bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effect of Simple Carbohydrates on the Vulcanization of Rubber
Authors: Bishop R. O. , Rhodes E. 
Published: February 2011

Abstract
In continuation of investigations on the vulcanization effects of Hevea lipin (Quarterly Journal, Vol. 2, No. 3) the question arose as to the possible influence of the sugar with which lipin is known to be associated. The fact that, in spite of the presence of sugars, the behavior of raw rubber plus lipin on the mixing rolls is apparently similar to that of raw rubber plus lecithin, suggests that the sugars might be without influence. While it is recognized that, for the proper understanding of their influence, it is essential to isolate and characterize the free sugars present in latex, it was considered that the vulcanization effects which we had observed were sufficiently significant in their possible bearing on plantation rubber variation to call for further investigation, and although our subsequent observations cover only a limited field somewhat divergent from the main line of work, it appears that the present results are worth recording.
Studies on the Aging of Vulcanized Rubber. XI. Consideration of the Influence of Free Sulfur on Aging of Vulcanized Rubber
Authors: Yamazaki T. , Okumura K. 
Published: February 2011

Abstract
Although it has been generally known that free sulfur in a vulcanized rubber is likely to change into sulfuric acid during aging, the authors pointed out in their Ninth Report that a part of the combined sulfur also decomposes during aging, with the formation of sulfuric acid. Therefore the authors in this report proceeded to find the relation between the proportions of free sulfur in vulcanized rubber at the state of optimum cure and its aging. The samples used for these experiments were as follows:
The Elasticity Constants of Rubber under High Tensions
Authors: Weise Rudolf 
Published: February 2011

Abstract
The problem of determining the elasticity constants of rubber involves various difficulties. Since the material under investigation frequently has very different chemical properties, even when under the same name, no wholly consistent results are to be expected of physical tests. Moreover, it has been found by experience that tests of samples cut from the same sheet differ greatly. Ordinarily these variations must be accepted as inevitable. However, as the present work will show by way of example, these variations can be kept within certain limits through a proper utilization of a number of experiments. From a technical point of view, the study of elasticity is concerned chiefly with the properties of isotropic substances. Since, upon stretching, rubber becomes anisotropic, the question naturally arises whether mathematical formulas which are valid for isotropic substances have in general any meaning when applied to rubber. Furthermore, it should be mentioned at the beginning that Scherrer has proved by x-ray photographs that in the unstretched state rubber is an amorphous substance. Only at an elongation of about 100 per cent do interferences appear, so that, at least for our purpose, rubber can be regarded as “quasi-isotropic” up to this degree of elongation. This may also be justifiable to a certain extent even at higher elongations since, in describing the elastic properties, the volume is the only function used besides direct measurements, and the volume changes at the most only 2 per cent up to the highest elongations. A large amount of work has been done on the modulus of elasticity and the Poisson constant of rubber. An examination of the literature at present showed, however, that measurements cover at the most only a small part of the possible range of elongation. Only Bjerken and Villari have undertaken experiments at higher elongations as well. The latter investigated the modulus of elasticity up to 6 times, the former the Poisson constant up to 5 times the initial length. The object of the present work therefore has been to determine both constants of elasticity, viz., the modulus of elasticity and the Poisson constant; over the entire range of elongation, with particular attention to determinations of the modulus of elasticity just previous to rupture. To eliminate the temporary after-effect a kinematographic method of measurement was used to advantage. By the same method it was possible to obtain data upon the behavior of rubber up to the point of rupture. To complete the picture of elastic properties, the permanent set as a function of the time and tension was determined.
Laboratory Rubber Testing. Its Relation to Service
Authors: Dinsmore R. P. 
Published: February 2011

Abstract
The rubber technologist of today is situated in one of the most competitive and rapidly changing industries. He is faced with the necessity of producing an important structural material of varied forms and compositions which must constantly be modified to meet new requirements of economy and service. He must be prepared to furnish, upon demand, rubber in new forms and colors, which will serve successfully in increasingly exacting conditions of temperature, flexing, abrasion, and more often than not in conjunction with a totally dissimilar material. To anticipate these demands he must engage in a ceaseless search for new and more effective materials, both in his own research laboratory and amid the countless new natural and synthetic materials which appear on the market. The time has passed when long periods of preparation can be utilized for the development of new compounds and products. The pressure of modern industrial development constantly brings about new conditions which must be met when they arise. The success with which the technologist fulfils these obligations depends in large measure upon his ability to predict the behavior of his materials under the conditions of service. When, as is often the case, his knowledge of both materials and service conditions is limited, results frequently fall far short of expectations.
Factory Mixed Stocks Method for Maintaining Uniformity
Authors: McCarty J. E. , Cousins Edward 
Published: February 2011

Abstract
Close control of milled rubber stocks is important to all rubber manufacturers. The present system developed by the authors is based on the determination of loads for given elongations, using a modified dumbbell strip. An outline of the testing routine follows. Samples from every milled or Banbury mixed batch come to the control laboratory, each sample being accompanied by an identifying card which contains provision for recording all data of interest on that particular batch. As the samples arrive, they are weighed on a laboratory scale to give a definite volume. The molds used for curing contain 32 cavities, each with overflow channels; the cavities are numbered to permit identification of the samples. Each cavity is 1.25 inches (3.18 cm.) by 2.5 inches (6.35 cm.) by 0.125 inch (0.32 cm.). The samples are placed in the hot mold, each in its appropriate cavity, and given a short cure at 320° F. The pieces are then removed and cut out with a die to give a dumbbell strip of the dimensions given in Fig. 1. The die is open at the ends but is long enough to overlap the edges of the small slabs, thereby facilitating the separation of the test strips from the remainder of the slab.
The Rubber Pendulum, the Joule Effect, and the Dynamic Stress-Strain Curve
Authors: Wiegand W. B. , Snyder J. W. 
Published: February 2011

Abstract
General Description.—The rubber pendulum is one of two devices (Wiegand, Trans. Inst. Rubber Ind., 1, 141 (1925)) which, by employing the Joule effect, constitute rubber heat engines in that they continuously convert heat into mechanical work. In Fig. 1 is shown the original pendulum. It consists of an ordinary pendulum of slow period fitted with a rubber band, one end of which is attached to the bob; the other to the upright support. This rubber band is stretched to four or five times its original length. Behind the upright is a metal shield so arranged that when the bob has reached the extremity of its swing the rubber band is clear of the shield, during the rest of the oscillation being in its shadow. Behind the pendulum and shield is an electric heating element with a copper reflector. The pendulum is started by displacement from the center towards one or other extremity. As this is done the rubber band is increased in length. At the extremity of the oscillation the stretch band is exposed to the radiant heat from the element, the Joule effect is brought into play and the band tends to shrink, thus pulling back the bob. Directly the band moves back within the shadow of the shield it cools, relaxes, and so allows the bob to swing out to the other side. Thereupon the band is once more heated up, contracts and so repeats the oscillation, which continues as long as the heat energy is supplied. When the electric current is turned off the pendulum dies down.
Studies on the Joule Effect in Rubber. I. The Thermal Effect on Stretched Vulcanized Rubber
Authors: Tanaka Yoshio , Kambara Shū , Fujita Hironosuke 
Published: February 2011

Abstract
The experiments may be summarized as follows: 1. With an increase in the time of cure, the elongation and heating elongation diminish and the Joule effect increases. 2. An increase in the vulcanization coefficient is followed by a decrease in the elongation and heating elongation and an increase in the Joule effect. The increase in the Joule effect, however, has a limit. 3. An organic accelerator reduces the elongation and heating elongation and increases the Joule effect. 4. The greater the degree of mastication the greater the elongation and the heating elongation and the less the Joule effect. 5. By exposure to ultra-violet radiation, the elongation and heating elongation are increased and the Joule effect decreased. 6. A filler increases the heating elongation and decreases the elongation and the Joule effect. Thus samples with relatively high elongations at a definite tension have relatively high heating elongations and low Joule effects. Such specimens seem to have been affected by the disaggregation and depolymerization of the rubber molecules. The effects of the time of cure, mastication, and exposure to ultra-violet radiation prove this fact. Vulcanization increases the Joule effect, but on the other hand, it is accompanied by a disaggregation and depolymerization of the rubber molecules, so the increase in the Joule effect with the progress of vulcanization has a limit. On vulcanization with an accelerator, the combination of sulfur occurs so rapidly that the increase in the Joule effect is predominant. A filler, such as carbon black, behaves only as a diluent of Joule effect. These results lead to the conclusion that the more highly polymerized rubber molecules and their sulfur compounds seem to be the chief factor in the Joule effect of vulcanized rubber.
Viscometric Studies of Rubber Solutions
Authors: Reiner Markus 
Published: February 2011

Abstract
A former communication reported viscometric observations on rubber-toluene solutions in different capillary and rotation viscometers. The consistency curve of solutions from 0.08 to 1.77 per cent concentration starts at the origin as a straight line, inclined at a definite angle until it reaches a certain point a (see Fig. 1). From there it becomes convex toward the stress axis. This convex part extends to an inflection point b where the curve becomes concave up to a point c, where it again becomes a straight line which by extrapolation passes through the origin. The solutions therefore behave as Newtonian liquids between points o and a, and c and ∞. Between point a and c they are non-Newtonian liquids. It was furthermore shown that the “relative” consistency curve, i. e., a curve in which the shearing stress is reduced or the rate of shear increased in proportion to the viscosity of the solvent, is independent of the temperature at which the viscosity measurement is made. From this latter property the conclusion was drawn that the phenomenon of non-Newtonian behavior is a purely mechanical one. It cannot be due, as has been suggested by Staudinger, to a competition between orientation due to laminar flow and rotational diffusion due to Brownian movement because the magnitude of the latter depends on the temperature.
Rubber from Latex Coagulated with Sulfuric Acid
Authors: Martin G. , Davey W. S. 
Published: February 2011

Abstract
The results of tests carried out in the laboratories of the London Advisory Committee show that when sheet rubber is prepared by coagulation of latex with sulfuric acid: (1) Only a trace of free sulfuric acid remains in the dry rubber. (2) The rubber is somewhat easier to manipulate in rubber manufacturing operations than that prepared by coagulating latex with acetic acid. (3) The rubber has satisfactory mechanical properties when vulcanized in rubbers sulfur or accelerator mixings. (4) The rubber ages satisfactorily in rubber-sulfur and accelerator mixings. (5) The use of sulfuric acid would tend to increase the variability in vulcanization of first-grade rubber unless its use became general.
The Specific Gravity of Preserved Latex
Authors: Rhodes Edgar 
Published: February 2011

Abstract
The literature on latex contains a number of references to the specific gravity of fresh latex, but published information on the specific gravity of preserved latex in the condition In which it reaches the consumer appears to be practically non-existent. de Vries and Scholtz and Klotz investigated the specific gravity of undiluted fresh latices of various dry rubber contents, and from their results each deduced the specific gravity of the disperse or rubber phase. The average specific gravity of the rubber globule as deduced by de Vries is 0.914. Scholtz and Klotz's value for the disperse phase is 0.901, which is appreciably lower than that of de Vries. Although. the published literature contains no references to the specific gravity of commercial preserved latex, the Rubber Trade Association of London gives a table of values in its latex contract forms, but details are lacking as to the total number of experimental observations which the table represents. A significant feature is that, by extrapolation of the dry rubber content values to 100 per cent, after the manner of Scholtz and Klotz, the figures obtained for the specific gravity of the rubber disperse phase is 0.912, which agrees fairly well with that of de Vries for fresh latex, and which is considerably higher than that of Scholtz and Klotz. In view of the paucity of information available on the specific gravity of preserved latex, it seemed desirable to obtain additional data and incidentally to make a further check on the published values for the specific gravity of the rubber disperse phase.
Influence of the Gaseous Medium on Hot Vulcanization
Authors: Buizov B. V. , Popova M. K. 
Published: February 2011

Abstract
The results of our previous study of the thermal vulcanization of rubber made it sufficiently clear that during the heating of rubber mixed with sulfur two complex phenomena take place. On the one hand, sulfur interacts with rubber, and on the other, rubber itself undergoes a depolymerization, as well as a polymerization. In reality, however, vulcanization does not proceed under ideal conditions. The rubber and sulfur in the mixture cannot be conceived in an isolated state. On the one hand, the mixture contains the accompanying substances of rubber, such as resins, albumin, etc., whose role in the vulcanization is far from being explained, and on the other hand, the system: rubber + sulfur always exists in some medium. The latter may be either a gaseous or a liquid medium. Hot vulcanization in the industry is most frequently performed in an atmosphere of hot air or in water vapor. We know how great is the difference in the effects of these two conditions. To be sure, the pressure under which the vulcanization takes place is also of importance here; however, the nature of the gaseous medium has evidently a considerable influence on the vulcanization process, which has never been investigated. It seemed to us therefore of interest to investigate this problem, considering the above mentioned two factors, i. e., chemical binding of sulfur and physical changes in the rubber. The previous investigation had shown that the chemical binding of sulfur alone does not explain the nature of vulcanization. Thus, in some cases rubber on heating combines with sulfur, but at the same time disintegrates into a sticky mass and shows no signs of vulcanization with respect to its physico-mechanical properties. Conversely, cases are known where the chemical combination of sulfur proceeds only feebly (and which with chloroprene rubber is entirely unnecessary), whereas the physico-mechanical effects of vulcanization are well pronounced. We therefore undertook an investigation of the processes of chemical combination of sulfur and changes in the solubility of rubber on heating its mixtures with sulfur in atmospheres of various gases. For these vulcanization tests, a mixture of rubber with 7% sulfur and 0.4% magnesium carbonate in the form of sheets of 0.5 mm. thickness containing 6.5% sulfur was used. A piece of such a sheet was wound in one layer around the glass tube A and was then inserted into the test tube B. Gas was slowly conducted at the top of the tube A escaping through the side tube of the test tube B. In the vulcanization tests in alcohol, water and formaldehyde solution, the liquid was poured into the teat tube B, and on evaporation filled the entire space of the tube. All gases were previously dried.
The Specific Gravity of Rubber in Latex
Authors: Vries Ode 
Published: February 2011

Abstract
In a study on the specific gravity of preserved latex, Rhodes comes to the conclusion that the specific gravity of rubber in latex may be estimated at 0.902, and that the figure of 0.914, found by us several years ago, and the figure of 0.912 used as a basis for the tables in the contracts of the Rubber Trade Association of London, are high. Rhodes's figure is based on a large experimental material (852 samples of preserved latex from nine different estates), and agrees well with the estimated figure of 0.901, to which Scholtz and Klotz came from 85 observations on fresh later in Malaya. Our figure was based on a large number of observations on normal estate latex, as well as on latex from specially tapped groups of trees; the difference between 0.902 and 0.914 is too large to be ascribed to experimental errors, though these of necessity are rather high, as the specific gravity of rubber can only be calculated by extrapolation over a zone much greater than the experimental zone itself. It seems of sufficient interest to subject these deviating results to a closer study, as this may, perhaps, throw some further light on a rather complicated problem which is not without practical interest.
Surface Chemistry of Carbon Black. Effect on Vulcanization of Rubber
Authors: Schoenfeld Frank K. 
Published: February 2011

Abstract
In an attempt to develop a theory for the retardation of the rate of cure of rubber stocks by carbon black the adsorption theory is critically reviewed. Experimental evidence is presented that is not readily explainable on the basis of this theory. It is shown that the retarding action of gas black is analogous to the action of organic acid retarders of cure. The mechanism of this action is unknown. Gas black activatedly adsorbs oxygen to form an acid complex that retards the cure of rubber compounds. Organic acids have been obtained from commercial blacks by washing with alkalies.
The Shock-Absorbing Quality of Rubber
Authors: Frumkin L. , Margaritov V. 
Published: February 2011

Abstract
The extensive use of rubber as a shock-absorbing and vibration-absorbing material makes necessary a definite criterion for this property of rubber. In his work on the problem of the shock-absorbing quality of rubber, Morrison states: “To make possible an easy calculation of the rubber buffer, it is necessary to know (1) the permissible working strain at the static loading for a given rubber, (2) the maximum strain permissible at the shock loading, and (3) the energy absorbed by a unit volume of rubber in tile transition from static to shock loading.” Reference to static load is made because, in this calculation, it is necessary to consider those static forces which act on the rubber before shock. The energy absorbed by the rubber in the transition from the static to the shock load is supposed by Morrison to be that energy which is absorbed by the rubber in its deformation by the shock. The question of the energy returned by the rubber in resuming its original form is not considered by him. Vetchinkin in his study of the work of shock-absorbing aeroplane cords fails also to take into consideration the energy returned by the cord on resuming its original form, and bases his calculation only on the absorption by the rubber of a definite quantity of energy during stretching caused by the impact of the aeroplane against the ground. He mentions only casually that, by increasing the preliminary tautness of tile cords, their hysteresis losses of energy are increased. However, such a concept of the work of a rubber shock-absorber seem to us inadequate. In fact, let us distinguish clearly between the work of shock-absorption of rubber and a steel spring. Of course it should be noted that for deformations by the highest possible stresses for rubber and for a steel spring, the former requires more energy per unit of weight. Thus, according to the above quoted paper by Morrison, 1 kg. of rubber absorbs 172 kg. of energy and 1 kg. of steel only 119 kg., i.e., 44% less. According to Geer (cf. “The Reign of Rubber” the difference is many times greater, viz., 10,000 kg. for rubber and 230 kg. for steel.
Semi-Ebonite. Part 1
Authors: Gibbons P. A. 
Published: February 2011

Abstract
Hitherto two products of the reaction between sulfur and rubber have been studied and used commercially, soft rubber and ebonite. Few publications have appeared concerning the products obtained by vulcanization of proportions between 5 and 30 parts of sulfur with 100 parts of rubber. Before the introduction of organic accelerators of vulcanization the coefficient of vulcanization was considered a satisfactory criterion of the quality of soft vulcanized rubber. Mixes of rubber and sulfur vulcanized to a coefficient of more than 3.5 to 4 were usually considered overvulcanized in that experience showed that the optimum properties as regards tensile strength and elongation at rupture occurred at this degree of vulcanization. Semi-ebonites differ from soft rubber and ebonite in as much as they are extremely sensitive to small changes in the time of vulcanization. Their plasticity is such that the velocity of plastic flow just prior to break is relatively great, and thus they may experience a large elongation at constant load. Their plasticity decreases with further vulcanization, in fact, with advance in vulcanization they become almost rigid at room temperature. The decrease in plastic flow is accompanied by an increase in hardness and brittleness and the ultimate stage in the rubber-sulfur reaction, ebonite, is reached.
Fatty Acid Softeners in Rubber Compounding
Authors: Blow C. M. , Garner T. L. 
Published: February 2011

Abstract
1. A method is outlined for the investigation of softeners in rubber compounding; their softening action, their effect on the tensile strength abrasion and flexing properties in a carbon-black tread stock, and their effect on the dispersion of carbon black. 2. The method is applied to the study of a series of fatty acids, their zinc, magnesium, barium salts, and glycerides. 3. Some results are given of the change of abrasion resistance with temperature. 4. A theory of softening action is suggested.