bluuebunny/crossref_metadata_2025_split huggingface dataset:
Specific Volume, Compressibility, and Volume Thermal Expansivity of Rubber-Sulfur Compounds
Authors: Scott Arnold H. 
Published: February 2011

Abstract
The specific volume, compressibility, and volume thermal expansivity of rubber-sulfur compounds containing from 3 to 31 per cent of sulfur have been measured at pressures from 1 to 800 bars and at temperatures from 10° to 85° C. The results are expressed in tables, curves, and equations, so that within the indicated limits the value of any of the above properties can be readily determined for a compound of specified composition under specified conditions of temperature and pressure. Specific volume, which is the reciprocal of the density, has been used throughout this paper, because this term is the one which is used directly in the definitions of compressibility and volume thermal expansivity. The work of Kimura and Namikawa indicated that the specific volume of rubber-sulfur compounds at atmospheric pressure was a linear function of the temperature. The use of the specific volume thus leads to equations which are simpler than if the density is used.
Synthetic Rubber. Its Industrial Production in the U. S. S. R.
Authors: Akobzhanov I. G. 
Published: February 2011

Abstract
The subject of synthetic rubber has not been neglected in the literature. However, all the publications, including those of Harries or some of the work of Dubosc and Luttringer or even the less complete works such as articles by Jacobs and by Whitby and Katz, contain systematic discussions of the various possibilities of synthesizing rubber, but these deal only with established laboratory procedures, which are for the most part theoretical for the very reason that they have been merely abstract researches and have not been applied on an industrial scale. It should, however, be mentioned that the recent publications of Carothers and his collaborators are not of this character, and Gottlob, who described the great efforts in the Beyer and Co. plant at Leverkusen where 200 tons per month of synthetic rubber were produced during the war, should likewise not be overlooked. Nevertheless a description of this latter process is not of much practical value, because it deals with a process which was abandoned a long time ago. As far as any interest today in the industrial synthesis of rubber is concerned, there is only the work being carried out in U. S. S. R. The author would refer economists and rubber technologists who may be interested in the details to his earlier article, and the purpose of the present article is limited to a detailed survey of the chemical process as applied in the U. S. S. R., leaving out of consideration an analysis of the reasons why it has been considered necessary in the U. S. S. R. to carry out this undertaking, and why ethyl alcohol has been adopted as a raw material for the synthesis of the new rubber, and leaving out of consideration all the statistics of the development of this industry and also technical information for the use of this new substance in rubber factories.
Elastic Hysteresis and Increase in Tensile Strength at Low Temperatures
Authors: Khvostovskaya S. , Margaritov B. 
Published: February 2011

Abstract
1. The increase in tensile strength and the elastic hysteresis are undoubtedly conditioned by the surface processes at the boundary of rubber and filler. 2. On freezing, the optimum increase in tensile strength is shifted toward a smaller volume loading. 3. Because of the considerable increase of viscosity of the medium upon freezing, the forces of friction increase to such a degree that they mask the usual relations existing between A, R, and H for all ingredients.
The Determination of the Optimum Vulcanization by Means of the Residual Elongation
Authors: Kusov A. 
Published: February 2011

Abstract
As is well known, various methods have been proposed for determining the optimum vulcanization of rubber. These methods depend either upon physico-chemical examination or upon mechanical tests. In routine control the mechanical method of determination is used for the most part, because it requires but little time, and in addition this method has the advantage of showing directly by mechanical tests whether the vulcanizate being tested passes the requirements or not. The results obtained by this method frequently do not agree with those obtained by other methods. Of the many common methods of testing, determinations of the tensile strength and of the ultimate and residual elongation are the methods most frequently used. These three properties are measured simultaneously by one determination with the apparatus in most widespread use, i. e., the Schopper and the Scott machines. In special cases the resistance to abrasion, bending strength, hardness, and other properties are determined in addition. Considerably less often the hysteresis and Young's modulus of elasticity are determined. All these determinations are of significance in only a limited way, for the conditions under which the tests are carried out in the laboratory are not comparable to the actual service of the products. For basic reasons, this fundamental shortcoming cannot be avoided in the laboratory, though a few of the measurements do approach the true properties found in service. Of course, the results obtained in the laboratory are greatly influenced and made less reliable by other secondary factors, among which are the phenomenon of aging under natural conditions, prolonged stressing, etc.
Rubber in Paints
Authors: Stevens H. P. , Stevens W. H. , Heaton Noel 
Published: February 2011

Abstract
As a result of our previous publication (Rubber Chemistry and Technology, 7' 486 (1934)) it is now well known that oil gloss and flat paints which contain a small proportion of rubber have greatly improved flowing and non-settling properties. A flat paint made with a medium containing equal parts of rubber and stand oil requires no stippling to produce a smooth surface, but will flow out perfectly when brushed on, while pigments which quickly settle out to a hard cake in a plain oil medium can be used in the oil/rubber medium with much greater safety. Such paints soon become dust-dry after brushing out, and also have the advantage of “keeping open,” thereby enabling the decorator to brush out a large surface without fear of the paint drying at the edges and so preventing a clean “join up.” Adhesion is also good, and the paints can be used equally as well for undercoatings as they can for flat finishes. In ready-mixed oil paints the addition of a smaller proportion of rubber is sufficient to give the paint the required flowing properties, 15–20 per cent of rubber on the oil being a suitable proportion. Matters of first importance are the method of adding the rubber and the stage at which it is incorporated into the paint. The obvious way to add the rubber is in the form of a solution in the usual paint solvents. Raw rubber, however, gives extremely viscous solutions, and additions of only small proportions necessitate excessive thinning. Raw rubber also has a great tendency to cause the paint to thicken (“liver up”).
The Effect of the Conditions of Drying on the Aging Properties of Sheet Rubber
Authors: Hastings J. D. 
Published: February 2011

Abstract
An examination of sheet rubber prepared in identical manner up to the drying stage shows that hot-air-dried sheet and smoked sheet have different aging properties. Hot-air-dried sheet is invariably inferior to smoked sheet, except when prepared from very dilute latex. Further work is required before any explanation is offered.
Properties of Higher Polymers in Solution. III. The Action of Ultra-Violet Light on Dissolved Rubber
Authors: Meyer Kurt H. , Ferri Cesare 
Published: February 2011

Abstract
The action of ultra-violet radiation on rubber has been the object of a long series of investigations. According to van Rossem, rubber is depolymerized under the action of light. Asano on the other hand thinks that ultra-violet light, is able to bring about either polymerization or depolymerization according to its wave-length. More recently Dogadkin and Pantschenkov have carried out experiments in an atmosphere of nitrogen, during the course of which they have found a strong diminution in the viscosity. From this fact they have concluded that light is able to cause depolymerization and micellar degradation. We have undertaken a study of the action of ultra-violet light on rubber in order to prove whether the double cis-linkages of rubber undergo a transposition into trans-linkages, for numerous instances are known where light causes these cis-trans-transpositions. In the case of rubber, one should obtain, therefore, either a hydrocarbon of the gutta-percha type or, if light causes a sort of cis-trans-equilibrium, a hydrocarbon with double cis-linkages distributed irregularly. In our experiments we were extremely careful to exclude oxygen, since some years ago Henri proved that ultra-violet light activates greatly the oxidation of rubber. On the other hand it is known that oxidation causes a diminution in the length of the chains which modifies considerably the physical properties, for example, the viscosity, and which may mask the effect produced by light.
Production of Gasoline by Means of Hydrodepolymerization of Rubber
Authors: Kobayasi Ryo^nosuke , Furihata Minao , Kajimoto Shunji 
Published: February 2011

Abstract
Hydrogenation applied to the production of motor fuels from rubber has recently been investigated (C. M. Cowley and J. G. King, J. Soc. Chem. Ind., 54, 177T (1935)), but this must not be confused with the much more simple hydrogenation process employed in the hardening of fat oils, for a substance of such high molecular weight as rubber may be depolymerized into hydrocarbon oils of much lower molecular weight by hydrogenation, so the process is described more accurately as “hydrodepolymerization.” A further important fact concerning the hydrodepolymerization of rubber is that the product probably contains very large amounts of iso-paraffin hydrocarbons. The present authors naturally assume that motor fuels thus obtained are of high knock-rating, since branched-chain paraffin hydrocarbons have much higher knock-ratings than their straight-chain homologs (Lovell, Campbell, and Boyd, Ind. Eng. Chem., 23, 26 (1931)). The following experimental results prove this assumption correct.
The Oil Resistance of Rubber. III. Viscosities and Molecular Polarizations of Rubber Solutions
Authors: Lambara Shû 
Published: February 2011

Abstract
The molecular polarization of crude rubber has no relation to the viscosities of its solutions. For instance, ultra-violet irradiation of crude rubber solutions reduces their viscosities, but does not change essentially their molecular polarizations. With increased refining of crude rubber, its polarization increases, as shown in Experiment B and in the previous work. This may be caused by autoöxidation of purified rubber, which contains a lower proportion of impurities which act as natural anti-oxidants. It is probable that by such autoöxidation, oxygen combines at the extremity of the rubber molecule, where free isoprene bonds remain. If thread-like molecules of rubber exist, as maintained by Staudinger, a decrease of molecular polarization with reduction of viscosity which results by “cracking” of such long molecules should be observed. Such an effect was not obtained in this experiment. From this point of view, the macro-molecular theory of Staudinger seems to be questionable. The molecular polarization of rubber extracted by acetone for 40 hours and dissolved in benzene in an atmosphere of nitrogen is far smaller than that of purified rubber which has been refined with access of air. By ultra-violet irradiation in nitrogen of the rubber solutions having small polarization, there is no remarkable increase in the polarization of the rubber. From these experiments it is concluded that rubber is a substance having a small polarity, and that it dissolves in benzene in a micellar state or a more complex state having some “structure, ” but not as thread-like molecules.
Iron Oxide as a Substance for Increasing the Adhesion of Ebonite to Metal
Authors: Bartenev S. , Zhuravlev A. , Lozovskaya I. 
Published: February 2011

Abstract
1. Information from various sources on the increase in adhesive strength between iron surfaces and ebonite brought about by the inclusion of iron oxide in the ebonite was confirmed. 2. In all tests the best results were obtained with ebonite samples No. 1 and No. 2 with addition of 8.2 per cent of red iron oxide (20 per cent based on rubber). 3. Inclusion of 8.2 per cent of red iron oxide in the cement increased the adhesive strength between an iron plate and ebonite 260 per cent measured by the rupture under direct tension as shown in Fig. 1, and 233 per cent measured by the method shown in Fig. 2. These results were confirmed in factory production. A new formula for ebonite cement containing red iron oxide was developed, which considerably increased the adhesive power. In conclusion it should be stated that previous to the laboratory experiment, red iron oxide was used for one year in ebonite formulas for magneto parts. As is well known, most of the parts of a magneto consist of ebonite and cadmium-coated copper armature. However, it has been considered hitherto that red iron oxide acts only as a coloring agent. Red iron oxide is evidently a valuable ingredient for securing strong adhesion between ebonite and metal. Since the Kautchuk factory has adopted the use of red iron oxide in the production of ebonite, the percentage of rejections caused by the separation of armature from ebonite in magnetos had been considerably reduced. This subject requires further experimental confirmation, and the results will be reported in forthcoming publications.
Fundamental Studies on the Attributes of Organic Accelerators. XII. Action of Organic Bases on Rubber Sols
Authors: Shimada Keiiti 
Published: February 2011

Abstract
1. To confirm the action of organic acids on rubber sols, small proportions of butyric, valeric, propionic, monochloroacetic, bromoacetic, p-bromobenzoic, and o-iodobenzoic acids, respectively, were added to dilute solutions of rubber in benzene, and the viscosity-time curves were determined for each case. 2. That organic acids, as in the case of organic bases, cause the disaggregation of rubber was determined from the character of the changes in the viscosity when the acids were added. 3. Among organic acids, only o-iodobenzoic acid caused a lowering of the viscosity of a rubber sol, similar to the lowering by the author's C-type accelerators, and the depolymerization of rubber caused by the addition of this acid is due to the presence of iodine in its molecule. Furthermore, the characteristic behavior of C-type accelerators with rubber sols is attributable to the presence of such reactive groups in the molecule.
Determination of Total and Free Selenium in Vulcanizates
Authors: Cheraskova E. , Veisbrute L. 
Published: February 2011

Abstract
The total selenium in rubber compounds may be determined by disintegrating with nitric acid and then separating the selenium by reducing the nitric acid solution with hydrazine sulfate, or by reducing with sulfurous acid after evaporation of the nitric acid. Free selenium is determined by extracting the rubber with aqueous sodium sulfite, from which selenium is precipitated by formalin. Free sulfur is determined volumetrically by iodometric titration after precipitating selenium from sulfite solution.
Self-Vulcanizing Cements
Authors: Fabritziev B. , Buiko G. , Pakhomova E. 
Published: February 2011

Abstract
By self-vulcanizing cements is to be understood cements, films of which at regular room temperature assume within a period of one or two days a vulcanized state. As implied by this definition, self-vulcanizing cements must be based on exceedingly active accelerators. The ultra-accelerators regularly used, such as thiuram disulfides, “Zimate,” and so forth, are not suitable for the purpose. We tested them in our preliminary work, and have proved their inadequacy in this respect. Nevertheless the industry used, under the name of self-vulcanizing cements, cements based on these accelerators. In self-vulcanizing cements accelerators with the lowest critical temperature must be used. Of those available, we chose Vulkacit P, Pipsol X, and zinc butylxanthate, and have established their critical temperature of vulcanization, with the following results: Critical temperature for tetramethylthiuram disulfide 110° C. Critical temperature for Vulkacit P 60° C. Critical temperature for Pipsol X (American) 60° C. Critical temperature for zinc butylxanthate 59° C. On the basis of the above results, we chose zinc butylxanthate. For an activator we used p-toluidine, the critical temperature of the accelerator being lowered from 50° C. to 40° C. by the p-toluidine. It was with this combination of zinc butylxanthate and p-toluidine that we carried out our next work on the following lines: 1. Development of a cement formula. 2. Testing the cement of the chosen formula under laboratory conditions by cementing leather specimens or canvas with rubber, and separating same after curing them in different conditions. 3. Study of gelling in the process of storing cements.
Crystals and Fused Substance in Stretched Rubber. (A Preliminary Communication)
Authors: Thiessen Peter A. , Wittstadt Werner 
Published: February 2011

Abstract
When rubber is stretched, the arrangement of the molecules in the space lattice does not come to an end when the elongation is terminated, but continues for a certain time afterward. The final state of orientation for any elongation depends upon the temperature in the sense that within a wide temperature range there is at each temperature a definite ratio between the quantity of crystallized substance and the glass-like fused component. Within this temperature range, the proportion of crystallized substance diminishes with increase in temperature. This change is reversible, and the equilibrium is greatly influenced by the pressure. It may be considered as an established fact today that natural rubber is essentially a mixture of various polymers of an unsaturated hydrocarbon. At ordinary temperatures and in the absence of mechanical stress, it is an isotropic glass, both in the raw and vulcanized states. When deformed mechanically, particularly when stretched, it becomes anisotropic, a change which is evidenced by the appearance of an optical double refraction and an x-ray fiber diagram. This phenomenon is attributable to an orientation of the molecules in the direction of stretching and their arrangement into a space lattice which can be measured and defined accurately. The increase in double refraction as well as the clearness of the reflection interference pattern in the Roentgen diagram is proportional to the degree of elongation of both raw and vulcanized rubber, and it is reversible after a certain time of relaxation. In natural rubber, the reversibility of the phenomenon is disturbed by flow phenomena, which upon prolonged mechanical stress lead to permanent deformation. In well vulcanized rubber these phenomena are of little significance over a wide range of temperatures.
Natural and Synthetic Rubber. XV. Oxygen in Rubber
Authors: Midgley Thomas , Henne A. L. , Shepard A. F. , Renoll Mary W. 
Published: February 2011

Abstract
It has been shown that natural rubber conthins oxygen, while synthetic rubber is oxygen free. This oxygen appears to be of an hydroxylic type, and its quantity corresponds to about one hydroxyl group for each one thousand isoprene units of the rubber molecule. Rubber has been allowed to oxidize and a mechanism is proposed to interpret the quantitative data recorded.
Uniform Vulcanization
Authors: Leduc Henri 
Published: February 2011

Abstract
All rubber technologists are familiar from experience with the difficulties of vulcanizing objects which are bulky, thick, or porous, and they are as well informed as the writer on this problem. The properties of a vulcanizate reach their maximum at a certain cure which is defined by a certain temperature and a certain time. Rubber is a very poor conductor of heat, and up to the present time it has been necessary in order to cure it to have the surface of the object in contact with a hot fluid or a hot surface, in which case the heat penetrates with difficulty into the mass, and its distribution is far from uniform. It is clear therefore that the uniform curing of large masses is almost impossible in spite of any artifice employed. To make evident the order of magnitude of the differences in the state of cure, two experiments will be described. (1) A cylindrical iron mold, 105 millimeters in diameter and 60 millimeters high, was constructed with a cavity for a thermometer at its middle point. The mold was filled with a mixture composed of:
Contribution to the Study of the Vulcanization Reaction
Authors: Meyer Kurt H. , Hohenemser W. 
Published: February 2011

Abstract
In spite of the great technical importance of vulcanization, the chemical reaction involved is not yet entirely understood, although at the present time it is assumed that chemical phenomena take part in this operation. To C. O. Weber in particular is due much of the research in the field of rubber. It was he who proved the chemical combination with sulfur. He assumed that during hot vulcanization, sulfur combines with two polyprene chains and that they unite chemically, but he was not able to go into this subject in more detail or to prove anything further. The process of cold vulcanization is better understood. There are good reasons for assuming that sulfur chloride reacts with the double bond of polyprene chains in the same way that it does with olefins of low molecular weight, for example with ethylene. It is known that sulfur chloride unites with this latter according to the following scheme:
The Oil Resistance of Rubber. II. Molecular Polarization and Dipole Moment of Purified Natural Rubber
Authors: Kambara Shû 
Published: February 2011

Abstract
Natural rubber was purified by Pummerer's method and was dissolved in benzene and ether. The dielectric constant, refractive index, density, and concentration of the solutions were determined. From these data, the molecular polarization and dipole moment were calculated on the assumption that the rubber was dissolved in a molecular state of (C5H8)8. The dipole moments of total and gel rubber were found to be 2.45 and 2.91 × 10−18, respectively. These values are of the same order of magnitude as those of masticated crude rubber obtained by Ostwald. It may be said that the impurities of rubber are interlocked mechanically on the rubber molecule and are not combined chemically. Sol rubber in ether solution shows a far lower value than the values of total and gel rubber. These latter values may be influenced by autoöxidation, and the true value of the rubber hydrocarbon may be far smaller than the result described in this paper.