bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sorption and diffusion of water vapor by nylon 6
Authors: Kawasaki Koji , Sekita Yoshiyasu 
Published: April 2003

AbstractThe interaction between nylon 6 and water has been studied from water vapor sorption isotherms, diffusion of water vapor in the polymer, and nuclear magnetic resonance (NMR) properties. The variations in water sorption properties of various heat treated specimens seem to result from the difference in the degree of loose packing in the amorphous regions. From the effect of water vapor on NMR narrow line intensity, it has been found that there are two characteristic sorption types of water vapor in nylon 6, that is, water molecule is comparatively immobile at the lower water content, and considerably mobile at water contents above 4 wt.‐%. Furthermore, it may be supposed that there is in addition another sorption state of water vapor below 2 wt.‐% that corresponds to the monolayer capacity of water vapor in the polymer.
Synthetic polysaccharides. I. Methyl mono‐ and methyl di‐O‐allyl‐α‐D‐glucosides and their polymerization
Authors: Schweiger Richard G. 
Published: April 2003

AbstractMethyl mono‐ and methyl di‐O‐allyl‐α‐D‐glucosides are prepared by the reaction of methyl α‐D‐glucoside with allyl chloride in alkali in a two‐phase system. The monoallyl ether consists mainly of a mixture of methyl 2‐, 4‐, and 6‐O‐allyl‐α‐D‐glucosides, the diallyl compound of 2,6‐ and 4,6‐di‐O‐allyl‐α‐D‐glucosides in approximately a 1 : 1 ratio. Both compounds are homopolymerized with oxygen as the catalyst. The poly(monoallyl glucoside) is a water‐soluble, brittle, clear resin with a softening point of 100–110°C. The poly(diallyl glucoside) is a brittle, clear, but completely insoluble resin with no softening point. Copolymerization with acrylamide under certain conditions yields water‐soluble polymers, aqueous solutions of which exhibit high viscosities and have the typical appearance and consistencies of those of polysaccharides.
Polymerization behavior of aziridines with 1,2‐epoxides
Authors: Overberger C. G. , Tobkes Martin 
Published: April 2003

AbstractA number of Lewis acid catalysts have been investigated for the copolymerization of 1,2‐butylenimine with 1,2‐epoxides. The most active catalyst, boron trifluoride etherate, has been shown to give polymers containing a polyimine backbone in which the residual NH groups in the polymer chain are β‐hydroxyalkylated by the epoxide. It has been demonstrated that the imine is far more reactive than the epoxide under these conditions, regardless of the chain length of the epoxide monomer. The polyimine chain appears to grow to an appreciable extent before any epoxide enters the polymer. These results are interpreted as being due to the preferential complexing of the catalyst by the basic imine residues in the polymer, which renders the catalyst unavailable for polymerization of the epoxide. The homo‐ and copolymerization behavior of 1‐(p‐toluenesulfonyl)‐aziridine, N,N‐diphenyl‐1‐aziridinecarboxamide and N,N‐diethyl‐1‐aziridinecarboxamide with 1,2‐epoxides has been investigated under conditions of catalysis by boron trifluoride etherate and by triethylamine. In no instance could copolymers be obtained.
A series of poly(methylene acetals) derived from aliphatic aldehydes
Authors: Schonfeld Edward 
Published: April 2003

AbstractA series of poly(methylene acetals) were prepared from 1,5‐pentanediol by systematically varying the aldehyde. The viscosity of each polymer was measured, and, for the first four members of the series, shown to vary inversely with the length of the pendant chain of the aldehyde. A comparison of the viscosity of a polyether (a polyoxypropylene glycol) in which the ratio of carbon to oxygen in the chain is 2/1 with that of a poly(methylene acetal) in which the carbon to oxygen ratio is 3/1 indicated a significant decrease in viscosity with increasing concentration of ethereal oxygen.
A poly(ethylene oxide)–mercuric chloride complex
Authors: Blumberg Avrom A. , Pollack Sidney S. , Hoeve C. A. J. 
Published: April 2003

AbstractOriented poly(ethylene oxide) fibers form a complex with mercuric chloride, with the empirical formula (CH2CH2O)4·HgCl2. Tentatively the unit cell of the complex is orthorhombic with dimensions 13.5, 17.1, and 11.6 A. (c, the fiber axis). In spite of a major change in the unit cell, fiber orientation is maintained. The infrared spectrum of the complex is more detailed than that of the polymer alone, a fact consistent with a change from trans to gauche state of one OC bond.
Kinetics of the γ‐radiation‐induced polymerization of ethylene in alkyl chlorides
Authors: Wiley Richard H. , Lipscomb N. T. , Parrish C. F. , Guillet J. E. 
Published: April 2003

AbstractA study has been made of the kinetics and mechanism of the liquid‐phase, γ‐radiation‐induced, alkyl chloride solution polymerization of ethylene. The γ‐radiation was provided by a 4.07 × 105 r/hr. Co60 source. The kinetics of these polymerizations were studied up to 10% conversion and over the temperature range 0 to −25°C. Three solvents (n‐propyl chloride, iso‐propyl chloride, and tert‐butyl chloride) were used with concentrations of ethylene ranging from 6.76 to 8.89 moles/l. Two different grades of ethylene were used: the first contained an upper limit of 1000 ppm of oxygen, the second 60 ppm. The ethylene containing only 60 ppm of oxygen was found to give a smaller induction period, and faster rate of polymerization than the ethylene containing 1000 ppm. Activation energies of 5.0 kcal./mole for the reaction in n‐propyl chloride and 7.4 kcal./mole for the reaction in tert‐butyl chloride were observed for the temperature range studied. These values were higher than the 4.4 kcal./mole obtained for the bulk polymerization of ethylene in this temperature range. The order of the reaction with respect to ethylene concentration in n‐propyl chloride at 0°C. was found to be 1.41. Although the heterogeneity of the system is a complicating factor, this rate expression agrees well with the general scheme proposed for other heterogeneous polymerizations. Molecular weight information which shows an increase in molecular weight with increasing temperature leads to the conclusion that a termination step involving weakly reactive solvent radicals may be important.
α,ω‐Glycols and dicarboxylic acids from butadiene, isoprene, and styrene and some derived block polymers, esters, and urethans
Authors: Hayashi Katsumi , Marvel C. S. 
Published: April 2003

AbstractThe living polymer technique of Szwarc has been employed to synthesize α,ω‐bifunctional derivatives of polybutadiene, polyisoprene, and polystyrene. The glycols derived from polybutadiene have been hydrogenated to give saturated glycols. The glycols from polyisoprene have been partially hydrogenated. Some block polymer esters and urethans have been characterized.
Ring‐opening polymerization of a sugar episulfide
Authors: Whistler Roy L. , Seib Paul A. 
Published: April 2003

AbstractRing‐opening polymerization of 5,6‐dideoxy‐5,6‐epithio‐1,2‐O‐isopropylidene‐α‐L‐idofuranose is catalyzed by boron trifluoride at 60°C. Soluble polymer is produced at monomer: catalyst ratio of 7 : 1 and monomer concentration 0.077M after 1 1‐hr. polymerization period. This polymer has a wide molecular weight distribution. A number‐average molecular weight of 72,000 is found for the first 40% of the polymer precipitated from a N,N‐dimethylformamide solution by the addition of water. Polymer is produced in increasing amounts as temperature is raised, catalyst concentration increased, and as water concentration is decreased. Transglycosylation may be the cause of branch formation or crosslinking. Hydrolysis of the soluble polymer removes isopropylidene groups to produce a water soluble reducing polymer which oxidizes with hypoiodite to a polymer containing carboxyl groups.
Polyphenylenebenzimidazoles
Authors: Iwakura Yoshio , Uno Keikichi , Imai Yoshio 
Published: April 2003

AbstractThe solution polycondensation of 3,3′ ‐diaminobenzidine tetrahydrochloride with aromatic dicarboxylic acid derivatives in polyphosphoric acid was found to give high molecular weight polyphenylenebenzimidazoles easily. Their preparation and physical properties, such as thermal stability, solubility, crystallinity, are described.
Polymerization in solid solutions of acrylamide in propionamide
Authors: Adler G. , Reams W. 
Published: April 2003

AbstractIt has previously been shown that the polymer formed in solid‐state polymerization of acrylamide is amorphous in spite of the fact that the reaction takes place within a crystalline solid. The stage at which it becomes amorphous is not known at present. Work with dilute solid solutions of acrylamide in propionamide suggests that this occurs after the addition of, at most, a very few monomer units.
Nuclear magnetic absorption in polystyrene‐styrene systems
Authors: Borsa F. , Lanzi G. 
Published: April 2003

AbstractMeasurements of line width at different temperatures for samples of styrene partially polymerized are reported. The results obtained point out the importance of segmental motion of polymer chains at low temperatures in relation to the motion of the monomer molecules still present. There is some experimental evidence that under certain conditions the monomer molecules can facilitate the motions of polymer molecules, which seem to pull along in their motion a lot of the monomer molecules.
Radiation‐induced copolymerization of acrylonitrile with methyl methacrylate
Authors: Tabata Yoneho , Hasizume Yoshio , Sobue Hiroshi 
Published: April 2003

AbstractRadiation‐induced copolymerization of acrylonitrile (1) with methyl methacrylate (2) was investigated over a wide range of temperatures. The rate of copolymerization decreased linearly with the molar concentration of acrylonitrile in the liquid‐state copolymerization at 15°C. On the contrary, the rate of copolymerization increased linearly with the concentration of acrylonitrile in the solid state at −78°C. The rate of copolymerization was proportional to the square root of the dose rate in an equimolar mixture of the monomers at 15°C. The apparent activation energy of the copolymerization was 4.62 kcal./mole in an equimolar mixture of the monomers. Monomer reactivity ratios r1 and r2 were determined from the experiments at various temperatures. From these results, the differences of the activation energies in the propagation steps were obtained as follows: E‡11 − E‡12 = 2.76 kcal./mole; E‡22 − E‡21 = 2.58 kcal./mole.
Poly(xylylenylpiperazine), a novel polyamine
Authors: Klebe J. F. 
Published: April 2003

AbstractThe condensation polymerization of α,α‐dichloroxylene and similar reactive halides with difunctional silylamines leads to novel high molecular weight polyamines of the type
magnified image
The halogen is eliminated in the form of halosilane which is inert in this reaction system and acts as a solvent for the polymer. The polymers can be cast from solution or pressed to strong films. They exhibit typical amine properties; they are soluble in inorganic and organic acids and form polyelectrolyte solutions, from which stable polyelectrolyte films can be cast. Reactions with alkyliodides lead to polyquaternary compounds. Ammonium salts and a cyclic sulfone were found to enhance catalytically the rate of reaction of benzylchloride with silylamines.
Preparation of polyamides, polyurethanes, polysulfonamides, and polyesters by low temperature solution polycondensation
Authors: Kwolek Stephanie L. , Morgan Paul W. 
Published: April 2003

AbstractSolution polycondensation was used to prepare four classes of polymers. Polymers in each class were obtained with molecular weights high enough for formation into flexible, tough structures. In all instances the molecular weights were not as high as could be obtained from the same reactants by the interfacial polycondensation process. Many of the polyamides from aliphatic diamines were highly branched through diacylation of the amino groups. On the other hand, polysulfonamides were linear. Despite some limitations, as indicated above, the solution polycondensation process provides another route to forming condensation polymers and should be of special advantage in use with hydrolytically unstable intermediates, with water‐insoluble diamines and diols, and for forming uniform or block copolymers.
Amylose V complexes. II. Lower molecular weight ketones
Authors: Germino Felix J. , Moshy R. J. , Valletta Robert M. 
Published: April 2003

AbstractThe acetone‐ and methyl ethyl ketone‐amylose V complexes have been prepared and their unit cell dimensions calculated from their x‐ray powder patterns. This work demonstrates the size‐determining effect of these two ketones on the amylose V complex. The small unit cell, with a helix diameter of 13.0 A., observed with the wet methanol and ethanol complexes, is not found with the acetone and methyl ethyl ketone complexes. The wet ketone‐amylose V complexes and the thoroughly dried ketone complexes have the larger helix diameter of 13.7 A. This is the first report of an anhydrous amylose V complex with the expanded helix diameter. Thorough extraction of the methyl ethyl ketone‐amylose complex with methyl alcohol did not change the 13.7 A. helix diameter, although methyl alcohol‐extracted acetone‐amylose complex resulted in a mixture of the 13.0 A. and 13.7 A. helix diameter types. This work demonstrates the size effect of the lower molecular weight ketones on the amylose crystalline structure.
Redox polymerization of unsaturated polyester resins. I. Effect of metal species on polymerization rates in the presence of a variety of peroxides and hydroperoxides
Authors: Svoboda Glenn R. 
Published: April 2003

AbstractA study of a series of metal compounds as promoters of acyl peroxide and hydroperoxide dissociation in an unsaturated polyester‐styrene resin solution has shown vanadie and vanadyl chelates to be the most active. All of the results were compared to a standard cobalt‐methyl ethyl ketone peroxide promoter‐catalyst system. It was found that the reactivity of 2 mg. of vanadium or vanadyl ion as vanadic or vanadyl acetyl acetonate with respect to 1% cumene hydroperoxide was greater than 24 mg. of cobalt as cobalt naphthenate with respect to 1% methyl ethyl ketone peroxide. This is significant, in that considerably less metallic promoter can be used at ambient temperatures for the fabrication of finished articles with considerably less associated color. Of the vanadium compounds studied, vanadic and vanadyl chelates were about equally reactive. Vanadyl acetyl acetonate was considered the promoter of choice, since vanadic acetyl acetonate solutions appeared to be air‐oxidized readily. Study has shown that benzene solutions of vanadic acetyl acetonate lost some activity after a week, whereas chloroform solutions of vanadyl acetyl acetonate remained stable for a period of six to nine months. The utility of vanadium promoters for ambient temperature redox polymerization would be enhanced if they could be incorporated into unsaturated polyester resins at the time of preparation. However, results obtained indicated that both vanadic and vanadyl chelates limit the stability of such prepromoted resins, normally leading to gelation in about 17 days. A further indication of the utility of vanadium chelates as redox promoters was the observation that these materials are reactive towards diacyl peroxides as well as hydroperoxides. Vanadium chelates were the only materials studied which showed this wide spectrum of reactivity.
Synthesis of new monomers and polymers. IV. Synthesis and properties of polydiphenyldiacetylenes
Authors: Teyssié Ph. , Korn‐Girard A. C. 
Published: April 2003

AbstractPolymerization of diphenyldiacetylene was effected in the presence of Ziegler type catalysts. The polymers, studied as obtained from the polymerization or after further reaction, are soluble products of relatively low molecular weight with interesting properties: very high thermal resistance, continuous absorption in ultraviolet and near visible regions, broad visible fluorescence spectra, semiconducting and catalytic properties.
Vinyl polymerization. LXXIX. Effect of the alkyl group on the radical polymerization of alkyl methacrylates
Authors: Otsu Takayuki , Ito Toshio , Imoto Minoru 
Published: April 2003

AbstractThe effect of the alkyl group on the rates of polymerization of alkyl methacrylates initiated by α,α′‐azobisisobutyronitrile in benzene at 60°C. has been investigated. The rate of polymerization increased with increasing length of the alkyl group. This has already been attributed to the increased steric effect of the alkyl group in the termination process. In the present study, it was proved that the viscosities of alkyl methacrylate monomers increased with increasing length of the alkyl group, and that overall polymerization rate constants were inversely proportional to the viscosities. Accordingly, the above result might be explained by an increase in the contribution of the diffusioncontrolled termination with increasing length of the alkyl group in alkyl methacrylate.
Comparison of the effects of allylamine and n‐propylamine on cellulose
Authors: Segal Leon 
Published: April 2003

AbstractAllylamine partially penetrates the cellulose crystal lattice and effects only partial transformation to the cellulose‐amine complex. The 101 interplanar spacing of the allylamine complex is similar to that of the propylamine complex. Differences in amme interaction with cellulose are not explained by considerations of base strength of amines, stereochemistry, or degree of association of the amines. Cellulose treated with ethylamine, then allylamine is completely transformed to what seems to be the cellulose‐allylamine complex. Slow evaporation of allylamine from the cellulose I complex seems to produce cellulose III; from the cellulose II complex, cellulose II. Fast evaporation of ethyl‐, propyl‐, or allylamine from amine‐wet cellulose restores the initial cellulose lattice. Slow evaporation of ethylamine produces cellulose III; of propylamine a mixed lattice of cellulose I with little cellulose III and much of the complex.
Polymerization of butadiene in the presence of triethylaluminum and n‐butyl titanate
Authors: Dawes D. H. , Winkler C. A. 
Published: April 2003

AbstractMeasurement of butadiene absorption at constant volume, and of polymer formation, indicated that the rate of polymerization was first order in monomer concentration, up to 1.5 mole/l., and also in initial total catalyst concentration, for given molar ratio of alkyl to titanium ester. The overall activation energy was 11.5 kcal./mole. A fast initiation, accompanied by the evolution of ethylene or a mixture of ethane and ethylene, a relatively slow propagation, and chain transfer to monomer, appeared to be the main steps of the reaction. Termination was essentially absent. Insoluble, gellike material was formed roughly at 20% conversion and was attributed to a random crosslinking, involveing very few crosslinks per molecule, or possibly trifunctional branching. The molecular weight distribution was very narrow. A polymer of over 80% in 1,2 units, having a predominantly syndiotactic structure and about 10% crystallinity, was obtained. In the absence of monomer, the catalyst components reacted rapidly to form complexes, accompanied by strong ethane evolution. A complex series of reactions leading to the possible formation of more than one active species was indicated. The active catalyst suffered bimolecular decomposition on prolonged standing. For optimal molar ratio of alkyl to ester of 5/1, the concentration of active species was estimated as having an upper limit of 4.8 × 10−6 mole/l.
Temperature coefficient of unperturbed polymer dimensions from thermoelastic properties
Authors: Ciferri A. 
Published: April 2003

AbstractResults enabling the determination of the temperature variation of the unperturbed mean‐square end‐to‐end distance r02 for linear polymer chains from stress–temperature measurements are surveyed. Out of 31 polymer systems which have been studied, only two show a clear decrease of r02 with temperature. An increase or an independence of r02 upon temperature is the most common trend. These results appear at variance with expectations and with theoretical considerations. Experimental difficulties and possible limitations of said theories are discussed.
Polymerization of styrene in N,N‐dimethylformamide and N,N‐dimethylacetamide
Authors: George M. H. 
Published: April 2003

AbstractThe polymerization of styrene in N,N‐dimethylformamide and N,N‐dimethylacetamide at 60°C. initiated by 2,2′‐azobisisobutyronitrile has been studied. Rates of polymerization were measured dilatometrically and gravimetrically, and degrees of polymerization were determined viscometrically. The transfer constants to N,N‐dimethylformamide and N,N‐dimethylacetamide are 4.0 × 10−4 and 4.6 × 10−4, respectively. None of the existing reaction mechanisms of vinyl polymerization can account for all the experimental results, and various alternatives are examined.
Clay‐catalyzed reactions of olefins. III. Kinetics of polymerization of styrene
Authors: Bittles James A. , Chaudhuri A. K. , Benson Sidney W. 
Published: April 2003

AbstractThe polymerization of styrene in the presence of acid clay catalysts has been reported previously. The kinetics were studied in solution at 0°C. by a dilatometric method relating monomer concentration to volume and heat of reaction. An approximately linear rate law was derived which fit the data over a 100‐fold range of concentration. The integrated rate equation is:

The equilibrium constant KM for monomer absorption was found to be 863 ± 70 cc./mole and the propagation constant kp was found to be 191 ± 14 cc./mole/sec. An Arrhenius plot is in accord with the equation k′p = Ae−7.7/RT with an activation energy 7.7 ± 1.5 kcal. and an Arrhenius factor of 3.39 × 108 cc./mole/sec. The effect of added inhibitor I was interpreted qualitatively on the basis of an exact rate equation which in differential form is:

The factor KI[I]/[I0] was estimated from the equation:

and found to be negligible at 0.1M monomer concentration and consistent with experiment. An explanation for low values of kp in the presence of added inhibitor was proposed based upon the exact rate law.
1,3‐Cyclohexadiene polymers. Part II. Copolymerization of 1,3‐cyclohexadiene and isoprene
Authors: Dawans F. 
Published: April 2003

AbstractReactivity ratios of isoprene and 1,3‐cyclohexadiene were determined during copolymerization runs carried out with several initiators, such as titanium tetrachloride, n‐butyllithium, and Ziegler‐type catalysts. Reactivity ratios observed are in general very similar and are influenced by the nature of the initiator and of the reaction medium.
Investigations on the radiation‐produced peroxide of poly(methyl methacrylate) and its copolymers
Authors: Połowiński Stefan , Turska Eligia , Kroh Jerzy 
Published: April 2003

AbstractThe concentration of peroxide groups produced in poly(methyl methacrylate), (PMMA) and PMMA–styrene copolymers (random, graft, and block) irradiated in the presence of air by γ‐rays from Co60 was determined. The dependence of the above concentration on the radiation dose and polymer composition was investigated. In copolymers containing more than 10% styrene the number of peroxide groups corresponding to PMMA decreases as the concentration of styrene increases. This phenomenon is ascribed to the transfer of energy toward benzene rings. The influence of these rings is much stronger in block and graft copolymers then in the statistic ones. In the case of small quantities of polystyrene in random copolymers there was a certain increase of the number of peroxide groups in comparison with pure PMMA.