bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photodegradation of polypropylene in the presence of ferric chloride
Authors: Negishi Akio , Ogiwara Yoshitaka , Osawa Zenjiro 
Published: April 2003

AbstractThe effect of ferric chloride (FeCl3) on photodegradation of isotactic polypropylene (PP) was investigated using mainly ESR spectrometry. PP powder, its oxidized samples, and FeCl3‐adsorbing PP samples were irradiated under a nitrogen atmosphere at 77°K with ultraviolet light from a high‐pressure mercury lamp and a superhigh‐pressure mercury lamp modified by various filters. Methyl, polymerci alkyl, and peroxy radicals were observed in the ESR spectra of the irradiated samples, and it was found that FeCl3 depresses the formation of alkyl radicals and accelerates the formation of peroxy radicals catalyzing the reaction. From infrared study of UV‐irradiated film samples, it was also inferred that FeCl3 accelerates the photodegradation the hydroperoxide and carbonyl groups.
Hercosett‐57 resin deposition on wool and modified wools
Authors: Asquith R. S. , Gardner K. L. , McGarel W. S. , Otterburn M. S. 
Published: April 2003

AbstractA study has been made of the uptake of a commercial polyaminoamide resin (Hercosett‐57) by wool fibers. The effect of various chemical pretreatments on the uptake of the resin was monitored in order to investigate the mechanism of bonding of the polymer with the wool. From the results obtained it would appear that the deposition of the resin is not controlled by simple chemical reaction with the fiber. Surface treatments to the wool fibers and adhesion play a more important part in the resin‐bonding process. Insoluble chlorinating agents such as DCCA and Chloramine T proved more effective in bringing about resin deposition than did the more widely used acid chlorination treatments, which use free chlorine in solution.
Radical formation and graft copolymerization on photo‐irradiated aldehyde cellulose
Authors: Ogiwara Yoshitaka , Hayase Koji , Kubota Hitoshi 
Published: April 2003

AbstractThe relationship between the activity to initiate graft copolymerization under photo‐irradiation and the photo‐induced radicals of periodic acid‐oxidized cellulose (aldehyde cellulose) was investigated. Aldehyde cellulose proved to have a high activity to initiate graft copolymerization under photo‐irradiation, and the effect was profound, especially for hydrophilic vinyl monomers such as acrylic acid and acrylamide. By studying the ESR spectrum of photo‐irradiated aldehyde cellulose, the formation of a radical giving a singlet spectrum with linewidth of 14–15 G and a g value of 2.001 was observed. This was assigned to an acyl radical orginating in the aldehyde group of the sample. Employing low molecular weight aldehydes, it was confirmed that an acyl radical formed on aldehyde compounds by photo‐irradiation has a function sufficient to initiate the graft copolymerization of vinyl monomers. It was concluded that the high activity needed to induce the graft copolymerization of aldehyde cellulose under photo‐irradiation was based on an acyl radical which originated in the aldehyde group of the sample.
Reverse osmosis separations of polyethylene glycols in dilute aqueous solutions using porous cellulose acetate membranes
Authors: Hsieh Fu‐Hung , Matsuura Takeshi , Sourirajan S. 
Published: April 2003

AbstractReverse osmosis separations of eight polyethylene glycol (PEG) solutes in the average molecular weight range of 200 to 6750 in single‐solute dilute aqueous solutions have been studied using porous cellulose acetate membranes at the operating pressures of 50, 75, and 100 psig. Diffusivity data for the above PEG solutes have also been obtained from experimental data on intrinsic viscosities. From an analysis of all experimental data, numerical values for the parameters representing the polar (−ΔΔG/RT), steric (δ*ΣEs), and nonpolar (ω*Σs*) forces governing reverse osmosis separations of PEG solutes have been generated. These numerical values are useful for precise characterization of cellulose acetate membranes for whose specifications sodium chloride is not the appropriate reference solute because of its low or practically negligible separation under reverse osmosis operating conditions. This work also illustrates that solute separation in reverse osmosis can predictably increase or decrease with increase in operating pressure depending on experimental conditions.
Low‐pressure reverse osmosis desalination with improved cellulose acetate membranes
Authors: Ghosh Ajit K. , Sirkar Kamalesh K. 
Published: April 2003

AbstractThe advantages of carrying out reverse osmosis desalination with improved membranes at low pressures have been pointed out. Cellulose acetate (CA) semipermeable membranes developed with low air‐exposure periods by Sirkar et al. from novel Manjikian‐type casting solutions having high CA content, partial replacement of acetone by dioxane, and small amounts of ZnCl2 (or none) have been tested for the following combinations of operating pressure (lb/in.2)/feed brine concentration (in ppm): 250/5000; 300/7500; 400/10,000; 600/30,000; 700/40,000; 750/50,000; 800/60,000. In the pressure range of 250‐600 lb/in.2 (psig), the pure water permeability (PWP) constants of membranes for a given salt transport parameter are greater than those of similar membranes tested earlier by Sirkar et al. at 600 psig with a 5000‐ppm brine feed. The PWP constants decrease faster with pressure as the casting solution CA concentration is reduced from 32% to 30% and the dioxane content of the solvent is raised from 40% to 60%. The intrinsic performances of membranes from a 32% CA casting solution with 40% dioxane improve as the pressure is increased from 250 to 600 psig. The solution structure‐rate of evaporation concept along with the phenomenon of fingerlike cavities and protrusions in membranes from high dioxane casting solutions explain most of the observations of this work. The superior low‐pressure performance of these CA membranes provide a basis for systematically lowering the operating pressure in reverse osmosis desalination.
1‐chlorobutadiene–butadiene rubber. IV. Increasing the hydroxyl group content in the rubber
Authors: Yamashita Shinzo , Sando Katsumi , Kohjiya Shinzo 
Published: April 2003

AbstractThe hydroxyl group content in 1‐chlorobutadiene–butadiene rubber (CB–BR) was increased by the following two methods: (1) heating of the CB–BR latex to hydrolyze the unstable chlorine in CB–BR and (2) introduction of hydroxyl by the Menschutkin‐type reaction between 2‐dimethylaminoethanol (DMAE) and the chlorine in CB–BR. By heating the latex at 70°C for 12 hr, 55% chlorine was hydrolyzed to result in a marked increase in hydroxyl group content in CB–BR, i.e., at least 55% chlorine is situated in the CB units of the 1,4‐configuration. Heat‐treated CB–BR was found to contain a small amount of conjugated triene structure by UV spectroscopy, which indicates that elimination of some unstable chlorine as hydrogen chloride occurs during latex heating. By reaction with DMAE, 44% chlorine was converted into hydroxyl in toluene at 27°C. CB–BR compounded with DMAE does not suffer from gelation by milling on an open roll. Thus, by these methods, high molecular weight butadiene rubber having various concentrations of hydroxyl groups is obtained.
High‐strength, high‐modulus fibers from hydrazide polymers and copolymers
Authors: Dobinson Frank , Pelezo C. A. , Black W. B. , Lea K. R. , Saunders J. H. 
Published: April 2003

AbstractA polyhydrazide was prepared from terephthaldihydrazide (TDH) and terephthaloyl chloride (TCl) and copolyhydrazides from oxalicdihydrazide (ODH) and from TCl with a 50:50 molar mixture of ODH and TDH. The 50:50 copolymer gave superior spinning performance and fiber properties and was studied extensively as a candidate for tire cords. The best yarn tensile properties were 21.6 gpd (grams/denier) tenacity, 6% elongation, and 443 gpd modulus. Temperature resistance and creep resistance were good, while the resistance to uv light was only fair. Stability in rubber and adhesion to rubber were good. In radial tires built with equal‐strength belts, mileage from tires having the copolymer cord in the belts was equal to that of steel‐belted tires.
Adhesives from divalent metal salts of mono(hydroxyethyl)phthalate, anhydrides, and bisepoxides
Authors: Matsuda Hideaki 
Published: April 2003

AbstractSystems of divalent metal salts of mono(ydroxyethyl)phthalate‐anhydride‐bisepoxide were evaluated as adhesives. The bisepoxides, bisphenol A diglycidyl ether (BADG) and hexahydrophthalic acid diglycidyl ester and the anhydrides, maleic anhydride and hexahydrophthalic anhydride (HPA) were used. The adhesive properties of the above metal‐containing systems were generally superior to those of the systems not containing metal, due to the polarity effect of metal carboxylate groups. The effect of introducing metal (ionic links) on tensile shear and peel strenghths clearly appeared, especially in the metal salt‐HPA‐BADG systems.
Diffusion of hydrocarbons in rubber, measured by the pulsed gradient NMR method
Authors: Von Meerwall E. , Ferguson R. D. 
Published: April 2003

AbstractThe pulsed field gradient spin echo method was used to measure the diffusion of ten paraffin hydrocarbons in several uncrosslinked rubbers at 51°C. We obtain various free volume parameters from the concentration dependences, establish the approximate proportionality of the translational friction coefficient to paraffin molecular weight, and confirm the equal intrinsic efficiency of the diffusion mechanism of decane and hexadecane in rubbers.
Graft copolymerization of styrene onto poly(p‐nitrophenyl acrylate) by chain transfer reaction
Authors: Nakamura Shigeo , Kasatani Hideo , Matsuzaki Kei 
Published: April 2003

AbstractStyrene (St) was polymerized in the presence of poly(p‐nitrophenyl acrylate) (PNPA) with azobisisobutyronitrile as an initiator to prepare graft copolymers through the chain transfer reaction of growing polystyrene (PSt) radicals to the aromatic nitro groups on PNPA. The maximum number of branches attained was 16.4 (Pn of PNPA was 1780), which corresponds to 108 monomer units per PSt branch. This is far less than the value of 43, previously obtained for poly(vinyl p‐nitrobenzoate) as a trunk polymer. Therefore, several model compounds for trunk polymers were prepared, and the chain transfer constants of PSt radicals to these model compounds were determined. As a result of the Hammett plot, it is concluded that higher electron attracting property of the substituents increases the reactivity of nitro groups to the growing PSt radicals, resulting in more highly branched graft copolymers.
Water and solute transport across cellulose acetate membranes in the treatment of soybean whey by reverse osmosis
Authors: Baker E. C. , Mustakas G. C. , Moosemiller M. D. , Bagley E. B. 
Published: April 2003

AbstractIn processing full‐fat soy flour to produce an acid‐precipitated lipid protein concentrate, there results a by‐product whey fraction which, because of its high biological oxygen demand, represents a serious disposal problem. Processing of food waste streams by reverse osmosis has received considerable attention because of its low theoretical energy requirement, since no phase change is involved. A series of statistically designed and analyzed experiments were conducted on a pilot‐plant reverse osmosis unit to study the effect of the operating parameters on solute and solvent transport in cellulose acetate membranes. Sucrose and sodium chloride solutions were tested in addition to soybean whey to relate the mixed solute system in whey to that of single‐solute organic and inorganic feed solutions. Water flux was shown to have an Arrhenius dependency on temperature, and some membrane compaction was observed with the more porous membrane. Concentration polarization for sucrose and sodium chloride solutions increased linearly with water flux. Solute flux for soybean whey solutions decreased with molarity and was independent of pressure, whereas solute rejection increased with temperature and pressure and was independent of molarity. Good agreement was obtained using the derived parameters A, B, and τ for soy whey in the diffusion transport model when compared to the observed experimental values.
Silicone‐toughened poly(styrene‐co‐acrylonitrile)
Authors: Saam John C. , Mettler Claudia M. , Falender James R. , Dill Timothy J. 
Published: April 2003

AbstractUniform dispersions of high‐molecular‐weight poly(dimethylsiloxane) (PDMS) in a matrix of poly(styrene‐co‐acrylonitrile) (SAN) are prepared where the degree of crosslinking in the elastomer and its extent of grafting to the SAN matrix are controlled. This gives an impact resistant plastic at ambient and low temperatures which is resistant to outdoor exposure. The Tg of PDMS is shown to be greatly reduced when grafted to the SAN matrix. Plots of impact resistance versus shift factor aT of the elastomer added for toughening coincide for PDMS and polybutadiene over a 150°C temperature range.
Photocrosslinkable unsaturated polyesters
Authors: Sadafule D. S. , Panda S. P. 
Published: April 2003

AbstractNine photocrosslinkable unsaturated polyesters containing pendent chalconyl and cinnamylidenemalonyl moieties have been synthesized by a route involving no water elimination. The resins are insolubilized by visible and UV irradiation. They can also be cured with styrene, MEK peroxide, and cobalt naphthenate. A study of the photoreactions reveals that the resins containing 4′‐chalconyl groups crosslink and isomerize simultaneously, whereas those containing 4‐chalconyl groups undergo crosslinking only, due to the steric suppression of isomerization. Photoinsolubility is also achieved by introducing the cinnamylidenemalonyl group into the resin structure. It is found that the resins containing both the chalconyl and cinnamylidenemalonyl groups in the repeat units do not exhibit any pronounced photofastness.
Classification of properties of elastomers using the “optimum property concept.” I. Introduction
Authors: Lautenschlaeger F. K. , Myhre M. 
Published: April 2003

AbstractAn attempt is made to distinguish properties of elastomers by types. “Basic properties of materials” or “network properties” in elastomers are properties which either increase or decrease from the liquid to the solid state of materials or over the range of the “elastomeric plateau” of elastomers. From these are distinguished properties that exhibit characteristic maxima and are therefore “maximum properties” or bivalued properties. Mechanical failure properties show the characteristics of “maximum properties.” The maxima in “maximum properties” generally do not coincide. This noncoincidence of the maxima with a change in a “basic property of a material” has major theoretical and practical implications, for example, it is the cause of the crossovers in the relative performance rating of materials under different test conditions. The implications of this noncoincidence of the failure property maxima on the relevance of correlations between these properties are discussed. A change in the testing conditions is reflected in a shift of the optimum value in a “basic property of a material” with respect to a specific “maximum property.” Data and certain conclusions in the literature are interpreted on the basis of this concept. Examples of the limitations of the validity of mathematical relationships are presented. Also, a definition of the term “state of cure” is proposed and a suggestion for the rating of severities of test equipment and applications of elastomeric materials recommended. The effect of increased degrees of crosslinking for a series of polymers and crosslinking agents is assessed. It is suggested that the “mechanisms” of failure properties will remain elusive if their rationalization is attempted on the basis of other failure properties, e.g., the mechanism of abrasion on that of tear strength or cut growth. The main purpose of this proposal is to provide support for a drastic reduction in laboratory testing by identifying those properties which can lead to different relative ratings in routine evaluations and actual applications. A more empirical approach to materials evaluations is recommended based on the calibration of laboratory instrumentation with respect to specific applications. A de‐emphasis of routine evaluations of materials on the basis of their “maximum properties” seems to be justified.
Measurement of the absolute molecular weight and molecular weight distribution of polyolefins using low‐angle laser light scattering
Authors: MacRury T. B. , McConnell M. L. 
Published: April 2003

AbstractBy connecting a low‐angle laser light scattering photometer (LALLSP) on line with a high‐temperature gel permeation chromatograph (GPC), molecular weight distributions were determined for three polyethylene standards (two high density and one low density) without resorting to column calibration procedures. In addition, the absolute weight‐average molecular weight and second virial coefficients of four polyethylene standards (three high density and one low density) were obtained using low‐angle laser light scattering. The molecular weights measured were in excellent agreement with those specified by the National Bureau of Standards. For the low density material, a microgel fraction was detected by the on‐line LALLSP but not by the conventional GPC detector. This resulted in a z‐average molecular weight of over 3 × 106 daltons, an order of magnitude greater than that determined by conventional GPC techniques.
Preferential wetting phenomenon in bicomponent polymer melt flow
Authors: Southern John H. , Ballman Richard L. 
Published: April 2003

AbstractFor two polymer melts spun in a side‐by‐side configuration through a capillary, interface shape and spinneret exit angle data are presented as a function of viscosity ratio, spinneret dimensions, and relative polymer‐steel wettability. Nylon‐nylon versus nylon‐polyurethane bicomponent flow systems are compared. A surface tension phenomenon is postulated to be significant in controlling the bicomponent fiber interface shape for capillary length‐to‐diameter ratios of the order of unity.
Kinetics of the emulsion polymerization of vinyl acetate
Authors: Zollars R. L. 
Published: April 2003

AbstractRecent investigations of the emulsion polymerization of vinyl acetate report a variable behavior. The reaction has been reported to exhibit a half‐order rate dependence and no particle number dependence on the initiator level, or a first‐order dependence for both the reaction rate and particle number on the initiator concentration, or some behavior between these two extremes. While two recent models have attempted to account for the changes in the reaction rate dependence by postulating either an aqueous phase or a polymer phase termination, no adequate explanation of the particle number behavior has been given, nor has a single model been suggested that agrees with all of the experimental data. This investigation confirms the results of previous investigators and develops an empirical model for the particle number, taking into account the effects of the initiator level, emulsifier level and alkyl chain length, temperature, and ionic strength on the particle number. This particle number model, used with a polymer phase termination reaction model, yields a polymerization rate expression which agrees with all previous data.
DRY‐RO membranes from cellulose acetate carbamates
Authors: Kesting R. E. , Ditter J. F. , Jackson K. F. , Murray A. S. , Newman J. M. 
Published: April 2003

AbstractCellulose acetate carbamates (CACs) are the polymers which result when organic isocyanates are reacted with the free hydroxyl groups of cellulose acetate (CA). CACs are more hydrolytically stable and exhibit physical properties which are superior to those of their CA mixed ester analogs. Two synthetic approaches to CACs have been utilized in this study: (1) preformation, i.e., separate synthesis of such polymers prior to their inclusion in solutions for membrane casting; and (2) in situ formation, i.e., the inclusion of blocked isocyanates in standard dry process casting solutions of CA followed by thermal activation of the resultant dry membranes leading to regeneration of free isocyanate and subsequent CAC formation. Preformed CAC polymers have been prepared utilizing phenyl‐, 3‐chloropropyl‐, 3‐bromopropyl‐, and 3‐bromopropyl‐(isothio)‐, isocyanates. Polymers containing omega‐halocarbamate moieties were quaternized with dimethylbenzylamine to produce ionogenic (QCAC) polymers containing quaternary ammonium groups. DRY‐RO membranes from the QCACs exhibit flux/rejection values varying between 6–8 gfd at 98% rejection and 20 gfd at 90% rejection (0.5% NaCl feed at 400 psi and 25°C). In situ formation of CAC membranes has been effected with tolylene‐ and hexamethylene‐diisocyantes, with quaternized isocyanate monomers employed for the preformed CAC polymers, and with specially tailored diisocyanates containing ionogenic groups. Crosslinking rendered all of the membranes acetone insoluble. Inasmuch as in situ formation substitutes the easy synthesis of blocked isocyanate monomers for the more difficult separate synthesis of preformed CAC polymers, it is anticipated that the former will replace the latter.
Analysis of amino resins by carbon/nitrogen analyzer. I. Mole ratios of components
Authors: Rybicky J. , Kambanis S. M. 
Published: April 2003

AbstractTechniques for the determination of the formaldehyde to urea and the formaldehyde to melamine ratios by means of an elemental carbon‐nitrogen analyzer are described. Etherified resins require additionally an NMR spectrum of the analyzed sample. Mathematical equations are presented which relate the experimentally determined carbon and nitrogen contents to the compositional characteristics of amino resins. For etherified resins, the ratio of alkoxy groups to the total formaldehyde is also determined. The techniques are assessed by analyzing model samples and by the propagation‐of‐error treatment of the equations. It is shown that the F/U and F/M ratios can be determined with a good accuracy whether or not the resin is etherified.
Grafting onto wool. VI. Effect of amines in ceric ion‐initiated grafting of poly(vinyl acetate)
Authors: Misra B. N. , Kaur Inderjeet , Dogra Ramesh 
Published: April 2003

AbstractPoly(vinyl acetate) has been graft copolymerized onto Himachali wool in the presence of ceric ammonium nitrate alone and in presence of amines in aqueous medium under a wide variety of reaction conditions. Nitric acid was found to catalyze the graft copolymerization. Maximum grafting under optimum conditions has been determined. Several grafting experiments were carried out in presence of triethylamine and triethanolamine. Both amines were found to reduce the extent of grafting. The decrease in the percent grafting in presence of amines has been explained in terms of a chain‐transfer mechanism.