Amorphous, elastic AB copolymer networks from acrylates and poly[(L-lactide)-ran-glycolide]dimethacrylates

An alternative concept for the introduction of second amorphous phase was reported using di-methacylates (DM) as oligomeric crosslinker for polyacrylates forming amorphous AB copolymer networks. The aim is is to retain the poly[(L-lactide)-ran-glycolide)] segments forming the phase with the high glass transition temperature T g.h as network component but to incorporate a second amorphous phase with a low glass transition temperature T g.l. This low glass transition temperature keeps the material elastic even below Tg.h of poly[(L-lactide)-ran-glycolide)]-phase. Amorphous AB copolymer network was prepared by polymerizing various acrylates and poly[(L-lactide)-ran-glycolide)] dimethyacrylate using UV-light. Thermal properties of polymer networks were investigated by DSC and DMTA. The values for Tg were found to decrease gradually with increasing acrylate content, ranging from 55°C to -12°C for the PDMAEt.