bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of alicyclic polyimides based on cyclobutane ring dianhydride and aromatic diamine
Authors: Tsujita Y. , Tanaka H. , Yoshimizu H. , Kinoshita T. , Abe T. , Kohtoh N. 
Published: April 2003

AbstractFilms of alicyclic polyamic acid and polyimide containing cyclobutane ring in dianhydride moiety and aromatic ring with p‐ or m‐linkages in diamine moiety were characterized by infrared (IR) spectroscopy, dynamic viscoelasticity, differential‐scanning calorimetry (DSC), density, and wide‐angle X‐ray diffraction analyses. Partially and fully imidized polyimides were obtained by varying the imidization temperature, e.g., 150°C, 250°C, and 350°C. It was found from the results of IR spectra, dynamic viscoelasticity, and DSC measurements that the imidization of alicyclic polyamic acid was reduced at about 150°C and needed a higher imidization temperature than aromatic polyamic acid. Alicyclic polyimide with m‐linkage in the diamine moiety had a higher density and a much more ordered structure than with p‐linkage. © 1994 John Wiley & Sons, Inc.
Compatibility studies of solution‐blended poly(acrylonitrile)/poly(n‐butyl methacrylate)
Authors: Somanathan N. , Senthil P. , Viswanathan S. , Arumugam V. 
Published: April 2003

AbstractPoly(acrylonitrile) (PAN) was solution blended with poly(n‐butyl methacrylate) (PnBMA) in various proportions. Compatibility in these blend systems was analyzed using ultrasound. The ultrasound velocity and attenuation results show that the two polymers formed a compatible blend. Viscosity and other derived parameters like free volume and internal pressure of the blends show that PAN form into an ideal blend with PnBMA in the compositions of 60 : 40 and 40 : 60. © 1994 John Wiley & Sons, Inc.
Synthesis and characterization of styrene‐based microbeads possessing amine functionality
Authors: Cousin P. , Smith P. 
Published: April 2003

AbstractMicrobeads possessing amine functionality at the surface have been prepared by two methods: In the first method, poly(4‐vinylpridine/styrene) P(4VP/S) copolymer microbeads containing 13–69 mol % 4‐vinylpridine (4VP) were synthesized from the monomers. In the second method, animated polystyrene (PS) particles were prepared by postpolymerization reactions on cross‐linked PS and polychloromethylstyrene particles to obtain poly(aminomethylstyrene/styrene) and polydiethylaminomethylstyrene particles, respectively. Scanning electronic microscopy of P(4VP/S) microbeads showed regular and spherical particles having a diameter between 80 and 200 nm depending on 4VP content. The chemical structure of the various particles made was studied using Fourier transform infrared spectroscopy, electron spectroscopy for chemical analysis (ESCA), and elemental analysis, whereas thermal properties were determined by differential scanning calorimetry and thermogravimetric analysis. © 1994 John Wiley & Sons, Inc.
Swelling of hydrophilic polymers. III
Authors: Ogawa Ikuko , Yamano Hideki , Miyagawa Kinjiro 
Published: April 2003

AbstractThe total volume change included gel and surrounded water with the swelling of five types of speherical cross‐linked dextran (Sephadex) that are either nonionic (G) or possess one of four different ionic groups in the same molecular skeleton: CM: sodium carboxymethyl, SP: sodium sulphopropyl, DEAE: diethylaminoethyl chloride, and QAE: diethyl‐(2‐hydroxypropyl) aminoethyl chloride. All have been studied by dilatometry. The total volume decreased with the swelling of all Sephadexes. The maximum changes of total volume with the swelling in water were all negatives of CM, G, SP, (DEAE, QAE), which decrease in that order. These values did not depend on the concentration of sodium chloride and were closely related to the maximum heats of swelling. Total volume changes occurred by the dissociation of the ionic group of dextran derivatives that subtracted the total volume change due to hydration of Sephadex skeleton from the total volume change: −21.6 ± 3.1 μL mmol−1 for CM, −2.8 ± 8.0 μL mmol−1 for SP, +13.2 ± 4.4 μL mmol−1 for DEAE, and +15.4 ± 4.6 μL mmol−1 for QAE. These values are assumed to be reflected in the quantities of ions‐water interaction of Sephadexes. © 1994 John Wiley & Sons, Inc.
Stereoblock polypropylene/isotactic polypropylene blends. I. Phase organization
Authors: Canevarolo S. , De Candia F. 
Published: April 2003

AbstractThe phase organization of stereoblock polypropylene/isotactic polypropylene blends has been analyzed. The different samples were prepared by a two‐stage process, that is, solvent casting followed by pressure molding. The analysis was carried out using techniques such as X‐ray diffraction, differential scanning calorimetry (DSC), and thermomicroscopy. The experimental results show that both the components segregate a crystalline phase and that the overall crystallinity, as well as the crystallinity of each component, is affected by the sample composition. Some evidence of co‐crystallization, at least for samples at low content in isotactic polypropylene, has been found. © 1994 John Wiley & Sons, Inc.
Tensile yield in phenolphthalein polyether ketone
Authors: Han Yanchun , Yang Yuming , Li Binyao , Feng Zhiliu 
Published: April 2003

AbstractUniaxial tension tests to the yield point were performed on phenolphthalein polyether ketone (PEK‐C) from room temperature to near the glass transition temperature (Tg) at a constant rate of 0.02 min−1. At room temperature, some measurements were also made at strain rates from 0.002 min−1 to 2 min−1. Yield stress was a linear function of temperature and log strain rate. The temperature and the strain rate dependence of yield stress could be modeled using Eyring theory. Yield energy was found to be a linear function of temperature. Young's modulus, yield strain, elastic strain, and plastic strain all decreased with temperature. © 1994 John Wiley & Sons, Inc.
Distributions of functionality and of molecular weights in an hydroxyl‐terminated polybutadiene by dual‐detection size exclusion chromatography
Authors: Bielsa R. O. , Brandolini M. C. , Akcelrud L. , Meira G. R. 
Published: April 2003

AbstractThe article deals with data treatment problems associated with the estimation (via dualdetection size exclusion chromatography) of the independent distributions of molecular weight and functionality in a derivatized hydroxyl‐terminated polybutadiene. Calculations are based on an approach originally developed for linear copolymers and include corrections for (a) effect of functional groups on instantaneous mass and molecular weights, (b) dependence of refractive index with molecular weight, and (c) instrumental broadening. Compared to other more laborious analytical methods, the proposed technique is simple and provides accurate results. © 1994 John Wiley & Sons, Inc.
Miniemulsion polymerization of vinyl acetate with nonionic surfactant
Authors: Wang S. , Schork F. J. 
Published: April 2003

AbstractThe stability of vinyl acetate miniemulsions employing polyvinyl alcohol (PVOH) as the surfactant, and hexadecane and/or various polymers as the cosurfactant, were studied. Shelf lives (to phase separation) and monomer droplet sizes were measured. The results indicate that it is possible to prepare stable miniemulsions using a nonionic surfactant (PVOH) and hexadecane as the cosurfactant. Polymeric cosurfactants do not create stable miniemulsions but retard Ostwald ripening to an extent that allows predominant droplet nucleation. The polymerization behavior of these miniemulsion systems was investigated using on‐line conductance measurements to differentiate droplet versus micellar/homogeneous nucleation. The effect of cosurfactant concentration on the reaction rate was compared for hexadecane and polymeric cosurfactants. © 1994 John Wiley & Sons, Inc.
Synthesis and characterization of a new block copolymer: Poly(butylene terephthalate‐co‐olefin) application on PP/PBT blend and PBT homopolymer
Authors: Boutevin B. , Khamlichi M. , Pietrasanta Y. , Robin J. J. 
Published: April 2003

AbstractThe synthesis of a new block copolymer was investigated by the condensation of terephthaloyl chloride, hydrogenated α,ω‐dihydroxy polybutadiene and butanediol. The resulting (PBT) product is termed as the hard segment, and the hydrogenated α,ω‐dihydroxy poly‐butadiene is termed as the corresponding soft segment. This block copolymer was characterized by FTIR, 1H and 13C‐NMR, DSC, and SEC. Quantitative estimations of the contents of block segments have been carried out by NMR. The product was used either to increase the properties of PBT/PP blends or the impact strength of PBT. In both cases the mechanical properties are described. © 1995 John Wiley & Sons, Inc.
Crystallization kinetics of a PEEK/LCP blend
Authors: de Carvalho Benjamim , Bretas Rosario E. S. 
Published: April 2003

AbstractThe crystallization kinetics of a polyetheretherketone (PEEK)/liquid crystalline polymer (LCP) blend was studied by using differential scanning calorimetry. Nonisothermal runnings were performed on heating and on cooling at different rates. Isothermal crystallization experiments at 315, 312, 310, and 307°C, from the melt state (380°C) were performed in order to calculate the Avrami parameters n and k and the fold surface free energy, σe. Polarized light optical micrographs were also obtained to confirm the Avrami predictions. It was observed that the LCP retarded the PEEK crystallization process and that the PEEK melting temperature decreased with the amount of LCP, but the LCP melting temperature increased with the amount of PEEK. Probably the PEEK improves the perfection of the LCP crystalline domains. A spherulitic morphology in pure PEEK and its blends was predicted by the Avrami analysis; however this morphology was only observed for pure PEEK and for the 80/20 composition. The other compositions presented a droplet and fibrillar‐like morphology. The overall crystallization rate was observed to decrease with the crystallization temperature for all compositions. Finally, σe was found to decrease with the increase of LCP in the blends, having unrealistic negative values. Thus, calculations were made assuming σe constant at all compositions. It was observed that δ, the interfacial lateral free energy, decreased but still remained positive. It was concluded that in these blends neither σe nor σ could be considered constant. © 1995 John Wiley & Sons, Inc.
Concentration and separation of aqueous solutions of Cu2+, Ni2+, Fe3+ by dextran
Authors: Şolpan D. , Şahan M. 
Published: April 2003

AbstractThe effects of water‐soluble polymers on the concentration and separation of the aqueous solutions of the metal ions have been studied. The separation of metal ions can be possible by ultrafiltration‐complexation process. The effect of Dextran, which is a water‐soluble polymer, on the concentration and separation of metal ions (Cu2+, Ni2+, Fe3+) have been investigated by using EC‐PEG 4000 alloy membranes. The permeability of these membranes for metal ions has been rrecorded at constant pressure but different pH values. It has been notices that the highest water‐permeable membrane is also permeable towards Cu2+ and Ni2+, but has shown a considerable retention for Fe3+ as a result of the hydrolysis of Fe3+. The retentions of metallic ions and metallic‐ion‐Dextran couples have been determined at constant pressure but different pH and polymer concentration values. It has been shown that Fe3+/Ni2+ and Fe3+/Cu2+ couples can be separated by using Dextran. © 1995 John Wiley & Sons, Inc.
Stereoblock polypropylene/isotactic polypropylene blends. II. Mechanical behavior
Authors: Canevarolo S. V. , De Candia F. , Russo R. 
Published: April 2003

AbstractThe mechanical properties of stereoblock polypropylene/isotactic polypropylene blends have been analyzed at different temperatures and at large deformations. The samples at a lower content of isotactic polypropylene show good elastic properties, both in terms of deformation reversibility and in terms of energy dissipation in the hystersis cycles. Considering the dependence of the elastic behavior on the temperature, the model that can be suggested is based on the presence of a physical network in which the cross‐linking is due to cocrystallization between the matrix (the stereblock polypropylene) and the crystalline domains of isotactic polypropylene. © 1995 John Wiley & Sons, Inc.
Miscibility and transesterification in bisphenol‐a polycarbonate/ethylene terephthalate–caprolactone copolyester blends
Authors: Zhang Ruiyun , Luo Xiaolie , Ma Dezhu 
Published: April 2003

AbstractThe miscibility and microstructure of blends of bisphenol‐A polycarbonate (PC) with ethylene terephthalate (ET)‐caprolactone (CL) copolyesters (TCL) were studied by differential scanning calorimetry (DSC), infrared spectroscopy (IR) and phase contrast microscopy (PCM). The DSC results showed that PC were immiscible or partially miscible with the copolyesters having ethylene terephthatate contents higher than 60 (wt %), and miscible with the copolyesters having ET contents lower than 60(wt %). After annealing at elevated temperature, homogenization will take place in the immiscible or partially miscible blends of PC with higher ET‐content copolyesters. The IR and PCM results revealed that the homogenization of the blend are caused by the transesterification between the PC and copolyesters. © 1995 John Wiley & Sons, Inc.
Sorption and polymerization of methyl isopropenyl ketone in low‐density polyethylene
Authors: Agarwal Mini , Choi Kyu Yong 
Published: April 2003

AbstractThe polymerization of methyl isopropenyl ketone (MIPK) inside low‐density polyethylene beads has been studied with lauroyl peroxide as the initiator. The reaction was carried out by first immersing the polymer beads in a liquid solution of MIPK monomer and initiator for 5 h at 55°C and then draining the excess liquid. The temperature of these monomersoaked beads was increased to a reaction temperature (85°C) and the monomer was polymerized in the solid resins. The bulk polymerization of MIPK and the sorption characteristics of MIPK and initiator were also investigated through experimentation and model simulation. It has been observed that the monomer uptake in the solid polymer increased considerably in the presence of the lauroyl peroxide initiator in the liquid phase during the sorption stage. The differential scanning calorimetry study also indicated that some changes in the polymer morphology have occurred due to the incorporation of poly‐MIPK into the polyethylene resins. © 1995 John Wiley & Sons, Inc.
Preparation and characterization of end‐alkoxysilylated polystrene and the grafting behaviors onto inorganic pigments. I. Utilization of 4‐isopropoxydimethylsilyl‐α‐methylstyrene
Authors: Ohata Masatoshi , Yamamoto Masaharu , Isono Yoshinobu 
Published: April 2003

AbstractNovel end‐functional polystyrene having isopropoxydimethylsilyl (IPS) groups at the end part of the chain was prepared. IPS groups were introduced by the reaction between the living polystyryl anion and 4‐isopropoxydimethylsilyl‐α‐methylstyrene (1) in THF at 195 K. The resultant polymer was characterized by GPC, 1H‐NMR, and TLC. It was confirmed that the polymer had several units of 1 at the chain end and a fairly narrow molecular weight distribution. IPS groups in the polymer can be hydrolyzed with strong acid such as mono‐n‐butylphosphate (MBP) but not with weak acid and base. Grafting behaviors of the polymer onto silica and alumina were studied in toluene in the presence of MBP as a catalyst. The polymer was grafted onto silica effectively. However, it cannot be grafted onto alumina because of predominant adsorption of MBP onto alumina having a basic surface. © 1995 John Wiley & Sons, Inc.
A differential scanning calorimetry study of plasma irradiation grafting of nascent polyethylene reactor powder
Authors: Tian Jun , Lin Xiao , Xu Jiping , Huang Baotong 
Published: April 2003

AbstractThe melting behavior of poly(methyl methacrylate)‐grafted nascent polyethylene reactor powder by plasma irradiation was studied by differential scanning calorimetry (DSC). The grafting yield ranged from 11 to 190% Grafting was found to lower both melting point and heat of fusion during the first run of DSC determination. The heat of fusion was used to calculate the apparent grafting yield of the samples. There was little strain induced by plasma‐irradiated grafting on the surface of the polyethylene crystals. A method to determine the covalent grafting yield in the graft copolymer systems was developed. © 1995 John Wiley & Sons, Inc.
Injection molding of semicrystalline polymers. I. Material characterization
Authors: Isayev A. I. , Chan T. W. , Shimojo K. , Gmerek M. 
Published: April 2003

AbstractVarious material data for an isotactic polypropylene were acquired for the simulation of the injection molding of this material. Viscosity as a function of shear rate and temperature was measured using a capillary rheometer at high shear rates and a cone‐and‐plate rheometer at low shear rates. Heat‐flow properties, characterizing kinetics and induction time of quiescent crystallization, were obtained from DSC measurements. Material data characterizing shear‐induced crystallization were obtained from extrusion experiments through a slit die with subsequent quenching of the material in the die after various rest times. The thickness of the shear‐induced crystallization layer was measured along with the birefringence in this layer. A model of shear‐induced crystallization developed by Janeschitz‐Kriegl and co‐workers was used to fit the kinetic data. Thus, kinetic parameters such as the limiting shear rate below which no shear‐induced crystallization can occur and the characteristic time for the relaxation of birefringence were obtained. © 1995 John Wiley & Sons, Inc.
Utilization of wastes of foam polystyrene as sorbents
Authors: Simitzis J. , Fountas D. 
Published: April 2003

AbstractWastes of foam polystyrene were dissolved in styrene and copolymerized with DVB and the final product was sulfonated with H2SO4 (group B). Group A of cross‐linked polystyrene was synthesized using styrene and divinylbenzene (DVB) in the presence of n‐heptane (macroporous ion exchangers) and then was sulfonated with H2SO4. The chemical structure of the cross‐linked polymers before and after sulfonation was determined by infrared spectroscopy. The ion‐exchange capacity was higher for the polymers of group A. The poresize distribution for polymers of group A was determined and the average pore diameter (4V/A) of 39.9 nm for a representative polymer resulted. The degree of swelling of the polymers and their adsorption for methylene blue and alizarin yellow were also determined. The degree of swelling in toluene is decreased by increasing the ratio of DVB in the initial mixture and by sulfonation. The adsorption of methylene blue and alizarin yellow is strongly increased by the sulfonated polymers in comparison with the unsulfonated. As far as group B is concerned, the adsorption of alizarin yellow on the sulfonated polymers, which have higher cross‐linking and lower sulfonation, increased more, especially at the initial time. The networks of both groups examined are different. The polystyrene wastes were incorporated into the whole network to an extent of 15–35%. Such investigations could contribute to the utilization of wastes of polystyrene in the direction of sorbents and especially if the polystrene wastes are contaminated with other polymers. © 1995 John Wiley & Sons, Inc.
Semiinterpenetrating polymer network latexes via concentrated emulsion polymerization
Authors: Ruckenstein Eli , Li Hangquan 
Published: April 2003

AbstractLatexes of semiinterpenetrating polymer networks (SIPN) of polyurethane (PU) and poly(methyl methacrylate) (PMMA) were prepared via the concentrated emulsion polymerization. In this procedure, a partially cross‐linked PU was first prepared in a low polarity solvent from the appropriate precursors. Subsequently, MMA and an initiator were introduced into the solution, and the solution was used as the dispersed phase of a concentrated emulsion in water. Finally, SIPN latexes were obtained via the polymerization of the concentrated emulsion. For comparison purposes, SIPN materials have been also prepared via bulk polymerization. The studies with differential scanning calorimetry and transmission electronic microscopy showed that partial interpenetration was achieved in the SIPN latexes. The tensile behavior and particle morphology of the SIPN materials were investigated by changing the proportion of PU, the molar ratio of NCO/OH, the theoretical cross‐link density, and the concentration of the initiator. The SIPN latexes prepared possess a high toughness. © 1995 John Wiley & Sons, Inc.
Coating water‐swellable polymer latexes by interfacial polymerization
Authors: Ruckenstein Eli , Hong Liang 
Published: April 2003

AbstractTwo techniques of coating water‐swellable polymer latexes (hydrogels) with an inorganic or organic layer were developed, based on interfacial polymerization. The hydrogel latexes were prepared by inverse suspension polymerization. The first kind of interfacial polymerization is hydrolysis and polycondensation of tetraethyl orthosilicate (TEOS) or 3‐(trimethoxysilyl) propylmethacrylate (TMS‐PMA) on the surface of hydrogel latexes. The hydrochloric acid, which is the catalyst for this reaction, was previously loaded into the hydrogel latexes. The HCL‐containing hydrogel latexes were then suspended in an organic solution of TEOS or TMS‐PMA. The hydrolysis and condensation occur only at the surface of each hydrogel particle and the generated SiO2 or SiO(PMA) network covers the hydrogel latexes. The second interfacial polymerization is polymerization of methylenedi‐p‐phenyl diisocyanate (MDI) and triethylene glycol (TEG) on the surface of hydrogel latexes. TEG was deposited on the hydrogel by suspending the hydrogel powder in a tetrahydrofuran (THF) solution of TEG and evaporating the THF. The TEG‐deposited hydrogel powder was then suspended in an organic solution containing both MDI and the catalyst dibutyltin dilaurate (DBTL). The MDI and DBTL molecules react with the TEG molecules only at the surface of the hydrogel particles, and the polyurethane P(MDI‐TEG) thus formed wraps the particles. Based on these two coating procedures, three kinds of materials were obtained: SiO2 coated hydrogels, SiO‐(PMA) coated hydrogels and P(MDI‐TEG) coated hydrogels. Soft polyether brushes were grafted to the SiO‐(PAM) coated latexes. The P(MDI‐TEG) coated hydrogels were used as reservoirs for β‐hydroethyltheophylline (β‐HETP), and the release of the latter molecules from the coated hydrogels was investigated. © 1995 John Wiley & Sons, Inc.
Vulcanization of 1‐chlorobutadiene–butadiene rubber with diepoxy compound
Authors: Sando Katsumi , Hashim Azanam Shah , Ikeda Yuko , Kohjiya Shinzo , Yamashita Shinzo , Kawabata Nariyoshi 
Published: April 2003

AbstractDiepoxy vulcanization system of 1‐chlorobutadiene–butadiene rubber(CB–BR) having hydroxyl groups with diglycidyl ether of bisphenol A (DGEBA) was studied in the presence of acid anhydrides. Phthalic anhydride (PAn), hexahydrophthalic anhydride (HAn), maleic anhydride (MAn), and succinic anhydride (SAn) were investigated as occuring agents. The results of this investigation indicated that the hydroxyl groups attached to the polybutadiene backbone react with DGEBA to afford a CB–BR vulcanizate rate depended on the kinds of acid anhydrides in the following order: PAn > MAn > SAn > HAn. It is assumed that the reaction between the hydroxyl group in CB–BR and acid anhydride was the rate‐determining step. The vulcanization of CB–BR with a higher amount of DGEBA afforded resinous rubber vulcanizates. Thus, DGEBA was concluded to act not only as a curing agent, but also as a reinforcing agent for CB–BR. © 1995 John Wiley & Sons, Inc.