , Wang Zhigang , Wan Lijun , Shi Yanqiao , Chen Guanwen , Bai Chunli 
Published: February 2003

AbstractBy the use of atomic force microscopy (AFM), formation mechanism of nodular structure in cellulose acetate membranes was systematically investigated. Elementary factors affecting the nodule formation were delineated on the basis of both kinetic and thermodynamic considerations. It was shown that (1) the exact nature of nodular structure is thermodynamic equilibrium glassy state; nodular structure will vanish in the rubbery state; (2) the thermodynamic factor affecting nodule formation is the membrane formation temperature; with the membrane formation temperature decreasing, more chain segments are able to form nodular structures; (3) nodule formation is dependent on the segment rearrangement; variation of the solvent environment is the major kinetic factor affecting the segment rearrangement and nodule formation. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1328–1335, 2003
Production and properties of highly oriented polyoxymethylene by die‐drawing
Authors: Taraiya A. K. , Mirza M. S. , Mohanraj J. , Barton D. C. , Ward I. M. 
Published: February 2003

AbstractHighly oriented monofilaments were produced by a high‐temperature die‐drawing process followed by tensile drawing. It was shown that a successful high‐speed process required high‐quality melt‐extruded rod. The mechanical properties and structure of the die‐drawn products were investigated by means of tensile and bending tests, dynamic mechanical measurements, DSC, and X‐ray diffraction. The bending modulus and the tensile strength increased with increasing draw ratio. It was also observed that at high draw ratios the γ‐dispersion peak in the dynamic mechanical tan δ curve, which is associated with main chain micro‐Brownian motion in the amorphous regions, diminishes, implying that these chains become taut. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1268–1278, 2003