bluuebunny/crossref_metadata_2025_split huggingface dataset:
The continuous measurement of the damping and fatigue properties of high‐impact polystyrene with a controlled‐amplitude torsion pendulum
Authors: Bartesch H. , Williams D. R. G. 
Published: April 2003

AbstractTorsional damping and fatigue studies were made on high‐impact polystyrene using a controlled‐amplitude, continuously recording torsion pendulum. The damping behavior was measured as a function of the angular displacement, axial tensile stress, and the number of repeated cycles. At a critical axial tensile stress, the damping behavior changed from amplitude‐independent to amplitude‐dependent behavior. Damping measurements on high‐impact polystyrene specimens that had been previously crazed in tension showed that both the damping and the tensile stress necessary to produce amplitude‐dependent damping varied with the orientation of the craze. Repeated cycling of HIPS specimens produced crazing and amplitude‐dependent damping at a tensile stress below that expected from simple static tensile loading. Scanning electron micrographs of fracture surfaces from these specimens revealed that the rubber particles could be clearly distinguished from the surrounding matrix.
Chemical modification of viscose rayon by dimethyl and methylvinyl diacetoxysilanes
Authors: Bajaj P. , Mandal T. K. 
Published: April 2003

AbstractCrosslinking of viscose rayon filament with dimethyl and methylvinyl diacetoxysilanes in benzene has been studied. The extent of crosslinking appears to depend on the nature of the reactant, material‐to‐reactant ratio, time, and temperature of the reaction. An increase in the breaking stress, initial modulus, and recovery properties was observed with increase in the crosslink density. Birefringence values as well as orientation index decrease in the treated samples. Thermal behavior of the crosslinked viscose was also studied by TGA and DTA, and it was found that IPDT (integral procedural decomposition temperature) and Dmax (maximum decomposition temperature) values of the crosslinked samples are higher than those of the untreated viscose.
Thermal decomposition behavior of sericin cocoon
Authors: Tsukada Masuhiro 
Published: April 2003

AbstractThe behavior on thermal degradation of the sericin cocoon consisting of a sericin and a few fibroin has been examined by means of evolved gas analysis (EGA), evolved gas detection (EGD), and differential thermal analysis (DTA). The sericin cocoons produced from the silkworm (Nd, Nd‐s/Nd‐s,Nd‐s/+) and sericin stripped from the silk gland in the silkworm show two endothermic peaks at 220°C and 270°C according to differential thermal analysis. From the x‐ray diffraction pattern, dynamic mechanical measurement, and the thermal gravity analysis (TG), the former peak occurs by the scission of the structural state and the change from crystalline to amorphous. Moreover, at 220°C, the weight changes markedly, the yellowness index (L/b) measured by the color difference meter abruptly decreases, and the gas (CO2), evolved from the sericin cocoon, shows increases above 200°C.
Evidence for the reduction of quinones added during thermal processing of polypropylene and the resultant effect on polymer light stability
Authors: Allen N. S. , McKellar J. F. , Protopapas S. A. 
Published: April 2003

AbstractThe thermal and photochemical oxidation of anthraquinone‐ and p‐benzoquinone‐doped polypropylene has been studied by absorption, luminescence, and infrared spectroscopy. Prior to irradiation, fluorescence and phosphorescence measurements showed that some of the anthraquinone and most of the p‐benzoquinone had been converted into their corresponding hydroquinones during processing. The p‐benzoquinone, unlike anthraquinone, also imparted a blue coloration to the polymer before irradiation, which is associated with the formation of a quinhydrone complex (or complexes). These results indicate that the quinones are thermally reduced to their corresponding hydroquinones during processing by a mechanism of hydrogen atom abstraction from the polymer substrate. On photo‐oxidation, whereas anthraquinone acted as a photosensitizer, p‐benzoquinone acted as a photostabilizer.
Foam inhibition in an aqueous sodium dodecylbenzene sulfonate solution by poly(dimethylaminoethyl methacrylate)
Authors: Matsumoto Tsunetaka , Baccay Romeo A. , Okubo Masayoshi , Nakamae Katsuhiko 
Published: April 2003

AbstractThe mechanism of foam inhibition in an aqueous sodium dodecylbenzene sulfonate (DBSNa) solution by temperature‐sensitive, water‐soluble poly(dimethylaminoethyl methacrylate) (PDM) was investigated. The solution's foam collapsing rate, % transmittance, surface tension, pH, temperature, and degree of hydrophobicity of PDM showed that aging a PDM–DBS solution 125 to 280 hr produced a turbid solution and effectively inhibited foaming. Likewise, controlling the pH at 4 ≤ pH ≤ 7 and increasing the hydrophobicity of PDM enhanced the foam‐inhibiting action of the polymer. The reaction between DBSNa and PDM was temperature dependent and the temperature effect was almost reversible. When compared with other available commercial antifoaming agents, PDM was found most effective in suppressing foam formation in aqueous DBSNa solution.
Fiber recovery
Authors: Brody H. 
Published: April 2003

AbstractThe recovery portions of the stress–strain cycles of poly(ethylene terephthalate), poly(tetramethylene terephthalate), nylon 66, poly(vinyl chloride), and rayon were analyzed and shown to be superposable if appropriate horizontal and vertical shifts are made. The recovery curves are postulated to represent the stress–strain behavior of an elastomeric portion of the fiber which controls recovery, and the scaling factors necessary for superposition are interpreted as indicating changes in the “length” and “modulus” of the elastomer. The elastomer modulus correlates very well with the slope of the stress–strain curve, showing that the elastomer governs the fiber stress during extension. Temporary set is assumed to be due to a temporary localized ordering of the elastomer modulus, which disappears when stress is completely removed. This local ordering lowers the elastomer modulus, which leads to yield points in the stress–strain curves. Permanent set is initiated just before the temporary set approaches a constant value and increases at almost the same rate as the rate of extension. It is completely recovered by heating to near the Tg.
Molecular motion in cured epoxy resin filled with mica flakes
Authors: Iisaka K. , Shibayama K. 
Published: April 2003

AbstractMolecular motion in cured epoxy resin filled with mica flakes was investigated by dynamic mechanical and broad‐line nuclear magnetic resonance measurements. Temperature dependences of dynamic modulus and tanδ were determined at 10 Hz for samples containing various amounts of filler. A primary dispersion temperature, T∞, corresponding to the glass transition, shifts to higher temperature with increasing filler volume fraction Vf. The magnitudes of the slope parameters Hr (representing storage modulus E′ data below Tg) decreased with increasing Vf, but Hg (representing E′ data below Tg) remained nearly constant over the whole loading range studied here. NMR line shapes were observed over the temperature range from room temperature to about 200°C for unfilled and filled samples. Each sample showed a distorted line shape in the transition region where major narrowing occurs. The distorted line shape was decomposed into both broad and narrow components by Gaussian analysis. The temperature range where both components can be obtained becomes broader with increasing filler content. The possibility is set forth that the filler immobilizes the chain segments and causes a different distribution of local mobility around the junction point.
Molecular weight–viscosity relationships for poly(1,4‐butylene terephthalate)
Authors: Borman W. F. H. 
Published: April 2003

AbstractThe correlation between number‐average molecular weight and intrinsic viscosity in 60:40 phenol‐sym‐tetrachloroethane at 30°C for poly(1,4‐butylene terephthalate) was established from endgroup determinations as well as by gel permeation chromatography, eqs. (1) and (10a). The GPC data also yielded relationships between weight‐ and z‐average molecular weight and intrinsic viscosity, eqs. (10b) and (10c). Melt viscosities, corrected for the thermal history of the melt, were measured at shear stresses in the range of 0.02–0.55 MPa. Linear PBT melts were found to become non‐Newtonian at a shear stress of approximately 0.11 MPa, independent of molecular weight within the range studied. Correlations between melt viscosity at low shear stress versus intrinsic viscosity are presented, as well as the dependence of melt viscosity in the non‐Newtonian region on shear stress and low‐stress (Newtonian) melt viscosity.
Copolymerizations initiated by mechano‐radicals on particle surfaces of poly(tetrafluoroethylene)
Authors: Sakaguchi Masato , Sohma Junkichi 
Published: April 2003

AbstractMechanical fracture of solid poly(tetrafluoroethylene) (PTFE) produces main‐chain scissions of the polymer, and free radicals, called mechano‐radicals, are trapped on fresh surfaces generated by the fracture. These radical conversions were verified by ESR observation when several monomers—methylmethacrylate, vinylacetate, and ethylene—were brought into contact with these mechano‐radical, and the copolymerizations of PTFE with these monomers were demonstrated. It was found that a new surface property, wettability of water, was added to the solid PTFE by the copolymerization with vinyl acetate, although the bulk nature of PTFE was not changed.
Water‐soluble photocurable elastomer
Authors: Jones G. D. , Hoornstra C. W. , Leonard D. E. , Smith H. B. 
Published: April 2003

AbstractA low molecular weight copolymer of vinylbenzyl chloride and butadiene was quaternized with N‐dimethylaminoethylmethacrylamide. The resin was coated from water solution to give a photorelief plate which could be developed with water. A photocured protective coating on steel showed good toughness.
γ‐radiation‐induced telomerization of vinyl acetate, styrene, and methyl methacrylate
Authors: Altmann O. , Fehrmann U. , Schnabel W. 
Published: April 2003

AbstractVinyl acetate (VAc), styrene (St), and methyl methacrylate (MMA) were irradiated in dilute solution at an absorbed dose rate of 0.5 Mrad/hr in the absence of oxygen at room temperature. In homogeneous systems, telomers are formed with a rate ∝ [M]1 at monomer concentrations [M] > ca. 0.4M. The chain length (D.P..n) increases with increasing [M]. (D.P..n)−1 depends over large ranges of [M] linearly on the ratio [S]/[M] (S = solvent) in accordance with the Mayo equation. These findings were obtained with VAc in methanol and with St in cyclohexane. In heterogeneous systems, telomer is formed at all monomer concentrations. The 100‐eV yield for telomer formation passes a maximum of GT(–M) = 40 (MMA in 2‐propanol) and GT(–M) = 27 (MMA in cyclohexane) at the onset of polymer formation ([M] ∼ 3 vol‐%). With the system St/2‐propanol, GT(–M) ∼ 15 was found being independent of [M]. The molecular weight Mn (telomer) increased from ca. 600 to ca. 1200 by increasing [M] up to 100 vol‐% (MMA/2‐propanol). Mn (telomer) does not depend on [M] in the other two cases (Mn ∼ 500, MMA/cyclohexane; Mn ∼ 700, St/2‐propanol).
Cationic latex interaction with pulp fibers. I. Deposition of styrene‐butadiene latex having quaternized amino groups
Authors: Alince B. , Inoue M. , Robertson A. A. 
Published: April 2003

AbstractFour experimental latexes of different styrene‐butadiene ratios stabilized with quaternized amino groups were employed in deposition studies on unbeaten kraft pulp fibers. The attraction between the oppositely charged latex and fibers facilitates a ready latex deposition in the pH region between the points of zero charge of the latex and of the fibers. The rate of deposition appears to be controlled by latex diffusion and convection up to the fiber surface. The distribution of latex particles deposited on the fiber surface is related to the butadiene content and the latex stability. Polystyrene latex is the most stable and covers the fibers uniformly as individual particles. With increased butadiene content, the coagulation region of the latex is more extended and the tendency to deposit as aggregates is promoted.
Preparation of soapless latexes by sonification of starch‐based poly(isoprene–co–acrylonitrile) graft reaction mixtures
Authors: Gugliemelli L. A. , Doane W. M. , Russell C. R. 
Published: April 2003

AbstractGraft copolymerization of isoprene (IP) and acrylonitrile (AN) onto gelatinized starch (S) and cationic starch having quaternary amine functionality through cerium(IV) initiation gave grafted side chains of poly(IP–co–AN). Grafts of various compositions are obtained by controlling the amounts and ratios of monomers added to starch. IP alone does not homograft onto gelatinized starch at 25° or 50°C by cerium(IV) initiation and requires the presence of an “initiator–monomer” such as AN to obtain copolymer side chains. Although cografting of IP and AN onto starch depends on AN to initiate radical chains, the ratio employed of the two monomers is critical for graft polymerization to occur. For example, at a molar ratio of IP to AN of 1 or greater, little polymer was produced; at molar ratios in the range of 0.4 to 0.67, considerable amounts of polymer were produced; and at a molar ratio of 0.13 or less, polymerization of AN was greatly retarded. Concentration of HNO3 in the cerium(IV) reagent and reaction temperature also influence the grafting reaction. Lower HNO3 concentrations favor grafting at 50°C, while higher acid concentrations favor grafting at 25°C. Starch graft reaction mixtures were sonified at 20 kHz to form latexes that air dry to clear pliable films. Poly(IP–co–AN) obtained by acid hydrolysis of the starch portion of the grafts failed to dissolve in either dimethylformamide or benzene, thus indicating presence of crosslinks. S–g–poly(IP–co–AN), having about one third starch and grafted side chains averaging about 2 parts polymerized IP per part of polymerized AN, was masticated on steel rolls at 100°C to a tough pliable film which was subsequently vulcanized to a rubber.
The effects of weathering and atmospheric pollutants on cotton fabric and cotton fabric treated with selected flame retardants. I. Physical, chemical, and flammability properties
Authors: Slaten B. L. , Spivak S. M. , Smith B. F. 
Published: April 2003

AbstractThe effects of weathering and atmospheric pollutants on the physical, chemical, and flammability properties of cotton fabric treated with Pyrovatex 3805 and with THPOH‐NH3 flame retardant finishes and untreated controls were determined. The fabrics were exposed to SO2, NO2, and ozone singly and in combination for 50, 100, and 150 hr in a 2500‐watt xenon arc Weather‐Ometer using gas controls with and without light at a temperature of 35°C and a relative humidity of 90%. Excessive strength losses and large changes in D.P. for the untreated control occurred under all exposure conditions after 150 hr. Changes in the physical and chemical properties of the treated fabrics were moderated by the finishes, with Pyrovatex 3805 providing better protection to the cellulose than THPOH‐NH3. Elemental analysis and oxygen index measurements indicate that the Pyrovatex 3805 finish was severely degraded under these exposure conditions, with a resultant loss in flammability properties of the treated fabric after weathering. The THPOH‐NH3 finish was not appreciably affected by these exposure conditions and the treated fabric retained most of its flammability properties after weathering.
Syntheses of functional condensation polymers. II. A polyamide having epoxy groups and its ring‐opening derivatives
Authors: Shimozato Yasuyuki , Sanui Kohei , Ogata Naoya 
Published: April 2003

AbstractPolyamides having epoxy groups and their ring‐opening derivatives were prepared and characterized, and some of their properties were investigated. Reaction conditions for the low‐temperature polycondensation of cis‐2,3‐epoxysuccinyl chloride (ESC) with aromatic diamines and the interfacial copolycondensation of ESC and adipyl chloride (AC) with aromatic diamines were established to obtain a high molecular weight polyamide having epoxy groups. In addition, the ring‐opening reactions of the epoxy groups in the polyamides were carried out with various amines in order to obtain polyamides having hydrophilic pendent groups such as amino and hydroxyl. It was found that the polyamides prepared by ring‐opening reaction of the epoxy group with ethylenediamine (EDA) or ethanolamine (EA) had a higher affinity for moisture than those with hexamethylenediamine (HMD) or n‐butylamine (n‐BA), which might be ascribed to the distance of hydrophilic groups from the polyamide chain. Those polyamides having hydrophilic pendent groups decomposed upon heating at less than 200°C.
Uniplanar orientation of poly(p‐phenylene terephthalamide) crystal in thin film and its effect on mechanical properties
Authors: Haraguchi Kazutoshi , Kajiyama Tisato , Takayanagi Motowo 
Published: April 2003

AbstractThe uniplanar orientation of poly(p‐phenylene terephthalamide) (PPTA) crystal was investigated by x‐ray and infrared measurements. Thin PPTA films 3–15 μm thick were prepared by coagulating a sulfuric acid solution of PPTA with various coagulants. Two types of uniplanar orientation were observed, depending on the coagulant used. Thin film coagulated with water exhibits (0k0) uniplanar orientation and film coagulated with other coagulants such as methanol, ethanol, and acetone exhibits (h00) uniplanar orientation. These (h00) and (0k0) uniplanar orientations are formed with crystal modifications I and II, respectively. The (0k0) uniplanar orientation transforms to (h00) upon annealing, accompanying crystal transformation from modification II to modifications I. These uniplanar orientations may result from anisotropic crystal growth due to polymer–coagulant interaction along the hydrogen bond direction. The effect of these uniplanar orientations on the mechanical properties was also examined. The thin film having the (0k0) uniplanar orientation shows ductile fracture, whereas the one having the (h00) uniplanar orientation shows brittle fracture upon tensile deformation. These results are explained on the basis of the direction of the uniplanar orientation of the hydrogen‐bonded sheet.
The effect of grafting on rubber‐phase oxidative etch resistance in high‐impact polystyrene
Authors: Hall R. A. , Jacoby P. 
Published: April 2003

AbstractA relatively simple, reproducible method for the determination of grafting in high‐impact polystyrene (HIPS) shows that high‐ and low‐graft HIPS exhibit differences in morphology following treatment with an oxidative etching solution. Because this method is quite sensitive to small differences, it yields a more definitive evaluation of grafting in the finished polymer than any other previously used analytical procedure. These differences have been quantified, and the data used to compare relative grafting in polystyrenes reinforced with the same or different rubber types. The method shows an increase in grafting when either the peroxide initiator feed level or 1,2‐vinyl content of the polybutadiene is increased.
Chemical modification of nylon 6 by organoacetoxy‐ and ethoxysilanes
Authors: Bajaj P. , Sharma A. K. 
Published: April 2003

AbstractChemical crosslinks were introduced in nylon 6 filament by means of organoacetoxy‐ and ethoxysilanes in benzene under anhydrous conditions. A comparison of the relative reactivities of these silanes toward nylon was made on the basis of the weight add‐on calculated from silicon analysis. Application of acetoxysilanes on preswollen nylon caused an increase in the breaking stress and extensibility. However, a decrease in the initial modulus, birefringence, and moisture regain was observed. An improvement in the thermal stability has also been observed in the crosslinked samples.
Degradation of poly(vinyl chloride) to small molecules
Authors: Schwenk Ulrich , Lömker Franz , König Inge , Streitberger Horst 
Published: April 2003

AbstractBy treatment with alkali in 2‐methoxyethanol, poly(vinyl chloride) is converted to an insoluble network structure. On subsequent oxidation with 65% HNO3, a water‐soluble mixture of acids is obtained. Per 1000 carbon atoms of the original polymer chain, approximately 4 moles succinic acid, 2 moles glutaric acid, and 1 mole adipic acid are found. In spite of the fact that the occurrence of succinic acid is in the same order as tail‐to‐tail polymerization in PVC, it must be assumed that unexpected aggregation of more than two CH2 groups is due to rearrangement during the alkali treatment or the oxidation procedure.
Flocculation of dispersions by preferential adsorption of solvents from polymer solution
Authors: Sato Tatsuo 
Published: April 2003

AbstractAn attempt was made to account for the adverse effect of the preferential adsorption of solvents onto particles from polymer solution (negative adsorption of polymer) on the stability of a dispersion in terms of osmotic attraction. The change in the energy of osmotic attraction on collision of solvated particles in a solution of macromolecules was calculated as a function of an osmotic pressure of the media, the thickness of the solvation layers, and the size of solute molecules, based on the assumption that the adsorption is irreversible and the adsorbed layers are impenetrable. The result showed that the energy of osmotic attraction is of the same order of magnitude as that of the electrostatic repulsion, indicating that the flocculation caused by the negative adsorption of polymers is mainly due to the osmotic attraction.
The determination of particle size distribution by hydrodynamic chromatography. An analysis of dispersion and methods for improved signal resolution
Authors: Silebi C. A. , McHugh A. J. 
Published: April 2003

AbstractVarious methods are described and compared for the determination of particle size distributions (PSD) in the submicron range by a technique known as hydrodynamic chromatography (HDC). Data are presented for a series of monodisperse latexes to establish the validity of the Mie theory of light scattering in describing the detector optical density signal. Analyses for the PSD involve corrections to the experimental HDC chromatograms for the effects of dispersion and are broadly classified as integral and numerical methods. Comparisons of calculations are made to chromatograms for polydisperse latexes as well as synthetic, discontinuous distributions and show the critical role of the optical density–particle size relationship in determining resolution and calculation stability. An integral method involving a non‐Gaussian form for the dispersion function and a polynomial expansion for the chromatogram and an iterative numerical method involving modifications of a previously published technique are shown to give the best results for the PSD. The discussion includes an analysis of the possibility of improved signal resolution using turbidity in the absorption wavelength region and refractive index measurements. The conclusion is reached that increased resolution with turbidity is preferable to refractive index measurement since lower particle concentrations can be used.
Diffusivity and solubility of organic vapors in modified polyethylene films. I. Technique and analysis of results
Authors: Aboul‐Nasr Osman T. , Huang Robert Y. M. 
Published: April 2003

AbstractA new method of analyzing unsteady‐state sorption data was developed to determine the diffusivity and solubility of vapors in polymer films. The equilibrium weight increase yields the solubility directly. Analysis of the unsteady‐state data gives the diffusion coefficient and its concentration dependence. A complete method for the analysis of either absorption or desorption results is presented for any type of concentration dependence of the diffusion coefficient. In this paper the method is applied to the Fujita free volume theory. The apparatus and the experimental procedures are discussed in detail.