Performances of epoxy resins modified by hyperbranched polymers with different types of terminal groups

The thermal and mechanical performances of DGEBA epoxy resin/anhydride curing systems (the matrix resin) modified by hyperbranched polyesters with two different types of terminal groups were studied in this paper and the improving mechanisms when using two types of hyperbranched polyesters were analyzed too. The results show that using hyperbranched polyester with epoxy terminal groups (EHBP) can improve the performances of the matrix resin better than using hyperbranched polyester with hydroxyl terminal groups (HBPE). It is found that the compatibility of two types of hyperbranched polyesters with the matrix resin are different due to the different types of terminal groups. EHBP has better compatibility than that of HBPE with the matrix resin so that the controlled chemical induced phase separation (CIPS) can occurred easily which benefits the improving effect.