bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polyelectrolytes. II. Poly‐4‐vinylpyridonium chloride and poly‐4‐vinyl‐N‐n‐butylpyridonium bromide
Authors: Fuoss Raymond M. , Strauss Ulrich P. 
Published: April 2003

AbstractPoly‐4‐vinylpyridine was precipitated from a toluene solution of the monomer after addition of benzoyl Peroxide. The sample used in these experiments had a molecular weight of 77,000, (DP 730) as determined by osmotic pressure in alcohol solution, and an intrinsic viscosity of 0.36 in this solvent. The hydrochloride is water soluble and behaves like the salt of an extremely weak base with an over‐all average base dissociation constant of 0.011 × 10−9, about one thousandth that of 4‐ethylpyridine. The decrease in apparent base strength is ascribed to the chain structure which produces high local concentrations of pyridine groups, independent of the total concentration. By addition of butyl bromide to the polymer in nitromethane, a long chain quaternary ammonium salt is formed which is also water soluble. Its conductance is not sensitive to concentration down to about 0.003 N, after which the conductance rises sharply with further dilution. Dissociation, calculated by the classical Arrhenius method, indicates that a minimum of about 20% of the bromide ions are free, the remainder being associated by Coulomb attraction to the chainlike positive ion. As the dielectric constant of the solvent is decreased by addition of ethanol, the relative amount of free bromide ions decreases. The viscosity of the polyelectrolyte in aqueous or alcoholic solution, when plotted in the conventional way (ηsp/c versus c), approaches infinity at zero concentration instead of approaching a limiting constant linearly. A plot of $ {{\eta _{sp} } \mathord{\left/ {\vphantom {{\eta _{sp} } {\sqrt c }}} \right. \kern&#x02010;\nulldelimiterspace} {\sqrt c }} $ versus $ \sqrt c $ is, however, linear; this behavior is characteristic of strong electrolytes. The coefficient of the square root term in concentration for the polymer is larger, by orders of magnitude, than that for ordinary electrolytes. The coefficient of the linear term in the square root function is about equal to the intrinsic viscosity of the parent polymer.
Vapor phase polymerization of 1,3‐butadiene with sodium
Authors: Eberly Kenneth C. , Johnson B. L. 
Published: April 2003

AbstractApparatus and technique have been described for the polymerization of 1,3‐butadiene in the vapor phase with sodium as catalyst. Research grade butadiene or that obtained from alcohol is necessary for production of high molecular weight polymers by this method. Unmodified polymerizations with increased sodium surface go faster and produce polymers of lower gel content and inherent viscosity. Increase in polymerization temperature reduces the rate, gel content, and inherent viscosity. The chemical structure of the modifier seems to be the predominant factor in its efficiency within a concentration range of 0.1 to 1.0 %. Ethyl chloride is the most powerful modifier of those examined, followed in order by dimethylamine, acetaldehyde, and acetoue. Gelfree polymers with average inherent viscosities of the whole sol between 0.4 and 4.6 were vulcanized and evaluated. The weight distribution was found to be rather narrow for the low viscosity polymers but to become broader as the average inherent viscosity of the polymer increased. Optimum processing and tensile properties were obtained on the polymers of medium viscosity. The dynamic properties of the vulcanizates improve with increase in average inherent viscosity of the raw polymer; the ethyl chloride modified polymer is exceptionally good. The physical properties of the vulcanizate of a blend of equal parts of five polymers of inherent viscosity 1.0 to 4.6 were near those of the lowest molecular weight polymer.
Beiträge zur kinetik der indenpolymerisation. II. Die verteilungsfunktion der thermischen polymeren des indens
Authors: Pass F. 
Published: April 2003

AbstractPolyindenpräparate werden durch Ausfällung mit Butylalkohol aus Benzol oder mit Methylalkohol aus Äther in Fraktionen von Molekulargewichten von 200–1200 zerlegt. Diese Werte werden benutzt um die Verteilungsfunktion dieser Polymeren mit extrem niedrigen Molekulargewichten zu berechnen.
Beiträge zur kinetik der indenpolymerisation. III. Über den einfluss molekularen sauerstoffes auf die indenpolymerisation
Authors: Gutmann V. 
Published: April 2003

AbstractEs wird die Polymerisation von Inden unter Sauerstoffeinfluss bei 30 und 40°C. untersucht. Sauerstoff wird absorbiert unter Bildung eines labilen “Oxydpolymers” oder “Polyindenperoxyds,” das vom normalen Polymer mittels einer Fällungsreaktion getrennt werden kann.
Surface tension of polyoxyethylene glycol solutions
Authors: Couper A. , Eley D. D. 
Published: April 2003

AbstractThe surface tension of polyoxyethylene glycol in water leads to a value for the area per molecule which shows that the polymer molecules lie approximately flat in the surface. Molecular weight determinations by end‐group analysis and freezing‐point depression are compared with values of the intrinsic viscosity and limiting area per molecule.
Hydrogen peroxide as catalyst for emulsion polymerization of butadiene and styrene
Authors: Marvel C. S. , Deanin Rudolph , Claus C. J. , Wyld Mary B. , Seitz Rachel L. 
Published: April 2003

AbstractEvidence is presented to show that either sodium ferri‐ or ferropyrophosphate with hydrogen peroxide effectively initiates emulsion copolymerization of butadiene and styrene. The hydrogen peroxide appears to be destroyed as such before polymerization begins, thus indicating that it converts some other constituent of the recipe into the effective catalyst for polymerization.
Processes for modifying rosin
Authors: Rinse J. 
Published: April 2003

AbstractRosin can be modified by two fundamentally different methods. which usually are combined to get the best results. These methods are based on neutralization of the carboxyl group and reaction with the unsaturated part of the rosin molecule. The products are used as a filler to improve gloss and hardness of the paint or varnish film. They are easily soluble in the common solvents and the harder types promote drying. Depending upon the method of treatment, they are more or less liable to oxidation. The molecular weight increases most for the phenolic‐ and maleic‐modified ester gums and especially when esterified with penta‐erythritol.
Adiabatic reaction kinetics of buna S vulcanization
Authors: Gordon M. 
Published: April 2003

AbstractThe adiabatic technique of making kinetic measurements has been applied to published time‐–temperature data concerning the vulcanization of Buna S with 6% sulfur. The kinetic parameters of the rate‐determining step are calculated within stated limits of accuracy; the rate‐determining step is thereby identified as the reaction S8 (ring) → S8 (chain biradical) which has been speculatively advanced as the first step in vulcanization by some investigators.
Inhibiting effects of certain phenols on GR‐S polymerization
Authors: Marvel C. S. , Higgins N. A. 
Published: April 2003

AbstractThe inhibiting action of several phenols on the GR‐S 10 (rosin soap) recipe for synthetic 2,5‐Di‐t‐butylhydroquinone is shown to be a particularly powerful inhibitor rubber is reportor in this recipe.
Refractometric determination of second‐order transition temperatures in polymers. II. Some acrylic, vinyl halide, and styrene polymers
Authors: Wiley Richard H. , Brauer G. M. 
Published: April 2003

AbstractA refractometric method for determination of second‐order transition temperatures of polymers has been extended to include a series of polymers for which the transition occurs between 0° and 75°C. Refractive index data within ±30° to 50°C. of the transition temperature are given for some acrylate, methacrylate, vinyl chloride, vinylidene chloride, and styrene polymers and copolymers. These data show discontinuities which locate the second‐order transition temperatures for these polymers. Deviation from the linear relation near Tm has been related to a time effect.
Beiträge zur kinetik der indenpolymerisation. IV. Über polyindenperoxyde
Authors: Gutmann V. 
Published: April 2003

AbstractPolymeres Indol, das in Gegenwart von Sauerstoff dargestellt wurde, kann durch Fällen mit Methylalkohol in 2 Fraktionen getrennt werden. Polyindol ist unlöslich. Die methylalkohollösliche Fraktion kann aus Benzol mit Petroläther als ein weisses, pulveriges “Polyindolperoxyd” ausgefällt werden. Fraktionierung führte zu Substanzen mit Molekulargewichten zwischen 300 und 3000. Bromtitration deutete darauf hin, dass die niedrigmolekularen Proben ungefähr eine Doppelbindung pro Polymermolekül enthielten. Die qualitative Prüfung für Peroxyd war positiv, aber die jodometrische Titration einer Probe ergab nur 42.5% des berechneten aktiven Sauerstoffgehaltes.
Beiträge zur kinetik der indenpolymerisation. VI. Weiterpolymerisierung von indenfraktionen
Authors: Halla F. , Schützner W. 
Published: April 2003

AbstractEine Probe von Polyindol (mittleres Molekulargewicht 400) wird sorgfältig in 9 Fraktionen von steigendem Molekulargewicht von 300 bis 800 zerlegt. Die Beobachtung von Whitby und Katz, dass Bromtitrierung zu einer Doppelbindung pro Polymermolekül führt wird bestätigt. Diese Doppelbindung ist aber nicht länger zur Polymerisation fähig, da sich die Molekulargewichte verschiedener Fraktionen nicht mehr wesentlich änderten, wenn sie Polymerisationsbedingungen—Erhitzen für 500 Stunden bei 175° in Stickstoffatmosphäre—ausgesetzt wurden.
Transport and equilibrium phenomena in gas–elastomer systems. II. Equilibrium phenomena
Authors: Barrer R. M. , Skirrow G. 
Published: April 2003

AbstractThe solubility of nitrogen, ethylene, and the n‐paraffins from methane to pentane has been measured in a series of natural rubber vulcanizates in relation to chain length of paraffin, temperature, and degree of cross linking of vulcanizates which contained between 1.7 to 21.9% combined sulfur.For smaller, less soluble paraffins the degree of vulcanization had little influence upon the solubility but for higher molecular paraffins such as pentane this influence became significant. A qualitative interpretation of the effects observed was given. The solubility data are in all cases represented by a statistical theory of one of the authors for a mean frequency of vibration of the solute in the medium corresponding to the infrared (0.5 to 1.0 × 1012 sec.−1). The solubility constants, σ, and critical temperature, Tc, are also empirically related by the equation:

Heats and standard free energies of solution for the earlier homologous paraffins show steady trends as the chain length increases. The heats are exothermal and are adequately interpreted as the sum of the heats of liquefaction together with a small heat‐of‐mixing term for liquid and rubber which was usually close to that given by Hildebrand's cohesive energy density equation:

As anticipated from statistical theory, entropies were usually several entropy units more negative than those for solutions of gases in monomeric solvents.
Physical properties of fractions of GR‐S and their vulcanizates
Authors: Yanko John A. 
Published: April 2003

AbstractA large‐scale precise fractionation of GR‐S (X‐55) was performed using the fractional precipitation technique at 25°C. 9 fractions, each weighing approximately 150 g. and comprising approximately 11% by weight of the original unfractionated sample, were obtained and a detailed study was made showing the effect of number‐average molecular weight and related sol–gel properties on various physical and chemical properties of the crude and vulcanized fractions. Using a Santocure tread‐type recipe, preliminary compounding work indicated the sulfur ratios required to give vulcanizates with 300% modulus values of 1000 p.s.i. All fractions were recompounded using these indicated optimum sulfur values. Generally, as the number‐average molecular weight increased, better stress–strain and quality index data were obtained. These and other physical properties of the vulcanizates of these fractions are discussed in detail. As found in past fractionation studies pertaining to unsaturated high polymers, the higher molecular weight fractions, obtained from the unfractionated sample which was totally soluble in benzene, undergo considerable gelation when isolated and vacuum dried at 25°C. in the dark. As the indicated molecular weight of the fraction increased, higher per cent gel contents were obtained. Compared to unfractionated butadiene‐styrene copolymers of similar gel contents, the gel portions of the higher molecular weight fractions had unusually high swelling indices. indicating qualitatively that the average molecular weights between points of effective cross linking in the three‐dimensional gel structure were higher than those encountered in the past in unfractionated samples of similar gel contents. Other data are given pertaining to these fractions, such as the bound styrene content, per cent shrinkage of the compounded unvulcanized stocks, and the rate of gel breakdown with cold milling.
Polymer constitution and fiber properties
Authors: Hill R. , Walker E. E. 
Published: April 2003

AbstractThe chemical structure of a large number of linear condensation polymers is correlated with their ability to assume a polycrystalline form possessing the right degree of thermal stability, and with the possession of fiber‐forming properties. Certain structures lead to the absence of crystallinity and of fiber‐forming properties, while, under certain conditions, a low degree of crystallinity or its complete absence leads to polymers possessing rubberlike properties, which may form highly elastic threads. Some properties of fibers such as solubility, sensitivity to mositure, and certain dyeing characteristics, can be correlated to some extent with chemical structure. These effects are considered on the basis of the introduction of various polar links and ring structures, according to regular patterns, into the polymethylene chain (polythee). The ehter (RO) and ester (CO·O) links lower the crystallite melting point to such an extent that some polymers containing them are completely noncrystalline at normal room temperatures. Urethan (O·CONH), amide (CO·NH) and urea (NH·CO·NH) links raise the crystallite melting point to an extent which increases in the order named. Most other polar links raise the melting point. The introduction into the aliphatic chain of ring structures, particularly aromatic rings directly attached to polar groups, raises the crystallite melting point, but in this case symmetry exerts an over‐ruling effect. A low degree of symmetry may lower the melting point and even eliminate crystallinity entirely to the detriment of fiber‐forming properties. Inert side chains lower the melting point considerably, and in some cases render the polymer completely noncrystalline at normal room temperatures.
Polyvinyl chloroacetate
Authors: Wiley Richard H. , Brauer G. M. 
Published: April 2003

AbstractSeries of bulk and solution polymerizations of vinyl chloroacetate have shown that the properties of the polymer vary widely with variation in polymerization conditions. The highest viscosity polymer, intrinsic viscosity polymer, intrinsic viscosity of 1.32, is prepared by bulk polymerization with 0.028% benzoyl peroxide initiator at 70°C. At polymerization temperatures sdover 70°C. and at catalyst concentrations over 0.14%, the polymer is discolored, insoluble, or has relatively poor aging characteristics. Polymerization in an equal volume of methyl isobutyl ketone at 80°C. and with 0.013% benzoyl peroxide gave 93% yield of polymer of intrinsic viscosity 0.15. In nitrobenzene, toluence, trichloroethylene, or ethyl acetate, only traces of polymer are obtained. In carbon tetrachloride, unstable telomers are produced.
Interaction between cellulose nitrate in solution and inorganic salts
Authors: Campbell H. , Johnson P. 
Published: April 2003

AbstractPartI. It was confirmed that certain cellulose nitrates in 1% solution in acetone become more viscous and finally gel on standing over CaO, PbO, the basic salts of weak acids and strong bases, and certain other materials. The gels, whose formation was facilitated by increased temperature, were broken by the addition of a small amount of acid. The rate of gelling increased with the nitrogen content of the cellulose nitrate, indicating that residual hydroxyl groups were not involved. Nor did gelling occur under the same conditions in 1% solutions of cellulose acetate and ethyl cellulose of comparable degree of substitution. The rate of gelling was enormously increased when COOH groups were artificially introduced into the cellulose before nitration. Gelation is most probably due, therefore, to the cross‐linking of different cellulose nitrate chains through COOH or possibly SO3H groups.Part II. Dilute (< 0.2%) cellulose nitrate solutions on standing over CaO show a fall in viscosity with time (contrast 1). By ultracentrifuge examination this was shown to be due (for CaO and PbO treated solutions), not to degradation of the cellulose nitrate chains, but to association processes leading to the formation of aggregates of higher sedimentation constant and molecular weight. Sedimentation constants corresponding to molecular weights of several millions were observed from a cellulose nitrate of initial molecular weight ca. 100,000. Untreated control solutions showed no change in the state of aggregation. The association processes followed an approximately first‐order law at room temperature and were made more rapid by increase in temperature. After sedimentation, the association products could not be redispersed. Calcium introduced into cellulose nitrate before solution in acetone did not cause association or any other noticeable effect at low concentration.
Influence of structure on polymer–liquid interaction. III. Swelling and mechanical properties of some partly crystallized polymers
Authors: Salomon G. 
Published: April 2003

AbstractSwelling and rate of crystallization from solution and gels of raw and vulcanized guttapercha have been studied. Sulfur vulcanization of gutta‐percha causes a reduction in the amount of crystalline phase that becomes evident from typical changes in mechanical and swelling properties. Liquid–polymer interaction of the crystalline phase in gutta‐percha, raw rubber, and “racked” rubber lead to different equilibria, which are probably due to differences in the free energy contents of the crystalline phases. A series of vulcanized rubber hydrochlorides with gradually increasing chlorine content show analogous changes in rate of elastic recovery and swelling equilibria that are also due to the gradual formation of a crystalline phase. Correlations between molecular structure and rate of crystallization in plastics and elastomers are discussed. Symmetry of the shape, as well as of inter molecular forces in the molecular units, size of substituents, and regularity of the polymer chain all have an essential influence on the rate and ease of crystallization.
X‐ray diffraction patterns of stretched low‐temperature polybutadiene using molybdenum, copper, and chromium radiations
Authors: Beu Karl E. 
Published: April 2003

AbstractX‐ray diffraction patterns of stretched crystallized polybutadiene polymerized at −20°C were obtained using molybdenum, copper, and chromium characteristic x‐radiations on the same sample. The pattern obtained using molybdenum radiation showed diffraction effects in the 0, 1st, 2nd, 3rd, and 4th orders. The lack of detail in this pattern is partly due to the relatively intense background. By using the longer wavelength copper and chromium radiations the diffraction effects of the zero‐ and first‐order layer lines were brought out in considerable detail. The diffraction data obtainable from these layer line patterns may be useful in carrying out a structural analysis of crystalline polybutadiene.
Factors influencing the activation energies of reactions involving double bonds and radicals
Authors: Evans M. G. , Gergely J. , Seaman E. C. 
Published: April 2003

AbstractBy using the methods which have been developed to describe the activation energy of chemical reactions in terms of bond energies and the repulsing energies between reacting centers, the factors influencing the activation energies of reactions between radicals and monomers are discussed. Calculations are reported on a number of simple prototype reactions involving radicals and atoms and ethylenic bonds. It is found that the heat of reactions is a most important factor in determining the activation energies of such reactions and this result is extended to a wide variety of substituted radicals and monomers. The variation in the heat of reaction is expressed in terms of the resonance energies of the reacting radicals and molecules. Another important factor is the energy of repulsion between the reacting centers, and this energy is affected by (a) the charge distribution on the reacting centers and (b) the steric effect of substituent groups. The effect of substituents on the charge distribution is discussed in terms of the molecular orbital method, an attempt being made to distinguish between the influence on the π electrons of the inductive and mesomeric effect of substituents.
Thermal degradation of polystyrene. Part II
Authors: Jellinek H. H. G. 
Published: April 2003

AbstractThe production of monomer during degradation of polystyrene in vacuo below 310°C. has been investigated. A mechanism has been proposed which explains the dependence of monomer formation on the initial breaks in the chain. The degradation in presence of oxygen has been studied. A mechanism for this reaction has been proposed which accounts for the type of curves obtained experimentally. The role of antioxidants has been briefly indicated. The elementary steps for the degradation in vacuo and in the presence of oxygen have been discussed.
Adhesion. III. Adhesion of polymers to cellulose and alumina
Authors: McLaren A. D. , Seiler Charles J. 
Published: April 2003

AbstractA relationship between tack temperature and molecular weight has been deduced and illustrated with polyvinyl acetate polymers. Provided the molecular weight is high enough to prevent cohesive failure, the adhesion of polyvinyl acetate to cellulose and aluminum is independent of molecular weight. The influence of humidity on adhesion of polymers to cellulose is shown. The influence of polymer composition on adhesion is illustrated with copolymers of vinyl acetate and methyl vinyl ketone and with styrene and methyl vinyl ketone. Above a mole fraction of ketone of 0.8, adhesion increases rapidly. The interdependence of tack temperature and composition on adhesion is exemplified with ethylene ‐ vinyl chloride copolymers. A temperature dependence of adhesion is cited for copolymers containing maleic acid.
Photochemistry of phosphonitrilic chlorides. I. A photochemical reaction of low‐polymeric phosphonitrilic chlorides
Authors: Dishon B. R. , Hirshberg Y. 
Published: April 2003

AbstractPhotochemical reactions of trimeric and tetrameric phosphonitrilic chlorides with some hydrocarbons are described. Soluble and insoluble photoreaction products are formed. From the soluble fraction, distillable phenyl‐ and decahydronaphthyl‐phosphonitrilic chlorides were separated; the indistillable and deposit fractions were also found to contain high percentages of carbon and hydrogen. This shows that successive substitution of the chlorine atoms by radicals, R, of the solvents, RH, had taken place.