POLY(ETHYLENE)

synthetischeIn the preparation of chlorosulphonated polyethylene the polymer (commonly, a low density polyethylene with molecular weight (Mn) of about 20000) is treated with chlorine in the presence of a small amount of sulphur dioxide. Typically, the reaction is carried out in solution in hot carbon tetrachloride. Both chloride and sulphonyl chloride groups are introduced into the polymer, the degree of substitution and the ratio of the two types of groups depending on the reaction conditions. Commercial products generally contain about 30% chlorine and 1.5% sulphur, which corresponds to approximately one chlorine group per 7 carbon atoms and one sulphonyl chloride group per 85 carbon atoms. Such a product may be represented as follows:The reaction probably proceeds by the following radical mechanism: