Kinetics and Modeling of Ring-Opening Copolymerization of l-Lactide and ε-Caprolactone

The bulk ring-opening copolymerization of l-lactide with ε-caprolactone was conducted at 140°C. The reaction was catalyzed with stannous octoate and initiated using hydroxyethyl methylacrylate to produce acrylated biomass macromonomers. The effects of varying monomer compositions as well as polymer chain lengths on the copolymerizations were experimentally investigated. A mathematical model is developed considering reversible initiation, propagation, chain transfer, and transesterification reactions. The diffusion control associated with polymer chain length is considered in the model. The model successfully predicts monomers conversions, number-average molecular weights, polydispersity index values, and cumulative copolymer compositions for ring-opening copolymerizations of l-lactide with ε-caprolactone.