bluuebunny/crossref_metadata_2025_split huggingface dataset:
Textile Finishes Research
Authors: Stevens H. P. 
Published: February 2011

Abstract
The investigation was initiated with the object of using latex or rubber dispersions as a component of the sizes used for calico printing, dyeing, and stiffening, particularly as regards retention of stiffening ingredients and fillers. Dr. Stevens had, as collaborator, in the investigation, Dr. R. Gaunt, of Manchester, and facilities placed at the disposal of the Association by a firm of Textile Manufacturers. The research assistant who worked under Dr. Gaunt's supervision also availed himself of facilities afforded by the College of Technology, Manchester. The present report summarizes experimental work carried out by the research assistant, and the following are the more important matters dealt with: The microscopic examination of latex impregnated threads is of importance in showing that latex merely penetrates between the fibers but does not penetrate the fiber itself, and that modification of the fiber surface such as by mercerization or xanthation does not result in a closer union of fiber and rubber. The basic conditions under which fabrics take up latex have been investigated and it has been shown that the method of “padding” adopted considerably modifies the results. Under some conditions latex serum appears to be preferentially absorbed so that there is a deficiency of rubber in the cloth. The loss of rubber on soaping padded cloths is a mystery which has not been solved. Much of the work has been devoted to preventing the stickiness or damp feel of latex-treated fabrics. This defect can be eliminated to a great extent by soaking the finished fabric in warm water, but such treatment would not be practicable on a large scale. A satisfactory method of eliminating stickiness has not yet been found. In some cases when tackiness had disappeared the improvement had resulted from the oxidation of the rubber. The cause of the tackiness is not known except that it is probably due to a component in the latex. Attempts to remove this from the latex as by dialysis or the use of centrifuged latex were unsuccessful. A new material made by impregnating stockinette with latex is of interest. The stretch is greatly reduced, but a strip returns after stretching and maintains a tension when stretched like elastic webbing, though to a much less extent. This product may prove useful for bandaging and similar purposes. Also the use of latex as an adhesive for joining lengths of cloth in finishing processes is under trial. Preliminary work on the treatment of cloth with colored latex has been done. This mode of producing colored finishes will require further investigation. The full report is as follows.
Effect of Temperature and Frequency on the Dielectric Constant, Power Factor, and Conductivity of Compounds of Purified Rubber and Sulfur
Authors: Scott A. H. , McPherson A. T. , Curtis Harvey L. 
Published: February 2011

Abstract
The electrical measurements given in this paper differ from those previously reported by the authors and by other investigators in that they were made on specimens prepared from purified rubber. The purification, which involved the removal of proteins, resins, and water-soluble salts, affected all the electrical properties to some extent, but did not alter the general character of the variation in electrical properties with composition, temperature, or frequency. The results of the present investigation afford comprehensive data on the electrical properties of rubber-sulfur compounds, and may form a basis for designing rubber compounds for specific electrical uses. They also demonstrate the inadequacy of the simple numerical coefficients that are sometimes employed to evaluate the changes in the electrical properties with temperature and frequency. A discussion of the results from the standpoint of modern dielectric theory is not included in the present paper, but is contemplated for a separate paper.
Effect of Temperature on Tensile Properties of Vulcanized Rubber
Authors: Somerville A. A. , Russell W. F. 
Published: February 2011

Abstract
The tensile properties and tear resistance of a large number of commercial inner tubes, before and after aging by different methods, are studied at 0°, 25°, and 100° C. A number of uncured bus-truck tube stocks are also studied from the point of view of their capacity to withstand high temperatures. The effect of testing rubber at 100° C. as compared with room temperature is discussed; how some compounds collapse at 100° C., while others have tensile properties equal to, or better than those at 25°, is shown. The effect of testing artificially aged specimens at 100° C., as well as at 25° C., is discussed; the high-temperature test may reveal conditions of deterioration and overcure that are not noticeable in the 25° tests. The compounding and curing conditions that lead to high tensile properties at 100° C., as well as those which cause inferior quality, are discussed.
Physical Properties of DuPrene Compounds
Authors: Bridgwater E. R. 
Published: February 2011

Abstract
Although DuPrene differs chemically from natural rubber, it bears a closer physical resemblance to rubber than any of the previously known synthetic rubbers. It differs from natural rubber in many respects which makes it more suitable for certain purposes and less suitable for others. Its physical properties are susceptible of wide variation depending on the nature and amounts of vulcanizing agents, reënforcing pigments, etc., that are compounded with it, and it tills the need for a rubber-like material having greater resistance to the action of oils and solvents and greater resistance to the deteriorating influences of heat and oxidation than natural rubber.
Research on Modified Rubbers. Part III. Adhesive Latex (b) Characteristics of and Tests on Sticky Latex
Authors: Schidrowitz P. 
Published: February 2011

Abstract
In the course of an investigation on the oxidation products of dry rubber and of latex, the reaction of latex with hydrogen peroxide was studied. One result of this work was that a latex possessing distinctive adhesive or sticky qualities was prepared, and it is believed that the so modified latex may prove to be of commercial interest. It is proposed, for the sake of brevity, to refer to this product as “sticky” latex. Attention was first drawn to the apparent advantage of “sticky” latex as a result of difficulties which arose in connection with the problem of making a good joint between leather and a certain type of rubbered fabric. The latter was coated with rubber cement, according to the well-known practice, and the leather treated with latex. Using “ordinary” 36 per cent latex, 60 per cent concentrated (by centrifugation) latex, ditto diluted to 36 per cent, 70 per cent concentrated (by evaporation) latex, and ditto diluted to 36 per cent, the results were not as satisfactory as was desired. “Sticky” latex was then tried and found to give distinctly better results. The process of handling was facilitated and a joint was obtained which could not be broken without tearing the fabric, and which, moreover, resisted the action of fresh and sea-water acting over a period of several days. When using a self-curing rubber cement on the fabric, it was found that whereas the joints made with the standard varieties of latex mentioned tended to open up (unless constant pressure was applied prior to the completion of the vulcanization stage), this undesirable effect did not take place when “sticky” latex was employed. The readiness with which surfaces treated with “sticky” latex adhere to one another, and the fact that prolonged pressure is not necessary to obtain good results, should be of considerable practical importance in certain classes of work. Another advantage is that if a piece of material has been applied in a wrong position, making an adjustment necessary, the broken joint may readily be remade when “sticky” latex has been used. The other fabrics tried do not possess this property to the same degree, and if a joint made with these is pulled apart, the surfaces do not readily adhere again.
Research on Modified Rubbers. Part IV. The Oxidation of Rubber with Aqueous Hydrogen Peroxide-Acetic Acid Mixtures
Authors: Bloomfield G. F. , Farmer E. H. 
Published: February 2011

Abstract
Mair and Todd (J. Chem. Soc., 1932,, 386), in extending the earlier work of Robertson and Mair (J. Soc. Chem. Ind., 46, 41T (1927)), studied the interaction of a chloroform solution of purified rubber with concentrated hydrogen peroxide (100 vols.) dissolved in glacial acetic acid; by this means they obtained a non-acidic substance of the empirical formula C50H92O16, which was unsaturated toward bromine and permanganate, and was considered to have all its oxygen present in the form of hydroxyl groups. Other workers have reported that when peracetic acid dissolved in glacial acetic acid is used in place of the hydrogen peroxide—acetic acid mixture, the products of reaction are acetylated derivatives of rubber (British Patent 369,716). These acetylated derivatives are stated to be obtainable either from solid rubber or from solutions of rubber, but no evidence as to their constitution has been advanced. Now the oxidative degradation of rubber is of considerable interest from two points of view: first, with regard to the light which it may throw on the size, structure, homogeneity, and normality of chemical behavior of the molecules of rubber; and, second, with regard to its efficacy as a means of transforming rubber into derivatives of similar or smaller molecular weight, capable of useful application in industry. The very careful work of Mair and Todd has gone far to show that hydrogen peroxide under the conditions of their experiments attacks the unsaturated centers of the rubber molecule and effects more or less complete hydroxylation of the carbon chain; at the same time it brings about a considerable degree of degradation of the molecule. The product of Mair and Todd, however, is produced under rather restricted conditions of reaction and the reagents employed are costly; consequently the extent to which the character of the product can be modified (i. e., by controlling the degree of degradation, hydroxylation, and acetylation) is left undetermined, and the possibility of producing useful materials at a reasonably low cost by modifying the conditions of reaction and the form of reactants is left unexplored. On the other hand, the employment of peracetic acid as an oxidizing agent, though offering a theoretically elegant way of effecting hydroxylation or acetoxylation at the unsaturated centers of the rubber molecule, is not without drawbacks: the preparation of the reagent is expensive and on a large scale dangerous; moreover, in spite of the fact that it is claimed to be employable either with solutions of rubber or with solid rubber, its reaction with rubber is so vigorous that the prospect of exercising any effective control over the extent of degradation or degree of hydroxylation (acetoxylation) is greatly diminished.
Isoprene and Rubber. Part 41. The Hydrogenation of Rubber and Balata
Authors: Staudinger H. , Leupold E. O. 
Published: February 2011

Abstract
Viscosity measurements of dilute solutions of rubber and of balata led to the following values for the size and form of the molecules of these hydrocarbons. It is therefore not a question of definition whether the particle sizes shown above are to be regarded as the molecular or the micellar weights of these substances, for here the concept of molecular weight has the same significance as in the case of lower molecular substances, i. e., the molecule comprises the sum of all atoms combined by normal, i. e., homopolar atoms. The only difference between low and high molecular substances is that low molecular substances are composed of molecules of uniform size, whereas high molecular substances are a mixture of homologous polymers, so that the values above refer to average molecular weights. These results, which explain the nature of colloidal solutions of rubber, are at variance with the views of most investigators of colloids, who ascribe a micellar structure to the rubber particles, and in this way explain the property which rubber has of forming colloidal solutions. This makes clear why until very recently explanations of the constitution of rubber have been open to question among these particular investigators themselves. In order to lend further support to our opinion, the reduction of rubber and balata and low molecular homologous polymeric hydrocarbons was undertaken from certain points of view, as shown in the work which follows.
Natural and Synthetic Rubber. XII. Reversible Vulcanization, by Organo-Metallic Derivatives
Authors: Midgley Thomas , Henne Albert L. , Shepard Alvin F. 
Published: February 2011

Abstract
Rubber has been vulcanized with organo-metallic compounds; this vulcanization has been reversed, then repeated. An interpretation of the experiments is proposed and the bearing on sulfur vulcanization is pointed out.
Natural and Synthetic Rubber. XIV. A Structural Formula for Ebonite
Authors: Midgley Thomas , Henne Albert L. , Shepard A. F. 
Published: February 2011

Abstract
A formula for ebonite has been proposed, where sulfur is linked to a carbon atom bearing a methyl group on the one side and to the next third carbon atom of the rubber chain on the other side This formula is based on a consideration of the pyrolysis products of ebonite.
Plantation Studies of Crude Rubber Variation
Authors: Sackett George A. 
Published: February 2011

Abstract
1. A comparison of the results of the present work with that of previous investigators shows that certain natural and processing variations have the same effect on a Captax-accelerated stock as they have on a rubber-sulfur stock. 2. In attempting to produce a uniform sheet on a plantation the following points should be remembered: Latex should be blended so that the effect of the tapping system is minimized. Latex should be brought to a standard dry rubber content before coagulation. The anticoagulant and coagulant must be carefully controlled as to quality and quantity. The length of time between acid addition and rolling should be carefully standardized. The rolling equipment should be sturdily constructed and the rolls so fixed that they cannot be easily changed. The temperature of drying should be so fixed that it is always the same and at such a point that fuel consumption is at a minimum. 3. The causes of variation are so many that unless everything is held absolutely constant, the product may vary in rate of cure as much as if nothing is done in the way of standardization. 4. While it is conceivable that a plantation may produce a uniform product for a short space of time through careful supervision, no amount of care in processing can entirely overcome the seasonal variation, or the variations due to rainfall and wind. It is not probable, however, that all plantations will be able to produce a material with the same rate of cure as all the others, for they must overcome variations caused by climate and geographical location as well as those caused by different types of all the manufacturing equipment of all kinds. The consumer of crude rubber must bear the burden of eliminating most of these variables by blending the crude rubber just prior to use, for only at that time does the rubber accumulate in such a way that blending is economical.
Iodine Value of Rubber and Gutta-Percha Hydrocarbons As Determined by Iodine Chloride
Authors: Kemp A. R. , Mueller G. S. 
Published: February 2011

Abstract
HALOGEN absorption methods employing solutions of bromine, iodine bromide, or iodine chloride are widely used for determining the unsaturation of organic compounds. In the use of these methods the choice of halogen reagent, the amount employed, and the time and temperature for the reaction are all important factors which must be given careful consideration in order that the best results may be obtained. Certain structural differences in unsaturated organic compounds may have a decided influence on the reactivity of these substances toward halogens. For example, the presence of negative groups on one or both of the unsaturated carbon atoms protects against halogen addition; thus maleic or fumaric acids do not add iodine chloride (7). Styrene adds iodine chloride quantitatively, but in the case of cinnamic acid only a slight reaction takes place (4). No addition of iodine chloride occurs with dichloroethylene and very little with vinyl bromide (3). The authors have found that polyvinyl chloride (DuPrene) adds iodine chloride to only 30 per cent of theory. A triple-bonded compound, such as diphenylacetylene (4), shows only partial addition of iodine chloride, as would be expected from the negative effect of the first additive halogen. The unsaturated terpenes vary widely in their reactivity with halogens, extensive substitution occurring along with addition (5), particularly in the case of pinene. Aside from these complications, however, numerous investigators have shown that one or more of the halogens add quantitatively to a wide range of unsaturated hydrocarbons, acids, glycerides, alcohols, esters, etc. Of the many methods proposed the well-known Wijs procedure involving the use of 0.2 N iodine chloride in glacial acetic acid has been widely used and accepted.
Rubber. XVIth Communication. The Method of A. R. Kemp for the Determination of the Iodine Number of Rubber
Authors: Pummerer Rudolf , Stark Hermann 
Published: February 2011

Abstract
In a communication of Pummerer and Mann in 1929 on the determination of the iodine number of rubber by means of iodine chloride in chloroform solution, Fisher and Gray were erroneously mentioned as the originators of the method, because of the fact that these authors were the first to publish the method in accessible form. The fact was overlooked that Fisher and Gray state in a footnote that the method was not their own but was that of A. R. Kemp of the Bell Telephone Laboratories. We are greatly indebted to Kemp for calling to our attention the error, which also appears in our XIVth Communication. The first paper of Kemp on the subject appeared a year later, and contains precise information. Kemp worked with a solution of iodine chloride in glacial acetic acid and a solution of rubber in carbon disulfide at 0° C., and as long ago as 1927 he showed that rubber obtained by extraction of crepe with petroleum ether (b. p. 35–60° C.), and precipitation with alcohol according to the method of Weber, Caspari and Feuchter, gave very satisfactory iodine numbers of 99.43–99.76 per cent of the theoretical value. At 15–20° C. disturbing effects of substitution occurred.
The Impact Resiliometer
Authors: Lüpke Paul 
Published: February 2011

Abstract
Original Purpose The writer's first conception of an instrument for quickly measuring the resilience of rubber samples arose in connection with the basic idea for and development of the present A.S.T.M. hardness tester, in an endeavor to provide a reproducible means of measuring and expressing those properties of rubber compounds superficially apparent to the average user. It seemed that if the resistance to pressure (indenting or flexing) and the pressure, or force, of recovery, of a sample were duplicated, the article produced would “feel” the same as the sample, and under normal conditions of use would act mechanically the same. Nature of Problem This problem of measurement, as is generally known, is complicated by the time-hysteresis characteristic of vulcanized rubber compounds, arising through a dual nature, and causing them to manifest both elastic and plastic properties. Any instrument which applies load momentarily measures the almost purely elastic properties, while one which applies a more or less sustained load measures elastic properties modified by the material's partially plastic nature. These ideas are expressed from commercial and industrial viewpoints without regard to their possible deviations from the strict definitions accepted in physical science.
The Degradation of Rubber Solutions
Authors: Bary P. , Fleurent B. 
Published: February 2011

Abstract
From the beginning of our experiments we have called attention to the fact that the character of the degradation varies nit only with the prevailing temperature but also with the solvent used. In particular, if one compares the solutions obtained by the degradation of a given rubber (pale crepe) at a concentration of 0.02 in aromatic hydrocarbons, it is found that the color of the solution changes in the following way: In benzene at 80° the degraded solution remains colorless. In toluene at 93° the degraded solution becomes golden yellow. In xylene at 138–140° the degraded solution becomes dark brown. In cumene at 150–155° the degraded solution becomes brown-yellow. The temperature takes part in these changes through a pyrogenic action which in the case of xylene, can easily be detected by the odor, but this is not the only cause since cumene, used like xylene at the boiling temperature, gives a much lighter solution than would have been expected, and there is no pyrogenation or only a very slight one. Moreover, it is observed that when the degradation has reached a sufficiently high point, coagulation of rubber by the addition of alcohol or of acetone becomes impossible, and sometimes a very stable emulsion is formed, but the part emulsified does not represent anywhere nearly the total quantity of rubber, since the latter has been converted to a great extent into a form soluble in acetone. If the solution is evaporated by a method which makes possible a determination of the rubber it contained when it was not degraded, the quantity found after evaporation is very much less than that which should be present, and furthermore the product obtained is in a pasty state, almost liquid and gluey, as rubber would be if it had turned to a fatty condition.
The Formation of Sulfur from Hydrogen Sulfide and Sulfur Dioxide. A Contribution to the Vulcanization Process of Peachey
Authors: Hock Lothar , Schmidt Hans 
Published: February 2011

Abstract
In the reduction of sulfur dioxide by hydrogen sulfide, the course of the reaction depends wholly upon whether water is present or the gases are dry. With water present, there is a ready separation of sulfur, even at room temperature, according to the general reaction: SO2+2H2S→3S+2H2O, though accompanied by more complicated reactions involving the formation of polythionic acids. On the contrary at room temperature the dried gases do not react, and only at elevated temperatures do they give rise to sulfur and water vapor, in which case because the reaction is exothermic the equilibrium is displaced more and more toward the original sulfur dioxide and hydrogen sulfide. Conversely then, the formation of free sulfur is favored by lowering the temperature. The heat of activation of the reaction is however so great, even at room temperature, that the rate of the reaction is imperceptibly small, and accordingly no reaction is observable. In the presence of rubber, on the other hand, conditions are extremely favorable for activation, because the rubber hydrocarbon plays the part of an acceptor of the liberated sulfur and is vulcanized by it, as Peachey and Skipsey were able to show in their well-known work. The question then arises whether, in this form of vulcanization, the water which is already present or which is formed plays a decisive role in starting and continuing the reaction (in which case the formation of polythionic acids might also play a part), or whether the essential reaction takes place between the two gases in the dry state, in which case the reaction progresses in a much more unrestrained way than in the absence of substances which activate the reaction. In view of this, two series of experiments were planned with the object of obtaining a better insight into the reaction. In one series the rate of the reaction with both gases in the dry state was studied by some trial measurements only; in the other series the part played by moisture in vulcanization by the Peachey process and in the vulcanization of rubber swollen in benzene was investigated.