bluuebunny/crossref_metadata_2025 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

Microwave 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

The 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

Poly(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

The 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

Water‐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

This 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

Composites 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

A 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

Tailored 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

A 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

Poly(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

Core–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

A 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

A 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

The 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

Water‐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

Acid 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
Separation characteristics of molecular imprinted poly(methacrylic acid) for retinoid derivatives
Authors: Hoon Nam Gi , Kim Dukjoon
Published: September 2003

Methacrylic acid monomer was crosslinked in the presence of a template of either all‐trans‐retinoic acid or all‐trans‐retinol to prepare molecular imprinted polymers. The prepared molecular imprinted polymers showed good performance in the high‐performance liquid chromatography (HPLC) separation of objective molecules from retinoid derivatives. The retention time increased with an increasing ratio of monomer to template, as more binding sites were statistically generated between host molecules and the template. The column capacity factor and selectivity were determined from the HPLC data. Not only specific interactions such as hydrogen bonding but also a tailor‐made spatial cavity were the main functions of the separation of objective molecules. Thermal stability and prepared polymer particle shape were also investigated. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1081–1087, 2003
Two‐phase model for continuous final‐stage melt polycondensation of poly(ethylene terephthalate). III. Modeling of multiple reactors with multiple reaction zones
Authors: Kim In Sun , Woo Boo Gon , Choi Kyu Yong , Kiang Chang
Published: September 2003

A steady‐state two‐phase model has been developed for a continuous finishing stage of the melt polycondensation process that consists of two rotating‐disk reactors in series. Each reactor has multiple reaction zones with different types of rotating disks to establish plug flow profiles and to facilitate the removal of volatile reaction byproducts. The effect on reactor performance of varying the mass transfer parameter was found to be small for the reaction conditions used. The simulation results show that the use of two reactors offers increased flexibility in reactor operations to obtain the desired polymer properties. Although the proposed model has not been fully validated with experimental or plant data, it has illustrated that the complex multizone reactor system can be easily modeled by the two‐phase modeling technique and that added physical insights can be made through numerical model simulations. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1088–1095, 2003
Differential scanning photocalorimetry studies of 1,6‐hexanedioldiacrylate photopolymerization initiated by some organic azides
Authors: Abadie M. J. M. , Novikova O. O. , Voytekunas V. Yu. , Syromyatnikov V. G. , Kolendo A. Yu.
Published: September 2003

New types of radical photoinitiators, based on azido and diazido structures, were compared to the reactivity of pure xanthone by using a photocalorimetry technique. Our results show that these photoinitiators are good candidates for radical polymerization. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1096–1101, 2003
Comparison of the viscous and elastic components of two ABS materials with creep, stress relaxation and constant strain rate measurements using the universal viscoelastic model
Authors: Sudduth Richard D.
Published: September 2003

In general, the universal viscoelastic model evaluated in this study was found to adequately predict constant strain rate, creep, and/or stress relaxation measurements from the constants determined from constant strain rate measurements. The elastic and viscous components for two acrylonitrile–butadiene–styrene (ABS) viscoelastic materials were also easily isolated using this new universal viscoelastic model. The creep measurements for ABS‐A (25383‐A) and ABS‐N (LL‐4102‐N) at three different stresses allowed elucidation of the common creep intercept strain of the calculated creep slopes that was designated as the “projected elastic limit.” Once the values for n and β were evaluated from creep measurements, then the creep variation of the universal viscoelastic model yielded a reasonably good fit of the measured creep data for both ABS‐A and ABS‐N. The extensional viscosity constant λE was found to be 7.2% greater for ABS‐A than for ABS‐N. Consequently, ABS‐N was found to have a lower extensional viscosity in secondary creep than that of ABS‐A at any specific strain rate. The value of the efficiency of yield energy dissipation n for ABS‐N as determined from creep measurements was also 37.6% larger than the value of n for ABS‐A. In addition, the projected elastic limit ϵI for ABS‐A was 2% greater than the projected elastic limit for ABS‐N. These observations indicated that ABS‐A should be slightly more solidlike than ABS‐N. However, both ABS‐A and ABS‐N were significantly more solidlike than liquidlike because both of their values for the efficiency of yield energy dissipation n were very close to zero. In general, values of n range from 0 < n < 1 with a material characterized as being essentially pure elastic having a value of n = 0. Using the yield strain as the failure condition for constant strain rate and stress relaxation measurements and the strain at critical creep, the failure condition for creep, it was found that the universal viscoelastic model allowed these failure criteria to yield remarkably good agreement on a projected time scale. This agreement resulted even though separate and independent data were used to evaluate these three different techniques for both ABS‐A and ABS‐N. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1298–1318, 2003
Gas‐phase ethylene polymerization over polymer‐supported metallocene catalysts
Authors: Zhou Jia‐Min , Li Nai‐Hong , Bu Nai‐Yu , Lynch David T. , Wanke Sieghard E.
Published: September 2003

The activities of two (n‐BuCp)2ZrCl2 catalysts supported on methylaluminoxane (MAO)‐treated polymer particles were evaluated. The supports were spherical polymeric particles, containing macropores and prepared by suspension polymerization of 2‐hydroxyethyl methacrylate, divinyl benzene, ethyl styrene, and styrene. Both catalysts had a Zr content of 0.31 mass % and an Al/Zr ratio of 185; the supports for one of the catalysts contained 59 mass % 2‐hydroxyethyl methacrylate, whereas the support for the other catalyst had a 2‐hydroxyethyl methacrylate content of 10 mass %. Ethylene homo‐ and ethylene/1‐hexene copolymerization activities were determined for gas‐phase operation at temperatures of 50 to 90°C and ethylene pressures of ≈1.4 MPa. Polymerization activities were strong functions of temperature and 1‐hexene concentration; copolymerization activities of up to 23,200 kg PE/(mol Zr h−1) were obtained for 1‐h polymerization runs. The product particle morphology was excellent, mostly spherical particles essentially without fines. Scanning electron microscopy showed that the spherical copolymer particles, for all copolymerization conditions, consisted of well‐defined concentric spherical shells. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90:1319–1330, 2003
Oxidative degradation of polyamide reverse osmosis membranes: Studies of molecular model compounds and selected membranes
Authors: Soice Neil P. , Maladono Adrian C. , Takigawa Doreen Y. , Norman Arlan D. , Krantz William B. , Greenberg Alan R.
Published: September 2003

Selected aromatic amides were used to model the chemical reactivity of aromatic polyamides found in thin‐film composite reverse osmosis (RO) membranes. Chlorination and possible amide bond cleavage of aromatic amides upon exposure to aqueous chlorine, which can lead to membrane failure, were investigated. Correlations are made of the available chlorine concentration, pH, and exposure time with chemical changes in the model compounds. From the observed reactivity trends, insights are obtained into the mechanism of RO membrane performance loss upon chlorine exposure. Two chemical pathways for degradation are shown, one at constant pH and another that is pH‐history dependent. An alternative strategy is presented for the design of chlorine‐resistant RO membranes, and an initial performance study of RO membranes incorporating this strategy is reported. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1173–1184, 2003
Wettability and antibacterial assessment of chitosan containing radiation‐induced graft nonwoven fabric of polypropylene‐g‐acrylic acid
Authors: Yang Jen Ming , Lin Hao Tzu , Wu Te Hsing , Chen Chia‐Chieh
Published: September 2003

The grafting of acrylic acid (AA) onto polypropylene (PP) nonwoven fabric was induced by γ‐ray irradiation without degassing to obtain PP‐g‐AA–modified nonwoven fabric. Chitosan was immobilized onto the PP‐g‐AA–modified nonwoven fabric with 1‐ethyl‐3‐(3‐dimethyamino propyl) carbidiimide to get the chitosan‐containing PP‐g‐AA–modified nonwoven fabric. The PP‐g‐AA–modified nonwoven fabrics were characterized by IR spectroscopy. In addition to the absorption peaks associated with pure PP nonwoven fabric, absorption peaks at 1700 cm−1 (CO) and at about 2950 cm−1 for the COOH group were also found for the PP‐g‐AA–modified nonwoven fabric. The chitosan‐containing PP‐g‐AA nonwoven fabric obtained had an absorption peak at about 1475–1580 cm−1 (CONH), in addition to those of the PP‐g‐AA nonwoven fabric. The effects of acrylic acid grafting content and chitosan on the wettability and antibacterial assessment were investigated. The wicking time of water on the PP‐g‐AA–modified nonwoven fabric decreased with increasing acrylic acid grafting content and chitosan, whereas the water content on the PP‐g‐AA–modified nonwoven fabric increased. Because the concentration of Pseudomonas aeruginosa on the PP‐g‐AA–modified nonwoven fabric decreased with increasing acrylic acid grafting content and chitosan, it means that the antibacterial activity of the PP nonwoven fabric was enhanced by the modification of γ‐ray radiation–induced grafting of acrylic acid and the immobilization of chitosan onto the PP‐g‐AA–modified nonwoven fabric. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1331–1336, 2003
In situ modulus enhancement of polypropylene monofilament through blending with a liquid‐crystalline copolyester
Authors: Sukananta Pakavadee , Bualek‐Limcharoen Sauvarop
Published: September 2003

An immiscible blend of poly(propylene) (PP) with a thermotropic liquid‐crystalline polymer (TLCP, trade name Rodrun LC5000), a copolyester of 80/20 mol ratio of p‐hydroxy benzoic acid and polyethylene terephthalate was prepared in a twin‐screw extruder. The blend extrudate was fabricated as monofilament by using a single‐screw extruder equipped with a fiber line. The as‐spun filament was drawn at 120°C to enhance molecular orientation. Morphology, thermal, tensile, and dynamic mechanical properties of both as‐spun and drawn monofilaments were investigated. Almost continuously long TLCP fibers dispersed in PP matrix were obtained in the composite as‐spun monofilaments. The maximum modulus was found in 15 wt % TLCP/PP composite as‐spun filament, an increase of about 2.4 times that of the as‐spun neat PP. For the drawn filaments, the 10 wt % TLCP/PP composite showed a maximum modulus, an increase of about 1.5 times that of the drawn neat PP. The increase in the moduli was attributed not only to the reinforcement by TLCP fibrils with very high aspect ratio but also to the increases in PP crystallinity and molecular orientation through the drawing process. A remarkable improvement in the dynamic mechanical properties of the composite monofilaments was observed, especially in the high‐temperature region. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90:1337–1346, 2003
Mastic of polymer‐modified bitumen and poly(vinyl chloride) wastes
Authors: Singh B. , Gupta M. , Tarannum Hina
Published: September 2003

Micronized poly(vinyl chloride) (PVC) pipe waste has been employed as a soft filler in making bituminous products. The binder used in this study consists of styrene–butadiene–styrene‐modified bitumen, isocyanate production waste, and an antioxidant. The time‐dependent properties of these binders were assessed by constructing a master curve using frequency multiplexing. A plateau at intermediate and low frequencies in the storage modulus curves of modified bitumen implies the existence of molecular association among the constituents compared to neat bitumen. The enhanced adhesion between the PVC particles activated by H2O2 and the bitumen was verified in terms of bitumen anchorage onto particles after washing in hot toluene. Confirmation of these effects can also be seen by increased stiffness of the bituminous mix with the activated particles over that with nonactivated particles. Consequently, a suitable mastic composition consisting of these activated coarse and micronized particles, limestone dust, and polymeric bituminous binder has been achieved. The results indicate that the optimized mix can be used as waterproof roof mastic as an alternative to conventional bituminous mastic. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1347–1356, 2003
Preparation and characterization of novel flame retardant (aliphatic phosphate)cyclotriphosphazene‐containing polyurethanes
Authors: Chen‐Yang Y. W. , Yuan C. Y. , Li C. H. , Yang H. C.
Published: September 2003

A novel reactive flame retardant, (4‐diethoxyphosphoryloxyphenoxy)(4‐hydroxyphenoxy)cyclotriphosphazene (EPPZ), was prepared and characterized by FTIR,31P‐NMR, and1H‐NMR analyses. Polyurethanes that contain (aliphatic phosphate)cyclotriphosphazene, with various phosphorus contents, were prepared from EPPZ, poly(propylene glycol), 1,4‐butanediol, and 2,4‐toluene diisocyanate. The polyurethanes were characterized by measurements of FTIR, TGA, DSC, limiting oxygen index (LOI), and tensile testing. The results indicated that the EPPZ‐containing polyurethanes prepared in this study have higher glass‐transition temperature, higher tensile strength, lower temperature of degradation, and higher char yield residues than those of the pure polyurethane. The activation energies at various degradation stages for the polyurethanes were calculated by Ozawa's method. The LOI of the EPPZ‐containing polyurethane was increased with increasing EPPZ content and the polyurethanes showed flame‐extinguishable behavior. Moreover, it was found that the effect of the flame retardancy of the polyurethanes took place primarily in the condensed phase. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1357–1364, 2003
Viscosity correlation for aqueous polyvinylpyrrolidone (PVP) solutions
Authors: Swei Jason , Talbot Jan B.
Published: September 2003

Polyvinylpyrrolidone (PVP) is characterized by its K‐value, which is a function of the average molecular weight, the degree of polymerization, and the intrinsic viscosity. The viscosity was measured for aqueous PVP solutions with K‐values ranging from 92.1 to 95.4 and with concentrations from 2 to 3 weight percent. A correlation was determined that relates solution viscosity to the K value and weight percent PVP, which is particularly useful in its use as a photoresist in the manufacture of high resolution display screens. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1153–1155, 2003
Study of polyvinylpyrrolidone (PVP) photoresist for CRTs
Authors: Swei Jason , Talbot Jan B.
Published: September 2003

The properties of the polyvinylpyrrolidone (PVP) photoresist activated by DAS (4,4′‐diazidostilbene‐2,2′‐disulfonic acid disodium salt) were studied for a period of one week while exposing the photoresist to different lighting conditions. The results from this study showed that white light caused the DAS in the photoresist to degrade and also caused the PVP and DAS to crosslink. The exposure of the photoresist to yellow light and no light caused minimal DAS degradation and crosslinking of the photoresist. Exposure to air caused the DAS degradation rate to increase and inhibited the crosslinking reaction between PVP and DAS. Finally, both unexposed and exposed DAS were determined to be crystalline, each with different structures. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1156–1162, 2003
Graft copolymers of lignin with electron poor alkenes
Authors: Bonini Carlo , D'Auria Maurizio , Ferri Rachele , Pucciariello Rachele , Sabia Anna Rita
Published: September 2003

The synthesis of copolymers between lignin and electron poor alkenes is described. Lignin from steam‐exploded pine, from steam‐exploded straw, and organosolv were used as starting materials. Beforehand, lignins were fully characterized by using elemental analysis, ultraviolet spectroscopy, gel permeation chromatography (GPC), Fourier transform infrared (FTIR), and both1H and 13C nuclear magnetic resonance (NMR) spectroscopy. The synthesis of copolymers was performed using a previously described procedure utilizing calcium chloride and hydrogen peroxide as reagents. FTIR of copolymers showed absorptions due to the presence of both lignin and the electron withdrawing group on the alkene. GPC analysis showed the presence of fractions with high molecular weights: the Mz of lignin from pine was 3729 while the copolymer with methyl acrylate showed Mz = 383790. Differential calorimetry showed the presence of glass transitions in the range of −9 to 4.5°C due to the presence of grafted polyalkene chains. When acrylonitrile was used as starting material DSC analysis of the product showed a glass transition at 119°C, which can be attributed to grafted polyacrylonitrile chain. Lignin from steam explosion could be a good raw material in the preparation of graft copolymers. Furthermore, lignin from pine gave better results than that from straw. Finally, lignin from steam explosion gave better results than organosolv lignin. These results can be explained on the basis of the structural properties of used lignins. Both UV and 13C NMR spectra showed that lignin from pine contained a consistent amount of double bonds. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1163–1171, 2003
Electrical and optical properties of plasma polymerized eucalyptus oil films
Authors: Sakthi Kumar D. , Nakamura Kenji , Nishiyama Satoko , Noguchi Hiromichi , Ishii Shigeru , Kashiwagi Kunihiro , Yoshida Yasuhiko
Published: September 2003

Electrical and optical properties of the plasma polymerized eucalyptus oil (PPEo) films are discussed in this article. As part of our electrical studies, we have found that the conduction mechanism in the PPEo film is a Schottky type. We have also found that iodine doping can enhance the conductivity of the film. IR studies revealed that PPEo film is a highly crosslinked polymer, and UV‐vis‐NIR studies revealed the information that optical band gap energy of the PPEo film had been reduced as a result of iodine doping. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1102–1107, 2003
Polystyrene foams. I. Processing‐structure relationships
Authors: Doroudiani Saeed , Kortschot Mark T.
Published: September 2003

In this study, processing‐structure relationships in expanded polystyrene (EPS) made using near‐critical carbon dioxide as a physical blowing agent were investigated. In order to investigate the relationship between structure and properties of EPS it was necessary to be able to make samples with a wide range of controlled structures. For this reason, a systematic investigation of the relationship between processing conditions and structure was performed based on a statistical experimental design. Regression analysis was conducted on the data and expressions were developed to quantify the relationships between structural parameters and processing conditions. The samples were saturated with carbon dioxide at relatively high pressure and ambient temperature and the saturated specimens were expanded at elevated temperatures. The importance of the individual processing parameters was determined. Statistical analysis of data showed that foaming time was the most important factor determining foam density, whereas saturation pressure was the most important factor determining cell size and cell density. By controlling the foaming conditions, EPS samples having the same densities and different cell sizes were produced. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1412–1420, 2003
Polystyrene foams. II. Structure–impact properties relationships
Authors: Doroudiani Saeed , Kortschot Mark T.
Published: September 2003

In the first part of this series of articles, the relations between the foaming conditions and the microstructure of expanded polystyrene (EPS) were explored. In this part, the effects of the foaming conditions and the microstructure of EPS on impact properties are discussed. Regression analysis was conducted on the data and expressions were developed to quantify these relationships. Moreover, the importance of the individual structural parameters was determined. Statistical analysis of the data showed that foaming time was the most important factor determining the impact strength, while foaming temperature was the most important factor controlling the specific impact strength. The deformation of cells at the crack tip, as a result of bending and/or buckling of cell walls, can increase the failure strain, which leads to an increase in failure energy. In expanded polymers, the majority of the absorbed energy during impact loading is dissipated as plastic work. The transition of plane stress conditions to plane strain conditions, due to expansion, can be considered as another source of toughening in EPS. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1421–1426, 2003
Polystyrene foams. III. Structure–tensile properties relationships
Authors: Doroudiani Saeed , Kortschot Mark T.
Published: September 2003

In the previous two parts of this series of articles, the relations among the foaming conditions, microstructure, and impact properties of expanded microcellular polystyrene (EPS) were discussed. In this article, the effects of the foaming conditions and structure on the tensile properties of EPS were investigated. A systematic investigation was performed based on a statistical experimental design. Various processing conditions were used and a wide range of cellular structures was developed. Regression analysis was conducted on the data and expressions were developed to quantify the relationship between the tensile properties and the cellular structure. Foaming time and foaming temperature were the most important processing parameters influencing the tensile modulus and strength. The tensile modulus and strength increased with an increasing foam density, but they decreased slightly when the cell size increased. Two different approaches were used to develop models relating the modulus to the foam density of EPS. Both models fitted the experimental data quite well. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1427–1434, 2003
Use of isocyanate production waste in the preparation of improved waterproofing bitumen
Authors: Singh B. , Tarannum Hina , Gupta M.
Published: September 2003

Waste residue generated during the production of toluene diisocyanate was used as a modifier in making improved waterproofing bitumen. The waste particles were surface‐modified with stearic acid. Various bitumen blends based on untreated particles, surface‐treated particles, and a combination of an SBS elastomer and waste particles were prepared. The optimized blends were subjected to evaluate their response against temperature and frequency sweeps. It was observed that improvement of the softening point and reduction in penetration could be correlated with the blend morphology in terms of the compatibility between the waste particles and the bitumen. The increased glass transition temperature and satisfactory phase miscibility in the modified bitumen observed in MDSC and DMA traces supported these findings. The coefficient of linear thermal expansion of the modified bitumen was found to be 1.21 × 10−4/°C. The rheological studies revealed that time‐dependent properties of the modified bitumen were better in terms of its stiffness and elasticity than that of neat bitumen. The applicability of the Williams–Landel–Ferry (WLF) equation confirms the superior temperature‐dependent response of the modified systems over the control. It was noticed that stearate‐treated waste‐modified bitumen gives the best results in terms of a high complex modulus and a low phase angle. The newly formulated bituminous blend based on stearate‐treated waste meets the requirement of existing standard specifications for waterproofing felt. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1365–1377, 2003