Goodyear Medalist Lecture. Goodyear Medalist Lecture Towards Understanding of the Rheology of Rubber Compounds and their Processing

2009 ◽  
Vol 82 (2) ◽  
pp. 131-148 ◽  
Author(s):  
James L. White
Keyword(s):  
Rheological Properties ◽  
Processing Technology ◽  
Early Age ◽  
Technical Literature ◽  
Technical Problems ◽  
Rubber Industry ◽  
Professional Career ◽  
Synthetic Rubber ◽  
Rubber Compounds ◽  
The Usa

Abstract The problems of the rheological properties of rubber compounds and the understanding of the processing operations that are used to produce rubber products have received relatively little study in the literature compared to thermoplastics. This seems in part due to an almost 200 year old tradition of industrial secrecy and the vertically integrated nature of the synthetic rubber producer — tire manufacturer combines in the USA. Thus while abundant information has always been available from thermoplastics suppliers on processing technology, little has been available on rubber. Because I began my professional career in the rubber industry and became from an early age concerned with its technical problems, I have not been swayed to the same extent by the thermoplastics dominated technical literature as others in the polymer community.

Tack in Rubber

1964 ◽  
Vol 37 (5) ◽  
pp. 1178-1189 ◽  
Author(s):  
O. K. F. Bussemaker
Keyword(s):  
Natural Rubber ◽  
Theoretical Approach ◽  
Point Of View ◽  
Rubber Industry ◽  
Highly Active ◽  
Synthetic Rubber ◽  
The Usa ◽  
The Subject ◽  
The Difference ◽  
Definition Of

Abstract The expressions tack, tackiness, and stickiness have been in use since the beginning of the rubber industry. During the years their meaning has changed considerably. The first occasion where tackiness was mentioned was in the case of crude natural rubber. The surface of the rubber became tacky or sticky during storage. This phenomenon has been thoroughly discussed in the literature. As a general conclusion it was accepted that both oxidation and depolymerisation occurred. Three factors were reported to be the cause of these processes: light, traces of copper, and manganese. From our point of view we would call this effect stickiness, as we are only interested in the building tack of rubber. In the period when the only rubber was natural rubber and high loadings of highly active fillers were not generally used in compounds, building tack was no problem. Building tack was first mentioned in a publication by Griffith and Jones in 1928. They started their experiments by measuring tack in their search for methods to prevent cotton liners from sticking to unvulcanized rubber. One would have expected much work on the measurement and improvement of tack in Germany and Russia during the development of synthetic rubbers. However, this only proved to be the case in Russia. The first publication available was the translation of an article by Voyutskii and Margolina in 1957. From Voyutskii's work we were able to trace the first article in 1935 by Zhukov and Talmud, who studied the adhesive power of synthetic rubber. In the USA the first theoretical approach to the subject was by Josefowitz and Mark in 1942, who at that time did not realize the difference between stickiness and tack. This difference became clear when lack of tack became the big problem in the use of synthetic rubber. In many cases it was found that addition of resins and softeners gave a very sticky compound which had no building tack at all. The tack problem was first discussed at the ASTM symposium on the application of synthetic rubbers in 1944 by Juve who gave a definition of building tack. From that time, the problem has been studied regularly, especially from the practical side, to find ways and means to improve the building tack of synthetic rubbers.

INFLUENCE OF EPOXIDIZED EXTENDER OIL PROPERTIES ON RUBBER PERFORMANCES

2021 ◽  
Author(s):  
◽  
Olga Govedarica ◽  
Predrag Kojić ◽  
Oskar Bera ◽  
Mirjana Jovičić ◽  
...  
Keyword(s):  
Soybean Oil ◽  
Main Function ◽  
Elongation At Break ◽  
Rubber Industry ◽  
Mineral Oils ◽  
Synthetic Rubber ◽  
Rubber Compounds ◽  
Reinforcing Fillers ◽  
Batch Mixer ◽  
Processing Aids

The rubber compounds are obtained by blending natural or synthetic rubber, reinforcing fillers, rubber extender oil and other additives. Choosing the best components for rubber compounding are essential in rubber industry. The main function of rubber process oil (extender oil) is to reduce viscosity and improve mobility of the rubber chains and thus enable better processing and dispersion of the filler particles. Mineral oils, particularly aromatic ones, were widely used as extender oil in rubber industry, however, due to their influence on environment and the toxicity, there is a demand for their replacement in rubber compounds. One of the environmentally friendly extender oils with possible use in the compounding process as processing aids are epoxidized vegetable oils. In this study, influence of the epoxidizes soybean oil as extender oil on the properties of compound based on natural rubber was investigated. Characteristics of epoxidizes soybean oil as extender oil was experimentally measured or calculated. The experiments were performed on a laboratory internal batch mixer, at the constant temperature of 90°C and a rotor speed of 60 rpm. The hardness, tensile strength, elongation at break, modulus at 100 and 300% elongation, and rheological properties of rubber compounds were determined. Power consumption during rubber compounding mixing phase was calculated on the basis of experimentally measured voltage and amperage.

The Use of Synthetic Rubber in the Automotive Industry from the Viewpoint of the Rubber Technologist

1941 ◽  
Vol 14 (1) ◽  
pp. 211-220
Author(s):  
J. N. Street ◽  
H. L. Ebert
Keyword(s):  
Automotive Industry ◽  
Primary Interest ◽  
Rubber Industry ◽  
Synthetic Rubber ◽  
Self Sufficiency ◽  
Rubber Compounds ◽  
The Subject ◽  
Service Conditions ◽  
State Of Affairs ◽  
Economic Price

Abstract The primary interest of the automotive and of the rubber industry in so-called synthetic rubbers is to obtain products which will stand up under service conditions in which present rubber compounds either do not perform satisfactorily over their entire expected life, or are approaching their limit; or because of these factors, are limiting automotive engineering development. In addition, the last few months have seen a trend of thinking toward a nationalistic program of at least partial self-sufficiency, in case of emergency, or a possibility of the limitation of the poundages of crude rubber available to us at an economic price. The subject “The Use of Synthetic Rubber in the Automotive Industry” is consequently being considered in the light of both viewpoints. Activity in the field of synthetic rubbers as far as laboratories in this country are concerned has increased considerably over the last three years, and it is quite likely that the data and viewpoints herein presented on present polymers may very well be obsolete within a matter of months, and certainly within a year or two, with the appearance of new polymers and modifications of present ones. The object of this paper is consequently to summarize the present state of affairs regarding materials now available. The literature on synthetic rubbers is abundant as to the preparation of the various kinds and varieties, their compounding, and the characteristics of fabricated products. A very excellent and interesting summary is that by Wood. From a general viewpoint, the article entitled “Synthetic Rubber” in the August issue of Fortune is very much to the point. The characteristics of Neoprene are well known. Those of the butadiene types have been described in several articles by Stöcklin and by Koch. Similarly other products have been described. Anderson and Garner and Westhead have given some comparative data on Neoprene and Buna types. In view of these articles, the present paper appears superfluous. It has been pointed out by Wood, however, that it would be desirable to have additional confirming data on a comparable basis on the materials now available. It has been with the hope of supplying such data, at least in part, and particularly as applied to usage of synthetic rubbers in the automotive field, that the authors continued with the preparation of this paper.

Selection and Use of Age Resistors in Rubber Compounds

1934 ◽  
Vol 7 (4) ◽  
pp. 663-687
Author(s):  
Richard A. Crawford
Keyword(s):  
Surface Treatment ◽  
Early Development ◽  
Reducing Agents ◽  
Adhesive Properties ◽  
Temperature Changes ◽  
Rubber Industry ◽  
Beneficial Effects ◽  
Organic Bases ◽  
Rapid Deterioration ◽  
Rubber Compounds

Abstract THE early development of the rubber industry was handicapped by two serious defects in rubber articles. They were not stable to temperature changes, and they deteriorated rapidly with age. Although the process of vulcanization corrected the first difficulty, rapid deterioration with age was common until the discovery of certain organic accelerators, such as p-aminodimethylaniline, the aldehydeamines, and mercaptobenzothiazole. Prior to these discoveries a number of materials had been patented for the purpose of improving the age-resisting properties of rubber, but many of them were of little merit and most of the others possessed some accelerating value, a fact which was not appreciated at the time. Typical of the more useful early patents for age-resisting materials are American patents by Murphy in 1870 (15), Moore in 1901 (14), and Martin in 1922 (12), and the German and English patents of the Ostwalds in 1908 and 1910 (19, 20). Murphy patented phenol, cresol, and cresylic acid, either added to the uncured stock or as dipping solutions for vulcanized articles for the purpose of improving their resistance to aging. Moore used reducing agents, including hydroquinone, pyrogallol, and p-aminophenol hydrochloride, to preserve the adhesive properties of rubber cements. Martin suggested aniline and other organic bases as a surface treatment for vulcanized articles. The Ostwalds also recognized the beneficial effects of aniline on rubber and stated that it could be added at any convenient stage of manufacture. (It is interesting to note that these inventors considered that addition of aniline to uncured stock or dipping the cured article in aniline were equivalent, and they, therefore, evidently did not recognize the accelerating effect of aniline.)

scholarly journals Problems and possibilities of using telephone technology in education

2002 ◽  
pp. 133-140
Author(s):  
Mirceta Danilovic
Keyword(s):  
Educational Process ◽  
Economic Conditions ◽  
Technology In Education ◽  
Local Learning ◽  
Learning Center ◽  
Technical Problems ◽  
Telephone Networks ◽  
Material Sources ◽  
The Usa ◽  
At Home

The paper explores the possibilities of using telephone technology in educational process. It is emphasized how valuable audio-teleconference and tutorial teaching are by means of telephone technology but skepticism is also expressed concerning the possibilities of using this type of technology in our educational system. The causes for such skepticism are mostly to be found in our economic conditions, inadequacy of material sources and technical problems i.e. underdeveloped telephone networks. Telephone technology is not suitable for work with a whole class. It is primarily intended for one-to-one teaching, in the USA most often called 'tutorship'. Accordingly, 'telephone tutorship' is the most widespread form of telephone application in the teaching process. When it is being accomplished, a student (user) has only to have a telephone at home or that public phone network is operating and he/she can communicate with his/her 'tutor', (teacher). 'A tutor' can be at home and communicate with his/her students or at a local learning center wherefrom he/she can communicate with a student. Students can also be at their local learning center or at home.

Rheological Properties of Rubber Compounds with Finely Divided Carbon Additives

2018 ◽  
Vol 91 (1) ◽  
pp. 146-151 ◽  
Author(s):  
Zh. S. Shashok ◽  
N. R. Prokopchuk ◽  
K. V. Vishnevskii ◽  
A. V. Krauklis ◽  
K. O. Borisevich ◽  
...  
Keyword(s):  
Rheological Properties ◽  
Rubber Compounds ◽  
Carbon Additives

scholarly journals Harold Garnet Callan. 5 March 1917 — 3 November 1993 Elected FRS 1963

2003 ◽  
Vol 49 ◽  
pp. 107-118
Author(s):  
Joseph G. Gall
Keyword(s):  
World War Ii ◽  
Air Force ◽  
Personal Information ◽  
World War ◽  
Royal Air Force ◽  
Professional Career ◽  
The Usa ◽  
Chief Interest ◽  
The University ◽  
Insight Into

With the death of Harold Garnet (‘Mick’) Callan on 3 November 1993, the community of cell biologists lost one of the twentieth century's most profound and colourful students of chromosomes. During his 50-year scientific career the study of chromosomes and genes went from purely descriptive and morphological to deeply analytical and molecular. Steeped by training in the earlier tradition, Callan nevertheless contributed enormously to this revolution with his meticulous studies on the giant chromosomes of amphibians, all the while maintaining that he was a ‘mere cytologist’ on whom much of the molecular analysis was lost. Mick Callan and I were professional colleagues and close personal friends whose careers intersected at many points. We visited and worked in each other's laboratories, we published together, we generated a voluminous correspondence (much of it in the days when letters were handwritten), and our families enjoyed many good times together in Scotland and the USA. My most difficult task in writing this biography has been to extract from the vast amount of public and personal information in my possession those parts of Mick Callan's life and work that will be of chief interest to a broader audience. I have been helped in this by a 30 000-word autobiography written by him near the end of his life, covering the period from his birth in 1917 to the end of World War II in 1945. This account provides considerable insight into the factors that shaped his later professional career and is an engrossing account of the life of a boy in prewar England and a young man at Oxford and in the Royal Air Force (RAF) during the worst days of the war. Callan's autobiography has been deposited in the University library, St Andrews, Scotland.

High-Temperature Oven Aging of Oil-Resisting Synthetic Rubber Compounds

1945 ◽  
Vol 18 (3) ◽  
pp. 667-678
Author(s):  
G. D. McCarthy ◽  
A. E. Juve ◽  
H. Boxser ◽  
M. Sanger ◽  
S. R. Doner ◽  
...  
Keyword(s):  
High Temperature ◽  
Constant Temperature ◽  
Test Tube ◽  
Principal Factor ◽  
Synthetic Rubber ◽  
Rubber Compounds ◽  
Exposure Temperature ◽  
Hardness Change ◽  
Temperature Exposure ◽  
Good Heat

Abstract An investigation of the effect of varying conditions of high-temperature exposure has shown that, at a constant temperature, the supply of oxygen is the principal factor which causes stiffening of the vulcanizates. The loss of volatile plasticizers, when present, also contributes to the stiffening. The test-tube technique, developed in the course of this investigation, in which dumbbell samples are suspended in stoppered test-tubes (38 by 300-mm.) heated by immersion in an oil bath, appears to give results which are considerably more duplicable than those obtained by the usual aging in circulating air ovens. The test-tube technique also gives somewhat better differentiation between good-heat aging and poor-heat aging compounds. The rate of deterioration as measured by elongation change is doubled for an 18° F increase in the exposure temperature. As measured by hardness change the rate is doubled by an increase of 42° F. Tests run at 250° F by this method are no more reproducible than those run at 300° F.

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