bluuebunny/crossref_metadata_2025_split huggingface dataset:
Separation characteristics of molecular imprinted poly(methacrylic acid) for retinoid derivatives
Authors: Hoon Nam Gi , Kim Dukjoon 
Published: September 2003

AbstractMethacrylic 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

AbstractA 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

AbstractNew 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

AbstractIn 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

AbstractThe 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

AbstractSelected 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

AbstractThe 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

AbstractAn 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

AbstractMicronized 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

AbstractA 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

AbstractPolyvinylpyrrolidone (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

AbstractThe 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

AbstractThe 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

AbstractElectrical 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

AbstractIn 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

AbstractIn 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

AbstractIn 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