bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vacuum ultraviolet–induced photochemical nitriding of polyolefin surfaces
Authors: Truica‐Marasescu F. , Wertheimer M. R. 
Published: January 2004

AbstractFilm samples of two very pure polyolefins, low‐density polyethylene (LDPE) and biaxially oriented polypropylene (BOPP), were surface‐modified by vacuum ultraviolet (VUV) photochemistry in low‐pressure ammonia. The influence of experimental conditions such as wavelength and intensity (photon flux) of the VUV radiation, ammonia pressure, and treatment duration, as well as the mechanisms involved in the surface modification were discussed. Changes in the surface energy and chemistry were investigated using suitable techniques like contact angle goniometry (surface energy) measurements, X‐ray photoelectron spectroscopy (XPS), attenuated total reflectance infrared spectroscopy, and time‐of‐flight secondary ion mass spectroscopy. We show that chemically bonded nitrogen concentrations [N], up to 25%, can be achieved on the polymer surfaces by VUV photochemistry, and that N is predominantly bonded as amine groups, thus leading to an important increase in the surface energy of treated samples. Finally, XPS, surface energy measurements, and atomic force microscopy were used to characterize possible degradation of the polymer surfaces during the VUV treatments. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3886–3898, 2004
Chemical modification of Bombyx mori silk with epoxide EPSIB
Authors: Cai Zaisheng , Jiang Guochuan , Qiu Yiping 
Published: January 2004

AbstractBombyx mori silk fabrics were chemically modified by EPSIB (a multifunctional silicone‐containing epoxy crosslinking agent). The reactivity of the epoxy groups with silk fibroin was studied by using amino acid analysis. The physical properties of the modified silks such as resiliency (both wet and dry), moisture regain, dyeing behaviors, and solubility in a mixture solvent (C2H5OH × CaCl2 : H2O = 2 : 1 : 8, molar ratio) were examined. The modified silk fabrics exhibited a significantly improved resiliency, a small increase in moisture regain and whiteness, and a slightly decreased tensile strength. The contents of Serine, Trosine, Lysine, and Histidine decreased linearly as the wet crease recovery angle (CRA) increased. The solubility in the mixture solvent also decreased as the wet CRA increased. The changes of physical properties, especially the wet CRA, were mainly due to the presence of stable cross‐links between silk fibroin and epoxy groups. The DSC and TGA analyses showed that EPSIB‐modified silk fibroin had a higher thermal stability compared with the control. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3579–3586, 2004
Effect of blending sodium polyethylene‐5‐sulfoisophthalate on adhesion of clinical bacteria on polyethylene terephthalate
Authors: Hu S.‐G. , Jou C.‐S. , Yang M.‐C. 
Published: January 2004

AbstractThis work studies the adhesion of clinical infecting bacteria, S. aureus and E. coli, on prosthetic polymeric materials. Membranes were prepared from polyethylene terephthalate (PET) blending at various ratios with sodium polyethylene‐5‐sulfoisophthalate (SPES). The membranes were characterized by measuring the contact angle, equilibrium water content, and the surface concentration of sodium sulfonate. The results show that sulfonate makes the membrane more hydrophilic. The surface properties of bacteria were determined by measuring the adhesion to n‐octane (B%) and the contact angles to water and α‐bromonaphthalene. For the four bacteria studied, encapsulated S. aureus was the most hydrophobic and had the highest amount of bacteria attached to the surface of SPES/PET membrane. Furthermore, the attached amount decreased with the increase of the content of SPES. Empirical correlations for predicting the attached amount from the surface properties of both polymer and bacteria were obtained from linear regression. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3587–3594, 2004
Miscibility and crystallization kinetics of poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate)/ poly(methyl methacrylate) blends
Authors: Chiu Hsiu‐Jung 
Published: January 2004

AbstractThe miscibility and crystallization kinetics of the blends of random poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) [P(HB‐co‐HV)] copolymer and poly(methyl methacrylate) (PMMA) were investigated by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). It was found that P(HB‐co‐HV)/PMMA blends were miscible in the melt. Thus the single glass‐transition temperature (Tg) of the blends within the whole composition range suggests that P(HB‐co‐HV) and PMMA were totally miscible for the miscible blends. The equilibrium melting point (T°m) of P(HB‐co‐HV) in the P(HB‐co‐HV)/PMMA blends decreased with increasing PMMA. The T°m depression supports the miscibility of the blends. With respect to the results of crystallization kinetics, it was found that both the spherulitic growth rate and the overall crystallization rate decreased with the addition of PMMA. The kinetics retardation was attributed to the decrease in P(HB‐co‐HV) molecular mobility and dilution of P(HB‐co‐HV) concentration resulting from the addition of PMMA, which has a higher Tg. According to secondary nucleation theory, the kinetics of spherulitic crystallization of P(HB‐co‐HV) in the blends was analyzed in the studied temperature range. The crystallizations of P(HB‐co‐HV) in P(HB‐co‐HV)/PMMA blends were assigned to n = 4, regime III growth process. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3595–3603, 2004
Homopolymer and copolymers of 4‐benzyloxycarbonylphenyl acrylate with glycidyl methacrylate: Synthesis, characterization, reactivity ratios, and application as adhesive for leather
Authors: Selvamalar C. S. Jone , Vijayanand P. S. , Penlidis A. , Nanjundan S. 
Published: January 2004

Abstract4‐Benzyloxycarbonylphenyl acrylate (BCPA) was prepared by reacting benzyl‐4‐hydroxy benzoate dissolved in methyl ethyl ketone with acryloyl chloride in the presence of triethylamine. The homopolymer and copolymers of BCPA with glycidyl methacrylate (GMA) having different compositions were synthesized in methyl ethyl ketone using benzoyl peroxide as a free‐radical initiator at 70 ± 1°C. All the polymers were characterized by FTIR, 1H‐NMR, and 13C‐NMR spectroscopic techniques. The solubility of the polymers was tested in various polar and nonpolar solvents. The molecular weights (Mw and Mn) and polydispersity indices of the polymers were determined using gel permeation chromatography. The glass‐transition temperatures of the copolymers increased with increasing GMA content in the copolymer. Thermogravimetric analysis of the polymers performed in air showed that the thermal stability of the copolymer increased with increasing BCPA content. Copolymer compositions were determined using 1H‐NMR analysis. The monomer reactivity ratios were determined by the application of conventional linearization methods such as Fineman–Ross (r1 = 0.5237; r2 = 1.9646), Kelen–Tüdös (r1 = 0.4996; r2 = 1.8741), and extended Kelen–Tüdös (r1 = 0.4652; r2 = 1.9046) as well as a nonlinear error‐in‐variables model (EVM) method, using the computer program RREVM (r1 = 0.4644; r2 = 1.8324). The peel strength of the leather adhesives prepared from the copolymers was also determined. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3604–3612, 2004
Crystallization and melt behavior of magnesium hydroxide/polypropylene composites modified by functionalized polypropylene
Authors: Lin Zhidan , Qiu Yixin , Mai Kanchen 
Published: January 2004

AbstractThe crystallization and melting behavior of Mg(OH)2/polypropylene (PP) composites modified by the addition of functionalized polypropylene (FPP) or acrylic acid (AA) and the formation of in situ FPP were investigated by DSC. The results indicated that addition of FPP increased crystallization temperatures of PP attributed to the nucleation effect of FPP. The formation of in situ FPP resulted in a reduced crystallization rate, melting point, and degree of crystallization because of the decreased regularity of the PP chain. For the Mg(OH)2/PP composites, addition of Mg(OH)2 increased the crystallization temperatures of PP attributed to a heterogeneous nucleation effect of Mg(OH)2. Addition of FPP into Mg(OH)2/PP composites further enhanced the crystallization temperatures of PP. It is suggested that there is an activation of FPP to the heterogeneous nucleation effect of Mg(OH)2 surface. The addition of AA also increased the crystallization temperatures of PP in Mg(OH)2/PP composites, but crystallization temperatures of PP were not influenced by the AA content, a phenomenon explained by the heterogeneous nucleation effect of the Mg(OH)2 surface activated by FPP and AA. A synergistic effect on crystallization of PP in Mg(OH)2/PP composites further increased the crystallization temperatures of PP. However, the crystallization temperatures of Mg(OH)2/PP composites modified by in situ FPP were lower than those of Mg(OH)2/PP composites modified by the addition of FPP or AA. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91:3899–3908, 2004
Electrical sensitivity behavior of a hydrogel composed of polymethacrylic acid/poly(vinyl alcohol)
Authors: Kim Seon Jeong , Yoon Seoung Gil , Lee Sang Min , Lee Sang Hoon , Kim Sun I. 
Published: January 2004

AbstractAn interpenetrating polymer network (IPN) composed of polymethacrylic acid (PMAA) and poly(vinyl alcohol) (PVA) was prepared and exhibited electrical sensitivity behavior. The swelling behavior of the PMAA/PVA IPN hydrogel was studied by immersion of the gel in aqueous NaCl solutions at various concentrations and pH values. The stimuli response of the PMAA/PVA IPN hydrogel in electric fields was also investigated. When swollen IPN hydrogel was placed between a pair of electrodes, the PMAA/PVA IPN hydrogel exhibited bending behavior upon the application of an electric field. The PMAA/PVA IPN hydrogel also showed stepwise bending behavior depending on the electric stimulus. Also, for biomedical applications, the bending behavior of PMAA/PVA IPN hydrogel in Hank's solution at pH 7.4 was studied. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91:3613–3617, 2004
Effect of diblock copolymers on morphology and mechanical properties for syndiotactic polystyrene/ethylene‐propylene copolymer blends
Authors: Choi Won Mook , Park O Ok , Lim Jae‐Gon 
Published: January 2004

AbstractInterfacial agents are often used to compatibilize immiscible polymer blends. They are known to reduce the interfacial tension, homogenize the morphology, and improve adhesion between phases. In this study, two diblock copolymers of styrene/ethylene‐propylene (SEP), which have different molecular weights, were used to compatibilize a blend of syndiotactic polystyrene (sPS) 75% and ethylene‐propylene rubber (EPR) 25% so as to extend the applications of sPS as incoming thermoplastics. The morphological analysis and emulsification curve, which relates the average size of the dispersion particles to the concentration of diblock copolymers added, was used to investigate the efficiency of the interfacial agents on the blend morphology. A notched izod impact test and a tensile test were also performed to determine the compatibilization effect of different molecular weight copolymers on the mechanical properties of the blends and to establish links between morphology and mechanical properties. Results suggest that the lower molecular weight diblock copolymer showed an effective emulsifying capacity for sPS/ERP immiscible blend in morphology and mechanical properties. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91:3618–3626, 2004
Kinetics of thermal degradation of thermotropic poly(p‐oxybenzoate‐co‐ethylene‐2,6‐naphthalate) by single heating rate methods
Authors: Zhang Li , Ma Jinghong , Zhu Xinyuan , Liang Borun 
Published: January 2004

AbstractThe kinetics of thermal degradation of thermotropic liquid crystalline poly(p‐oxybenzoate‐co‐ethylene‐2,6‐naphthalate) (PHB/PEN) with the monomer ratio of 60 : 40 and PEN in nitrogen was studied by dynamic thermogravimetry (TG). The kinetic parameters, including the activation energy Ea, the reaction order n, and the frequency factor ln(Z) of the degradation reaction for PHB/PEN (60 : 40) and PEN were analyzed by the single heating rate methods of Friedman and Chang. The effects of the heating rate and the calculating method on the thermostable and degradation kinetic parameters are systematically discussed. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91:3915–3920, 2004
NMR study of the early stages of gel formation in the PEG/poly(AMPS‐co‐NIPA) semi‐interpenetrating network system
Authors: Zhang Chi , Easteal Allan J. 
Published: January 2004

AbstractThe rate of conversion of the monomers and crosslinker in the formation of a novel semi‐interpenetrating poly(ethylene glycol)/ poly(2‐acrylamido‐2‐methylpropane sulfonic acid‐co‐N‐isopropylacrylamide) copolymer hydrogel was determined by using 1H‐NMR spectrometry. It was established that poly(ethylene glycol) does not participate in the polymerization reactions and that crosslinking by methylenebisacrylamide occurs predominantly in the early stages of copolymer chain growth. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3635–3641, 2004
Development of discrete nanopores I: Tension of polypropylene/ polyethylene copolymer blends
Authors: Lee Jonghwi , Macosko Christopher W. , Bates Frank S. 
Published: January 2004

AbstractPorous polymeric materials can be prepared by using micromechanical deformations. The development of porous structures in the tension of polyolefin blends are studied with the goal of developing a novel technique to make porous films. It is found in polypropylene/polyethylene copolymer blends of near 50/50 weight ratio that a metallocene polymer pair can produce stable nanopores throughout a wide range of strain, ∼50–700%. Its strain‐to‐break was relatively high, although its continuous phase is a brittle polypropylene. The typical size of nanopores is 10–300 nm; they start to develop at approximately 50% strain. The disruption of craze‐like structures into discrete nanopores seems to be the key mechanism in stabilizing pore development. Varying stretching direction and speed controls the pore morphology. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3642–3650, 2004
Electrical property and stability of electrochemically synthesized polypyrrole films
Authors: Oh Kyung Wha , Park Hyun Jin , Kim Seong Hun 
Published: January 2004

AbstractPolypyrrole (PPy) films doped with arylsulfonate dopants were prepared by electrochemical polymerization, to investigate the effects of various dopants on conductivities, thermal stabilities, and morphologies of PPy films. Also, HCl was added to those dopants as a cooperating dopant, to improve conductivity of PPy films. Conductivity of PPy film doped with the mixture of each dopant and HCl was improved. Temperature dependency on conductivity for PPy films doped with various dopants was investigated by heating them from 30 to 300°C. For the film doped with TSA, DBSA, and AQSA, conductivity increased up to 150°C and then rapidly decreased, whereas the conductivity of other films decreased after 200°C as temperature increased up to 300°C. Moreover, the film doped with small size dopant such as TSA and HCl/TSA had an interconnected porous fibrillar‐like morphology. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3659–3666, 2004
Synthesis and properties of water soluble polyurethanes based on poly(ethylene glycol)
Authors: Doseva Veneta , Shenkov Stoicho , Vasilev Sasho , Baranovsky Vladimir Y. 
Published: January 2004

AbstractWater soluble polyurethanes (WSPU)s have been prepared by polycondensation of isophorondiisocyanate and tolylene‐2,4‐diisocyanate with poly(ethylene glycol)s (PEGs) of molecular weights 400, 600, and 1,000. The physicochemical properties of the WSPUs depend on the hydrophilic–hydrophobic balance in their polymeric chain, i.e., the properties are determined by relative density of the hydrophobic diisocyanate residues in WSPU. X‐ray and differential scanning calorimetry studies show that the WSPUs have a degree of crystallinity lower than that of the pure PEGs of the same molecular weights. Like the PEGs the WSPUs prepared form interpolymer complexes with polyacrylic (PAA) and polymethacrylic (PMAA) acids. These complexes are more stable than the (PEG.PAA) and (PEG. PMAA) complexes. The novel compounds can be considered as modified linear PEGs. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3651–3658, 2004
Mechanical strength of durable press finished cotton fabric part V: Poly(vinyl alcohol) as an additive to improve fabric abrasion resistance
Authors: Zhou Wenlong , Yang Charles Q. , Lickfield Gary C. 
Published: January 2004

AbstractMultifunctional carboxylic acids, such as 1,2,3,4‐butanetetracarboxylic acid (BTCA), are effective crosslinking agents for cotton cellulose and have become the most promising nonformaldehyde durable press (DP) finishing agents to replace the traditional formaldehyde‐based dimethyloldihydroxylethyleneurea (DMDHEU) and its derivatives. DP finishing imparts wrinkle resistance to cotton fabrics and also severely reduces the strength and abrasion resistance of finished fabrics. In this research, we investigated the use of poly(vinyl alcohol) (PVA) as an additive to improve the abrasion resistance of the cotton fabric crosslinked by BTCA. We found that addition of PVA improves the abrasion resistance of the crosslinked cotton fabric when the concentration of PVA exceeds 0.6% in the finish solution. We also found that the use of PVA as an additive has no negative effect on the wrinkle recovery angle (WRA), DP rating, and tensile strength of the treated cotton fabric. This is probably because the molecules of PVA stay on the surfaces of the cotton fibers due to their large molecular sizes. PVA competes with cellulose to esterify BTCA, thus reducing the number of crosslinkages formed on the cotton fiber surface. The reaction of PVA and BTCA may also form a protective layer on the fiber surface, thus reinforcing the mechanically weak points on the fiber surface. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3940–3946, 2004
Study on the cure behavior of 2,7‐dihydroxynaphthalene dicyanate
Authors: Yan Hong‐Qiang , Ji Li , Qi Guo‐Rong 
Published: January 2004

AbstractThe cure behavior of 2,7‐dihydroxynaphthalene dicyanate (DNCY) was studied by means of nonisothermal DSC, isothermal DSC, and FTIR. In nonisothermal DSC, the cure kinetics parameters of DNCY were calculated by the Coats–Redfern method and compared with those of biphenol A dicyanate (BACY). It was revealed that the activation energy of DNCY was enhanced compared with that of BACY because of the presence of naphthalene, and the gelation of DNCY occurred within the conversion range 50–55%, which is lower than that of BACY. In isothermal DSC, a good time–temperature superposition of the conversion profiles of DNCY was obtained during conversions below about 50%. These results were consistent with those obtained by nonisothermal DSC. For the catalyzed system, the autocatalytic behavior prevailed at conversions below 30%, whereas the catalytic behavior occurred only at conversions above 30%.In situFTIR spectra revealed that a triazine network was formed by cyclotrimerization of the OCN functional group during the cure process for systems with and without catalysts. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3927–3939, 2004
Synthesis and properties of new polymerized monomer reactants matrix resins of pyrrolone–benzimidazole copolymers containing pyridine unit
Authors: Yang Hai‐Xia , Li Yan‐Feng , Liu Jin‐Gang , Yang Shi‐Yong , Yin Da‐Xue , Zhou Lincheng , Fan Lin 
Published: January 2004

AbstractA series of new polymerized monomer reactants (PMR) matrix resins of poly(pyrrolone‐benzimidazole)s containing a pyridine unit (PPBP) were synthesized by polycondensation of monoethyl ester of cis‐5‐norbornene‐endo‐2,3‐dicarboxylic acid, 2,6‐diphenyl ester pyridinedicarboxylic acid or 3,5‐diphenyl ester pyridinedicarboxylic acid, and diethyl ester of 4,4′‐oxydiphthalic acid with 3,3′‐diaminobenzidine in a mixing solution of anhydrous ethyl alcohol and N‐methylpyrrolidone under given temperature and pressure conditions. The resulting resin solutions showed good solubility in polar organic solvents and stability at room temperature. The corresponding PPBP matrix resin, molded powder, and molded plate were prepared by undergoing amidation, imidization, cyclization, and crosslinking reactions when the reaction temperature was increased from 80 to 350°C, successively; the crosslinking structure was formed by the reverse Diels–Alder reaction at 270–290°C under 50 MPa pressure (2.5–3.5 MPa displayed by the pressure meter). The chemical reactions and properties of the resulting PPBP were studied by means of FTIR, TGA, and DMA methods, and the results indicated that the kinds of PPBP materials retain excellent thermal stability and processability; when the initial decomposition temperature was above 620°C the Tg was at 413.5°C for 3,5‐PPBP‐20 molded plate. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3981–3990, 2004
Preparation and optical performance of chiral polymers having azobenzene segments
Authors: Liu Jui‐Hsiang , Yang Po‐Chih 
Published: January 2004

AbstractA series of monomeric azobenzene derivatives of 6‐(4‐nitro‐4′‐oxy‐azobenzene acrylate with carbon numbers of 6 and 11, and the chiral monomer of bornyl 4‐(6‐acryloyloxyhexyloxy)‐phenyl‐4′‐benzoate were synthesized. Chiral polymers having bornyl group end‐capped pendants with azobenzene‐derived segments were prepared. Molecular structures and polymer compositions were confirmed by using 1H‐NMR, elemental analysis, FTIR, and UV–vis analyzers. Thermodynamic properties of both monomers and polymers were investigated. Specific rotations of chiral monomers and polymers were estimated by using an automatic digital polarimeter. Liquid crystalline textures of monomers and polymers were analyzed by using a polarizing optical microscope and confirmed by a small‐angle X‐ray analyzer. The optical reflection characteristics of composite cells with chiral nematic liquid crystal and various amounts of azobenzene derivatives were evaluated by using a UV–vis spectrophotometer. The reliability and stability of the composite cells with E48/S811 and azobenzene derivatives were studied. The photoisomerization of the chiral polymer film was investigated by using SEM and AFM analyzers. It was found that the UV irradiation of a laser spot caused the shrinkage of polymer film due to the photoisomerization of azobenzene segments. The contraction of the polymer film can be recovered by heat treatment. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3693–3704, 2004
Synthesis and characteristics of interpenetrating polymer network hydrogels composed of alginate and poly(diallydimethylammonium chloride)
Authors: Kim Seon Jeong , Yoon Seoung Gil , Kim Sun I. 
Published: January 2004

AbstractTemperature‐ and pH‐responsive interpenetrating polymer network (IPN) hydrogels, with sodium alginate (SA) and poly(diallydimethylammonium chloride) (PDADMAC), constructed by a sequential IPN method, were studied. The characterizations of the IPN hydrogels were investigated by FTIR, DSC, and swelling tests under various conditions. The prepared IPN hydrogels exhibited relatively high swelling ratios, in the range of 380–690%, at 25°C. The swelling ratios of SA/PDADMAC IPN hydrogels were pH and temperature dependent. DSC was used for the quantitative determination of the freezing and nonfreezing water contents of the hydrogels. The amount of free water increased with the increasing PDADMAC content of the IPN hydrogels. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3705–3709, 2004