Influence of the end groups of hyperbranched poly(glycidol) on the cationic curing and morphology of diglycidylether of bisfenol A thermosets

The cationic curing of DGEBA with hyperbranched polymers (HBPs) based on poly(glycidol) using ytterbium triflate as initiator, has been studied. Poly(glycidol) (PG) has been synthesized and the terminal hydroxyl groups have been partially end-capped with benzoyl end groups to produce benzoylated poly(glycidol) (PGBz). The hydrophylic character caused by the high hydroxyl group content of unmodified PG limits its solubility in DGEBA, while a partial modification with benzoyl groups makes PGBz fully miscible in DGEBA. Therefore, important differences are observed with respect to the curing kinetics, network development, properties and morphology of the cured materials, which may be related to the hydroxyl group content of the HBPs.