Semiebonites

1949 ◽  
Vol 22 (1) ◽  
pp. 186-200
Author(s):  
Fritz S. Rostler

Abstract To summarize the principal results of the present investigation, it was found that whereas natural rubber is a poor raw material for the manufacture of semiebonite, butadiene-styrene and butadiene-acrylonitrile rubbers are suitable raw materials, especially in combination with unsaturated hydrocarbon extenders of the Naftolen type. The superiority of GR-S to natural rubber in the form of semiebonite should be an interesting piece of information for every compounder conscientious about the importance of keeping up the use and the manufacture of GR-S. With natural rubber becoming more and more available, there exists, as we all know, the definite danger that GR-S will be pushed into the background. As a matter of fact, we are approaching the situation where the supply of rubber hydrocarbons, natural and synthetic, will exceed the demand by multiples if new uses for rubber in large volume are not found. The increased use of rubber products in the building and construction industry and in road surfacing might provide such an outlet for rubber. Semiebonite with good aging qualities might find many uses along these lines. It might lend itself to the manufacture of floor coverings, of waterproof wall insulation, etc. The possibilities of using semiebonites from GR-S for tire beads has been suggested in a previously published article, but no detailed study comparing various rubbers has been reported. The primary purpose of this report is to present these basic data, which can be used as starting points for compound development and to point out that we have in the semiebonite range a possibility of using GR-S to advantage. As to butadiene-acrylonitrile rubbers, with which, in distinction to GR-S, very useful semihard rubber products can be made with phenolic resins, the medium sulfur range opens the possibility of making semiebonites which are easier to process and cheaper than resin combinations. The use of plastics in the rubber industry was recently discussed and summarized by Winkelmann. The compounding of semiebonites with Naftolen-type products offers a means of regulating the plasticity of the uncured stock as well as the elongation of the vulcanizate. Aging and prevention of sulfur bloom appear also improved. In other words, it was found that the combined use of 15 to 20 parts of sulfur with 15 to 50 parts of a Naftolen-type hydrocarbon gives a satisfactory semiebonite with GR-S, as well as with Hycar, and both these rubbers appear superior to natural rubber in semiebonites.

2021 ◽  
Vol 21 (3) ◽  
pp. 43-62
Author(s):  
Monisha Ravi ◽  
Balasubramanian Murugesan ◽  
Arul Jeyakumar ◽  
Kiranmayi Raparthi

Abstract This research mainly concentrates on eco-friendly construction material. Production of cement and concrete industries release huge amount of carbon dioxide (CO2) and greenhouse gases which affect the environment and also there is a demand in construction material by man-made or nature. The construction sector finds an economic and eco-friendly cement replacement material to achieve the demand for green concrete that improve the energy conservation and better energy saving material. In marine Bio-refinery waste produce huge quantity of calcium carbonate, whose disposal is cause of major concern. Pre-eminent solution for this problem is utilizing the marine shell waste in cement and concrete. It revises the manufacturing process to reduce the raw material usage in production and adoptable material for global warming. Therefore, the researchers focus on marine waste sea shells as the replacement material in construction industry to save the energy and also give sustainable green material. As per the previous studies by the researchers to determine the chemical composition, specific gravity, water absorption, particle size distribution of seashells and also compressive, flexural and tensile strength of concrete. It shows the seashell is filler material that slightly increases the strength when compared to the conventional materials and therefore the sea shells are suitable for the construction field to manufacture the cement and concrete with eco-friendly manner.


1977 ◽  
Vol 50 (4) ◽  
pp. 835-841 ◽  
Author(s):  
R. W. Smith ◽  
V. L. Folt

Abstract Hevea brasiliensis or natural rubber (NR) has been used for over 500 years. Until World War II, it was the basic raw material of the rubber industry. Since that time, the use of synthetic polymers has steadily increased, but the importance of NR has not diminished. In fact, the future for the natural product is very promising since it is the one polymer that is obtainable without depleting fossil fuel raw materials. Natural rubber latex has been extensively studied by a variety of methods, especially the microscope. All of the early work with NR latex was conducted, of course, with the optical microscope. In the late 1940's the electron microscope began to be used, but at that time synthetic rubbers began to demand attention, and work on NR latex diminished. Perhaps investigators felt they knew all there was to know about the microscopical characteristics of this material. Indeed, some very fine work had been done and keen observations made with optical microscopes that could not even resolve all of the particles in a latex material. This paper deals with the electron microscopy of natural rubber latexes with particular attention to the proteinaceous layer on the particle and the fate of particles during varying stages of mastication. The critical technique used was to stain the proteinaceous layer of the latex particle with silver nitrate.


1937 ◽  
Vol 10 (1) ◽  
pp. 17-28
Author(s):  
Albert Koch

Abstract Developments in the Synthesis of Rubber Because of the peculiar properties of natural rubber, its usefulness is somewhat limited, and in many fields of application it is quite unsuitable. In contact with oils and fats it swells rapidly and loses almost completely its good mechanical properties, and besides this natural rubber has poor resistance to heat. Again it is attacked rather easily by oxygen, and on exposure to oxygen and light simultaneously there is a particularly strong tendency to develop cracks within a short time; it is for such reasons that the chemical industries of various countries have been looking for an artificial or synthetic product which is free from the shortcomings of natural rubber or exhibits them to only a relatively small extent. Experimentation on artificial rubber has depended fundamentally on the discovery of Harries that the natural rubber molecule is constructed of isoprene units. Isoprene and its allied hydrocarbons were prepared by Hoffmann and his coworkers at the Elberfeld dye works, and these compounds were in turn polymerized to masses similar to rubber. These experiments were carried out before the World War. Because of a shortage of raw materials during the War, it was necessary to adapt the laboratory results to a factory scale sooner than should logically have been done. At that time the most readily available technical raw material was dimethylbutadiene, a compound which differs from isoprene by the presence of an extra methyl group, as may be seen in Table I.


1938 ◽  
Vol 11 (3) ◽  
pp. 598-600
Author(s):  
H. Walter Grote

Abstract Twenty-five years ago, a pneumatic tire for an automobile cost twenty-five dollars and gave service of about 3500 miles. Today a pneumatic tire costs only one-half as much and can be relied upon to give service of about 25,000 miles. These improvements are the result of various factors, such as the use of cord fabric, organic accelerators, antioxidants, and other carefully chosen raw materials. Among these latter, it is safe to say that carbon black is unquestionably the raw material which has contributed most of all to the increased mileage of pneumatic tires. Years ago when the reënforcing properties imparted to rubber by carbon black first became recognized, this product was furnished without any particular requirements other than freedom from impurities. Later, as the percentage of carbon black incorporated in rubber mixtures continued to increase, certain measures were taken to control the grit content. Ultimately, with the aim of furnishing the rubber industry with a product of the highest quality and greatest uniformity, the most important producers of carbon black, in coöperation with the laboratories of rubber factories, proceeded to develop a series of check tests and various other tests, which have led in turn to the development of the present-day specifications of carbon black.


1961 ◽  
Vol 34 (5) ◽  
pp. 1402-1484 ◽  
Author(s):  
E. B. Storey

Abstract One hesitates to close this review by adding a paragraph of conclusions. The term “oil-extension principle” introduced a new concept to the manufacturer of synthetic rubbers. The principle (if it may be identified by such a word) and the application of the products it generated do not involve any novel or unfamiliar approaches to the art of rubber compounding. Indeed, it would be rendering a disservice to the progress of their adoption by industry to suggest that it required a revision in the viewpoint of the rubber compounder. The use of softeners in compounding was almost coincidental with the discovery of rubberlike substances by the explorers of the 16th century. The development of carbon blacks having more useful characteristics in rubber came after the compounder had become familiar with the application of innumerable inorganic fillers in rubber and, indeed, soots and lampblacks. The tailor-made synthetic rubbers were developed by the chemical industry in the second-quarter of the 20th century and it is scarcely likely that higher molecular weight types would not be produced nor that any inherent processing problems would not be solved when there existed an economic and raw material incentive to do so. These are the contributions of the polymerization chemists and the synthetic rubber industry. Where it is more economically-attractive and technically-desirable to add softener and filler to the synthetic rubber in the manufacturing process, oil-extended rubbers and filler masterbatches will be provided as raw materials for the rubber industry. If on the other hand, these ingredients may be added quite readily during factory mixing operations, without any detrimental effects on the polymer quality, the synthetic rubber producer would be quite unwise to attempt to usurp the functions of the rubber manufacturer. The income of the rubber manufacturer, depends upon the skill and economy that he applies to the operation of mixing rubber with liquid and solid materials and this is the prime occupation of a rubber compounder. It would avail the synthetic rubber producer nothing to try and convince the compounder that he is doing something novel and unusual by preparing softener-filler masterbatches. However, the compounder will be receptive to a pre-blended product that enables him to produce rubber mixes of better or different quality at an equal, or lower, cost. This is the aim and accomplishment of oil-extended rubbers.


Clay Minerals ◽  
2007 ◽  
Vol 42 (2) ◽  
pp. 233-244 ◽  
Author(s):  
A. Aras ◽  
M. Albayrak ◽  
M. Arikan ◽  
K. Sobolev

AbstractTurkey has a long tradition (starting with prehistoric civilizations) and experience in exploring for raw clay materials and processing them into ceramic products. Many of these products, such as tiles and sanitary ware, are manufactured for domestic and export markets. Kaolin is one of the raw materials of major importance for the ceramic and paper industry, as well as for a number of auxiliary applications. There is ongoing interest in applying kaolin in the construction industry as a raw material in the production of white cement clinker and as an artificial pozzolanic additive for concrete (in the form of metakaolin). This report presents results related to search, assessment and evaluation of available resources for advanced cement and concrete additives.


1947 ◽  
Vol 20 (1) ◽  
pp. 99-115
Author(s):  
G. G. Winspear ◽  
D. B. Hermann ◽  
F. S. Malm ◽  
A. R. Kemp

Abstract The wartime replacement of natural rubber by synthetics required an unusual expenditure of effort by the hard rubber industry in a short time. At first, curtailment of normal production, coupled with War Production Board restrictions of formulations, mitigated the urgency for synthetic hard rubber research. It soon became evident, however, that a complete line of synthetic hard rubbers would be desirable. These materials could be fabricated with standard rubber processing equipment, and would offer physical and electrical equivalents for the various grades of natural hard rubber developed during nearly a century. A program was started in these laboratories with the realization that rapid progress might be difficult; research on the compounding of natural hard rubber over the years had failed to produce improvements in overall properties compared with the original “ebonites”. The latter, according to the accepted nomenclature, are simple mixtures of rubber with large proportions of sulfur vulcanized by heating until chemical saturation of the rubber is almost complete. The first approach to the problem was through a study of vulcanizing characteristics and through examination of the hard products resulting from the reaction of sulfur with butadiene-styrene copolymers. As the program progressed, the work was extended to cover the processing of GR-S for ebonite fabrication and the compounding of GR-S hard rubbers for specific applications. Studies also were conducted relating to the compounding and processing of hard nitrile rubbers, and new tests were developed to suplement standard procedures used in the physical evaluation of hard rubbers.


1941 ◽  
Vol 14 (2) ◽  
pp. 386-397 ◽  
Author(s):  
S. Longman

Abstract From the foregoing data on blends of Vistanex Polybutene and rubber, it is evident that these two materials complement one another. Each has properties which the other lacks, and blends of the two can be made to emphasize the more desirable properties of either one. Extreme flexibility in compounding these blends is possible, since they are perfectly compatible in milled compounds. Therefore, great latitude is given in compounding of these blends to secure any range or degree of properties possible with either of the components. Vistanex Polybutenes should not be considered as synthetic rubber, because they will not vulcanize, and they lack certain characteristics of vulcanized natural rubber. More properly Vistanex Polybutenes should be considered as modifying agents for partial substitution of natural rubber. In many cases, this substitution of a part of the natural rubber in a compound by Vistanex Polybutene confers definite advantages and improves qualities of such compounds for special uses. Therefore, Polybutenes, even in normal times, have a very definite field of usefulness and, in the event that imports of natural rubber become restricted, the availability of the Vistanex Polybutenes in quantity will be of increasing importance to the rubber industry. Since the raw materials for the manufacture of Vistanex Polybutene are petroleum products, the availability of raw materials is a source of no difficulty in this country. Likewise, the manufacturing equipment is not excessively expensive, and, with expanded production, lowered prices may confidently be expected.


2013 ◽  
Vol 404 ◽  
pp. 796-801
Author(s):  
Zhao Jun Wang ◽  
Zhou Lin ◽  
Shuai Liu

The rubber industry is an important sector in the national economy. The article took the natural rubber and synthetic rubber as the main studying objects to analyze and forecast the amount of supply and demand of Chinas rubber raw materials. Analyzed the status of supply and demand of Chinas rubber raw materials from 2006 to 2011, and established the Grey Forecasting Model to forecast the supply and demand from 2012 to 2017 in China, and concluded that the prosperous supply and demand of rubber raw materials would be continued in the future.


Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2047 ◽  
Author(s):  
Menéndez-Aguado L.D. ◽  
Marina Sánchez M. ◽  
Rodríguez M.A. ◽  
Coello Velázquez A.L. ◽  
Menéndez-Aguado J.M.

Mining activities in general, and quarrying processes in particular, generate huge amounts of tailings with a considerable presence of fine particles and with a variable composition of minerals, which could limit the direct application of those wastes. Under the paradigm of a circular economy, more effort has to be made to find adequate applications for those secondary raw materials. In this study, a process was proposed and tests were performed to valorise fine particle product as a raw material for the building and construction industry. Samples were taken from wastes in several aggregate production plants, being characterized and processed to remove the clayey components to obtain the cleanest quartz fraction. Then, different characterization and validation tests were carried out to analyse the application of these products as raw materials in the building and construction industry (cement and ceramics). Results showed that with no complex technologies, the tailings can be considered as a mineral raw material in different applications.


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