Studies of the reactions of the anhydrosulphites of α-hydroxy-carboxylic acids. Part I. Polymerisation of anhydrosulphite of α-hydroxyisobutyric acid

Abstract

The thermal decomposition of α-hydroxyisobutyric acid anhydrosulphite in organic solvents at 60–95° has been studied. It has been shown that in the presence of traces of water or α-hydroxyisobutyric acid poly-(α-hydroxyisobutyric acid) is obtained. Kinetic studies, using gas evolution measurements and radiochemical techniques have been used to study the polymerisation reaction. A mechanism for the polymerisation process is proposed in which the α-lactone of α-hydroxyisobutyric acid is the polymerisable species. A relationship between the concentration of reactants and the molecular weight of the polymer is derived, and the molecular weight distributions at different conversions are calculated.