bluuebunny/crossref_metadata_2025_split huggingface dataset:
Coordination polymers of copper(II) with some dicarboxysiloxane ligands
Authors: Cazacu Maria , Airinei Anton , Marcu Mihai 
Published: October 2002

AbstractSeveral new coordination polymers of copper(II) with different carboxylate ligands containing siloxane units were synthesized by equilibrium polycoordination reactions of copper(II) acetate with the proper dicarboxylic acid (i.e. 1,3‐bis(3‐carboxypropyl)tetramethyldisiloxane, α,ω‐bis(3‐carboxypropyl)oligodimethylsiloxane, and 1,3‐bis(sebacomethyl)tetramethyldisiloxane) in solution (methanol), at room temperature. Some variations in the feed molar ratios were made. The resulting polymers having a polycoordination degree between 5 and 71 are soluble in a wide range of common organic solvents. The formation of polymers was proved by IR and UV–VIS absorption spectroscopy. The thermal behaviour of the coordination polymers was analysed by thermogravimetry in air. The silicon and copper contents and inherent viscosities were also determined. Copyright © 2002 John Wiley & Sons, Ltd.
Hydroformylation – amidocarbonylation of androstene and pregnene derivatives
Authors: Nagy Emese , Benedek Csilla , Heil Bálint , Tőrös Szilárd 
Published: October 2002

AbstractAndrostene and pregnene derivatives were functionalized by amides with rhodium or binary rhodium–cobalt catalysts. Whereas the Rh–PPh3 catalyzed reaction results in the unsaturated amido‐methylidene derivatives, the rapid hydrogenation of these compounds takes place in the presence of a basic PR3 ligand. Using a binary rhodium–cobalt system, amidocarbonylation of the steroids occurs with high chemo‐ and regio‐selectivity. Our experiments did not support literature reports claiming the essential role of a bimetallic cluster as the active catalyst. Copyright © 2002 John Wiley & Sons, Ltd.
Study on a water‐swellable rubber compatibilized by amphiphilic block polymer based on poly(ethylene oxide) and poly(butyl acrylate)
Authors: Wang Caiqi , Zhang Guo , Dong Yuping , Chen Xingfang , Tan Huimin 
Published: October 2002

AbstractA water‐swellable rubber (WSR), compatibilized by the amphiphilic block copolymer, has been prepared by blending a natural rubber (NR) matrix with crosslinked sodium polyacrylate (CSP), poly(ethylene oxide)‐b‐poly(butyl acrylate) (PEO‐b‐PBA), poly(ethylene glycol) (PEG), reinforced filler, and vulcanizing agents. The preparation process was described. The microphase structure of WSR was characterized by a scanning electron microscopy (SEM) photograph. The dependence of the degree of the water‐absorbing and the water‐swelling, the water‐absorbing and water‐swelling rates on CSP, PEG, and PEO‐b‐PBA contents were investigated. The compatibilizing mechanism of PEO‐b‐PBA on WSR was studied. And the optimum composition range was identified: CSP (30–60 phr), PEG (10–20 phr) PEO‐b‐PBA (PEO/PBA = 0.36, 5 phr). © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3120–3125, 2002
Light‐scattering study on porous membrane formation by dry‐cast process
Authors: Matsuyama Hideto , Tachibana Masanori , Maki Taisuke , Teramoto Masaaki 
Published: October 2002

AbstractThe phase‐separation mechanism during porous membrane formation by the dry‐cast process was investigated by the light‐scattering method in poly(methyl methacrylate)/ethyl acetate (EA)/2‐methyl‐2,4‐pentanediol system. The evaporation of EA from the cast solution induced the phase separation and thus the porous membrane was obtained. By the light‐scattering measurement on the phase‐separation kinetics, the phase separation was found to occur by a spinodal decomposition mechanism. As the amount of nonsolvent in the cast solution decreased, the structure growth rate decreased and the growth stopped soon. The obtained porous structure was isotropic rather than asymmetric. The average interpore distances obtained from the SEM observation roughly agreed with the final constant interphase periodic distances measured by the light‐scattering method. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 10: 3205–3209, 2002
Accelerated cure of phenol–formaldehyde resins: Studies with model compounds
Authors: Conner Anthony H. , Lorenz Linda F. , Hirth Kolby C. 
Published: October 2002

Abstract2‐Hydroxymethylphenol (2‐HMP) and 4‐hydroxymethylphenol (4‐HMP) were used as model compounds to study the reactions that occur during cure of phenol–formaldehyde (PF) resin to which cure accelerators (ethyl formate, propylene carbonate, γ‐butyrolactone, and triacetin) have been added. The addition of cure accelerators significantly increased the rate of condensation reactions. The cure accelerators were consumed during the reaction, indicating that they do not act as true catalysts. Major dimeric and trimeric reaction products were isolated and their structures determined. The results are consistent with a mechanism in which the hydroxymethyl group of 2‐HMP (or 4‐HMP) is first transesterified by the cure accelerator. The ester group is then displaced by reaction with the negatively charged ortho or para position of a second molecule (SN2 mechanism) or is converted to a reactive quinone methide intermediate, which subsequently reacts with the negatively charged ortho or para position of a second molecule (quinone methide mechanism). When accelerators were added to the reaction mixture, the self‐condensation of 2‐HMP was faster than that of 4‐HMP. As is well documented in the literature, the exact opposite is true without added accelerators. This result would seem to indicate that the phenolic oxygen helps activate the esterified ortho‐hydroxymethyl group. The number and nature of crosslinks in a PF resin cured with added cure accelerator might be different than those in a PF resin cured without an added cure accelerator. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3256–3263, 2002
Linear thermoelastic characterization of anisotropic poly(ethylene terephthalate) films
Authors: Feng Ru , Farris Richard. J. 
Published: October 2002

AbstractAll nine independent elastic constants have been determined for a biaxially stretched poly(ethylene terephthalate) (PET) film using novel mechanical methods. The orthotropic directions and the in‐plane Poisson's ratios were first characterized using vibrational holographic interferometry of tensioned membrane samples. The out‐of‐plane Poisson's ratio was obtained by measuring the change in tension with the change in pressure for constant strain conditions. Pressure–volume–temperature (PVT) equipment was used to measure the bulk compressibility as well as the volumetric thermal expansion coefficient (TEC). The in‐plane Young's moduli were obtained by tensile tests, while the out‐of‐plane modulus was calculated from the compressibility and other elastic constants that describe the in‐plane behavior. The in‐plane TECs in the machine and transverse directions were determined using a thermal mechanical analyzer (TMA). The out‐of‐plane TEC was determined using these values and the volumetric TEC determined via PVT. The resulting compliance matrix satisfies all of the requirements of a positive‐definite energy criterion. The procedure of characterization utilized in this article can be applied to any orthotropic film. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2937–2947, 2002
Absorption behavior of the polyester type polyols containing benzene rings toward poly(ethylene terephthalate) fiber
Authors: Yen Meng‐Shung , Cheng Chien‐Chung 
Published: October 2002

AbstractPolyester‐type polyols with a single benzene ring and a double benzene ring attached to a polyethylene glycol (PEG) moiety on only one end (PT series and PTET series), or both ends (PTP series and PTETP series), or attached to a PEG and an ethylene glycol (EG) moiety each on the separate ends (PTE series and PTETE series), were synthesized, and absorption behavior of the polyester‐type polyols toward polyethylene terephthalate fibers (PET) was investigated. The results showed that all the synthesized and tested polyols structurally belonging to the single benzene ring series (whether PT, PTE, or PTP series) and a double benzene ring system with PEG attached on both ends (i.e., the PTETP series) fit nicely to the dual sorption mode of a combination of Henry type and Langmuir type. However, the other double benzene ring series, either with only PEG on one end (PTET series) or with a PEG and an EG moiety each separately attached on the two ends (PTETE series), displays a Freundlich‐type sorption. Furthermore, it was found that the HLB value of polyols, and the disposition of the PEG moiety in the structure of polyols, are also quite important in effecting the absorption parameters. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2967–2976, 2002
Free‐radical grafting of 4‐vinyl pyridine onto nylon 6 fiber
Authors: Anbarasan R. , Jayaseharan J. , Sudha M. , Gopalan A. 
Published: October 2002

AbstractThe chemistry of free‐radical graft copolymerization initiated with peroxomonosulfate (PMS)–thioglycolic acid (TGA) redox system has been investigated by using 4‐vinyl pyridine (4VP) as a model for nylon 6 fiber in aqueous solution under nitrogen atmosphere. Effects of concentration of 4VP, PMS, TGA, nylon 6, time, and temperature on Rh and graft parameters were studied. The FTIR spectrum of nylon 6‐g‐4VP was reported. Water retention capacity (WRC) of the grafted fiber was tested. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3108–3113, 2002
Preparation and properties of water‐soluble polyester surfactants. II. Preparation and surface activity of silicone‐modified polyester surfactants
Authors: Liu Hsin‐Jiant , Lin Li‐Huei , Chen Keng‐Ming 
Published: October 2002

AbstractWe prepared a novel series of water‐soluble silicone‐modified polyesters [poly(ethylene glycol) (PEG)–silicone polyesters] by reacting organopolysiloxane with a hydroxy‐terminated polyester. The polyesters were obtained by the polymerization of maleic anhydride and PEGs (molecular weights = 2000, 4000, 6000, 8000, and 10000). These water‐soluble PEG–silicone polyesters can be used as auxiliaries in dyeing process because they exhibit good surface activities such as surface tension, low foaming, and wetting power. The presence of these surfactants also retarded the rate of nylon dyeing with acid dyes. The retarding effect and low‐foaming property of these novel PEG–silicone polyesters make it possible for these surfactants to be used as leveling agents for modern nylon dyeing with acid dyes. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3005–3012, 2002
Metal‐chelated polyamide hollow fibers for human serum albumin separation
Authors: Uzun Lokman , Denizli Adil 
Published: October 2002

AbstractWe modified microporous polyamide hollow fibers by acid hydrolysis to amplify the reactive groups and subsequent binding of Cibacron Blue F3GA. Then, we loaded the Cibacron Blue F3GA‐attached hollow fibers with different metal ions (Cu2+, Ni2+, and Co2+) to form the metal chelates. We characterized the hollow fibers by scanning electron microscopy. The effect of pH and initial concentration of human serum albumin (HSA) on the adsorption of HSA to the metal‐chelated hollow fibers were examined in a batch system. Dye‐ and metal‐chelated hollow fibers had a higher HSA adsorption capacity and showed less nonspecific protein adsorption. The nonspecific adsorption of HSA onto the polyamide hollow fibers was 6.0 mg/g. Cibacron Blue F3GA immobilization onto the hollow fibers increased HSA adsorption up to 147 mg/g. Metal‐chelated hollow fibers showed further increases in the adsorption capacity. The maximum adsorption capacities of Co2+‐, Cu2+‐, and Ni2+‐chelated hollow fibers were 195, 226, and 289 mg/g, respectively. The recognition range of metal ions for HSA from human serum followed the order: Ni(II) > Cu(II) > Co(II). A higher HSA adsorption was observed from human serum (324 mg/g). A significant amount of the adsorbed HSA (up to 99%) was eluted for 1 h in the elution medium containing 1.0M sodium thiocyanide (NaSCN) at pH 8.0 and 25 mM ethylenediaminetetraacetic acid at pH 4.9. Repeated adsorption–desorption processes showed that these metal‐chelated polyamide hollow fibers were suitable for HSA adsorption. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3346–3354, 2002
Studies on the photodegradation of polarized UV‐exposed PMDA–ODA polyimide films
Authors: Ha KiRyong , West John L. 
Published: October 2002

AbstractPolarized Fourier transform infrared (FTIR) and ultraviolet‐visible (UV‐VIS) spectroscopy were used to investigate the photodegradation direction of polarized UV (PUV)‐irradiated polyimide (PI) films based on pyromellitic dianhydride (PMDA) and 4,4′‐oxydianiline (ODA). PI films strongly absorb below 350 nm, resulting in a photochemical reaction of the PI. PUV irradiation of the PI film caused a decrease of all existing peaks and formation of new peaks at 3258, 1748, and 1710 cm−1 in the IR, due to degradation of the PI molecules. The preferential degradation of PI molecules parallel to the PUV irradiation direction results in the predominant orientation of the remaining PI molecules perpendicular to the PUV irradiation direction. But rubbing of the PI films induced orientation of the PI molecules parallel to the rubbing direction. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3072–3077, 2002
Surface migration of carboxylic acid in styrene–butadiene rubber and its tribological consequences
Authors: Bielinski D. , Glab P. , Slusarski L. , Boiteux G. , Chapel J.‐P. 
Published: October 2002

AbstractSurface migration of the carboxylic acids (C10H21COOH, C11H23COOH, C12H25COOH, C15H31COOH, C16H33COOH, and C17H35COOH) in styrene–butadiene rubber (SBR) matrix was investigated together with its influence on tribological properties of the vulcanisates. Macro‐ and microtribological properties were correlated with properties that come from carboxylic acid addition to the samples. A plastifying effect was characterized by a decrease of the rubber glass transition temperature measured by the DSC method. Thickness of an acid bloom was directly determined from an indentation experiment and estimated from the DSC curve as well as from FTIR reflection spectra. Morphology of the bloom was studied using an AFM technique to characterize topography as well as microroughness of the bloom surface. Macrofriction was studied using block‐on‐ring tribometer. Microfriction was examined with a Nano Test apparatus, applying ball‐on‐plate contact. Despite correlation found between plastification, morphology, and bloom thickness on the one hand, and tribologic properties of the rubber on the other hand, influence of the chain length of carboxylic acids on properties of the samples still needs further qualitative investigation. Tribological properties of SBR modified with carboxylic acids are the result of balance of two opposite effects: plastification of rubber—leading to an increase of friction and lubrication—which causes a decrease of friction of the rubber. Apart from plastifying and lubrication effects microroughness also plays an important role in friction. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3368–3376, 2002
Radiation preparation of ultrafine carboxylated styrene–butadiene rubber powders and application for nylon 6 as an impact modifier
Authors: Peng Jing , Zhang Xiaohong , Qiao Jinliang , Wei Genshuan 
Published: October 2002

AbstractUltrafine carboxylated styrene–butadiene rubber(CSBR) powders were prepared by using gamma irradiation and following spray‐drying method. The influences of dose rate, absorbed dose, and sensitizer content on the crosslinking density of CSBR latices were studied in detail. Then the ultrafine CSBR powders were used to toughen nylon 6. The toughness and thermal properties of nylon 6/CSBR blends were measured by using notched lzod impact test and differential scanning calorimetry and thermogravimetry, respectively. Results showed that the crosslinking density of CSBR increased with increasing of dose and sensitizer content, and it is independent on dose rate. The notched Izod impact strength of nylon 6 under room temperature increased after incorporation of irradiation crosslinked CSBR powders with appropriate crosslinking density. The morphology of higher impact nylon 6/CSBR blends indicated that the finer dispersion existed with dispersed particles of 150‐nm diameter. Fracture morphology of nylon 6/CSBR blend suggested that the shear yielding in matrix is the primary toughening mechanism for nylon 6/CSBR blends. The crystallinity of nylon 6/CSBR blends decreased slightly compared with pure nylon 6, whereas the addition of CSBR powders had little influence on the thermal stability of nylon 6. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3040–3046, 2002
Direct measurement of additive migration from low‐density polyethylene as a function of space and time
Authors: Helmroth I. E. , Bekhuis H. A. M. , Linssen J. P. H. , Dekker M. 
Published: October 2002

AbstractA method, based on microtoming and GC analysis, for studying migration of additives inside polymers as a function of space and time was validated for Irganox 1076 migrating from low‐density polyethylene to ethanol. The consistency of the mass balance of the total amount of Irganox 1076 in the polymer and the solvent after different incubation times was acceptable considering errors introduced by the analytical procedure. A solution of Fick diffusion equations, fitted to concentration profiles inside the polymer at different incubation times, was found to describe well the transport process as a function of both position and time with a diffusion coefficient of 1.1 × 10−13 m2 s−1. This value corresponded to the diffusion coefficient obtained using conventional measurements of an Irganox 1076 concentration in ethanol as a function of time. Compared to a stationary solvent, no significant effect was observed on the diffusion coefficient by gently shaking the ethanol. Diffusion coefficients measured at different temperatures using the validated method followed an Arrhenius type of relationship with an activation energy of 113 kJ mol−1. Conclusively, the method was found to be well suitable for studying additive migration in polymers as a function of both space and time. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3185–3190, 2002
Synthesis and properties of chitosan‐modified poly(vinyl acetate)
Authors: Don Trong‐Ming , King Chia‐Fong , Chiu Wen‐Yen 
Published: October 2002

AbstractA redox initiator, cerium ammonium nitrate, was used to initiate the graft copolymerization of vinyl acetate (VAc) onto the chitosan chain in a dispersion polymerization at 60°C. With an addition of 0.5–7.5 g of chitosan based on 50 g of VAc, the monomer conversion was found to be between 70 and 80% after 2 h of reaction. The grafting efficiency increased with the amount of chitosan added; yet, the grafting ratio increased slightly and then decreased. After the reaction, a stable dispersion system was observed and the surface of the latex particles was found to be rich in chitosan. All the experimental results indicated that the chitosan molecules not only took part in the graft copolymerization, but also served as a surfactant, providing the stability of the dispersion particles. If the dispersion aqueous solution was oven‐dried, a particulate membrane was formed. The experimental results indicated that the incorporation of poly(vinyl acetate) to the chitosan chains increased the toughness and decreased the water absorption of the chitosan material. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3057–3063, 2002
Microporous anisotropic phase inversion membranes from bisphenol A polycarbonate: Effect of additives to the polymer solution
Authors: Di Luccio Marco , Nobrega Ronaldo , Borges Cristiano P. 
Published: October 2002

AbstractPhase inversion is a very flexible technique to obtain membranes with a large sort of morphologies. Membrane properties can vary greatly depending on the kind of polymer system used. Bisphenol A polycarbonate (PC) could be used as a phase inversion membrane base polymer, and presents very good properties. Nevertheless, very little information on membrane preparation using PC and the phase inversion process can be found in the literature. In this work flat‐sheet microporous membranes were obtained by the phase inversion process using the immersion precipitation technique. A new polymer system was studied, consisting of polycarbonate, N‐methyl‐2‐pyrrolidone as solvent, water as the nonsolvent, and an additive. The influence of some parameters on membrane morphology, such as polymer solution composition, exposition time before immersion into the precipitation bath, and the kind of additive was investigated. Precipitation was followed using light transmission experiments and membrane morphology was observed through Scanning Electron Microscopy (SEM). The viscosity and cloud points of all polymer solutions were also determined. The results were related to the studied synthesis parameters, using the basic principles of membrane formation by the phase inversion technique, looking forward to establishing criteria to control the morphology of flat‐sheet membranes using polycarbonate as the base polymer. The results showed that both additives were able to increase pore interconnectivity and even suppress macrovoid formation. The decrease in the miscibility region of the polymer system and increase in mass transfer resistance are found to be the determining factors during polymer solution precipitation. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3085–3096, 2002
Pervaporation of methanol/methyl tert‐butyl ether mixtures through agarose/hydroxyethylcellulose blended membranes
Authors: Yoshikawa Masakazu , Yoshioka Takahiro , Fujime Junko , Murakami Akira 
Published: October 2002

AbstractIn this study, we investigated methanol (MeOH)/methyl tert‐butyl ether (MTBE) separation with hydroxyethylcellulose (HEC)/agarose blended membranes by applying a pervaporation technique. The membranes permeated MeOH in preference to MTBE from MeOH/MTBE mixtures. From pervaporation and sorption data, the permselectivity of HEC/agarose blended membrane was dominantly due to solubility selectivity. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3408–3411, 2002
Polystyrene/Sn–Pb alloy blends. II. Effect of alloy particle surface treatment on dynamic rheological behavior
Authors: Zhang Xiang‐Wu , Pan Yi , Zheng Qiang , Yi Xiao‐Su 
Published: October 2002

AbstractThe effect of filler surface treatment on the dynamic rheological behaviors of polystyrene filled with Sn–Pb alloy particles was tested below and above the melting temperature (Tm) of the alloy. The mechanical relaxation relevant to the Tm of the alloy in the composite was diminished by the filler surface pretreatment. In the whole temperature range of interest, there existed a secondary plateau of the storage modulus at low frequencies. The effect of alloy particle surface treatment on the plateau was related to the matter‐state change (from solid to liquid) of the alloy. Above the Tm of the alloy, the surface treatment of the alloy affected the secondary plateau, but below the Tm, it did not. The analyses of Cole–Cole diagrams of the systems suggested that untreated and pretreated alloy fillers all retarded the relaxation processes in the molten state of polystyrene below the Tm of the alloy and that the relaxation process was separated into the high‐frequency relaxation of the phases and the low‐frequency relaxation of the droplets above the Tm. The surface treatments of the alloy filler further enhanced this action. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3173–3179, 2002