Kinetics of the ring-opening polymerization of D,L-lactide using zinc (II) octoate as catalyst

The kinetics of ring-opening polymerization of D,L-lactide with 2-ethylhexanoic acid zinc (II) salt as catalyst and methanol as co-catalyst at different temperatures is investigated. A previously proposed kinetic model accounting for reactions such as activation, propagation, chain transfer, transesterification and thermal non-radical random chain scission has been applied to simulate the experimental results of conversion and average molecular weights. The relevance of some side reactions, mainly transesterifications and chain scission, has been verified all over the studied temperature range and the corresponding rate constants have been estimated. (C) 2011 Society of Chemical Industry