bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plasma polymerization of organosilicon compounds
Authors: Inagaki N. , Kondo S. , Hirata M. , Urushibata H. 
Published: April 2003

AbstractPlasma polymerizations in five silicon compounds having chemical formula of (CH3)3SiXSi(CH3)3, X = none, CH2, NH, O, and S atoms, were investigated by elemental analysis, infrared spectroscopy, and ESCA. The chemical composition of polymers plasma‐polymerized was influenced by the X groups in (CH3)3SiXSi(CH3)3. Polymers, when X was S atoms, possessed no sulfur; and X was CH2 groups polymers rich in carbon and hydrogen atoms were formed. Details in chemical composition were discussed by IR and ESCA. Such differences in chemical composition reflected on gas permeability of the plasma films.
Radiation‐Induced graft copolymerization of methacrylic acid onto polypropylene fibers. IV. Thermal behavior
Authors: Mukherjee A. K. , Gupta B. D. 
Published: April 2003

AbstractThermal behavior of polypropylene‐g‐poly(methacrylic acid) fibers prepared by graft copolymerization of methacrylic acid onto polypropylene fibers, using simultaneous‐irradiation technique, was evaluated by thermogravimetric analysis, differential scanning calorimetry, and limiting oxygen index measurements. In general, the thermal properties of polypropylene fiber were markedly improved by the grafting of methacrylic acid. The inherent crystallinity of polypropylene, as deduced from DSC, did not show any change in the grafted fibers, suggesting that the grafting occurs in the amorphous region, without disrupting the crystalline part of the polymer. The LOI of grafted fibers showed an increase over the original fiber.
Diffusion/adsorption model of cellulose dyeing. II. Ordinary cellulose–direct dye system
Authors: Morita Zenzo , Tanaka Takaaki , Motomura Hiromi 
Published: April 2003

AbstractThe diffusion and adsorption of C.I. Direct Yellow 12 and Blue 15 in water‐swollen ordinary cellophane sheets were examined at various ionic strengths. The concentration dependence of apparent diffusion coefficients, Dc, for these dyes was obtained from the diffusion profiles in the substrate, which were measured by the use of the cylindrical film roll method. The decrease of apparent porosity with an increase in the amounts of adsorption was observed. To explain the diffusion/adsorption behaviors of these systems, a variable porosity model was proposed and was applied to analyze the concentration dependence of Dc's. The diffusion/adsorption behaviors of these dyes could be quantitatively described by this model at relatively low ionic strengths. At higher ionic strengths and/or lower values of C, i.e., at the large values of Cim/Cm, where the C's are the concentrations of immobilized (suffix im) and mobile (suffix m) species, it needed to introduce the concept of dynamic equilibria which occurred simultaneously with diffusion but deviated from the true equiliblia measured by the adsorption experiments.
A study of the drawing behavior of polyvinylidene fluoride
Authors: Humphreys J. , Ward I. M. , Nix E. L. , McGrath J. C. , Emi Thorn 
Published: April 2003

AbstractThe drawing behavior of different molecular weight PVDF grades has been investigated over the temperature range 140–160°C, with particular reference to the production of material with enhanced mechanical and electrical properties. Lower molecular weight grades, which have been subjected to a slow‐cooled rather than a quenched moulding procedure yield higher Young's moduli when drawn to a given draw ratio. X‐ray diffraction measurements have demonstrated that the crystalline regions of specimens drawn to high draw ratios under these conditions consist predominantly of the piezo‐ and pyroelectric form I phase. The relationship between the proportion of from I phase and the final drawing stress has been shown to be unique over the temperature range investigated, irrespective of molecular weight and thermal processing history.
Phase behavior of polyarylate blends
Authors: Robeson L. M. 
Published: April 2003

AbstractMelt mixtures of a polyarylate based on bisphenol A and tere/isophthalates were made with poly(ethylene terephthalate), several cyclohexane dimethanol‐based polyesters, polycarbonate, and the poly(hydroxy ether) of bisphenol A. The phase behavior was determined using classical methods. With minimum time and temperature exposure, polyarylate exhibits phase separation with poly(ethylene terephthalate) (PET) at >30 wt % PET. With moderate time and temperature exposure, adequate ester exchange occurs with polyarylate/PET blends to yield single‐phase behavior. The activation energy of the ester‐exchange reaction was determined to be 37.0 kcal/mole.Under minimum time and temperature exposure conditions, miscibility of polyarylate with three different cyclohexane dimethanol‐based polyesters was observed. A polyarylate‐polycarbonate 50:50 mixture was shown to be phase separated under minimum mixing conditions but capable of exchange reactions to yield single‐phase behavior with proper time and temperature exposure. Likewise, a 70:30 polyarylate‐poly(hydroxy ether of bisphenol A) blend was phase separated as mixed, but with further elevated temperature exposure, a cross‐linked single‐phase system resulted.The density versus composition of the polyarylate‐PET blends was linear with the phase‐separated systems but exhibited a slight densification with the miscible systems produced by higher temperature exposure. The glass transition of the miscible polyarylate‐polyester blends exhibited a significant deviation (lower) than predicted by a linear or Fox equation prediction. This was attributed to the low value of ΔCp (specific heat difference between the glass and rubber states) of polyarylate as noted by the Couchman equation to be a major factor in the Tg versus composition relationship. The optical characteristics of the blends paralleled the observed phase behavior as single‐phase blends were all transparent (in the amorphous state) whereas phase‐separated blends were translucent to opaque. These results clearly demonstrate the importance of ester‐exchange or transesterification reactions in the phase behavior of blends of polymers capable of these reactions.
Morphology of polyurethane–isocyanurate elastomers
Authors: Wang C. L. , Klempner D. , Frisch K. C. 
Published: April 2003

AbstractThe dynamic viscoelastic properties and thermal transition behavior of reaction injection molding (RIM) and cast polyurethane—isocyanurate elastomers have been studied as a function of various segments (soft and hard urethane, and hard isocyanurate) content. RIM and cast elastomers were prepared at different concentrations of soft and hard urethane, and hard isocyanurate segments. RIM elastomers with the higher isocyanate index (lower hard urethane and greater isocyanurate segment content) displayed an unchanged Tg (glass transition temperature of soft segment) and increasing Tgh (glass transition temperature of hard segment) related to the hard urethane and isocyanurate segments. This is due to the phase separation between the soft and the hard segments. Cast elastomers synthesized from the higher amount of 1,4‐butanediol (greater hard urethane and less hard isocyanurate segment content) showed an increasing Tgs, decreasing Tgh of hard urethane segments, and an unchanged Tgh of isocyanurate segments. This is related to the phase mixing between the soft and the hard urethane segments and the phase separation of hard isocyanurate and hard urethane segments.
Radiation‐induced emulsion ploymerization of vinyl acetate in a pilot plant reactor II. Kinetics
Authors: Challa R. R. , Drew J. H. , Stahel E. P. , Stannett V. 
Published: April 2003

AbstractThe recycle flow reactor pilot plant, described in Part I of this series, has been used to study some kinetic and other features of the emulsion polymerization of vinyl acetate. In particular, the dependence of the rate on the emulsifier concentration was determined and found to be 0.38 ± 0.09. Separate batch experiments were in reasonable agreement as 0.29 ± 0.10. The effects of temperature, dose rate, and agitation rate were also determined and were in agreement with most of the literature values.
New block copolymers II. Synthesis and characterization of an ABA‐type block copolymer
Authors: Shit Subhas C. , Mahato Beni Madhab , Maiti Mrinal M. , Maiti Sukumar 
Published: April 2003

AbstractA new regular ABA‐type triblock copolymer has been synthesized by polycondensation of the acid chloride of carboxy‐terminated butadience‐acrylonitrile rubber (CTBN) with hydroxyterminated polyethylene isophthalate (PEI) oligomer. This block copolymer was characterized by elemental (nitrogen) analysis, vapor pressure osmometry, viscometry, and IR and NMR spectroscopy. Quantitative estimation of block segments has been carried out by measuring the area under peaks assigned to various protons in the NMR spectrum of the polymer. NMR spectral analysis has been found to agree well with the nitrogen analysis of the polymer. The solubility and solution viscosity behavior of the polymer has also been studied.
The use of dyestuff‐treated rice hulls for removal of heavy metals from waste water
Authors: Suemitsu R. , Uenishi R. , Akashi I. , Nakano M. 
Published: April 2003

AbstractRice hulls, when coated with the reactive dye of Procion Red or Procion Yellow, was found to be highly effective for removal of many metal ions from aqueous solutions both in batch and column method. When 120–130 ppm solutions were used, quantitative removal could be achieved with Pb2+, Cd2+, and Hg2+. After the adsorption of metal ions, the substrate could be recovered almost completely by treating with dilute hydrochloric or nitric acid solution, and used repeatedly.
Modelization of matter transfers between plasticized PVC and liquids in case of a maximum for liquid‐time curves
Authors: Taverdet J. L. , Vergnaud J. M. 
Published: April 2003

AbstractWhen plasticized PVC and liquids are contacted with each other, as in liquid and packaging, some matter transfer may occur. The phenomenon is complicated, and no analytic solution can be found. A simultaneous transfer of the liquid into and plasticizer out from the PVC mass takes place with concentration‐dependent diffusivities. Very often, liquid concentrationtime curves have a maximum, when the rate of transfer is higher for the liquid than for the plasticizer at the beginning of the contact. Another application of short tests has been obtained with success in this hard case. A new model using short test data has been developed. It takes into account not only the diffusion of both liquids through the PVC, but also matter transfers through the liquid—PVC interface with a coefficient of matter transfer, as well as the data corresponding to the equilibrium. Some information of interest is given by way of the materials transferred through PVC faces, and the profile of concentration through the PVC for the liquid and plasticizer.
Preparation of Tri‐O‐alkylcellulose by the use of a nonaqueous cellulose solvent and their physical characteristics
Authors: Isogai Akira , Ishizu Atsushi , Nakano Junzo 
Published: April 2003

AbstractTri‐O‐methyl‐, ‐ethyl‐, ‐n‐propyl‐, ‐n‐butyl‐, ‐n‐pentyl‐, ‐iso‐amyl‐, ‐n‐hexyl‐, ‐n‐heptyl‐, ‐n‐octyl‐, ‐n‐decyl‐, and ‐3‐phenoxypropyl‐celluloses have been prepared with powdered sodium hydroxide and the corresponding alkyl iodides or bromides in one of nonaqueous cellulose solvents, SO2‐diethylamine‐dimethylsulfoxide. These new tri‐O‐alkylcelluloses were characterized by infrared spectra, 13C‐NMR spectra, and optical rotations. The first six tri‐O‐alkylcelluloses described above were obtained as white powders and most of them (tri‐O‐methyl‐, ‐ethyl‐, ‐n‐propyl‐, and ‐n‐pentyl‐celluloses) showed thermotropic liquid crystals due to smetic or short pitch cholesteric phases. On the other hand, the latter five derivatives were obtained as gummy solids even at room temperature, and easily showed lyotropic liquid crystals in their concentrated chloroform solutions due to choresteric phases. some of these tri‐O‐alkyl‐celluloses (tri‐O‐methyl‐, ‐ethyl‐, ‐n‐propyl‐, and ‐n‐butyl‐celluloses) were characterized by differential scanning calorimetric and X‐ray diffractometric analyses.
Postirradiation polymerization of vinyl monomers on poly(ethylene terephthalate)
Authors: Hsieh Y. ‐L. , Shinawatra M. , Castillo M. D. 
Published: April 2003

AbstractA postirradiation process was evaluated in polymerizing vinyl monomers on poly(ethylene terephthalate) (PET) film, fiber, and fabric. The use of DMF, pyridine, and DMSO as swelling agents to facilitate monomer incorporation and effective polymerization were also investigated. The solvents were effective in promoting the incorporation of acrylic acid (AA) in PET film and that of n‐vinyl‐2‐pyrrolidinone (VP) in Dacron 54. AA, a good swelling agent for PET, produced equivalent polymerization yield and moisture regain results with or without any solvent on Dacron 54 and 64. Polymerization yields on films increased with increasing total doses, but those on yarns and fabrics were independent of total dose. The different results obtained on film versus yarn and fabric from solvent treatment and total dose is thought to be due to the different surface‐volume ratio of these substrates. The moisture properties of the substrates were dependent mainly upon the monomer type. Among the monomers studied, VP gave highest moisture regain values, followed by AA. The tensile properties of the modified Dacron 54 were not affected. However the breaking elongation of the modified Dacron 64 was slightly lowered by postirradiation polymerization without solvent treatment and was increased when solvent treatment was included.
The viscosity of concentrated polymer solutions containing low molecular weight solvents
Authors: Richards William D. , Prud′homme Robert K. 
Published: April 2003

AbstractThe zero shear rate viscosities of polystyrene/ethylbenzene solutions having polymer weight fractions ranging from 0.5 to 1.0 have been measured using a novel sealed rheometer cell over a temperature range of 50 to 200°C. The concentration and temperature dependence of the solution viscosity has been found to be well described by the relation η0 = K caMw3.4ζ(c, T) where the monomeric friction coefficient ζ is determined by the free volume of the solution. Following the procedure of Berry, the free volume parameters, αf(c)/γ and T∞ (c), and the fractional free volume, f(c,T)/γ, have been determined. After using these parameters to account for the concentration dependence of the friction coefficient, the concentration exponent a has been evaluated and found to be in reasonable agreement with the value of 3.4 obtained by Berry and Fox for other polymer/solvent systems. A comparison of the relative conributions made by the friction coefficient and the term c3.4 to the overall concentration dependence of the viscosity of these highly concentrated solutions shows the friction coefficient to be the dominant factor
Diffusion/adsorption model of cellulose dyeing. I. The diffusion through never‐dry cellulose
Authors: Morita Zenzo , Tanaka Takaaki , Motomura Hiromi 
Published: April 2003

AbstractThe diffusion coefficients D0, of C.I. Direct Yellow 12, Red 2, Blue 1, and Blue 15 in aqueous NaCl solution were measured at 90°C by the diaphagm cell method. The values of D0 for Yellow 12 and Red 2 showed a salt concentration dependence and those for Blue 1 and Blue 15 were constant over the ionic strength range from 0.01 to 0.10. In the adsorption/diffusion models proposed so far for the direct dye–cellulose system, the Standing–Warwicker–Willis model was shown to be similar in principle to the Weisz–Zollinger model. The adsorption/diffusion behaviors in never‐dry cellophane sheet for C.I. Direct Yellow 12 and Blue 15 were examined by the method of cylindrical film roll at 90°C. The concentration dependence of the apparent diffusion coefficient for these dyes showed an incomplete validity of both the models.
Effect of pretreatment of cellulosic wastes on the production of cellulase enzymes by Trichoderma reesei
Authors: Kassim E. A. , Ghazi I. M. , Nagieb Z. A. 
Published: April 2003

AbstractThe cellulosic wastes, bagasse and sawdust, were treated with different acidified solvents: chloroform, dioxan, ethanol, ethylacetate, dimethyl sulfoxide and dimethyl formamide; for increasing periods up to 36 h. The treated materials were delignified, dried and introduced in the fermentation media as inducing carbon source for Trichoderma reesei. The untreated materials and pure cellulose powder were used individually in control and reference media, respectively. The fermentation media containing bagasse treated for 8 h in chloroform or dioxan gave a promising cellulase activity, nearly the same as that from the reference medium. The untreated bagasse gave a markedly low cellulase activity.The media with treated sawdust gave a relatively higher enzyme activity but far below the reference medium. The sawdust treatment with the solvents mentioned resulted in a very mild effect because of its high content of admixtures, lighin and hemicellulose bonding cellulose.
Preparation of polymers with pendant quinonoid groups and their photocrosslinking with visible light irradiation
Authors: Cha Younsik , Tsunooka Masahiro , Tanaka Makoto 
Published: April 2003

AbstractPhotosensitive polymers with pendant quinonoid groups were prepared by the reaction of p‐(benzoquinon‐2‐ylthio) acetic acid (QTAA) or p‐(p‐benzoquinon‐2‐ylthio)benzoic acid (QTBA) with hydroxyethyl methacrylate‐methyl methacrylate copolymer. The polymers showed a strong π‐π* absorption band at around 410 nm and were efficiently crosslinked by visible light irradiation. Somewhat higher photosensitivity of QTAA‐bound polymer compared with that of QTBA‐bound polymer suggested some contribution of intramolecular hydrogen abstraction of QTAA to the photocrosslinking.
Nonisothermal bulk copolymerization of styrene and methyl methacrylate in a CSTR: Multiplicity and stability analysis
Authors: Balaraman K. S. , Kulkarni B. D. , Mashelkar R. A. , Madhavan K. P. 
Published: April 2003

AbstractA theoretical investigation of the nonisothermal bulk copolymerization of styrene and methyl methacrylate in a CSTR is reported. A modified framework of free volume theory is developed for a copolymerization system to account for the effect of concentration and temperature on the propagation and termination processes. The evolution of multiple steady states for a set of system parameters has been demonstrated. The stability of these steady states has also been examined.
Thermotropic polyester amide‐carbon fiber composites
Authors: Chung Tai‐Shung , McMahon Paul E. 
Published: April 2003

AbstractLiquid crystal polymers (LCP) have been developed for the first time as a thermoplastic matrix for high‐performance composites. A successful melt impregnation method has been developed that results in the production of continuous carbon fiber (CF)‐reinforced LCP prepreg tape. Subsequent layup and molding of prepreg into laminates has yielded composites of good quality.Tensile and flexural properties of LCP‐CF composites are comparable to those of epoxy‐CF composites. LCP‐CF composites have better impact resistance than the latter, although epoxy‐CF composites possess superior compression and shear strength. LCP‐CF composites have good property retention until 200°F (67% of room temperature value). Above 200°F, mechanical properties are found to decrease significantly. Experimental results indicate that the poor compression and shear strength may be due to the poor interfacial adhesion between the matrix and carbon fiber.
Mechanical properties of crosslinked polyethylene
Authors: Andreopoulos A. G. , Kampouris E. M. 
Published: April 2003

AbstractThe mechanical properties of crosslinked polyethylene were studied in an extended range of test conditions in order to determine the recommended service conditions for articles made of crosslinked polyethylene. On the other hand, this study can clarify the advantages of crosslinked polyethylene against the unmodified polymer. In fact, the results referred in the literature concerning the changes of mechanical properties of polyethylene introduced by crosslinking are contradictory and cannot clearly distinguish the two types of polymer. The above study concluded that tensile tests at elevated temperatures (above 70°C) with low stresses (about 0.5 MPa) can clearly describe the effect of crosslinking on the mechanical properties of LDPE, i.e., an improvement at least for deformation and service life.
Flame‐resistant polycaproamide by anionic polymerization of ϵ‐caprolactam in the presence of suitable flame‐retardant agents
Authors: Alfonso Giovanni Carlo , Costa Giovanna , Pasolini Massimo , Russo Saverio , Ballistreri Alberto , Montaudo Giorgio , Puglisi Concetto 
Published: April 2003

AbstractPoly(ϵ‐caprolactam) (PCL) with improved flame‐retardant (FR) properties can be easily obtained by activated anionic polymerization of the monomer, ϵ‐caprolactam (C), in the presence of adequate amounts of red phosphorus (red P). Analogous results with reduced P content can be achieved by coupling red P with a synergistic compound such as a chlorinated hydrocarbon or magnesium oxide (MgO). A peculiar advantage of this method is the possibility of obtaining a very fine and homogeneous dispersion of the FR additive in the polymer matrix, meanwhile avoiding the typical compounding techniques, which are expensive, often unsafe, and require melt mixing of the ingredients. Molecular, thermal, and mechanical characterization, as well as morphology of the resultant products, have been determined: No significant properties change have been found when FR agents are present, apart from the relevant improvement of the flame‐resistance. Thus, by this novel procedure it is possible to prepare FR poly‐(ϵ‐caprolactam) without any appreciable deterioration of its typical properties.
Aging of pressure‐sensitive adhesives III. Studies of surface oxidation with multidetector size exclusion chromatography
Authors: Harrison Daniel J. , Yates W. Ross , Johnson Julian F. 
Published: April 2003

AbstractThe use of multidetector size exclusion chromatography is described for studying oxidation in styrene‐isoprene‐styrene block copolymer films. It is shown that exposure of these films to atmospheric oxygen causes surface oxidation of the isoprene midblocks and that the antioxidant system used is incapable of preventing this. Higher temperature exposure initially merely accelerates the surface reaction but is followed after an induction period by severe bulk‐phase degradation. The implications of ambient temperature surface oxidation of SIS‐based pressure‐sensitive adhesives are discussed.
Polyester polyurethane ionomers
Authors: Rutkowska Maria 
Published: April 2003

AbstractThe urethane elastomers based on 4,4′‐diphenylmethane diisocyanate (MDI), oligo (ethylene adipate) (OEA) with different chain extenders, and dibromohexane or ammonium salt were synthesized. Their mechanical and thermal properties were studied by stress‐strain analysis, thermomechanical methods, and differential thermal analysis. It was demonstrated that the incorporation of ionic groups in the structure of urethane elastomers due to the reaction of dibromohexane with a tertiary amine or urea NH group improves their tensile strength and thermal resistance.