Reaction of styrene oxide with starch alkoxide

The reaction of styrene oxide with potassium starch alkoxide in dimethyl sulphoxide has been studied. No graft polymerization occurred, even under drastic conditions, and the reaction was found to stop at the initiation stage, as seen from the non-disappearance of the monomer with time (gas chromatography) and from examination of the products of reaction, which on acid hydrolysis yielded phenyl hydroxyethyl ether of glucose. On the other hand, homopolymerization of styrene oxide catalysed by potassium naphthalene in dimethyl sulphoxide was successful, suggesting that the failure to obtain graft polymers of styrene oxide on starch is due to steric hindrance from the starch skeleton.