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Natural Rubber:

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Introduction

Natural rubber is made of repeating units. It is obtained from Latex from Trees. Natural: monomer polymer Isoprene poly(isoprene) (2-methylbuta-1,3-diene) natural rubber (Dienes are alkenes with two double bonds) In early attempts of producing synthetic rubber, polymerisation of dienes was used but this produced rubber with both a cis and trans isomer mixture. Only cis rubber was preferred because it had a higher boiling point than trans rubber. Better quality of rubber was obtained by polymerising butadiene to produce poly(cis-1,3-butadiene). Rubber of a higher quality is a copolymer, which can be obtained by combining dienes with alkenes. Synthetic: monomer polymer Butadiene poly(cis-1,3-butadiene) A process called emulsion polymerisation is used to produce a 'natural like' rubber. In this process different reactants are polymerised in water to produce rubber. Both Synthetic and Natural rubber are obtained by addition polymerisation. They both have double bonds in monomers of their isomers. When the monomers react to produce polymers, they both break two bonds and form one bond. ...read more.

Middle

208 (1) Vulcanisation improves the quality of the tyres because of the cross linking in polymer chains. This produces rubber, which is more rigid. These cross-links restrict the movement of the polymer chains so this makes harder and more durable tyres. This property is excellent for tyres as they eventually wear out due to many different forces. Table 1 in Article 1 The benfits of all the additives: * Carbon Black strengthens the rubber and aids abrasion resistance. * Oils are added to make the process to make the tyre easier, to make the tyre more flexible and to lower the cost of the tyre because oil is cheap as a raw material. * Resins improve the processing characteristics and adhesion of the rubber components during tyre building. They also make the tyre stiff. * When Carbon Black is added to improve the tyre, the tyre takes too long to cure so curing agents are added to accelerate this process. * Anti-ageing chemical are added to increase the lifetime of the tyre. ...read more.

Conclusion

This oil can be processed to produce oil with benzene. This benzene can either be used as industrial chemical feedstock (raw material for chemical processes) or can be processed further to produce other feedstocks such as cumene, phenol and propanone. Derivatives of benzene are used to produce commercially important products such as plastics and solvents. Cumene Process 259 Activated Carbon is obtained from the carbon left over from the pyrolysis. Its properties are that it has a high surface area of over 600 m2 g-1 and it is a good adsorbent. The activated carbon from scrap tyres has sulphur contents, which makes them excellent products to remove mercury (a toxic metal) from waste gases in industrial processes. Activated carbon is an excellent adsorbent and therefore is used in gas masks as it absorbs large quantities of gases and can therefore also be used to remove polluting gases from the air. A Gas Mask (5) Activated Carbon is produced from many feedstocks including some non-renewable sources such as coal and peat. Recycled tyres produce better activated carbon than commercially produced carbons. The recycling of tyres allows non-renewable source to be conserved. ...read more.

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