bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diffusion of Water through Organic Insulating Materials
Authors: Herrmann D. B. 
Published: February 2011

Abstract
Water has remarkable penetrating power. No organic substance is known to be entirely impervious to it. The life of plants and animals may be said to depend on the diffusion of water through their cell walls, and it is a familiar fact that the water which permeates the human body forms its largest single component. Water passes through materials often considered water-proof such as rubber, asphalts, and waxes. In the Bell System a number of organic materials are used as insulations which often are exposed to moisture. Though the actual quantity of water which diffuses through most organic substances is small, this small amount becomes important in condensers, coils, and terminal boxes and other apparatus which must be protected over a period of years. One of the methods used to evaluate insulations which are to be exposed to moisture is the measurement of the quantity of water absorbed. Such measurements do not always give a complete picture of water-proofing characteristics, since a considerable amount of water may diffuse through a layer of material into some interior space and only a small amount remain absorbed in the outer layer. Differences in molecular structure, phase relationships, and crystalline state may play important roles in diffusion, and often the absorption of water does not appear to be the principal controlling factor.
Research on Modified Rubbers. Part VI. The Oxidation of Rubber Solutions with Gaseous Oxygen in Presence of Catalysts
Authors: Bloomfield G. F. , Farmer E. H. 
Published: February 2011

Abstract
In a previous study of the oxidation of rubber, the oxidative action of peracetic acid, or mixtures behaving substantially as such, was examined (Bloomfield and Farmer, J. Soc. Chem Ind., 53, 121T(1934)). The results then obtained pointed to a course of reaction characterized by (a) additive attack at the unsaturated centers of the rubber molecules, resulting in the production of a high degree of hydroxylation, and (b) extensive molecular degradation with liberation of carbon dioxide (see also Mair and Todd, J. Chem. Soc., 1932, 386). In an extension of this work, attempts have been made to prepare peracetic acid by means other than the interaction of hydrogen peroxide with acetic acid or anhydride, and among other methods the autoxidation of acetaldehyde at low temperatures in the presence of cobalt acetate as catalyst (G P. 269,937; U.S.P. 1,179,121) was tried. Though peracetic acid was successfully obtained in this way in fair yield, an attempt to prepare it on a larger scale resulted in a violent explosion. In order to eliminate the danger arising from an accumulation of peracetic acid, oxygen was led into a chloroform solution of rubber containing a cobalt acetate catalyst together with acetaldehyde, with the hope that in this way peracetic acid might be formed in situ; at low temperatures (−20° to 0°) no reaction occurred, but on submitting such a solution to the action of oxygen at temperatures above 30° a very rapid reduction of viscosity set in, and the solution yielded a viscous gum containing a little oxygen. Now Stevens and his co-workers have recently shown that rubber solutions readily undergo oxidation by gaseous oxygen when certain catalysts (notably the heavy metal salts of organic acids) are present. It immediately became apparent that the oxidation phenomenon just described affords the basis for a greatly accelerated process of this type, the acceleration being due to the presence of acetaldehyde. It was thought desirable at this stage to investigate broadly the entire subject of oxidation of rubber solutions in the presence of catalysts of this nature, and a study has accordingly been made of the oxygen absorption of rubber solutions containing different catalysts, the oxygen intake being measured by the contraction occurring in a closed system containing oxygen, the latter being kept constantly circulating by means of a pump of the pattern designed by Finch (J. Chem. Soc., 1925, 2464). Since it was found that a considerable quantity of carbon dioxide was formed during oxidations of this type, the circulating gases were passed through a trap containing baryta water, and at any stage of the oxidation the amount of carbon dioxide formed could be ascertained by removing the contents of the trap, filtering off the precipitated barium carbonate, and determining the barium as sulfate.
The Hydrogenation-Cracking of Rubber
Authors: Cawley C. M. , King J. G. 
Published: February 2011

Abstract
Rubber is amenable to treatment by the process of hydrogenation-cracking at a pressure of 200 atmospheres of hydrogen and at temperatures above 360°. The rubber is suitably treated in a continuous plant in the form of a solution containing 50% of rubber and 50% of an oil boiling above 200° obtained by the hydrogenation of rubber. At a reaction temperature of 450–480°, and in the presence of a molybdenum catalyst, a high yield of spirit (boiling up to 200°) is obtained. In one passage of the raw material over the catalyst the yield is from 40 to 60% by weight of the rubber solution, the remainder being oil (53 to 18%) and gaseous hydrocarbons. The crude product is a pale yellow mobile oil, and the fraction boiling below 200° a water-clear spirit. The latter contains aromatic 15, unsaturated 1.5, and saturated hydrocarbons 83.5%. It therefore requires only very little refining to make it stable on storage. As the reaction temperature is lowered, the yield of spirit decreases, while that of high-boiling oil increases. The high-boiling oil also becomes more viscous. Thus at 370° the yields, as percentages by weight of the rubber solution, are: spirit boiling up to 200° 10.6%, and oil boiling above 200° 87.6%. The latter is distilled to produce 46.7% of Diesel oil, 21.5% of lubricating oil, and 19.4% of residue. The greater part of the Diesel oil and the high-boiling residue is required to prepare rubber solution for use as the raw material. Rubber can therefore be treated by a hydrogenation-cracking process to yield either motor spirit alone or motor spirit, fuel oil, and lubricating oil, depending on the temperature of treatment. As a commercial project the rubber treated would require to be surplus production available to the process at a much lower cost than that of rubber purchased in the normal market.
The Chlorination of Disaggregated Rubber
Authors: Buizov B. V. , Molodenskii V. S. , Mikhailov N. I. 
Published: February 2011

Abstract
1. Methods of production of chemical derivatives of rubber must be based upon the use of old, disaggregated raw material. The application of this principle to the production of chlorinated rubber has been firmly established, and thus offers the possibility, upon the basis of our first experiments, of developing methods for the production of chlorinated rubber. 2. The investigation of the process of chlorination of rubber disaggregated by means of copper compounds completely supports the authors' point of view concerning the character of the action of copper compounds on the rubber. The authors view this action as a disaggregation of the rubber, which destroys its elastic structure and transforms the rubber compounds into forms which are chemically reactive. 3. The process of chlorination of disaggregated rubber by the means of copper compounds proves the authors' hypothesis about the mechanism of this disaggregation, which leads to the formation of cyclic compounds of rubber.
Refractive Index of Rubber
Authors: McPherson Archibald T. , Cummings Arthur D. 
Published: February 2011

Abstract
This paper presents an exploratory study of the refractive index of rubber. Previous observations on the refractive index of rubber have been, for the most part, restricted to transparent samples. In the present investigation, however, by using reflected light rather than light at grazing incidence, it was found possible to extend the range of measurements to rubber samples that were somewhat dark in color or that were very nearly opaque. Such being the case, determinations of refractive index were made not only on translucent samples of unvulcanized or soft vulcanized rubber, but also on binary mixtures of rubber and different compounding materials, and on compounds of rubber and sulfur containing 0 to 19 per cent of sulfur and covering the range from soft to semi-hard rubber. Different samples of unvulcanized Hevea rubber, of plantation origin, all showed approximately the same refractive index, irrespective of considerable variations in the nonhydrocarbon components. The index was not appreciably altered by the amount of mastication which rubber ordinarily receives in processing and mixing with compounding ingredients. Mixtures of rubber with substances insoluble in it showed the same index as the rubber itself, while mixtures with soluble substances differed in index from rubber by an amount which depended upon the index of the substance and the amount in solution. Measurements of refractive index, therefore, afford a means of measuring the solubility of substances in rubber and were employed for determinations of the solubility of sulfur and of a common antioxidant, phenyl-β-naphthylamine. Sulfur in combination with rubber had a relatively greater effect on the refractive index than did sulfur in solution. For vulcanized rubber-sulfur compounds in the soft-rubber range, the refractive index was a simple linear function of the percentage of sulfur and also of the temperature. Preliminary measurements on vulcanized compounds in the hard-rubber range indicate that the change in physical properties of rubber-sulfur compounds from soft to hard was accompanied by a decrease in the slope of the curve relating refractive index to temperature.
The Coefficient of Friction of Rubber
Authors: Derieux J. B. 
Published: February 2011

Abstract
Coefficient of friction is defined as the ratio of the force of friction to the load producing it. The accepted laws of the coefficient of friction are: 1. It is independent of the area of the surface in contact. 2. It is independent of the load applied. 3. It is independent of the velocity, at low values. 4. The static value is greater than the kinetic, i. e., it is greater at the beginning of motion than after motion has been established. The accompanying data will show that every one of these accepted laws are violated by rubber. The following values for area were obtained by varying the pressure in an automobile tire in place on an automobile on concrete.
The Specific Gravity of Preserved Latex
Authors: Rhodes Edgar 
Published: February 2011

Abstract
The Journal of the Rubber Research Institute of Malaya, 5, 234 (1934), contained a paper on the specific gravity of preserved latex written by the writer of this note. The paper has recently been made the subject of constructive comment by de Vries. As a result of the examination of 852 samples of preserved latex, a specific gravity/dry rubber content table was derived for preserved natural latices, and the dry rubber content range covered was wide enough to include natural unconcentrated latex in all the phases in which it is likely to be required by or become available to the commercial user. By the unavoidable expedient of extrapolation from the experimental results, a value of 0.902 was also derived for the specific gravity of the rubber phase in preserved latex. This value was in good agreement with the figure of 0.901 obtained by Scholtz and Klotz for “rubber” in fresh latex. On the other hand, de Vries, working with fresh latex had previously derived a value of 0.914 for the specific gravity of the rubber phase, and the specific gravity table used by the Rubber Trade Association of London for preserved latex gives on straight line extrapolation a value of 0.912. It seemed that the value indicated by the work of De Vries and that deduced from the table of the Rubber Trade Association were probably rather high, and certain experiments with centrifugal concentrated and centrifugal concentrate-skim mixtures were cited which provided some confirmatory evidence of this conclusion.
Heats of Reaction of the System Rubber-Sulfur
Authors: McPherson Archibald T. , Bekkedahl Norman 
Published: February 2011

Abstract
PREVIOUS investigators have employed two methods for determining the heat effects when rubber is vulcanized. In one method the heats of vulcanization are found by subtracting the heats of combustion of vulcanized rubber—sulfur compounds from the heats of combustion of the corresponding mixtures of rubber and sulfur before vulcanization (1, 10, 11). This method is limited in precision by reason of the fact that the differences thus obtained are at most only a few per cent of the measured heath of combustion. The other method, which has been used previously, involves the determination of the temperature rise which occurs when mixtures of rubber and sulfur are vulcanized. This method has, for the most part, been used for relative measurements, but Blake (2) has recently employed it for quantitative determinations of the heats of reaction of rubber with proportions of sulfur up to about 8 per cent by weight. Recently Daynes (7) has employed a similar method for measurements over a wider range of composition. This investigation was undertaken for the purpose of measuring the heath of reaction of rubber with different percentages of sulfur over the entire range of composition in which combination takes place. The study was exploratory in character, the aim being to make the measurements by direct means with emphasis on simplicity rather than refinement of calorimetric procedure.
Dispersion of Channel Gas Black in Rubber. Effect of Stearic Acid and Other So-called Dispersing Agents
Authors: Park C. R. , Morris V. N. 
Published: February 2011

Abstract
THE completeness of wetting of carbon black by rubber, the consequent state of dispersion of the black, and the effect of the surface forces in the development of reënforcement of the rubber have been the subjects of much deliberation and experimentation. Of special interest has been the effect of stearic acid upon the dispersing power of rubber for carbon black. On the basis of Green's observation (6) that the dispersion of zinc oxide which had previously flocculated in kerosene resulted in a pronounced softening of the mixture, Goodwin and Park (5) concluded that stearic acid has little effect upon the dispersion of carbon black in rubber. They pointed out that stearic acid has a slight softening action in uncured stock and in cured stock containing no zinc oxide, and that the addition of fatty acid to a stock containing no zinc oxide affects its physical properties adversely. Although they considered that these facts furnished slight indications of a dispersing effect by the stearic acid, these authors offered no convincing evidence of the dispersing effect of stearic acid on carbon black in rubber. For various reasons, including the fact that the plasticity of uncured black stocks is not materially affected by the presence of zinc stearate, Goodwin and Park also concluded that zinc stearate is not a dispersing agent for blacks. In fact, they postulated that the effect of zinc stearate, if any, is to decrease the wetting of the black by the medium and hence to cause flocculation. Since the combined addition of zinc oxide and stearic acid to a rubber-sulfur mix results in an improvement in properties, these investigators were finally led to the conclusion that the principal effect of these soap-forming agents in a carbon black stock is on the curing properties of the rubber itself rather than on the dispersion of the black.
The Physico-Chemical Properties of Latex and Their Significance in Manufacture
Authors: Madge E. W. 
Published: February 2011

Abstract
The first physico-chemical property of latex to be discussed is that of viscosity, if latex can be said to have a viscosity. As will be seen later, this property is so important in many manufacturing processes, such as extrusion, dipping, and centrifuging that the fundamentals must be understood. Latex, as is well known, is a suspension of irregularly shaped particles, many pear-shaped, in an aqueous medium which itself contains an appreciable proportion of other dissolved and suspended matter. These particles, according to present ideas, are surrounded by a strong adsorption layer, which influences very considerably the properties of the latex. As a result of its composite structure, latex and more particularly latex compounds have rather interesting properties. From the point of view that latex creams under gravity, that the particle carries an appreciable electric charge, and depends partly on this for its stability, and that the swelling of the actual particle in water is very small, it may be called hydrophobic. On the other hand, in view of its behavior with respect to dehydrating agents, the manner in which it forms aqueous voluminous gels, and more particularly in its reaction to shearing forces, latex may be classed as hydrophilic. Its hydrophilic character is conditioned by the material adsorbed on the surface of the particles and is more pronounced in compounded and treated latices.
Heat Changes in the Vulcanization of Rubber. I. Qualitative Tests on a Comparative Basis
Authors: Horie Hukio , Monikawa Kikuo 
Published: February 2011

Abstract
As a preliminary test of the quantitative determination of the thermal changes in the vulcanization of rubber by sulfur, 100 parts of raw, resin-free and pure rubber were compounded with 5, 10, 15, and 20 parts sulfur, respectively, and vulcanized in a thermostat at 160 ± 0.2° C. The change in temperature was noted by reading a thermometer, the mercury bulb of which was inserted in the center of the sample, and the heating curves thus obtained were compared with the analytical results of free and combined sulfur determinations. 1. There was practically no exothermic or endothermic reaction in the samples without sulfur. 2. Those samples containing sulfur had but one maximum exothermic point, and the maximum temperatures decreased in the order: raw rubber system &gt; resin-free rubber system &gt; pure rubber system. 3. The times required to reach the maximum temperature decreased in the order: pure rubber system &gt; raw rubber system &gt; resin-free rubber system. 4. The time required to reach the maximum temperature was shortened by increasing the proportion of sulfur added, except for the 10 per cent mixtures. 5. The presence of nitrogenous substances was detrimental to the vulcanization process, in the reactions where less than 5 per cent of combined sulfur was obtained, but their presence was necessary to obtain more combined sulfur. 6. The agent which accelerates the vulcanization reaction seems to be the nitrogenous substances.
The Raman Spectrum of Rubber
Authors: Gehman S. D. 
Published: February 2011

Abstract
It has been previously reported that the Raman effect is exhibited by rubber as a continuous scattering together with the presence of broad bands (Franklin and Laird, Phys. Rev., 36, 147 (1930); Busse, J. Phys. Chem., 36, 2862 (1932)). Busse attributed this result to the viscosity of the solutions or to the possibility that the rubber groups respond to a wide range of frequencies. However, viscous solutions of polysterol in carbon tetrachloride give a line spectrum (Signer and Weiler, Helv. Chim. Acta, 15, 649 (1932)). As to the second explanation, this does not seem to be the nature of the Raman effect (Bär, Helv. Phys. Acta, 4, 369 (1931); Bär, Z. Physik, 79, 455 (1932)). The Raman effect has been investigated extensively for terpenes other than rubber. The bands and continuous background for rubber appear to be due to fluorescence of impurities, oxidation products, or the rubber hydrocarbon. The acetone extract of rubber is fluorescent as observed in ultra-violet light. The intensity of the bands and background for rubber decreases as the rubber is purified. However, acetone extraction and two diffusions with ethyl ether did not remove the fluorescence entirely, as could be seen by examination between complementary light filters. Some of the background is undoubtedly unmodified radiation, that is, Tyndall scattering by the colloidal structure and by motes. This can be reduced by a monochromatic light filter.
Studies on the Acetone Extraction of Raw Rubber
Authors: Endô Hidemaro 
Published: February 2011

Abstract
(1) For the determination of the saponification value of the acetone extract, 20 cc. 0.2 N alcoholic potash is added to the extract and the flask is heated on a water bath for 60 minutes. It is then titrated with 0.1 N HCl solution, using phenolphthalein as indicator. (2) When the saponification values of the acetone extracts of 8, 16, and 24 hours are compared, the saponification value of the 8 hour extract is seen to be high, while those of 16 and 24 hour extracts are low. This indicates (a) that the 8 hour extract contains a higher percentage of saponifiable matter than the 16 and 24 hour extracts; (b) the quantity of rubber hydrocarbon which is dissolved in the acetone extract increases with increasing time of extraction, and (c) the acid value of the acetone extract decreases during the period of extraction from 16 to 24 hours. (3) Regarding the saponification values (R) of the acetone extracts of 8, 16, and 24 hours, similar remarks may be made as in (2) above.
Research on Modified Rubbers. Part V. Technological Properties of Chlorinated Rubbers from Latex
Authors: Schidrowitz P. 
Published: February 2011

Abstract
Bloomfield and Farmer, in a paper on “The Preparation of Chlorinated Rubbers from Latex” (J. Soc. Chem. Ind., 53, 43 (1934); Rubber Chem. and Tech., 7, 320 (1934)) have described the chief chemical properties of the products prepared by them. The object of the present paper is to describe briefly some characteristics of these products from the technological standpoint. It will be remembered that, although Bloomfield and Farmer were able to prepare a soluble chlorohydrin from one batch of latex, all other batches yielded insoluble products, although some modification of this insolubility was attained by the addition of serum from the satisfactory latex to those latices which were refractory in this regard. Moreover, the latex which yielded soluble products at first, subsequently no longer did so. Similarly the products from the initially satisfactory latex, at first soluble, underwent a gradual change, becoming less and less soluble. The technical examination of the chlorohydrin from latex therefore proved to be difficult. However, as it was thought possible that a method producing substances of more or less consistent composition and solubility might be later developed, the soluble product referred to was examined from the point of view of ascertaining its suitability as a basis for lacquers, moldings, plastic masses and films.
APPENDIX The Composition of Some Chlorinated Rubbers
Authors: Bloomfield G. F. , Farmer E. H. , Miller C. H. 
Published: February 2011

Abstract
With a view to obtaining some information which might throw light on the nature of the expansion process and on certain differences observed in the readiness with which various chlorinated rubbers undergo expansion, the compositions of a number of chlorinated rubbers have been determined. For these determinations the commercial materials were dissolved in benzene and filtered free from insoluble matter, the solutions being then concentrated to small bulk under reduced pressure; the chlorinated rubbers were precipitated by the addition of methyl alcohol, washed and ground with chilled methyl alcohol, and finally maintained at 50–60° under high vacuum until constant weight was attained. The results of the various determinations are expressed in the table below.