TOUGHENING AND FAILURE MECHANISMS IN BLENDS OF THERMOSETS AND HYPERBRANCHED POLYMERS

摘要

The mechanical properties and toughening mechanisms corresponding to various processing conditions and modifier chemistries were investigated in blends of epoxy resins and dendritc hyperbranched polymers (HBP). Results showed that at fixed compositions and for every specific HBP used, temperature had an influence on blend toughness by affecting the second phase domain size. Similar trends were observed when the second phase domain diameter was increased by modifier content, although this had an additional influence on the glass transition temperature and the rigidity. Finally, a dependence of the overall thermomechanical properties on the modifier chemistry clearly showed that the solubility and the reactivity of the blend components were key parameters for the toughening mechanisms and the final properties of the blend.