PDI is poly disparity index defined as the ratio of the weight average and the number average molecular masses.
It is a very important parameter of polymers which is used to identify the disparity (anomaly) in the polymer. Natural polymers have PDI equal to one because in them the number of monomers in a chain are fixed and it does not change. But in case of synthetic polymers the PDI is greater than unity because the number of monomers does not remain same and are often more than the required amount.
Write the monomers used for getting the following polymers.
(i) Polyvinyl chloride (ii) Teflon (iii) Bakelite.
Write the names and structures of the monomers of the following polymers:
(1) Buna-S (2) Buna-N (3) Dacron (4)Neoprene.
How does the presence of double bonds in rubber molecules influence their structure and reactivity?