The structure of cyclized rubber

The history of cyclized rubber, including a series of structural formulae previously proposed for this polymer, is reviewed briefly. A new formula for cyclized rubber is suggested by applying electronic interpretations of reactions between electrophilic agents and tertiary alkyl olefins and tertiary halides respectively, to the corresponding reactions with rubber and rubber halides. It is shown that hydrochlorination can be used for the determination of the unsaturation of cyclized rubber. By varying the conditions of hydrochlorination two types of double bonds can be detected in cyclized rubber, a fact which is in agreement with the structure suggested. By using our method for the determination of the unsaturation, the rate of cyclization at different temperatures and the influence of solvents on the rate of reaction have been determined.