Logged out
Access All our Essays in an Instant
Swap your work for FREE access, or pay £4.99 for instant access
AS Chemistry – CourseworkOpen Book Paper 1. There are two types of rubbers, natural and synthetic rubber. Natural rubber is predominantly
Member rating: No Rating | Words: | Submitted: Wed May 10 2006
Page Preview
On the left is an image preview of every page of this document, and below are the first 150 words with formatting removed:
AS Chemistry - Coursework Open Book Paper 1. There are two types of rubbers, natural and synthetic rubber. Natural rubber is predominantly obtained from the Hevea brazilinesis tree, which originates from South America. Natural is obtained as latex, a colloidal dispersion of nanoscale rubber particles in water. C.D Harries showed that natural rubber consists of repeating units, which are joined together in long rings, as shown below. During this reaction the two double bonds are broken in the isoprene and poly(isoprene) forms only 1 double bond in its repeating unit. CH3 H CH3 H H2C CH2 CH2 H2C Isoprene Poly(isoprene) (2-methylbuta-1,3-diene) Natural Rubber Synthetic rubber is man made and was first produced by carrying out the polymerisation of dienes (alkenes containing 2 double bonds.) Below is the reaction of a synthetic rubber being polymerised. H H H H H2C CH2 CH2 H2C Butadiene Poly(cis-1,3-butadiene) There are many similarities...
To see the full version of this document, and 144,847 others
