bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polymers from the iterated addition of hydrogen sulfide to diolefins
Authors: Erickson John G. 
Published: April 2003

AbstractThis paper describes polyesters and polyamides obtained by the base‐catalyzed additions of hydrogen sulfide to α,β‐unsaturated diesters and diamides. The compounds employed were ethylene diacrylate, the diacrylate of trans‐1,4‐bis(hydroxymethyl)cyclohexane, p‐xylylene diacrylate, hydroquinone diacrylate, the diacrylate of 1,4‐butanedithiol, tetraethylene glycol dimethacrylate, 1,4‐butylene dicrotonate, 1,4‐butylene dicinnamate, methylene bisacrylamide, and m‐xylylene bisacrylamide. The polymers posses the general formula, , wherein R1 is hydrogen, methyl, or phenyl, R2 is hydrogen or methyl, R3 is an alkylene, aralkylene, or oxyalkylene group, and X is oxygen, sulfur, or the imino group. Polymers with as many as several hundred repeating units were obtained. Depending upon the structure, the products are liquids, rubbers, or solids, the polymers are obtained with vinyl or sulfhydryl termination and the efficiency of this termination is very high, as was shown by chain extension of a sulfhydryl‐terminated polymer through oxidation to a polydisulfide, $$ \rlap{&#x02010;&#x02010;} ({\rm RSS\rlap{&#x02010;&#x02010;} )}_n $$, having a molecular weight 30 times as great as that of the parent dimercaptan. The syntheses of several new monomers are described.
New high temperature polymers. I. Wholly aromatic ordered copolyamides
Authors: Preston J. 
Published: April 2003

AbstractWholly aromatic ordered copolyamides of unusually high thermal stability were prepared by the condensation of aromatic diacid chlorides with symmetrical diamines containing preformed aromatic amide units in an ordered arrangement. The preservation of order in the condensation step was assured by using interfacial or solution polymerization techniques at temperatures below 50°C. Each polymer contains units derived from aminobenzoic acids, arylene diamines, and arylene diacids. By use of para‐ and meta‐ phenylene units, eight different polymers are possible; all were prepared. Differential thermal analyses and thermogravimetric analyses showed these polymers to have melting points or decomposition temperatures in a range from 410°C. for the all‐meta polymer to 555°C. for the all‐para one. Substitution of the internal N‐hydrogens of the diamines with methyl groups or phenyl groups leads to additional ordered copolymers. Several were prepared, but their melting points were much lower than those of the parent polymers limiting their usefulness in high temperature applications. Tough pliable films were prepared from all eight unsubstituted polymers, and crystalline fibers with tenacities of ca. 6 g./den. were prepared from three of the polymers. The properties of the fibers were retained to a high degree even when determined at temperatures up to 400°C. Fibers aged at 300°C. for extended periods of time showed remarkable retention of fiber properties.
Sequence distribution of partially hydrolyzed poly(vinyl acetate)
Authors: Tubbs Robert K. 
Published: April 2003

AbstractCopolymers of vinyl acetate and vinyl alcohol were studied by differential thermal analysis. The melting points of the copolymers are not a simple function of the composition, but depend on the method of preparation of the copolymers. Partial saponification of poly(vinyl acetate) with sodium hydroxide leads to high melting, ordered copolymers, while reacetylation of poly(vinyl alcohol) leads to low melting, random copolymers. Catalytic alcoholysis of PVAc yields copolymers intermediate in melting point and order. The results are treated by assuming that equal melting points indicate similar sequence length distributions of crystallizable units.
Structure–property relationships of poly(vinyl alcohol). I. Influence of polymerization solvents and temperature on the structure and properties of poly(vinyl alcohol) derived from poly(vinyl acetate)
Authors: Friedlander H. N. , Harris H. E. , Pritchard J. G. 
Published: April 2003

AbstractThe solubility properties of poly(vinyl alcohol) (PVA) vary with the method of preparation of the poly(vinyl acetate) (PVAc) from which it is derived. PVAc was prepared with free‐radical catalysts over a range of temperatures from −78 to 90°C. with solvents of varying chain‐transfer ability. The corresponding PVA samples varied in their resistance to dissolution in water. Their high‐resolution proton nuclear magnetic resonance spectra showed on differences in tacticity. Data on 1,2‐diol content showed only minor differences. Hence, the increase in resistance of PVA to dissolution in water arising from changes in chain‐transfer activity of the solvent used in vinyl acetate polymerization is largely attributable to a decrease in molecular weight, and the increase in resistance of PVA to dissolution in water arising from a decrease in the temperature of the vinyl acetate polymerization is largely attributable to a decrease in both long and short branches. Evidently, with polar polymers having small side groups, tacticity is not the only factor influencing property variation; that is, variations in stereoregularity influence more the crystallinity of the sample as measured by density or x‐ray methods than the ultimate crystallizability under conditions of mechanical and thermal treatment. In this regard polar polymers having small side groups differ from nonpolar polymers.
Structure–Property relationships of poly(vinyl alcohol). III. Relationships between stereo‐regularity, crystallinity, and water resistance in poly(vinyl alcohol)
Authors: Kenney J. F. , Willcockson G. W. 
Published: April 2003

AbstractStructure–property relationships of poly(vinyl alcohol) have been studied by measuring the crystallinity and water resistance of films derived from samples of varying, known tacticity. Crystallinities of unannealed and annealed films were examined by means of density, infrared, and x‐ray measurements. Higher tacticity did not lead to higher crystallinity. The apparent order of crystallizability was atactic ≧ syndiotactic‐rich ≫ isotactic‐rich. Water resistance of these films was determined by measuring the swelling index at 30°C. and solubility at 70 and 130–140°C. Water resistance increases as tacticity increases, with syndiotactic‐rich PVA exhibiting the highest water resistance. Since water resistance also increases with crystallinity, both stereoregularity and crystallinity must be considered when evaluating structure–solubility relationships. Differential thermal and thermogravimetric analyses of these samples are also presented, together with a correlation of tacticity index as measured by an infrared technique with that of an NMR technique.
Catalytic polymerizations of nitrobenzene and aniline
Authors: Sigal Paul , Masciantonio Philip , Fugassi Paul 
Published: April 2003

AbstractNitrobenzene refluxed over a variety of solid catalysts near its standard boiling point of 211°C. Polymerizes to give compounds whose structure appears to be that of a triaryl amine polymer. Under similar conditions aniline gives polymers whose structure appears to be a mixture of diaryl and triaryl amine bonds.
Isothermal kinetic calorimeter applied to emulsion polymerization
Authors: Andersen H. M. 
Published: April 2003

AbstractA method for the direct measurement, by means of the heat of reaction, of essentially instantaneous polymerization rates is described. The polymerization is carried out isothermally, and the evolved heat is measured electrically over short time intervals. Applied to emulsion polymerization, the technique reveals several previously unobserved features.
Periodate oxidative decrystallization of cotton cellulose
Authors: Rowland Stanley P. , Cousins Edwin R. 
Published: April 2003

AbstractCotton cellulose is decrystallized by periodate oxidation to essentially zero crystallinity index (CI) at 100% oxidant consumption. The decrease in CI is pseudo zero‐order over 60% of the reaction and consistent with a diffusion‐controlled mechanism. The attack on regions of high order is indicated to be 100% in the latter phase of oxidation and 13% in the initial phase. Data allow an estimate that approximately 60% of the structural segments of the cotton cellulose under investigation lies in highly ordered arrangements.
Cyclobutane polymers from acrylonitrile dimer
Authors: Stueben K. C. 
Published: April 2003

AbstractA wide variety of polyesters and polyamides was prepared from 1,2‐ and 1,3‐disubstituted cyclobutane derivatives. In general, polyamides containing thetrans‐disubstituted cyclobutane ring were crystalline. Polyesters containing predominantly thetrans‐isomer tended to be crystalline but those containing mixtures ofcis‐transisomers were amorphous. Mechanical properties have been determined wherever possible. Appreciable yields of cyclic dimers were isolated during the preparation of certain polyesters. These cyclic dimers readily polymerized when treated with dibutylzinc. Examination of acrylonitrile dimer (1,2‐dicyanocyclobutane) by gas chromatography failed to reveal the presence of any 1,3‐dicyanocyclobutanes.
Macroreticular redox polymers. II. Further synthesis and properties of some redox polymers
Authors: Kun Kenneth A. 
Published: April 2003

AbstractA series of redox polymers was prepared by the addition of different redox groups to preformed, chloromethylated macroreticular styrene–divinylbenzene copolymers. These polymers contained the hydroquinone, hydroquinonesulfonic acid, methylhydroquinone, 2,5‐dimethylhydroquinone, 2,5‐dimethylhydroquinonesulfonic acid, 2,3,5‐trimethylhydroquinone, tert‐butylhydroquinone, chlorohydroquinone, benzyl mercaptan, anthraquinone, and the pyrogallol redox groups. Thus, a set of redox polymers is available having redox potentials that may range from approximately 150 to 700 mv.
Polymerization of β‐cyanopropionaldehyde
Authors: Sumitomo Hiroshi , Kobayashi Kazukiyo 
Published: April 2003

AbstractA new class of polyacetals, poly(cyanoethyl)oxymethylene, was obtained by the polymerization of β‐cyanopropionaldehyde at −78°C. with use of ionic initiators including boron trifluoride diethyl etherate, diethylzinc, triethylaluminum, and triethylaluminumtitanium tetrachloride complexes. The influence of temperature, initiator, and solvent upon the polymerization was studied. Infrared spectra of polymers obtained from different initiators are also illustrated. An attempt was made to fractionate the polymer by means of solvent extraction. The acetone‐soluble polymer is an elastomeric material having a low solution viscosity. The acetone‐insoluble, dimethylformamide‐soluble polymer obtained as a white powder was found to have extremely high solution viscosity. Some amounts of insoluble fraction could be also separated. The latter two fractions were observed to have a reasonable stability.
Stability of styrene–maleamic acid interpolymers
Authors: Minsk L. M. , Dunham K. R. 
Published: April 2003

AbstractThe response to heat and water of copoly(styrene–maleamic acid, ammonium salt), prepared by treatment with ammonia of the anhydride polymer in toluene suspension, is described. This polymer except for the ammonia bound by salt formation, is stable to heat within the range studied, i.e., to 100°C. The behavior of water solution is determined by the ammonia concentration. Above pH 9, the bound nitrogen remains as amide. If the pH is low, i.e., about 5, as occurs when a dried sample is dissolved in water, then rapid imidization occurs with concurrent hydrolysis. In the early stages of this conversion, imidization occurs mainly through loss of ammonia. This requires that two amide groups be adjacent. Classical imidization by loss of water also occurs, indicating that the normal‐amic acid structure is also present.
Silicon‐containing Schiff base and benzimidazole derivatives
Authors: Kovacs H. Nagy , Delman A. D. , Simms B. B. 
Published: April 2003

AbstractInvestigations were undertaken to obtain information for use in the development of new heat‐stable polymers. Model silicon‐containing Schiff base and benzimidazole derivatives were synthesized by reaction of p‐(triphenylsilyl)‐benzaldehyde with phenylenediamines. The structure and thermal stability of the products were studied. The reaction of p‐(triphenylsilyl)benzaldehyde and o‐phenylenediamine yielded N‐p‐(triphenylsilyl)benzylidene‐o‐phenylenediamine which readily oxidizes to form 2‐p‐(triphenylsilyl)phenylbenzimidazole. The di‐Schiff bases, which most probably exist in trans‐trans configurations, were obtained from reaction of the aldehyde derivative with m‐ and p‐phenylenediamine. In contrast to similar Schiff bases without silicon, the products are soluble in organic solvents. The good resistance of the di‐Schiff base and benzimidazole derivatives to thermal decomposition suggests that polymers with repeating units of such structures would also be heat‐stable and might possess useful properties.
Base‐catalyzed polymerization of maleimide and some derivatives and related unsaturated carbonamides
Authors: Kojima Kuniharu , Yoda N. , Marvel C. S. 
Published: April 2003

AbstractBasic catalysts in dimethylacetamide solution initiated the polymerization of maleimide to yield a low molecular weight polymer which has a copolymer structure. Approximately 75–85% of the recurring units are formed by hydrogen transfer and 15–25% by vinyl polymerization, as shown by hydrolysis, to yield aspartic acid on the one hand and ammonia and polymaleic acid on the other. Several maleimide derivatives have been prepared, but none has given a high molecular weight polymer by basic catalysis. Some unsaturated carbonamides such as p‐vinylbenzamide, mono‐N‐acrylyl‐hexamethylenediamine, and mono‐N‐acrylyl‐p‐phenylenediamine have been synthesized and polymerized by basic catalysts. Polymers with low molecular weights were obtained, but the complete structures of all these polymers were not established.
Graft polymerization kinetics of acrylamide initiated by ceric nitrate–dextran redox systems
Authors: Wallace R. A. , Young D. G. 
Published: April 2003

AbstractThe kinetics of the graft polymerization of acrylamide initiated by ceric nitrate—dextran polymeric redox systems was studied primarily at 25°C. Following an initial period of relatively fast reaction, the rate of polymerization is first‐order with respect to the concentrations of monomer and dextran and independent of the ceric ion concentration. The equilibrium constant for ceric ion—dextran complexation K is 3.0 ± 1.6 l./mole, the specific rate of dissociation of the complex, kd, is 3.0 ± 1.2 × 10−4 sec.−1, and the ratio of polymerization rate constants, kp/kt, is 0.44 ± 0.15. The number‐average degree of polymerization is directly proportional to the ratio of the initial concentrations of monomer and ceric ion and increases exponentially with increasing extent of conversion. The initial rapid rate of polymerization is accounted for by the high reactivity of ceric ion with cis‐glycol groups on the ends of the dextran chains. The polymerization in the slower period that follows is initiated by the breakdown of coordination complexes of ceric ions with secondary alcohols on the dextran chain and terminated by redox reaction with uncomplexed ceric ions.
Studies on poly(aquahydroxychromium diphenylphosphinate)
Authors: Delman A. D. , Kelly J. , Mironov J. , Simms B. B. 
Published: April 2003

AbstractThe novel inorganic polymer poly(aquahydroxychromium diphenylphosphinate) was investigated to obtain information concerning its degree of polydispersity and properties when dissolved in organic solvents. Viscometric, infrared absorption spectroscopic, and electrical conductimetric techniques were employed to ascertain the characteristics of the polymer dissolved in benzene, chlorobenzene, and chloroform. Gel permeation chromatography was used to determine the degree of heterogeneity of the polymer. Results indicate that the polymer, as prepared, is quite polydisperse. The polymer main chains do not undergo radical reactions with the solvents. High values of the Huggins interaction constant K′ suggest that polymer–solvent association reactions involving chain‐endgroups are probable. Such reactions are also indicated by association constant values and by the shapes of phoreograms obtained from electrical conductance data. Both “local” and “bulk” solvent properties, such as the dielectric constant, appear to influence the characteristics of the polymer when dissolved in the different solvents.
Anionic oligomerization of methacrylonitrile
Authors: Feit Ben‐Ami , Heller Eri , Zilkha Albert 
Published: April 2003

AbstractThe anionic oligomerization of methacrylonitrile by alcoholic solutions of sodium alkoxide in dimethyl sulfoxide, methanol and ethanol was studied. The DP of the oligomers was directly proportional to the monomer concentration and inversely proportional to the alcohol concentration, in accordance with the equation DP = K[MAN]/[ROH], K being equal to Kp/Ktr. The value of K in DMSO (with sodium methoxidemethanol) was 2.9 ± 0.2, in methanol was 1.5 ± 0.1, and in ethanol (with sodium ethoxide as initiator) was 1.9 ± 0.1. The physical properties of the oligomers are given.
Initiation and propagation in γ‐radiation‐induced polymerization of ethylene
Authors: Machi Sueo , Hagiwara Miyuki , Gotoda Masao , Kagiya Tsutomu 
Published: April 2003

AbstractThe initiation and propagation reaction in γ‐ray‐induced polymerization of ethylene was studied by the two‐stage irradiation method, i.e., a first stage in which initiation and propagation occur at a high dose rate, and a second stage where only the growth of polymer radical occurs. The rate of initiation is calculated from the amount of polymerized monomer and the degree of polymerization as the rate of increase in the number of polymer chains. The initiation rate is shown to be proportional to the ethylene density in the reactor and dose rate.GRof radical formation is found to be about 1.6 at 30°C. at a dose rate of 2.5 × 104rad/hr. and is almost independent of ethylene density but decreases slightly with increasing irradiation dose rate. The lifetime of the growing polymer chain radical is shown to be long at normal temperature. The absolute propagation rate is proportional to the square of ethylene fugacity and depends on dose rate to some extent. For chain growth, irradiation of low dose rate is necessary. The apparent activation energy for the propagation reaction is −9 kcal./mole.
Interactions of inorganic salts with poly(ethylene oxide)
Authors: Lundberg R. D. , Bailey F. E. , Callard R. W. 
Published: April 2003

AbstractEvidence is presented for the interaction of metal salts such as potassium iodide with polyethers such as poly(ethylene oxide). This interaction is sufficiently marked that the incorporation of 10–30% of the salt in the bulk polymer markedly reduces crystallinity while retaining compatibility. Examination of electroviscous effects in methanol demonstrates that the salt–polymer adduct behaves as a typical polyelectrolyte at low salt concentrations, while the polymer in absence of salt is essentially insoluble in methanol at room temperature. Measurements of the equilibrium between salt and polymer along with a study of various molecular weight polymers strongly suggest that one salt molecule associates with about nine ethylene oxide units. It is proposed that the association is due to an ion–dipole interaction, and the anion is tentatively postulated as the species directly associating with the polymer. The association of other metal salts and other polymers are interpreted in this light. The significance of these results in interpreting salting‐in phenomena is also discussed.
Cationic graft copolymerization of styrene onto chlorinated butyl rubber
Authors: Minoura Yuji , Hanada Takeshi , Kasabo Toshiyuki , Ueno Yukio 
Published: April 2003

AbstractThe graft copolymerization of styrene onto chlorinated butyl rubber (Cl‐IIR) with stannic chloride as cationic catalyst was studied in cyclohexane, and the rate of polymerization, per cent grafting and grafting efficiency were obtained. Polymerization was carried out in a sealed tube. The product was precipitated in methanol and dried. The increase in weight of Cl‐IIR used was regarded as styrene conversion, and the increase in weight after extraction by boiling acetone as the weight of grafted styrene. Grafting was confirmed by fractional dissolution and infrared spectra. The rate of polymerization of styrene was proportional to concentrations of styrene, Cl‐IIR and SnCl4. The per cent grafting increased with styrene and SnCl4 concentration, but was constant with Cl‐IIR concentration. It also increased with time and with halogen content in the polymer. The addition of a polar solvent such as nitrobenzene greatly promoted the grafting reaction and the per cent grafting was 200%.
Zinc oxide‐sensitized photopolymerization
Authors: Yamamoto Masahide , Oster Gerald 
Published: April 2003

AbstractZinc oxide under ultraviolet excitation causes the polymerization of vinyl monomers if water and oxygen are present. Analysis shows that hydroxyl radicals initiate the chain. Hydrogen peroxide is produced with light‐excited zinc oxide and is further decomposed by the reducing action of excited zinc oxide.
Ordered structures of styrene–butadiene block copolymers
Authors: Vanzo Ed 
Published: April 2003

AbstractAnionically prepared block copolymers of butadiene and styrene exhibit solution properties which result from a two‐dimensional ordering of the polymer molecules. The most notable of these properties is the iridescent colors of toluene solutions which are dependent on concentration and abruptly change on mechanical deformation. Electron micrographs of the surface of cast films indicate that the ordered structure is retained to some degree in the solid state.
Studies on polymers containing functional groups. II. Polymerization behavior of o‐hydroxystyrene
Authors: Kato Masao , Kamogawa Hiroyoshi 
Published: April 2003

AbstractThe polymerization behavior of o‐hydroxystyrene with free‐radical and cationic initiators and without an initiator was examined. The structures thus obtained were estimated. Although polymerization behavior of o‐hydroxystyrene was rather complicated, according to the results, it appeared that each polymerization more or less might simultaneously follow the two types of mechanisms: normal vinyl polymerization and polymerization through the addition to benzene nuclei. The proportion of addition to benzene nuclei was considered to be highest in the polymerization with BF3·(OEt)2 and lowest in that with azobisisobutyronitrile. Degrees of polymerization of these polymers were low in all cases (42–82). Some brief experiments on copolymerization of o‐hydroxystyrene were carried out.