bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of new polyethers derived from isoidide under phase‐transfer catalysis: Reactivity and selectivity under microwaves and classical heating
Authors: Chatti S. , Bortolussi M. , Loupy A. , Blais J. C. , Bogdal D. , Roger P. 
Published: September 2003

AbstractMicrowave irradiation was applied to the synthesis of polyethers from 1,8‐dibromo‐ and 1,8‐dimesyl‐octane under solid–liquid phase‐transfer catalytic conditions. To evaluate the influence of microwaves on the reaction rates and polyether properties, we carried out the polymerization reactions under similar conventional conditions (oil bath) with the same temperature profiles. First, the microwave‐assisted syntheses proceeded more rapidly in comparison with conventional heating, and the reaction time was reduced from 24 h to 30 min with higher yields of polyethers. Second, the structure of the polymers strictly depended on the activation mode. Under microwave conditions, the polyethers were characterized by higher molecular weights with better homogeneity. Third, the mechanism of chain termination was different under microwave and conventional conditions. The polyethers prepared with conventional heating possessed shorter chains with mainly hydroxylated ends, whereas under microwave irradiation, the polymer chains were longer with mainly ethylenic group ends. In fact, under microwave irradiation, ethylenic group ends were formed rather rapidly and set up a hindrance to further polymer growth. In contrast, under conventional conditions terminations were essentially constituted by hydroxyl functions; however, further polymerization was terminated as well. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1255–1266, 2003
Studies on the preparation of immersion‐type polypropylene fragrant fiber. II. The supermolecular structure of the matrix fiber and its sorption properties for fragrant molecules
Authors: Bing Wang , Jiasen Zhao 
Published: September 2003

AbstractThe supermolecular structure and mechanical properties of a matrix fiber were investigated with differential scanning calorimetry, wide‐angle X‐ray diffraction, sonic velocity instrumentation, and fiber electronic serimetry. The results indicated that the apparent crystallinity of the matrix fiber, the crystallinity of the polypropylene (PP) component, and the mechanical properties of the matrix fiber were all affected by ethylene vinyl acetate (EVA). Drawing increased the orientation and tensile strength of the matrix fiber at the proper temperature and ratio of PP to EVA. The matrix fiber, having good mechanical properties, was placed in a fragrance–alcohol solution or an essential oil for the preparation of a fragrant fiber. The fragrance property of the fiber was determined with generally a method using slow release time as a certain standard, and the results showed that the fragrance property of the fiber was good. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 973–981, 2003
Synthesis and biodegradation of aliphatic polyesters from dicarboxylic acids and diols
Authors: Zhu Changying , Zhang Zhiqiang , Liu Qingping , Wang Zhanping , Jin Jian 
Published: September 2003

AbstractPoly(butylene succinate) (PBS) and its copolymers, poly(butylene succinate‐co‐adipate) (PBSA) and poly(butylene‐co‐hexylene succinate) (PBHS), were synthesized by direct polyesterification of corresponding diols and dicarboxylic acids. Dimethyl benzene was used as solvent and water‐removing agent. Several catalysts were used to study the esterification of butanediol and succinic acid. Among them, SnCl2 demonstrated superior catalysis behavior. Kinetic behaviors of the synthesis of PBS, PBSA, and PBHS were investigated using SnCl2 as catalyst. By using a water trap containing a 4‐Å molecular sieve, a relatively faster reaction rate was achieved and the molecular weight of some polyesters surpassed 30,000. The variation of molecular weight distribution during the polymerization was monitored by GPC and Mw/Mn demonstrated a trend of decrease with the reaction time. The melting point (Tm) and the glass‐transition temperature (Tg) were measured by DSC technique. The results show that the incorporation of a third monomer unit to PBS lowered Tg and Tm. The biodegradation test was carried out both in the laboratory and in outdoor soil burial. The copolyesters displayed a faster degradation rate than that of PBS. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 982–990, 2003
Effects of diacrylate monomers on the bond strength of polymer concrete to wet substrates
Authors: Ahn Namshik 
Published: September 2003

AbstractThe bond strengths of polymer concretes containing up to 15% (based on polymer resin) of diacrylate (DA) monomers were examined and compared with those without DA. A change occurring with the addition of DA monomers was an increase in the bond strength of polymer concrete to wet substrates. Zinc diacrylate (ZDA) and calcium diacrylate (CDA) were each used as an additive to monomers and resins [methyl methacrylate (MMA), polyester, and two kinds of epoxies]. The variables were amount of the DA monomers and surface conditions (wet or dry and smooth or rough). Bond strengths were measured by tension bond. ZDA was found to improve the bond strength of MMA and polyester, whereas CDA improved the bond strength of epoxies. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 991–1000, 2003
Synthesis and functions of water‐soluble and thermosensitive copolymers having phosphonium groups from acryloyloxyethyl trialkyl phosphonium chloride, N‐isopropylacrylamide, and without/with butylmethacrylate
Authors: Nonaka Takamasa , Li Hua , Makinose Kaku , Ogata Tomonari , Kurihara Seiji 
Published: September 2003

AbstractWater‐soluble thermosensitive polymers were prepared by copolymerization of acryloyloxyethyl trialkyl phosphonium chlorides (AETRs) with having varying alkyl lengths, N‐isopropylacrylamide (NIPAAm), and without/with butyl methacrylate (BMA). The relative viscosity of the solutions of the AETR–NIPAAm copolymers increased with increasing AETR content. The thermosensitivity of the AETR–NIPAAm copolymers was affected by an introduction of hydrophobic BMA into the copolymers and the thermosensitivity of the AETR–BMA–NIPAAm copolymers increased with chain length of alkyl groups in phosphonium groups in AETR. The AETR–NIPAAm copolymers and the AETR–BMA–NIPAAm copolymers had high flocculating ability against kaolin or bacteria such as Escherichia coli. The flocculating ability of the copolymers was affected with the AETR content, BMA content, and the chain length of alkyl groups in phosphonium groups. Almost 100% of the AETB–BMA–NIPAAm and AETO–BMA–NIPAAm copolymers dissolved in water could be recovered by heating the solution above 30°C in the presence of NaCl. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1139–1147, 2003
Study on the phase behavior of ethylene–vinyl acetate copolymer and poly(methyl methacrylate) blends by in situ polymerization
Authors: Cheng Shih‐Kai , Chen Chuh‐Yung 
Published: September 2003

AbstractThis study examines the phase behavior of ethylene–vinyl acetate copolymer (EVA) and poly(methyl methacrylate) (PMMA) blends during MMA polymerization. The ternary PMMA/MMA/EVA mixtures are considered to create a triangular phase diagram, which responds the phase changes during polymerization. The phase changes during MMA polymerization are also examined by optical microscope and photometer. Since the PMMA and EVA are well‐known immiscibles, the polymer solution undergoes phase separation at the initial stage of the MMA polymerization. Additionally, the phase inversion occurs as the conversion of MMA between 13.8 and 20.8%. On the other hand, the EVA‐graft‐PMMA, which can reduce the dispersed EVA particle size, is induced efficiently by taking tert‐butyl peroctoate (t‐BO) as initiator during MMA polymerization. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1001–1008, 2003
Ecofriendly behavior of host matrix in composites prepared from agro‐waste and polypropylene
Authors: Pandey Jitendra K. , Ahmad A. , Singh R. P. 
Published: September 2003

AbstractComposites were prepared by two methods: (1) graft copolymerization (GFC) of isotactic polypropylene (PP) with coupling agent maleic anhydride (MAH), followed by esterification with coir fiber; (2) by direct reactive mixing (DFC) of PP, MAH, and peroxide with coir fiber in a minimax molder. These composites, after molding in films (5 × 5 cm, ∼100 μm thickness) were examined for susceptibility to biological attack by measuring the percentage weight loss in compost up to 6 months, periodically, and fungal colonization on surface of the samples, when kept as sole carbon source for the growth of Aspergillus niger in culture medium up to 40 days. Photodegradation was evaluated by monitoring the variations in a Fourier transform infrared spectrum and crack formation after successive treatment with ultraviolet (UV) light (≥290 nm) for 0, 20, 50, and 100 h at 60°C in the presence of air. Specimens of virgin PP were taken as a reference during all periods of photo‐ and biodegradations. Significant consequences of the manner of composite preparation on photo/biodegradation were observed during the whole study. DFC samples degraded faster than GFC during the composting whereas, in culture, GFC was covered by fungi in a highly well‐uniform way. It is shown that photo‐oxidative aging directly enhanced the biodegradability of composites, as an increase in fungal growth rate and decrease in weight during composting was found. It was concluded that extent of compatibilization has a profound effect on photo/biodegradation of composite material; consequently, ester bonds were the main units during fungal consumption. Surface erosion was maximum in the case of 100 h UV‐treated GFC and minimum for unirradiated PP after culture exposure, as shown by scanning electron microscopy, which is due to the use of composite films as energy source by microbes. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1009–1017, 2003
Proton‐conducting gel polyelectrolytes based on Lewis acid
Authors: Liu Chen , Zhang Jiaxin , Shi Gaoquan , Qu Liangti , Chen Feng'En 
Published: September 2003

AbstractA novel proton‐gel‐conducting polymer electrolyte was prepared by blending boron trifluoride diethyl etherate with poly(ethylene oxide) (PEO), glycerol, and propylene carbonate (PC) at certain molar ratios. The electrolytes exhibited ambient conductivity from 10−5 to 10−3 S/cm. DSC results indicated that the electrolytes were amorphous. The 1H‐NMR and Raman spectra showed strong interactions between the Lewis acid and the hydroxyl groups both of glycerol and of PEO. This resulted in the formation of protons for ionic conduction. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1267–1272, 2003
Monitoring and control of styrene solution polymerization using NIR spectroscopy
Authors: Fontoura J. M. R. , Santos A. F. , Silva F. M. , Lenzi M. K. , Lima E. L. , Pinto J. C. 
Published: September 2003

AbstractTailored polymer resins are frequently required for a given application. The lack of instruments for in‐line monitoring of polymer quality has long been recognized as an important problem in polymerization reactor control. Using the styrene solution polymerization system as an example, we present the use of near‐infrared (NIR) spectroscopy as an alternative tool for in‐line and in situ monitoring and control of monomer conversion and average molecular weight of polymer resins. By using a Kalman filter state estimator and an accurate first‐principle model, the control loop could be successfully closed to track desired monomer values and average molecular weights. Two process control strategies, one based on the optimal control theory and the other on model predictive control, were implemented both theoretically and experimentally. The experimental results showed that it is feasible to use NIR spectroscopy for the simultaneous control of monomer conversion and polymer average molecular weight. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1273–1289, 2003
Synthesis of novel polymethacrylate bearing an (S)‐(+)‐1‐cyclohexylethyl urea group in the side chain and its chiral recognition ability
Authors: Lee Yong‐Kyung , Nakashima Yuji , Onimura Kenjiro , Tsutsumi Hiromori , Oishi Tsutomu 
Published: September 2003

AbstractA new chiral methacrylate, (S)‐(+)‐1‐cyclohexylethyl‐(2‐methacryloyloxyethyl)urea (CEMOU), was synthesized from 2‐methacryloyloxyethyl isocyanate (MOI) and (S)‐(+)‐cyclohexylethylamine. Radical homopolymerization of CEMOU was performed in several solvents to obtain the corresponding chiral polymers having hydrogen bonds based on urea moieties. Specific optical rotations of poly(CEMOU) were slightly changed by the measurement temperature, which may be attributed in part to a change of conformation caused by hydrophobic interaction between the cyclohexyl groups. From the results of radical copolymerization of CEMOU (M1) with styrene (ST, M2) or methyl methacrylate (MMA, M2), monomer reactivity ratios (r1, r2) and Alfrey–Price Q–e values were determined: r1 = 0.89, r2 = 0.12, Q1 = 2.45, e1 = 0.68 for the CEMOU–ST system; r1 = 0.48, r2 = 0.18, Q1 = 8.39, e1 = 1.97 for the CEMOU–MMA system. The chiroptical property of the poly(CEMOU‐co‐ST) was slightly influenced by the co‐units. Poly(CEMOU)‐bonded silica gel as the chiral stationary phase (CSP) was prepared for high‐performance liquid chromatography (HPLC). The CSP resolved trans‐2‐dibenzyl‐4,5‐di(o‐hydroxyphenyl)‐1,3‐dioxolane in normal phase such as n‐hexane/2‐propanol by HPLC. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1018–1025, 2003
Preparation and characterization of long‐chain multimaleimide‐containing aralkyl group linkages
Authors: Ho Tsung‐Han , Leu Tsu‐Shang 
Published: September 2003

AbstractPoly(aralkyl maleimide) (PAMI) and poly(glycidyl ether of aralkyl novolac) resin (PANE) with phenyl‐methylene units were synthesized from the intermediates poly(aralkyl amino) resin (PAAR) and poly(aralkyl novolac) resin (PANR), which were obtained from the reactions of p‐xylylene glycol with aniline or phenol, respectively. The oligomers were characterized by 1H‐NMR, Fourier transform infrared spectroscopy, gel permeation chromatography, and potentiometry. The corresponding PAMI and PANE were cured with 4,4′‐diaminodiphenylmethane (DDM) at an equal equivalent ratio, and their curing behaviors were investigated by differential scanning calorimetry. The reaction involved a major chain extension and a minor homopolymerization. The thermal, mechanical, and electric properties of the PAMI–DDM system were better than that of those PANE–DDM system. Furthermore, the PAMI–DDM has a low internal stress. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1066–1072, 2003
Toughening modification of PS with n‐BA/MMA/styrene core–shell structured copolymer from emulsifier‐free emulsion polymerization
Authors: Guo T. Y. , Tang G. L. , Hao G. J. , Song M. D. , Zhang B. H. 
Published: September 2003

AbstractCore–shell structured particles, which comprise the rubbery core and glassy layers, were prepared by emulsifier‐free emulsion polymerization of poly(n‐butyl acrylate/methyl methacrylate)/polystyrene [P(n‐BA/MMA)/PS]. The particle diameter was about 0.22 μm, and the rubbery core was uncrosslinked and lightly crosslinked, respectively. The smaller core–shell structured particle–toughened PS blends were investigated in detail. The dynamic mechanical behavior and observation by scanning electron microscopy of the modified blend system with core–shell structured particles indicated good compatibility between PS and the particles, which is the necessary qualification for an effective toughening modifier. Notched‐impact strength and related mechanical properties were measured for further evaluation of the toughening efficiency. The notched‐impact strength of the toughened PS blends with uncrosslinked particles reached almost sixfold higher than that of the untoughened PS when 15 phr of the core–shell structured particles was added. For the crosslinked particles the toughening effect for PS was not obvious. The toughening mechanism for these smaller particles also is discussed in this article. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1290–1297, 2003
Facilitated oxygen transport in a novel silicone polymer membrane containing carboxylic cobalt groups
Authors: Zhang Zi‐Yong 
Published: September 2003

AbstractA novel silicone polymer membrane with facilitated oxygen transport properties was prepared by using 11‐alkene acid cobalt, a silicone rubber containing vinyl groups of 5 mol %, a hydrogen‐containing silicon oil, and chlorine platinum acid. The solution casting and the vulcanization were carried out simultaneously at room temperature. Investigation showed that PO2 increased and PN2 did not change with decreasing gas pressure difference. This facilitated oxygen transport behavior was contributed by a polymeric cobalt complex formed from carboxylic groups and cobaltous ions in the membrane to result in the simultaneous increase of both PO2 and αO2/N2 under lower gas pressure difference. For example, the PO2 and αO2/N2 of the membrane containing 11‐alkene acid cobalt of 2.5 wt% were 750 Barrer and 3.09 under a gas pressure difference of 0.05 mPa. As much as 5 wt% 11‐alkene acid cobalt could be added to the membranes; PO2 and αO2/N2 increased to 802 Barrer and 3.34 respectively when the membrane contained 11‐alkene acid cobalt of 5 wt %. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1038–1044, 2003
Synthesis and characterization of thermotropic liquid crystalline poly(ester‐imide‐ketone)
Authors: Chi Zhenguo , Xu Jiarui 
Published: September 2003

AbstractA series of poly(ester imide ketone)s derived from N,N′‐hexane‐1,6‐diylbis(trimellitimide), 4,4′‐dihydroxybenzophenone, and p‐hydroxybenzoic acid (PHB) were synthesized by the direct polycondensation method in benzene sulfonyl chloride, dimethylformamide, and pyridine with varied PHB contents. The liquid crystalline behavior and thermal properties of the poly(ester imide ketone)s were characterized by polarized‐light microscopy, wide‐angle X‐ray diffraction, thermogravimetric analysis, differential scanning calorimetry, and temperature‐modulated differential scanning calorimetry (MDSC). The results showed that the synthesized polymers possessed a nematic thermotropic liquid crystalline characteristic and high thermal stability. The liquid crystalline polymers, with a PHB content ranging from 0 to 50 mol %, exhibited multiple phase transitions as evidenced by the MDSC results. A transitional smectic phase from solid state to nematic thermotropic liquid crystalline state was observed, and a transition model is proposed. Under certain conditions, the polymer with 33 mol % PHB content showed two significantly different liquid crystalline textures. This type of liquid crystalline polymer exhibited excellent fiber forming. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1045–1052, 2003
Effect of processing on morphological structure of polyacrylonitrile matrix nano‐ZnO composites
Authors: Tang Jianguo , Wang Yao , Liu Haiyan , Xia Yanzhi , Schneider Bernd 
Published: September 2003

AbstractThe effects of processing methods—free casting and spinning—on dispersion of nano‐ZnO in a polyacrylonitrile (PAN) matrix were studied for this article. From observation with an transmission electron microscope, it was found that monoaxial drawing in spinning processing formed a fiberlike image of the nano‐ZnO phase in the PAN matrix. The geometric parameters—the diameter and ratio of the nanoparticle phase—were about 20 and 15 nm, respectively, when the concentration of nano‐ZnO was 1 wt % in the PAN matrix, whereas spherelike morphology was obtained by free casting, for which, naturally, the ratio of its length to its diameter was unity. This indicates that evidently the morphology of the nanoparticle phase is affected by processing methods. However, when the concentration of nano‐ZnO went up to 2 wt % in the PAN matrix spinning process, the linear ratio of length to diameter of the nanoparticle phase decreased to 2.9 because drawing energy adsorption, through deformation of the nanoparticle phase, became a marked effect. The degree of anisotropy, including crystallization and orientation of polymer, was also affected by the concentration of nano‐ZnO for the same reason. When the concentration of nano‐ZnO reached 2 wt %, the anisotropy of PAN was obviously depressed according to the results of wide‐angle X‐ray measurement. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1053–1057, 2003
Alumina‐based water‐dispersible conducting nanocomposites of polypyrrole and polypyrrole with poly(N‐vinylcarbazole)
Authors: Maity Arjun , Biswas Mukul 
Published: September 2003

AbstractWater‐dispersible nanocomposites of polypyrrole with Al2O3 (PPYAl2O3) and of poly(N‐vinylcarbazole) with Al2O3 (PNVCAl2O3) were prepared in an aqueous medium. Nanocomposites involving binary polymer systemsPNVC(PPYAl2O3) and PPY(PNVCAl2O3)were prepared by precipitating PNVC or PPY onto a suspension of PPYAl2O3 or PNVCAl2O3, respectively. The incorporation of the polymers in the composites was confirmed by Fourier transform infrared analyses. Scanning electron microscopy analyses revealed distinct morphological features of the composites. Transmission electron microscopy analyses of the PPYAl2O3, PNVCAl2O3, and PPY(PNVC Al2O3) composites confirmed the formation of spherical particles in the nanometer range. Thermogravimetric and differential thermal analyses revealed the stability order as: PNVCAl2O3 > PNVC(PPYAl2O3) > PPY(PNVCAl2O3) > PPYAl2O3. Direct current conductivity values of the PPYAl2O3, PNVC(PPYAl2O3), and PPY(PNVCAl2O3) composites were on the order of 2.8 × 10−4, 1.7 × 10−5, and 4.5 × 10−6 (S/cm), respectively. These nanocomposites dispersed in water, with stability decreasing in the order: PPYAl2O3 (∼40 h) > PNVC(PPYAl2O3) (30 h) > PPY(PNVCAl2O3) (20 h), and in the presence of polyvinylpyrrolidone a permanently stable suspension was obtained in all cases. The dispersibility appeared to be higher when the polymerization was conducted in a suspension containing a higher amount of Al2O3. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1058–1065, 2003
Sorption of Acid Green 25 on chitosan: Influence of experimental parameters on uptake kinetics and sorption isotherms
Authors: Gibbs Gwendolyn , Tobin John M. , Guibal Eric 
Published: September 2003

AbstractAcid Green 25, which is a diazoic dye bearing two sulfonic groups, is efficiently sorbed on chitosan. The protonation of chitosan may explain the electrostatic attraction of this anionic dye and that its optimum pH is close to 3. Preliminary protonation of amine groups (obtained by contact with a sulfuric acid solution) reduced the variation of solution pH following sorbent addition but significantly reduced sorption performance: the maximum sorption capacity of raw chitosan, 525 mg dye/g (0.84 mmol dye/g), was halved by acidic preconditioning. The acidic conditioning also reduced the kinetic rate—the time necessary to reach equilibrium increased up to threefold depending on the experimental conditions. The size of sorbent particles influenced sorption kinetics and equilibrium because of resistance to intraparticle diffusion, but the sorption appeared to occur not only at the surface of the sorbent but also in the intraparticle network of the polymer. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1073–1080, 2003