bluuebunny/crossref_metadata_2025_split huggingface dataset:
Drawing of nylon‐6 by the novel incremental drawing process
Authors: Misra Ashok , Dutta Bhaskar , Prasad V. Kali 
Published: April 2003

AbstractMultifilament nylon‐6 fibers are drawn by the novel incremental drawing process as well as by the conventional drawing process. In this process the fibers are stretched in 36 stages along the surface of two corotating cones fitted on the incremental drawing machine. Fibers are obtained from each stage, and from their diameter measurements it is shown that they are stretched in a predicted manner. Mechanical properties, as measured by Instron and by a sonic modulus tester, show higher tenacity and modulus values for the incremental process than for the conventional one at equivalent draw ratios. Structural properties are analyzed by density measurements, wide angle X‐ray diffraction and birefringence. These showed higher crystallinity and higher crystalline as well as amorphous orientation factors for the incremental process at equivalent draw ratios. The mechanical property results are explained on the basis of structural development during drawing. It has been shown that the incremental drawing process is a suitable technique for obtaining superior properties in fibers and has commercial potential.
Topographic orientation on buffed polymeric substrates: The mechanism of wax buffing
Authors: Pence S. B. , Sporer A. H. 
Published: April 2003

AbstractThis paper reports on the observation that buffed waxy polymers control the orientation of a vapor‐deposited material subsequently deposited thereon. The insight into the mechanism of the buffing process of waxy polycrystalline polymers that these observations provide is presented. When a polycrystalline waxy polymer is buffed, grooves are formed. The dimensions of the grooves on the waxy polymer surface are substantially finer than the dimensions of the fibers of the buffing cloth. It is proposed that the buffing process stretches the polymer sufficiently to cause fibrillation, which results in the fine grooves observed. The fine grooves provide the topography necessary for orientation of the material deposited thereon.
Efficiency of antioxidants in thick‐walled natural rubber samples evaluated by differential scanning calorimetry and compression stress–relaxation
Authors: Stenberg B. , Björk F. 
Published: April 2003

AbstractThe effect ot two antioxidants, IPPD and DENA, on the aging properties of TMTD‐vulcanized natural rubber was studied by DSC. In the case of IPPD, the results were compared with mechanical measurements. The DSC measurements were carried out on specimens taken at different depths from cylindrical samples. The decrease in oxidative induction time was less pronounced for IPPD than for DENA at the edge of the samples. In the interior, the opposite behaviour was observed.
Temperature dependence of sorption parameters near Tg for propane in a miscible blend of polystyrene and poly(vinyl methyl ether)
Authors: Yavorsky J. A. , Spencer H. G. 
Published: April 2003

AbstractThe sorption of propane by 75:25% (w/w) miscible blends of polystyrene and poly(vinyl methyl ether) with different thermal histories was investigated near Tg. The dual‐mode sorption model was used to analyze the results. The evidence indicates that the Henry's law constant for states below Tg cannot be smoothly extrapolated from the rubbery state.
Fiber of poly(vinyl alcohol) derived from vinyl trifluroacetate. III. Production and properties of fibers
Authors: Yamaura Kazuo , Mizutani Ittsusei , Monma Kumiko , Tanigami Tetsuya , Matsuzawa Shuji 
Published: April 2003

AbstractThe direct wet‐spinning of syndiotacticity‐rich poly(vinyl alcohol) from ammonolysis solutions of poly(vinyl trifluoroacetate) was carried out. The high draft in spinning could not be accomplished at lower and higher polymer concentration, but it was accomplished at a certain middle polymer concentration. The drawn fibers with high draft have not always high strength. The fibers with high strength were obtained from fibers wound at moderate draft in spinning and then drawn at higher times without solvent. The strength was independent on the degree of polymerization (in a range from DP = 1870 to DP = 5580), but it became higher in the case of thinner fibers obtained from the solutions of lower polymer concentration. Here, the highest Young's modulus and strength at break were 13.8 GPa and 12 gr/denier, respectively.
The mass burning rate of flame‐retarded polypropylene in an oxygen‐enriched atmosphere
Authors: Spilda I. , Košík M. , Blažej A. 
Published: April 2003

AbstractPolypropylene containing a bromophosphorous flame‐retardant exhibits a higher mass burning rate—in the atmosphere containing more than 30 vol % of oxygen — than nonretarded resin. These prodegradative reactions in combustion can be eliminated only by using a high concentration (ca. 40 phr) of inorganic alumina trihydrate. A method for distinguishing the physical and chemical effects of flame retardants is described.
Adhesive behavior of the two phase system: Polyisobutylene–sodium carboxymethylcellulose
Authors: Pigłowski J. , Kozłowski M. 
Published: April 2003

AbstractAdhesive properties of polyisobutylene filled with sodium carboxymethylcellulose have been studied. From the results obtained by the removing cylinders method the lifetimes of the cylinder–PIB/CMC composition joint were calculated. The compositional dependence of the lifetimes have a similar character to that representing the dependence of relaxation time on the composition.
Copolymers of ethylene with butene‐1 and long chain α‐olefins, III. Hexadecene‐1 as long chain α‐olefin
Authors: Seppälä Jukka Veli 
Published: April 2003

AbstractHexadecene‐1 was used as comonomer with ethylene in a slurry polymerization with Ziegler–Natta catalysts. Hexadecene contents remained at less than 4 wt % in ethylene/hexadecene‐1 copolymers. When butene‐1 was also present in the polymerization, hexadecene‐1 contents were significantly higher. With hexadecene content of 11 wt %, the terpolymer density was 910 g/dm3. The effect of butene addition was significantly smaller with less than 10 carbon atoms containing α‐olefins.
Combustion products from polydiallylamine
Authors: Galbraith M. N. , Hodgkin J. H. , Vit I. 
Published: April 2003

AbstractCrosslinked polydiallylamine (Sirorez Au1) was prepared by the redox‐initiated (K2S2O8/TiCl3) polymerization of freshly distilled diallylamine [containing 2% 1,6‐bis(N,N‐diallylamino)hexane] as a 30% solution in 80% phosphoric acid at 0°C. The resulting crosslinked resin is thoroughly washed with water and then sodium hydroxide solution (10%) before a final distilled water washing and air drying.Polydiallylamine resin containing ≃ 50% by weight gold was prepared by soaking the above resin in a three fold molar excess of gold cyanide solution (2 g/L at pH 8.5) overnight and then filtering the resin, washing with distilled water, and air drying. The samples were dried for 24 h over P2O5 before combustion.
Shear and thermal history effects in polypropylene melts
Authors: Schertzer Richard , Rudin Alfred , Schreiber Henry P. 
Published: April 2003

AbstractFiber grade polypropylenes with melt flow indices of 3 and 12 were studied in the aspolymerized (powder) state and after pelletization. Pelletizing operations caused very little change in the molecular weight distributions of these polymers. The lower melt flow index material exhibited much greater apparent viscosity and melt elasticity in the powder than in the pellet from during screw extrusion at 190°C. These results are consistent with the existence of a higher entanglement density in the powder version. Instron rheometer data showed no difference between the two polymer forms because of the possibility for entanglement in the rheometer reservoir during rheological experiments. The effects of sample history noted with the 3 melt flow polymer were less pronounced with the lower molecular weight 12 melt flow material. The differences in flow curves of powder and pelletized forms of the latter polymer were negligible at 175 and 190°C. Differences in die swell were more noticeable, however. The effects observed are attributable to reversible shear‐induced decreases in entanglement density. Similar phenomena have been reported for other polymers. The results reported here have implications in quality control procedures for thermoplastics and in the production of polymers with desired property balances.
Chemical conversion of wood to thermoplastic material
Authors: Morita Mitsuhiro , Sakata Isao 
Published: April 2003

AbstractA chemically modified wood meal (CE‐wood) was prepared by cyanoethylation in the presence of alkaline salts. The temperature Tf at which the wood could flow was measured by a simple mechanical flow tester. The CE‐wood demonstrated thermal flow at around 250°C. The Tf value decreased with increasing cyanoethyl content of the wood. Treatment of the wood meal before cyanoethylation with sodium periodate or sodium chlorite lowered Tf. The flow temperature was also decreased by blending the CE‐wood with appropriate synthetic polymers or plasticizers. Treatment of CE‐wood with chlorine solution was found to be the most effective method of lowering Tf. The Tf value of the slightly chlorinated CE‐wood (Cl content=2%) was about 100°C lower than that of the original CE‐wood. The lowering of Tf for CE‐wood by treatment with chlorine may be interpreted in terms of the plasticizing effect of chlorination on the lignin moiety in the wood.
A comparison of some rheological properties of concentrated solutions of chlorinated polyethylene and polyvinyl chloride in dioctyl phthalate
Authors: Muñoz M. E. , Peña J. J. , Santamaría A. 
Published: April 2003

AbstractSteady‐state and transient shear flow properties of poly(vinyl chloride) and chlorinated polyethylene dissolved in dioctyl phthalate were studied at different temperatures and polymer concentrations. In the case of poly(vinyl chloride)/dioctyl phthalate systems the presence of a sol–gel transition temperature was observed, whereas for chlorinated polyethylene/dioctyl phthalate systems the mechanism of flow was the same in the whole range of temperatures and concentrations. On the basis of the data obtained for both polymer/solution systems, we conclude that the presence of crystallites, rather than hydrogen bonds, determines the rheological behavior of poly(vinyl chloride)/dioctyl phthalate systems.
Analysis of the accuracy of determination of molar mass distribution by the GPC with the on‐line light‐scattering detector
Authors: Procházka Ondřej , Kratochvíl Pavel 
Published: April 2003

AbstractThe effect of errors of the concentration (c‐) and the light‐scattering molar mass (M‐) detector in gel permeation chromatography (GPC) on the accuracy of the determination of the molar mass distribution (MMD) was analyzed. Model calculations showed that the reliability of MMD obtained from c‐detector data and from a carefully performed calibration dependence is higher than that obtained by combining data of the M‐ and c‐detectors. A criterion of the uncertainty of the MMD determination by the GPC method with the M‐detector was suggested, and its dependence on MMD parameters of the analyzed polymer and on the magnitude of injection was investigated.
Epoxy resin cure III: Boron trifluoride catalysts
Authors: Smith R. E. , Smith C. H. 
Published: April 2003

AbstractBoron trifluoride forms complexes with nitrogen‐and oxygen‐containing Lewis bases. These acid–base complexes are sometimes added to epoxy resins to accelerate their cure at elevated temperature (120°C–160°C). Several possible processing concerns with the use of boron trifluoride complexes have been investigated. It was shown that each complex can be readily identified by its distinct fluorine‐19 NMR spectrum. All of the boron trifluoride complexes are converted to fluoroboric acid under normal epoxy resin cure conditions. The fluoroboric acid is the true catalyst for epoxy resins. Experimental results show that fluoroboric acid does not catalyze the polymerization of an epoxy resin at room temperature. Finally, it was shown that fluoroboric acid is not hydrolyzed to hydrofluoric acid.
Mass loss of wood and its components during transmission electron microscopy
Authors: Mary M. , Revol J.‐F. , Goring D. A. I. 
Published: April 2003

AbstractThe loss of mass of wood and its polymeric constituents in transmission electron microscopy has been determined by measurement of the decrease in the continuum x‐ray intensity for various doses of irradiation. It was found that for doses higher than 5 × 10−8 C/μm2, 42% of the original mass of the wood remained on the grid. The corresponding percentages for cellulose, xylan, and lignin were 32, 45, and 70, respectively. The significance of these results in the use of transmission electron microscopy for imaging and for quantitative microbeam analysis is discussed.
Photoregulated sorption dyes to polymers. II. Adsorption of acid yellow 38 to hydrophilic polymers and its light‐induced desorption
Authors: Petrak K. , Leyshon L. , Douglas P. 
Published: April 2003

AbstractAdsorption of Acid Yellow 38 to, and its light‐induced desorption from, various coated polymer layers in water have been studied. Diffusion studies were used to determine the degree of competitive binding between the dye and polymers. It was found that the extent of both adsorption and desorption were different for polymer mixtures as compared to single polymer films. The presence of gelatin crosslinked within the polymer layer increased the amount of dye desorbed upon irradiation.
The role of intumescence on the flammability of vinyl and vinylidene polymers
Authors: Impallomeni G. , Montaudo G. , Puglisi C. , Scamporrino E. , Vitalini D. 
Published: April 2003

AbstractThermal stability and flammability properties of six structurally related vinyl and vinylidene polymers fail to show correlation. Instead, it is found that the combustion of these polymers is dominated by their char‐forming ability. A remarkable intumescent effect is observed in PVC2, PVF2, and PVC which accounts for the high flame extinguence of these polymers.
Grafting acrylonitrile and acrylic acid monomers on cellulosic materials
Authors: Okieimen Ebhodaghe F. , Ebhoaye Justus E. 
Published: April 2003

AbstractGraft copolymers of acrylonitrile and of acrylic acid monomers on cellulosic materials were obtained by use of ceric ion initiator in aqueous medium at a 50% (w/w) cellulose‐monomer ratio. The variations of poly(acrylonitrile) grafts and of the efficiency of grafting with ceric ion concentration, and of poly(acrylic acid) grafts with temperature are examined. The dependence of water retention capacity of the grafted fibers with the graft level is reported.
Preparation and morphology of a silicone‐acrylate copolymer system
Authors: Williams Todd R. 
Published: April 2003

AbstractThis paper presents the synthesis and analysis of a new series of silicone acrylate (SiAc) copolymers. The building block oligomers are linear polydimethylsiloxanes with alkylene urethane methacrylate end groups (Mn 1000–3000). A variety of analyses were performed in order to elucidate the morphology of these copolymers. Data are presented from differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), permeability testing, small angle x‐ray scattering (SAXS), and electron microscopy. These data indicate that these co‐polymers possess a two‐phase morphology in the range of compositions studied. Conclusions are drawn about the continuity, shape, and size of the domains. Some comparisons are made between data for these “ladder” polymers and data for siloxane‐containing alternating block copolymers reported in the literature.
Durability of radiation‐sterilized polymers III. Oxidation layer determined by chemiluminescence
Authors: Yoshii Fumio , Sasaki Takashi , Makuuchi Keizo , Tamura Naouki 
Published: April 2003

AbstractChemiluminescence (CL) analysis was used for determining the oxidation layer formed by the irradiation of polypropylene for medical supplies. The depth of the oxidation layer from the surface depended on dose rate and increased with decreasing dose rate. The oxidation occurred remarkably at a region near the surface area of the film where the diffusion of oxygen is more sufficient. On the contrary, there was very little oxidation in the interior portion. The oxidation layers of polypropylene samples irradiated with electron beam showed U‐shaped profiles in the cross‐section of film as did as a sample irradiated with γ‐rays. However, the degree of oxidation by irradiation with electron beam was very small; CL intensity at the surface area was only one‐third that for the γ‐irradiated samples.
Sorption of N‐butane, propane, and ethane in ethylcellulose
Authors: Casur Ertugrul , Smith Theodore G. 
Published: April 2003

AbstractThe sorption of n‐butane, propane, and ethane in ethylcellulose has been investigated between 0 and 200 mm Hg pressure over the temperature range from 30 to 70°C. Sorption isotherms of n‐butane, propane, and ethane in ethylcellulose suggest that both Henry's law and the Langmuir forms of sorption, are operative. Sorption data were analyzed using the dual sorption model and sorption parameters determined. The sorption attributed to the Langmuir mode decreases as the temperature increases. This result indicates that the nonlinear Langmuir mode of sorption is more characteristic of the glassy state than sorption represented by the Henry's law mode. It was found that sorption attributed to the Henry's law and Langmuir modes decreases as the molecular size of gaseous hydrocarbon penetrants decrease. In this study, the molecular size of gaseous molecule decreased as the gases studied changed from n‐butane to propane to ethane. A correlation of the Henry's law constants for the solution of n‐butane, propane, and ethane in ethylcellulose with the Lennard‐Jones force constants, ϵ/k at different temperatures was also determined. The temperature dependence of the Henry's law constants were correlated by a van't Hoff relationship and heats of sorption determined.
(Photo) graft copolymerization of methyl methacrylate (MMA) on polyamine‐modified oxycellulose in a limited aqueous system
Authors: Ghosh Premamoy , Bandyopadhyay Arup Ratan 
Published: April 2003

AbstractGraft copolymerization of methyl methacrylate (MMA) on oxycellulose modified with a polyamine [diethylene triamine (DETA)] was studied in a limited aqueous system under photoactivation in visible light using K2S2O8 as the intiator. No polymerization was observed in the dark or in presence of light in 80 min in the case of DETA‐treated cellulose; however, ready graft copolymerization resulting in high percent grafting and grafting efficiencies took place in the case of DETA‐modified oxycellulose system under photoactivated conditions. DETA‐modified oxycellulose prepared from oxycellulose corresponding to low degrees of oxidation (copper nos. 1.5–3.5) produced optimum grafting. The grafting parameters under different sets of conditions were studied and compared, and the mechanism of graft copolymerization was discussed.
Ultrasonic detection of segmental relaxations in thermoplastic polyurethanes
Authors: Aziz A. W. , Lawandy S. N. 
Published: April 2003

AbstractThe change in attenuation of longitudinal waves has been measured as a function of frequency and temperature for thermoplastic polyurethanes of different hardness covering a range from rubbery hardness to plastic. Analysis of the results show some segmental relaxations and the activation energies were calculated from the ultrasonic measurements. These activation energies were indirectly related to the fatigue failure of the polymer. This failure was expressed as cut growth.
Effect of degradative treatments on cotton graft copolymers. Part V. Behavior of poly(acrylamide)‐cotton graft copolymers toward acid treatments
Authors: Hebeish A. , El Rafie M. H. , Khalil E. M. , Abdel‐Hafiz S. A. 
Published: April 2003

AbstractPolyacrylamide (Aam)‐cotton graft copolymers having 9, 14.5, and 20% graft were synthesized using ferrous cellulose thiocarbonate‐hydrogen peroxide redox system. These copolymers as well as ungrafted and initiator‐treated cottons were subjected to acid treatments (0.5 N HCl) at 40°, 60°, and 80°C for 15‐90 minutes. Hydrolytic susceptibility of the five substrates was assessed by monitoring carboxylic groups, copper, number, nitrogen content (in case of the copolymers), and tensile strength. Results obtained concluded that the copolymers exhibit higher resistance to acid hydrolysis than the ungrafted and initiator‐treated cottons. This was explained in terms of involvement of the CONH2 groups of the graft in an interaction with HCl.
Studies of selective adsorption resin. XXIV. Preparation and properties of macroreticular chelating resins containing both polyethylenepolyamine side chains and mercapto groups
Authors: Egawa Hiroaki , Nonaka Takamasa 
Published: April 2003

AbstractThe macroreticular chelating resins containing both polyethylenepolyamine side chains and mercapto groups were prepared by the reaction of 2,3‐epithiopropyl methacrylate‐divinylbenzene macroreticular copolymer beads with polyethylene‐polyamine. The adsorption behavior of metal ions on the obtained resins was then investigated. The amination of the macroreticular copolymer beads could effectively be carried out by treatment of the polymer beads with polyethylenepolyamine in organic solvent (benzene, terahydrofuran) or in the absence of organic solvent at 80°C or 100°C for 60 min. It was found that the adsorption capacity of the resins for metal ions is not only affected by the ion exchange capacity of the resins but also by the porosity of the resins. Hg2+, Ag+, and Cu2+ were effectively adsorbed on the resins even at a pH below 3, whereas Co2+, Ni2+, and Cd2+ were adsorbed at a pH above 3, Mn2+ at a pH above 7, and Ca2+ at a pH above 8. These metal ions adsorbed on the resins could easily be eluted with dilute mineral acid solution or dilute mineral acid solution containing thiourea.
Diffusion and solubility of n‐alkanes in polyolefines
Authors: Koszinowski J. 
Published: April 2003

AbstractThe diffusion and partition coefficients (relative solubility constants) of n‐alkanes (from carbon nos. 12–32) have been determined by a permeation method (pouch method) for the polyolefines LDPE, HDPE, and PP–copolymer, and PP–homopolymer at room temperature. The activation energies for the diffusion are interpreted in the meaning of the rate transition theory. Correlations exist between the activation energy δE and the heat of vapourization δvHs as well as between the activation energy δE and the Arrhenius preexponential factors D0. These correlations are useful for the prediction of the diffusion coefficients of n‐alkanes with carbon numbers larger than 32.
Irradiation of cotton celluloses I and II in presence of organic solvents
Authors: Hakeem Nagwa Abdel , Abd‐El‐Nour K. N. , Moharram M. A. 
Published: April 2003

AbstractThe infrared spectra and dielectric properties of cotton celluloses I and II, γ‐irradiated in the presence of organic solvents have been investigated. The obtained data showed that irradiation of cotton celluloses I and II in organic solvents helps in oxidation of these celluloses and increases their dielectric constant. Examination of the infrared spectra and X‐ray diffraction (XRD) patterns revealed that irradiation of cotton celluloses I and II in organic solvents produces considerable changes in their crystallinity. It was found that the highest values of crystallinity and dielectric constant are obtained when the samples are irradiated in chloroform whereas the lowest values are obtained when the samples are irradiated in toluene.