bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of water lubrication on polymer wear under rolling contact conditions
Authors: Lutton M. D. , Stolarski T. A. 
Published: April 2003

AbstractThe results of studies into the performance of three selected engineering polymers in rolling contact are presented. Both dry and water lubrication conditions were used. The polymers were machined into a cup simulating the outer race in a rolling contact bearing. Ceramic balls were used in order to create corrosion resistant combinations of materials. Post‐test studies were carried out using a scanning electron microscope. On the basis of microscopy examinations the effect of water on the morphology of contact path surfaces was assessed and the abilities of tested polymers to operate in the presence of water in a rolling contact were ranked. © 1994 John Wiley & Sons, Inc.
Ultimate properties of epoxy resins modified with a polysiloxane–polycaprolactone block copolymer
Authors: Könczöl L. , Döll W. , Buchholz U. , Mülhaupt R. 
Published: April 2003

AbstractMechanical and fracture mechanics properties of transparent multiphase epoxy resins toughened with various amounts of compatibilized silicone liquid rubbers consisting of polycaprolactone‐block‐poly(dimethylsiloxane)‐block‐polycaprolactone triblock copolymer have been investigated. At silicone liquid rubber contents < 10 wt % significantly improved toughness has been achieved without adversely affecting thermal and mechanical properties. Fractographic and interferometric methods have been applied to study crack propagation in such silicone‐modified resins. © 1994 John Wiley & Sons, Inc.
1H‐NMR investigation of quantitative functionalization of poly(ethylene glycol)s
Authors: Jankoa K. , Kops J. 
Published: April 2003

AbstractPoly(ethylene glycol)s, with different molecular weights (4,000–20,000) and a monomethoxy‐substituted poly(ethylene glyco) (molecular weight 5,000) have been quantitatively end group functionalized with bromo and amino groups. The bromination was carried out with thionyl bromide in toluene. 1H‐NMR was used for the determination of the degree of substitution by monitoring the characteristic signals for the CH2Br protons in relation to the signals from the remaining hydroxyl groups. Under the conditions used, qualitative substitution was obtained after repeating the bromination reaction. The results were in agreement with elemental analysis. The bromo end group could be quantitatively converted into amino groups by reaction in absolute ethanol with excess of ammonia or ethylenediamine. Also in this case, 1H‐NMR was used to determine the quantitative substitution by the characteristic signals for the aminomethyl protons and the simultaneous disappearnce of the bromomethyl proton signals. © 1994 John Wiley & Sons, Inc.
Blends of polyethylene terephthalate with Co[poly(ethylene terephthalate‐p‐oxybenzoate)] I. Crystallization kinetics by DSC study
Authors: Ou Cheng‐Fang , Lin Chen‐Chong 
Published: April 2003

AbstractThe dynamic and isothermal crystallization behaviors of polyethylene terephthalate (PET) blended with two types of co[poly(ethylene terephthalate‐p‐oxybenzoate)] copolyesters with different compositions, i.e., POB/PET = 20/80 (P28) and POB/PET = 80/20 (P82), has been studied by using differential scanning calorimetry (DSC). Both of these copolyesters in 10 wt % increase crystallization rate of PET in a manner similar to that of a nucleating agent. It is found that sample P28, which is an isotropic copolyester, accelerates the crystallization rate more significantly than that of P82, which is a thermotropic copolyester. The Avrami exponents n and rate constants k of these samples based on DSC studies were obtained in order to discuss the crystallization kinetics of PET accelerated by these copolyesters. The crystallization rate of the blends is also increased by 8 min blending due to the increased uniformity of the copolyester dispersed in the PET matrix. © 1994 John Wiley & Sons, Inc.
Graft copolymers of nylon 6 and polyphenylene oxide: Syntheses and their role in compatibilizing nylon 6/polyphenylene oxide blends
Authors: Lai Yu‐Chin 
Published: April 2003

AbstractPoly(2,6‐dimethyl‐p‐phenylene) oxides (PPO) grafted with nylon 6 were prepared by first quantitatively brominating the PPO, followed by reacting the brominated products with nylon 6 of different molecular weights. The molecular weights of PPOs were kept intact during bromination. These graft copolymers with well‐defined structures were used as compatibilizers for nylon 6/PPO blends. Some compatibilization phenomena were observed, as indicated by the mechanical properties of the blends. The best compatibilization was achieved when the graft copolymer is most block‐copolymer‐like. © 1994 John Wiley & Sons, Inc.
Polymers from renewable resources. V. Synthesis and characterization of thermosetting resins derived from cashew nut shell liquid (CNSL)–furfural‐substituted aromatic compounds
Authors: Swain S. K. , Sahoo S. , Mohapatra D. K. , Mishra B. K. , Lenka S. , Nayak P. L. 
Published: April 2003

AbstractA number of resins were synthesized by reacting cardanol, a byproduct of the cashew industry, with furfural and substituted aromatic compounds in the presence of acid and basic catalysts. The resins were characterized by IR and NMR spectra and shown to be selective ion exchangers for certain metal ions. A batch equilibrium method was used for studying the selectivity of the metal ions. The thermal behavior of the resins was also studied. A plausible degradation mechanism is suggested. © 1994 John Wiley & Sons, Inc.
Activated carbon from lignocellulosic biomass‐phenolic resin
Authors: Simitzis Johannis , Sfyrakis Johannis 
Published: April 2003

AbstractLignocellulosic biomass of agricultural/industrial by‐products residues was taken after the pressing and extraction of olive‐oil and lignin Klason and a‐cellulose were isolated. Also, phenol‐formaldehyde was polymerized by using an acid catalyst. Various mixtures of lignocellulosic materials and novolac resin were cured with haxamethylenetetramine and then pyrolyzed up to 1000°C. The IR‐Spectrum of the cured material consisted of 20% novolac and 80% cellulose is practically similar to that of 100% cellulose. The corresponding material with lignin Klason instead of cellulose has different IR‐Spectrum compared to that of 100% lignin, because of additional reactions taken place between lignin and novolac under curing conditions. The weight losses, the shrinkages at the end of the pyrolysis, the specific surface area of the carbonaceous materials produced and their adsorption abilities of methylene blue and alizarin yellow from aqueous solutions were determined. The material consisted of 20% novolac and 80% cellulose or 80% lignin, appears as optimum characteristics of production process. The experimental results are also discussed under the aspect of sample shapes that influence the adsorption as well as the electron donor–acceptor (EDA) interactions between the functional groups of dyes and the carbonaceous materials. © 1994 John Wiley & Sons, Inc.
Liquid chromatography of polymer mixtures applying combination of exclusion and full adsorption mechanisms. I. Analysis of polystyrene in its mixture with polymethylmethacrylate single column/single eluent approach
Authors: Janc̆o Miroslav , Prudskova Tatyana , Berek Dus̆an 
Published: April 2003

AbstractComponents of polymer mixtures with different chemical composition can be separated by liquid chromatography by applying appropriate conditions (column packing, eluent, temperature, and pressure) in which just one type of macromolecule is eluted in the size exclusion mode while the other component is fully retained within on column packing. The feasibility of this idea has been demonstrated using the mixtures of polystyrene (PS) plus polymethylmethacrylate (PMMA) with silica gel as the column packing and toluene as an eluent. The PMMA was retained by the silica get at ambient temperature and moderate pressures of several MPa while the PS was eluted by a typical SEC mecahanism. Furthermore, the molar mass distribution of the PS could be determined in one step with the same precision as if injected alone. Surprisingly large amounts of PMMA were trapped within the column prior to its SEc characteristics being influenced. After a series of analyses the column has to be regenerated with a brief flushing with a desorbing liquid, tetrahydrofuran in the system studied. The re‐equilibrization of the column with the initial eluent, toluene, was fast and a new series of analyses could be started soon after the characterization step had seen finished. © 1995 John Wiley & Sons, Inc.
Enzymatic and ultrasonic depolymerization of carboxymethylated β‐1,3‐D‐glucans derived from saccharomyces cerevisiae
Authors: Machová E. , Kogan G. , Alföldi J. , Šotés L. , Šandula J. 
Published: April 2003

AbstractEnzymatic and ultrasonic degradations of the carboxymethyl derivative of the β‐1,3‐D‐glucan, isolated from the cell walls of baker's yeast Saccharomyces cerevisiae, are described. The samples obtained upon partial depolymerization of the two carboxymethylated glucans with the substitution degree of 0.56 and 0.91 were characterized by the distributions of their molecular weights and 13C‐NMR spectra. © 1995 John Wiley & Sons, Inc.
Morphological studies of late‐stage spinodal decomposition in polystyrene–cyclohexanol system
Authors: Guo Hong‐Fei , Laxminarayan Anand , Caneba Gerard T. , Solc Karel 
Published: April 2003

AbstractWe studied the late‐stage spinodal decomposition of the polystyrene–cyclohexanol system in relation to membrane formation. Phase separation was effected by the removal of thermal energy from the homogeneous polymer solution. The ultimate morphology of the phase‐separated systems has been studied using electron microscopy and has been found to be strongly affected by the quenching time. A shift from a highly interconnected open‐cell structure to a closed‐cell structure has been observed, indicating the transition of the spinodal decomposition from early to late stages. The cell growth in the late stage has been quantitatively analyzed and a power‐law relationship between the cell size and quenching time has been found. The resulting exponent of 0.61 is consistent with literature values from light‐scattering measurements, as well as from theoretical derivations. © 1995 John Wiley & Sons, Inc.
Effect of added salt on properties of aqueous SMP solution
Authors: Zhuang Yinfeng , Zhu Zhongqi , Chao Hong , Yang Baochen 
Published: April 2003

AbstractSulfomethylated phenolic resin (SMP) is a drilling mud additive having good fluid loss and dispersion characters and may be resistant to the action of high temperature and high salt frequently encountered in well drilling, especially in deep wells. SMP is one kind of polyelectrolyte. There are dissociable groups (CH2SO−3Na+) along the chain of SMP. The conformations and properties of SMP in solution are affected greatly due to electrostatic attraction and repulsion. From the experimental results of viscosities and fluorescence spectra of polyelectrolyte SMP in pure water and aqueous solutions containing added salt, the effects of added salt on molecular conformations of SMP in aqueous solution and properties of reducing fluid loss of water base drilling mud are discussed. © 1995 John Wiley & Sons, Inc.
Studies on the block copolymerization of D,L‐lactide and poly(ethyle glycol) with aluminium complex catalyst
Authors: Deng X. M. , Xiong C. D. , Cheng L. M. , Huang H. H. , Xu R. P. 
Published: April 2003

AbstractA series of block copolymers from D,L‐lactide and poly(ethylene glycol) (PEG) with different molecular weight were synthesized by using Al(i‐Bu)3H3PO4H2O as the initiator and identified by 1H‐NMR, GPC, and DSC. The elongation at break of the material increased when PEG was introduced, but the strength of the material decreased. The copolymers degrade more smoothly in vitro than did the PLA homopolymer. © 1995 John Wiley & Sons, Inc.
Microstructural changes in homopolymers and polymer blends induced by elastic strain pulverization
Authors: Ahn Dongchan , Khait Klementina , Petrich Mark A. 
Published: April 2003

AbstractA novel polymer processing technique known as elastic strain pulverization (ESP) involves the simultaneous effects of high pressure and shear deformation to pulverize polymers. Homopolymers and blends of commercially important postconsumer plastics, including high‐density and low‐density polyethylene (HDPE, LDPE), polypropylene (PP), and poly styrene (PS) are studied by several characterization techniques to determine the effects of ESP on the microstructure. Electron spin resonance spectroscopy confirms that free radicals are generated by the mechanical rupture of main chain carbon bonds during pulverization by ESP. The possibility of these free radicals terminating by heterogeneous combination to form compatibilizing block or graft copolymers in coprocessed polymer blends establishes the potential of ESP in commingled plastics recycling. Differential scanning calorimetry (DSC) and polarized light microscopy of homopolymers and blends indicate that crystalline structure is drastically altered by ESP processing. Spherulite size reduction is also observed in both crystalline/crystalline and crystalline/amorphous blends after ESP. These results are consistent with homogenization that may be due to the formation of compatibilizing copolymers by heterogeneous macroradical combination. © 1995 John Wiley & Sons, Inc.
Frictional properties of polyolefins treated with fluoroelastomer processing aids
Authors: Gang Hong‐Goo , Cuculo John A. , Nam Sehyun , Crater Davis H. 
Published: April 2003

AbstractA friction measurement system was designed that made possible the measurement of the friction coefficient between a polymer melt and a metal die wall. The shear stresses developed in the capillary rheometer and the friction coefficient measured in the friction measurement system were compared in an attempt to understand the mechanism of fluoroelastomer processing aids (FPA) in the extrusions of polypropylene (PP) and linear low‐density polyethylene (LLDPE). The apparent viscosity drops of LLDPE treated with FPA were larger than those of PP treated with FPA. The friction coefficient drops of LLDPE treated with FPA were also larger than those of PP treated with FPA. High viscosity FPA showed a moderate friction coefficient drop in the actual extrusion of PP even though it showed only a poor effect in the capillary rheometer. The frictional forces were calculated from the friction coefficient measurement made during extrusions of FPA‐treated and untreated samples. © 1995 John Wiley & Sons, Inc.
Epoxy resins based on trimethylolpropane. II. Kinetic and thermodynamic parameters of cure withm‐XDA
Authors: Pellín M. Pazos , Regueira L. Núñez , Quintela A. Lopez , Losada P. Paseiro , Gándara J. Simal , AbuÍn S. Paz 
Published: April 2003

AbstractA study of cure of an epoxy resin based on trimethilolpropane (TMP) used as supplied and in purified form and m‐xylylenediamine (m‐XDA), as curing agent has been carried out. Thermodynamic functions such as activation energy, activation entropy, activation enthalpy, and free energy of activation were determinated. From kinetic study we have observed that there are two competitive mechanisms; autocatalyzed and n order, with the values of activation energy ranging between 52.9 and 64.6 kJ/mol. The overall order of reaction is found to be 2.5, and the order of reaction with respect to the hydroxyl group is clearly determined and equal to 1. Gelation study was carried out under two conditions: isothermal and adiabatic. From isothermal study we obtained the values of functionality of the resins (approximately two) and the apparent activation energy of the process. The adiabatic study allowed us the determination of the pot‐life taking into account the theoretical model used, with reasonable theoretical/experimental agreements. The importance of n‐order path for this kind of resins (with high OH contents) is well demonstrated through kinetic and thermodynamic parameters. The thermodynamic functions showed themselves as very sensitive parameters for the following and evolution of the reaction. © 1995 John Wiley & Sons, Inc.
Studies on graft copolymerization of acrylonitrile onto jute fiber with permanganate ion initiation system in presence of air
Authors: Sikdar B. , Basak R. K. , Mitra B. C. 
Published: April 2003

AbstractThe graft copolymerization of acrylonitrile with jute using potassium permanganate as the initiator has been studied in the presence of air. To establish reaction conditions for the graft copolymerization of acrylonitrile (AN) onto jute, the effect of different variables such as the residual lignin content of bleached jute (after bleaching with sodium chlorite), initiator concentration, monomer concentration, time of polymerization, reaction temperature, and amount of bleached jute fiber have been studied. As evidence of polymer grafting, some instrumental analyses such as scanning electron microscopy, infrared, and thermogravimetry have been carried out. The extent of grafting of acrylonitrile depends on how much lignin is present on the jute fiber. Percent grafting and grafting efficiency have also been studied. © 1995 John Wiley & Sons, Inc.
Synthesis and characterization of (3,4‐Difuryl‐2,5‐dimethyl) phenyl–polyvinyl silicon oils
Authors: Liu Zonglin , Lu Hongfang , Hao Shuxuan , Wen Xiaoyao , Du Zuodong 
Published: April 2003

Abstract(3,4‐Difuryl‐2,5‐dimethyl)phenyl–polyvinyl silicon oils (DDP–C‐gum) were synthesized by Diels–Alder reaction of polyvinyl silicon oil (C‐gum) with 3,4‐difuryl‐2,5‐dimethylcyclopentadienone (DDCP) in diphenyl ether at reflux temperature under atmospheric pressure. Their structures were characterized by 1H‐NMR, UV, and IR spectra. Properties such as viscosity, refractive index, color, and thermal stability of some DDP–C‐gums were obtained. © 1995 John Wiley & Sons, Inc.
Influence of pyrolysis temperature on the adsorptive properties of adsorbents produced from novolac and biomass
Authors: Sfyrakis J. , Faliagas A. , Simitzis J. 
Published: April 2003

AbstractMixtures of novolac resin and olive stone biomass are cured and pyrolyzed at different temperatures to yield carbonaceous adsorbents. The weight losses and the shrinkages taking place in the carbonization process increase up to ca. 600°C. The pyrolysis residues are investigated with respect to their ability to adsorb toluene and cyclohexane from the vapor phase. Toluene is adsorbed on all adsorbents stronger than cyclohexane. The overall diffusion coefficient D of the adsorption process, the specific surface area, and the pore volume of the adsobents are calculated. The adsorptive properties of the products are interpreted taking into account the size and shape of the pores, the polarity of the adsorbate, and the dispersion forces between adsorbent and adsorbate. Slit‐shaped pores, which are characteristic of carbon molecular sieves, are likely to be present in the adsorbents which are pyrolyzed at higher temperatures and particularly at 1000°C. This adsorbent shows the highest adsorption concerning the equilibrium uptake, specific surface area, and pore volume of toluene and cyclohexane. However, the diffusion coefficient D is lower as more micropores are present. © 1995 John Wiley & Sons, Inc.
Matrix–size interactions in epoxy–glass fibers composites in relation to mechanical relaxations and effects of thermal aging
Authors: Mascia L. , Zhang J. 
Published: April 2003

AbstractA study was carried out to examine the effect of removing the size from the surface of glass fibers in order to determine its role with respect to thermoxidative aging. Dynamic mechanical relaxation data have revealed that mechanical losses were always greater than the calculated upper bound values. The effects of removing the size from the surface glass fibers for epoxy matrix composites were found to be completely different when a fluoroligomer was used to modify the resin. Contrary to the case of the conventional epoxy resin, the characteristics of the composites containing fluoroligomer‐modified resin were found to be insensitive to the removal of the size from the glass fibers surface. The presence of the size on the surface of the fibers provides an interlayer that degrades through the formation of more lightly crosslinked products than the matrix, thereby providing a large increase in dynamic mechanical losses after thermal aging. © 1995 John Wiley & Sons, Inc.
Comparison of Sanchez–Lacombe and SAFT model in predicting solubility of polyethylene in high‐pressure fluids
Authors: Xiong Yan , Kiran Erdogan 
Published: April 2003

AbstractSanchez–Lacombe and SAFT (statistical associating fluid theory) models are used to describe phase behavior of polyethylene solutions (Mw = 2,150, 16,400, 108,000, and 420,000, and MwMn = 1.14, 1.16, 1.32, and 2.66, respectively) in n‐pentane and in n‐butane at high pressures. In order to test the predictive capability of the two models, all the predictions were conducted without any adjustment of the binary interaction parameter. Even though both models correctly predict the general trends of the phase envelopes and the LCST (lower critical solution temperature) nature of the systems, SAFT gives predictions that are much closer to the experimental data than the Sanchez–Lacombe model. © 1995 John Wiley & Sons, Inc.
Synthesis of diglicydilesters with alicyclic imide structure and their thermal and tertiary amine catalyzed curing
Authors: Galià M. , Serra A. , Mantecón A. , Cádiz V. 
Published: April 2003

AbstractThe synthesis of new diglycidylester compounds with bicyclo[2.2.2]oct‐7‐ene units was carried out from the previously synthesized diimide‐diacids and epichlorohydrin in excess using BTMA as catalyst. These compounds were characterized by spectroscopic techniques and have been cured either thermally or using 4‐dimethylaminopyridine as tertiary amine catalyst. The study of curing reaction was carried out through thermal analysis of the reaction by differential scanning calorimetry (DSC). The concentration of the tertiary amine affects the reaction mechanism of epoxide curing, but it does not influence the thermal properties of the final product. © 1995 John Wiley & Sons, Inc.
Miscibility behavior of blends of poly(alkyl methacrylate)s with poly(p‐methylstyrene‐co‐methacrylonitrile)
Authors: Chen Junjie , Goh S. H. , Lee S. Y. , Siow K. S. 
Published: April 2003

AbstractThe miscibility behavior of various poly(p‐methylstyrene‐co‐methacrylonitrile) (pMSMAN)/poly(alkyl methacrylate)s blends was studied using differential scanning calorimetry. pMSMAN is miscible with poly(methyl methacrylate), poly(ethyl methacrylate), poly(n‐propyl methacrylate), poly(isopropyl methacrylate), and poly(n‐butyl methacrylate) over certain copolymer composition ranges, but is immiscible with poly(isobutyl methacrylate) and poly(n‐amyl methacrylate). The width of the miscibility window decreases with increasing size of the pendant ester group of the poly(alkyl methacrylate), and is wider than that of the corresponding poly(p‐methylstyrene‐co‐acrylonitrile) blend system. Various segmental interaction parameters are calculated using a binary interaction model. © 1995 John Wiley & Sons, Inc.