Natural Rubber Producers Research Association

Natural Rubber Bureau-Natural Rubber Producers Research Association and the Rubber research Institute of Malaysia, Malaysia and Washington DC, Natural Rubber and Technical Information Sheets. 

Natural Rubber Producers Research Association, Technical Information Sheet No. 9, Revised (1997). 

NR Technology Rubber Developments Supplement, No. 2, Natural Rubber Producers Research Association, Brickendonbury, UK, 1970. 

L. Mullins, in Proceedings of the Natural Rubber Producers Research Association Jubilee Conference, Cambridge, Maclaren and Sons Ltd, London, 1964, pp. 136-169. 

Natural Rubber Producers Research Association Technical Information Sheet L14 (1977). 

The interaction between diene rubbers and sulphur is exceedingly complex and has been the subject of extensive investigation, particularly by workers at the Natural Rubber Producers Research Association. In this book it is possible to give only an extremely brief account of the main conclusions of this work more detailed reviews may be found elsewhere [2-4]. 

E. H. Andrews was appointed head of the Materials Department at Queen Mary College, London, in 1968. Prior to that, he had worked for ICI Fibres Division and for the Natural Rubber Producers Research Association. Prof. Andrews was awarded the A. A. Griffith Medal in 1977 for contributions to the science of fracture. More recently, he has worked on adhesion science and its applications to medicine. In 1981, he resigned the departmental headship to concentrate on research and industry-university liaison. He is an international consultant to several major companies and has published over 100 scientific papers and books on polymer science, fracture, and adhesion. 

In comparison with the developments in new rubbers that have occurred this century, developments concerned with the chemistry of the reactions of the already-formed rubbery polymers have been less immediately spectacular. It has already been pointed out that for about ISO years sulphur has been the dominant vulcanizing agent, almost exclusively used with diene rubbers. It must however be stressed that the efficiency with which the sulphur is used and the quality of the vulcanizates is today vastly superior. In part this is due to systematic semi-empirical studies which led to the development of a wide range of accelerators of vulcanization. It is also in part due to the excellent scientific studies undertaken by many chemists throughout the world but particularly by the Malaysian Rubber Producers Research Association (and its forerunners the Natural Rubber Producers Research Association and the British Rubber Producers Research Association). As a consequence of this work the mechanism of vulcanization and its control, at least in the major diene rubbers, is reasonably well understood. 

During the quarter of a century following World War II chemists at the British Rubber Producers Research Association (subsequently renamed the Natural Rubber Producers Research Association and, later, the Malaysian Rubber Producers Research Association) developed this work and using a variety of techniques have largely established the nature of the accelerated sulphur vulcanization of natural rubber. Important contributions have also been made by smaller research teams, for example Scheele and co-workers in Germany, and Craig, Juve, Campbell, Coran and Wise, and others in the United States. These studies have shown, not only that there are a variety of chemical structures present in a vulcanized natural rubber... 

Another interesting innovation is that developed by the Malaysian Rubber Producers Research Association. In this case the coupling agent is first joined to a natural rubber molecule involving an ene molecular reaction. The complex group added contains a silane portion which subsequently couples to filler particles when these are mixed into the rubber. 

Technical data sheets , Malaysian Rubber Producers Research Association, Ttin Abdul Razak Laboratory, Brickendonbury, Herts. SG13 8NL (1995). Data sheets for various blends of natural rubber. 

Improvement in the processing and vulcanized qualities of a range of systems have been reported over the past decades. Modification of natural rubber, due to work in the British Rubber Producers Research Association, yields some of the most striking applications of microgel. A detailed study at the MV Lomonosov Institute of Fine Chemical Technology, in Moscow, on the effect of microgels on mechanical properties of cis-polyisoprene and butadiene-styrene rubbers extensively illustrates the properties of blends from latex combination of microgel and conventional or linear systems.(31)... 

Development of Natural Rubber-Based Truck Tyre Retreading Compounds," in M. E. Cain and Siti Zubaidah bte Mohd Rashid, eds., Proceedings of a UNIDO-sponsored Workshop, Kuala Eumpur, Malaysia, Malaysian Rubber Producers Research Association, Hertford, U.K, 1992. 

The author wishes to thank Dr. M. Bristow of Malaysian Rubber Producers Research Association - Brickendonbury, U.K. who kindly supplied various grades of natural rubber. He is grateful to Dr. L.A, Goettler and Mr. J. Sezna from Monsanto Polymer Products Company, Akron, Ohio, for the experimental data on Santoprene thermoplastic rubbers used in this paper. 

Malaysian Rubber Producers Research Association, 1984. The Natural Rubber Formulary and Property Index. Imprint of Luton, England. 

Over the years, much of the research on accelerated-sulfur vulcanization was done by using natural rubber as a model substrate. Natural rubber was the first elastomer and therefore the search for understanding of vulcanization originated with work on natural rubber. Even in recent years most of the work published on the study of vulcanization has been related to natural rubber. This was because of the tradition of doing research on natural rubber and because of the fact that the largest knowledge base to build upon was with respect to natural rubber. It should be mentioned that a large factor in the establishment of the tradition of research on the vulcanization of natural rubber was the British Rubber Producers Research Association or BRPRA (now called the Malaysian Rubber Producers Research Association or MRPRA). Of course, this institution is essentially devoted to natural rubber. 

In recent years there has been increasing interest, particularly by research workers at the Malaysian Rubber Producers Research Association, (MRPRA), in certain reactions that involve the direct reaction between molecules and do not involve active species such as ions and free radicals as intermediates. Among the advantages of such reactions are the fact that catalysts are not involved and that they proceed smoothly, predictably and in a reasonably efficient manner. The reactions of particular interest are those which involve highly substituted ethylenes. These are of particular relevance to polyisoprenes such as natural rubber, which may be considered to be a poly-trisubstituted ethylene, as a means of introducing interesting groups into the polymer structure. 

Former positions include Manager of Technical Service Laboratory, Ashland Chemical Company. Technical Service Specialist, Malaysian Rubber Bureau, U.S.A. Initiator of testing program for natural-rubber-treaded tires for Canadian Safety Authority and Malaysian Rubber Producers Research Association Laboratories. Author of numerous papers and a book. 

The author wishes to thank the Board of the Malaysian Rubber Producers Research Association for permission to publish this chapter, the editor of Natural Rubber Technology, Deutsche Oelfabrik GmbH and Schill Seilacher for information and samples, and Mr P. M. Lewis for constructive criticism. 

In the 1960s, considerable work was undertaken by the Malaysian Rubber Producers Research Association and its forerunners to study the nature of sulphur crosslinks in natural rubber vulcanisates. It was found that whereas conventional accelerator-sulphur systems led to substantial amounts... 

Eindley, P.B. Engineering design with natural rubber, 4th edn. The Malaysian Rubber Producer s Research Association, Eondon, 1974. 

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