Rubber Producers

M. J. Rhoad, Proceedings ofithe 15th Annual Meeting International Institute of Synthetic Rubber Producers, Inc., Kyoto, Japan, 1974 Pubberlnd. (Eondon) 9(12), 68 (1975) Pubber Plast. News, 14 (fan. 23, 1978). 

Specialty Elastomers. Polychloroprene and polysulfide mbber were the first synthetic specialty elastomers discovered. Since theh invention in the 1930s the total number of classes of synthetic mbbers has grown to almost 30. The foUowing lists standard acronyms by the International Synthetic Rubber Producers (IISRP) and the American Society for Testing and Materials (ASTM) for several specialty elastomers. 

Worldwide Jihher Statistics International Institute of Synthetic Rubber Producers, Inc., 1994. 

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. 

Table 11.14 Production of natural and synthetic rubbers 1983-1992 ( 000 tonnes) (International Institute of Synthetic Rubber Producers)...

Many grades of recycled rubber produced from grinding and heating of vulcanized rubber products such as tyres, baby bottle nipples and other goods are also available. Although reclaimed rubber offers some processing advantages, its use has declined in recent years because of the extensive use of blended polymers. 

Bateman, Gee, Barnard, and others at the British Rubber Producers Research Association [6,7] developed a free radical chain reaction mechanism to explain the autoxidation of rubber which was later extended to other polymers and hydrocarbon compounds of technological importance [8,9]. Scheme 1 gives the main steps of the free radical chain reaction process involved in polymer oxidation and highlights the important role of hydroperoxides in the autoinitiation reaction, reaction lb and Ic. For most polymers, reaction le is rate determining and hence at normal oxygen pressures, the concentration of peroxyl radical (ROO ) is maximum and termination is favoured by reactions of ROO reactions If and Ig. 

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. 

The name originally applied to all synthetic rubbers produced by the sodium polymerisation of butadiene it is derived from Bu for butadiene and Na for sodium. The name was subsequently used in various forms, e.g., Buna N for nitrile rubber or NBR, and Buna S for SBR. The tradename Perbunan (Bayer) is also derived from Buna. 

An isomeric derivative of natural rubber produced by a variety of chemical treatments. The products are resinous and find application as reinforcing agents in natural rubber compounds (particularly in shoe soles) and as rubber-to-metal adhesives. 

An aqueous colloid/emulsion of rubber particles can be up to 65% solids content generally low viscosity compared to polymer solutions. Only rubbers produced by emulsion polymerisation or natural rubber can be found in this form. 

Combination with oxygen. On the basis of the electronic theory of valency the meaning of the term has been extended to include all reactions in which there occurs an increase in the ratio of the electronegative to the electropositive atoms or groups of a substance. The controlled oxidation of natural rubber produces resinous substances called Rubbones. 

This derivative of natural rubber produced by the action of hydrogen chloride (liquid or gaseous) found application as a transparent food packaging film, but has now been superseded by modem packaging materials such as PET. 

This is the generic name for the scheme originally introduced in Malaysia as Standard Malaysian Rubber (SMR). In effect it is the same specification but apphed to rubber produced in other countries, e g., Standard Indonesian Rubber (SIR). Both SMR and SIR are Technically Specified Rubbers. 

The amount of dry natural rubber produced per acre per annum. The yield from the original trees established in Malaysia was only about 400 kg per hectare per annum, but the best planting material available nowadays can product about 2000-2500 kg per hectare. See Bud Grafting, High Yielding, Ladder Tapping, Yield Stimulation. 

The application of plant hormones to the bark of rubber trees, or of copper sulphate placed in holes bored in the trunk, can produce a consistent increase in yield without any damage to the tree or any deleterious effect on either the latex or the rubber produced from it. 

Copolymers are formed when two different monomers are mixed and then polymerized. It is possible to produce a copolymer by addition polymerization. An example is SBR, the most important rubber produced in the United States. It is a copolymer of styrene and butadiene in a 1 3 ratio. 

But Farben was unable to meet the competition of the natural-rubber producers. They were millions in the red on this one dream. In 1931, by a very close margin, Ter Meer persuaded his colleagues to go along for another year in one last effort to keep buna in experimental production. By the time he met Hitler, Ter Meer stood alone in his faith that soon buna could be mass-produced at a profit. 

CARDINAL HEALTH INC. MALAYSIAN RUBBER PRODUCERS COUNCIL ALLEGIANCE CORP. 

The importance of the block and graft copolymers is that the resultant material tends to exhibit the properties of each homopolymer. For example, pure polystyrene is quite brittle, whereas polymerisation in the presence of about 5 per cent of rubber produces a material which is strong and tough. 

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)... 

Figure 2. Molecular weight distribution for soluble rubber produced from the devulcanization of a model BR vulcanizate.

The vulcanization of rubber is often called one of the great accidental discoveries. But really, it was because Charles persisted in his work despite setbacks, and because his mind was prepared to see the importance of the discovery.There are now over 21 million metric tons of natural and synthetic (manufactured) rubber produced each year. Over half of all manufactured rubber is used for tires the rest is used for hoses, gloves, and other products.The GoodyearTire Rubber Company was named after Charles Goodyear, although he died 30 years before it was founded. 

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