bluuebunny/crossref_metadata_2025_split huggingface dataset:
Melt polymerization of bisphenol‐A and diphenyl carbonate in a semibatch reactor
Authors: Woo Boo‐Gon , Choi Kyu Yong , Song Kwang Ho , Lee Sang Ho 
Published: August 2002

AbstractThe effect of thermodynamic phase equilibrium on the kinetics of semibatch melt polycondensation of bisphenol‐A and diphenyl carbonate was studied for the synthesis of polycarbonate. In the melt‐polymerization process, a partial loss of diphenyl carbonate occurs as the reaction by‐product phenol is removed from the reactor. To obtain a high molecular weight polymer under high temperature and low‐pressure conditions, a stoichiometric mol ratio of the two reactive end groups needs to be maintained during the polymerization. In this work, vapor–liquid equilibrium data for a binary mixture of phenol and diphenyl carbonate are reported and they are used in conjunction with the Wilson equation to calculate the exact amounts of diphenyl carbonate and phenol returned from a reflux column to the reactor. A good agreement between the reactor model simulations and the experimental polymerization data was obtained. It was also observed that diphenyl carbonate is quickly consumed during the early stage of polymerization and the fraction of evaporated diphenyl carbonate refluxed to the reactor is essentially constant during this period. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1253–1266, 2001
Evaluation of the permeability and blood‐compatibility properties of membranes formed by physical interpenetration of chitosan with PEO/PPO/PEO triblock copolymers
Authors: Anderson Derick , Nguyen Tragiang , Lai Phung‐Kim , Amiji Mansoor 
Published: August 2002

AbstractIn order to develop blood compatible membranes with controlled porosity, we have fabricated and examined the properties of physical interpenetrating network (PIN) of chitosan and poly(ethylene oxide)/poly(propylene oxide)/poly(ethylene oxide) (PEO/PPO/PEO) triblock copolymers (Pluronics®). Degree of equilibrium swelling, scanning electron microscopy, and electron spectroscopy for chemical analysis (ESCA) were used to characterize the bulk and surface properties. Vitamin B12 and human serum albumin were used as permeability markers. Platelet adhesion and activation were used to determine the blood‐interaction properties of the PIN membranes. Unlike chitosan membranes that were nonporous, the chitosan‐Pluronic PIN membranes were highly porous with the pore size, depending on the type of incorporated Pluronic polyol. ESCA results showed a significant increase in the CO signal of C1s spectra on the PIN membranes that correlates with the presence of PEO chains on the surface. The permeability coefficients of vitamin B12 and albumin were higher in the chitosan‐Pluronic PIN membranes than in the control. The number of adherent platelets and the extent of activation were significantly reduced on the chitosan‐Pluronic PIN membranes. The decrease in platelet adhesion and activation correlated positively with the PEO chain length of the incorporated Pluronic polyols. The results of this study show that chitosan‐Pluronic PIN membranes offer a blood‐compatible alternative with a higher‐molecular‐weight cutoff for use in hemodialysis and related applications. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1274–1284, 2001
Use of the unique properties of fluoropolymers in the design of new, highly effective, ecologically friendly technologies for the fine purification of hydrogen halides and their aqueous solutions
Authors: Blum G. Z. , Ryabenko E. A. , Yaroshenko A. M. , Zaikov G. E. , Zaikov V. G. 
Published: August 2002

AbstractA number of properties of fluoropolymers in aqueous solutions of hydrogen halides were investigated. The results enable fluoropolymers to be used in the purification of hydrogen halides and their aqueous solutions. The hydrophobicity of fluoropolymers and their diffusion permeability enable production of hydrogen halides of low moisture content. A second unit for hydroionic convection is based on hydroionic repulsion (determined by the hydrophobic properties of the fluoropolymer) and ionic elimination. The two units enable the highly effective, ecologically safe manufacture of highly pure hydrogen halides and their aqueous solutions to be carried out with minimum feedstock, cooling water, and power consumption. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1383–1387, 2001
Gas and water transport properties of epoxy–amine networks: Influence of crosslink density
Authors: Damian Catherine , Escoubes Marielle , Espuche Eliane 
Published: August 2002

AbstractThe gas and water transport properties were studied on seven epoxy–amine networks that differ by their di/mono epoxy composition and their cure cycle. The characteristic parameters of transport M∞ and D were determined in each case, and they show that the solubility and diffusion coefficients are influenced by their composition. The solubility increases with the extend of cure and with the decrease of dangling chains, and in both cases the evolution of the diffusivity is inverse. The variations of the solubility and diffusivity have been discussed as a function of two parameters: polar groups and unrelaxed holes of the glassy networks. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2058–2066, 2001
Unusual rheological behaviors of linear PE and PE/kaolin composite
Authors: Wu Qiye , Wang Xin , Gao Weiping , Hu Youliang , Qi Zongneng 
Published: August 2002

AbstractThe unusual flow behaviors of linear PE melts are caused by high molecular weight, tight entanglements of molecular chains, and strong adsorption of the melt at the capillary wall. Especially, the extreme change of interface adsorption is followed by an unusual flow, and at the molecular level, the dynamic variety of entanglement and disentanglement between the adsorption chain near the wall and the nonadsorption chain is the cause of the extrusion pressure vibration. Ultrahigh molecular weight polyethylene (UHMWPE)/kaolin composites prepared by polymerization filling could be smoothly extruded through the capillary. Also, with increase of the kaolin content, the apparent viscosity of the composite decreased and the processability was improved. Under slip boundary conditions, the real shear rate and shear stress of the melt near the capillary wall were reduced. The viscosity descent (desorption) and the deformation energy decrease of the melt near the wall were the important preconditions to gain a steady flow in a second glossy zone. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2154–2161, 2001
Synthesis and dispersion copolymerization of poly(2‐methyl‐2‐oxazoline) macromers with cinnamoyl end groups
Authors: David Geta , Ioanid Aurelia 
Published: August 2002

AbstractPoly(2‐methyl‐2‐oxazoline) (PMOZO) macromers bearing cinnamoyl functional groups were synthesized either by utilizing the end‐capping method of growing PMOZO living chains with cinnamic acid or by coupling glycolic PMOZO telomers with cinnamoyl chloride. The first approach was proved to be more efficient and convenient, giving rise easier to a quantitative functionalization. Dispersion copolymerization of styrene with the resulted macromers in an ethanol–water system has been studied in order to obtain monodisperse micrometer size beads. The effect of some variables, such as macromer dimension and concentration, initiator type, alcohol/water ratio, on conversion, particle size and size distribution was investigated. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2191–2199, 2001
Copolymerization of methylmethacrylate with styrene using triphenylbismuthoniumylide as radical initiator
Authors: Bajpai Radha , Srivastava A. K. 
Published: August 2002

AbstractBismuthoniumylide‐initiated radical copolymerization of methylmethacrylate with styrene at 60 ± 0.2°C using dioxane as an inert solvent, follows ideal kinetics (Rp ∝ [ylide]0.5 [MMA]1.0 [sty]1.0), and yields alternating copolymer as evident from NMR spectroscopy. The values of reactivity ratios r1 and r2, calculated from Finemann–Ross method are 0.48 and 0.45, respectively. The system follows ternary molecular complex mechanism. The radical mode of polymerization has been confirmed by ESR spectroscopy and the effect of hydroquinone. The value of activation energy and k/kt are 65.0 KJ mol−1 and 2.5 × 10−5 l mole−1 s−1, respectively. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2774–2781, 2001
Study on tribological properties of frictional material based aromatic polyamide
Authors: Liu Xujun , Li Tongsheng , Tian Nong , Liu Weimin 
Published: August 2002

AbstractThe effect of inorganic fillers on the friction and wear behavior of frictional material based poly(m‐phenylene isophthalamide) (PMIA) is investigated. The polymer composites are prepared by compression molding. The friction and wear of PMIA composites are investigated on a block‐on‐ring machine by running the PMIA composite block against plain carbon steel. The morphologies of the worn surface of PMIA composite and the ring counterface are examined by using electron probe microanalysis. It is found that copper compounds including CuCl, CuCl2, Cu2O, and CuO filled PMIA exhibit considerably higher friction coefficient than unfilled PMIA, while the wear rate of those composites decrease. Especially, CuCl is the optimal filler in the copper compounds investigated above. The filled PMIA composite containing CuCl, graphite, and short carbon fiber shows the best properties for frictional material. The friction coefficient of CuCl–PMIA composite is higher than that of unfilled PMIA because of the abrasive action of CuCl particle. It is probably the smoother surface of counterpart ring and composite block that resulted in the lower wear rate and friction coefficient of PMIA composite. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2790–2794, 2001
Miscibility study of cellulose acetate/carboxylated poly(vinyl chloride) blend in cyclohexanone by viscosity, ultrasonic velocity, refractive index, and polarizing microscopic methods
Authors: Rajulu A. Varada , Reddy R. Lakshminarayana , Rao G. Babu , He Jiasong , Zhang Jun 
Published: August 2002

AbstractThe viscosity, ultrasonic velocity, refractive index, and density of cellulose acetate/carboxylated poly(vinyl chloride) (CA/C‐PVC) blends in cyclohexanone, a common solvent, were measured at 30°C. After casting films of the blend for a 50:50 composition, polarizing micrographs were taken. Using the viscosity data, the interaction parameters were computed by employing two different equations. These values indicated that the CA/C‐PVC blend is miscible. This was confirmed by ultrasonic, refractive index, density, and polarizing microscopic methods. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 557–561, 2001
Oxidative destruction of chitosan under the effect of ozone and hydrogen peroxide
Authors: Kabal'Nova N. N. , Murinov K. Yu. , Mullagaliev I. R. , Krasnogorskaya N. N. , Shereshovets V. V. , Monakov Yu. B. , Zaikov G. E. 
Published: August 2002

AbstractIn the present work the results of the study of oxidative destruction of chitosan effected by ozone and hydrogen peroxide are listed. The results obtained verify the rupture of 1,4‐β‐D‐glucoside bonds in macromolecule to be the basic process during amino groups of chitosan protection by acids. The rate of ozone with chitosan interaction depends on the concentration of ions in reaction mass. Destruction of chitosan by hydrogen peroxide leads to the formation of oligosaccharides in contrast to ozonolysis. Hydrogen peroxide oxidizes functional groups of chitosan only under tough conditions. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 875–881, 2001
Characterization of poly(vinylpyrrolidone)–konjac glucomannan blend films
Authors: Xiao Chaobo , Liu Hongjuan , Lu Yongshang , Zhang Lina 
Published: August 2002

AbstractBlend films of konjac glucomannan (KGM) and poly(vinylpyrrolidone) (PVP) were prepared by using a conventional solvent‐casting technique and dried at room temperature. The structure and physical properties were studied by infrared spectroscopy (IR), wide‐angle X‐ray diffraction (WAXD), thermogravimetric analysis (TGA), differential thermal analysis (DTA), scanning electron microscope (SEM), and by measurement of mechanical properties. The changes of carbonyl stretching bands of KGM and PVP and hydroxyl stretching region of KGM were detected by FTIR analysis. WAXD analysis revealed that the film KP‐2 got the lowest crystallinity of all the films. The tensile strength and breaking elongation of the blend films reaches the maximum value at 10 wt % PVP content. The DTA curves indicated the existence of interaction between two kinds of macromolecules. Higher thermal stability was attained by konjac glucomannan through blending with PVP. These improvements are attributable to the existence of a certain degree of interaction between KGM and PVP molecules resulted from intermolecular hydrogen bonds. Air surface morphology of the films observed by SEM was consistent with the results mentioned above. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1049–1055, 2001
Poly(2,3‐dimethylaniline) as a competent material for humidity sensor
Authors: Kulkarni Milind V. , Athawale Anjali A. 
Published: August 2002

AbstractChemically synthesized polyaniline and its ring substituted derivatives such as poly(o‐toluidine), poly(2,3‐dimethylaniline) and poly(2,5‐dimethylaniline) were utilized as sensors for relative humidity (RH) between 6.4% and 97.3%. The conductivity of the polymers was found to decrease on exposure to RH between 6.4% and 75.3%. However, in presence of 97.3% RH the conductivity was seen to increase. A comparison of the observed results reveals that, though each of the polymers responds to various percentages of RH, poly(2,3‐dimethylaniline) shows the best response in terms of sensitivity and linear range. The percent sensitivity was found to be greater for poly(2,3‐dimethylaniline) than that for polyaniline. The observed change in conductivity as well as the degree of change in magnitude of conductivity in the polymers was supported by X‐ray diffraction studies and IR spectroscopy. The X‐ray analysis showed that crystallinity of the polymer changed both in the presence and the absence of a specific percent of RH. Similarly, the IR spectra exhibited variation in the peak intensities of the O—H and >N–H groups. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1382–1387, 2001
Influence of retention system and curing on paper wet strength improvement by a copolymer containing glycidyl groups
Authors: Zhang Xiumei , Tanaka Hiroo 
Published: August 2002

AbstractThe copolymer (PGS) synthesized by polymerization of glycidyl methacrylate with styrene had a significant effect on paper wet strength. Factors such as retention aids, curing temperature, and curing time were investigated. The results showed that among four kinds of partially aminated poly N‐vinylformamide (APNVF), APNVF‐4 that had the highest charge density was the most effective for strengthening paper. The effectiveness of the retention systems increased with their wet functionality in the order APNVF‐4 > C‐PAM ≈ PAAm > PEI > PDADMAC. The curing temperature and curing time had little influence on paper dry strength, but they influenced paper wet strength greatly. The FTIR studies on model reactions showed that glycidyl groups could react with amino groups and carboxyl groups under common curing conditions. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2791–2797, 2001
Influence of isomer ratio and ring substituents in decomposition activation energies of α,α,α′,α′‐tetrasubstituted dibenzyls
Authors: Qi Chenze , Hu Youhua , Ji Genzhong , Liu Weimin , Yan Fengyuan , Zheng Xiaoming 
Published: August 2002

AbstractDiethyl‐2,3‐dicyano‐2,3‐di‐(X‐substituted phenyl) succinates (X = p‐OCH3, p‐CH3, p‐Cl, H, p‐NO2) can initiate the free‐radical polymerization of styrene. The decomposition rate constant and activation energy were measured by means of a dilatometer, and the results showed that they were strongly dependent on the ratio of meso‐ and dl‐isomers in the polysubstituted dibenzyl compounds and the properties of the ring substituents. On the other hand, it was found that the polystyrenes, which were obtained by initiation with hydrogen, had a much larger average molecular weight than that with p‐OCH3 and p‐CH3. The experimental phenomena were correlated with the structure of the radical resulting from hydrogen. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2964–2971, 2001
Role of initial polymer concentration in the physical properties of zone‐drawn biodegradable poly(butylene adipate) film
Authors: Lyoo Won Seok , Kim Joon Ho , Yoon Won Sik , Ji Byung Chul , Lee Jinwon , Yang Su Bong , Yoo Yongtai , Nam Hyo‐Duk 
Published: August 2002

AbstractThe effects of initial polymer concentration and zone drawing on the physical properties and hydrolytic degradation of poly(butylenes adipate) (PBA) film were investigated to prepare PBA film with various biodegradabilities and physical properties for particular uses. It was identified from the results that the initial concentration of PBA solution in chloroform caused significant changes in draw ratio of the PBA film. The maximum draw ratio of 8.2, tensile strength of 0.59 GPa, and tensile modulus of 7.8 GPa were obtained at the initial concentration of 12 g/dL, measured as an optimum polymer concentration for film casting. The chain orientations and tensile properties of the PBA film cast at this concentration were superior to those of the PBA films cast at the other concentration, although they had the same draw ratio and similar crystallinity. The hydrolytic degradation rate of the film cast at 12 g/dL was lowest among the films having the same draw ratio, film dimension, and crystallinity, indicating that degradation behaviors were greatly affected by the initial polymer concentration and the molecular orientation. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1–7, 2001
Effect of heavy‐ion irradiation on the gas permeability of poly(ethylene terephthalate) (PET) membranes
Authors: Takahashi Shuichi , Yoshida Masaru , Asano Masaharu , Tanaka Tomohiro , Nakagawa Tsutomu 
Published: August 2002

AbstractA poly(ethylene terephthalate) (PET) membrane was used to study the effect of heavy‐ion irradiation on gas permeability and selectivity. In an ambient temperature range of 303–333 K, permeability coefficients for He, N2, O2, and CO2 were determined with the vacuum‐pressure and time‐lag methods. Gas‐permeability coefficients of the membranes, which were irradiated with some specific heavy ions, increased remarkably without a significant change in the polymer structure by ion irradiation. The permeation rates of these membranes were inversely proportional to the square root of the molecular weight of the gasses and showed Knudsen flow because of the formation of pores caused by heavy‐ion irradiation. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 206–216, 2001
Morphology of a linear polymer‐modified epoxy‐amine formulation cured by microwave energy at different heating rates
Authors: Hedreul Claire , Galy Jocelyne , Dupuy Jérôme , Delmotte Michel , More Claude 
Published: August 2002

AbstractMicrowave energy was used to cure a bisphenol A diglycidyl ether‐based epoxy resin with an aromatic diamine curing agent (4,4′‐diaminodiphenylsulfone) in the presence of a rubber (epoxy‐terminated butadiene–acrylonitrile copolymer) or a thermoplastic (polyetherimide). Because microwaves allow high flexibility in the choice of the cure schedule, samples were cured at different heating rates between 3 and 110°C/min. The morphologies of the systems were studied as a function of the cure schedule. Scanning and transmission electron microscopy and differential scanning calorimetry were used to characterize the generated morphologies. The influence of the heating rate on the particle size distribution, the volume fraction of the dispersed phase, and the composition of both phases are discussed. The generated morphologies were found to be conditioned by the time–temperature profile, no matter what kind of heating was used. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1118–1128, 2001
Pervaporation of nonaqueous ethanol azeotropes through interpenetrating polymer network membranes prepared from poly(4‐vinylpyridine) and poly(vinyl alcohol)
Authors: Oikawa Eizo , Nozawa Kayo , Kaneko Takashi , Aoki Toshiki 
Published: August 2002

AbstractHighly hydrophilic interpenetrating polymer network (IPN) membranes were prepared from a mixture system of poly(4‐vinylpyridine) (P4VP) and poly(vinyl alcohol) (PVA) by quaternizing crosslinking of P4VP with 1,4‐dibromobutane (DBB) and simultaneous crosslinking of PVA with hexamethylene diisocyanate (HMDI). The membrane performance in pervaporation (PV) for the azeotropic mixture of ethanol with a less polar organic liquid (chloroform, benzene, carbon tetrachloride, and cyclohexane) was investigated. The strength of these IPN membranes was higher than that of the cellulose acetate membrane and depended on the membrane composition. All the membranes were ethanol permselective for the azeotropic feeds and equimolar mixture feeds as well. Only the swelling degree Q of the membrane, among several physicochemical factors, showed a relationship with the separation performance for the four feeds; a lower value of Q generally corresponded to a higher separation factor and smaller permeability. The membrane composition, which exhibited an optimum membrane performance, was examined in detail for some membranes. Both the separation factor for sorption and that for diffusion far exceeded unity, but the latter was greater in most cases than was the former and dominated the overall separation. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2729–2738, 2001
Thermal and mechanical behaviors of poly(vinyl alcohol)–lactose blends
Authors: Fan Xiao‐Dong , Hsieh You‐Lo , Krochta John M. 
Published: August 2002

AbstractThermal and mechanical behaviors of poly(vinyl alcohol) (PVA)–lactose blends were studied by differential scanning calorimetry, thermal gravimetric analysis, and stress–strain analysis. The increase in glass transition temperature of the PVA–lactose blends with lactose contents suggests the formation of hydrogen‐bonded PVA–lactose complex in the PVA matrix. The hydrogen bonding interactions can improve thermal and mechanical properties of the blends. Results of this study demonstrate that lactose, a byproduct of dairy industry, can be used directly and in substantial quantity (33%) as a modifier to enforce the physical properties of PVA. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 929–935, 2002
Ostracoda (Crustacea) from the Turkish Ramsar site of Lake Kuş (Manyas Gölü)
Authors: Altınsaçlı Selçuk , Griffiths Huw I. 
Published: August 2002

Abstract1. Lake Kuş (Manyas Gölü), an important bird conservation area, was sampled in the summer, autumn, winter and spring of 1997, and the seasonal and spatial distributions of ostracods were investigated. Many of the taxa collected are useful indicator species for monitoring conditions within lake basins.2. The findings suggest that the L. Kuş ecosystem is already substantially degraded. Pollution, coupled with extensive water abstraction for irrigation, have damaged the value of the lake, both commercially (as an inland waters fishery), and as an important site for wetland bird conservation.3. This work shows that ostracod faunal analysis has value in the study of such sites, particularly where more formal physical, chemical and biological monitoring methods are inappropriate or unavailable. Copyright © 2001 John Wiley & Sons, Ltd.