Synergistically effects of copolymer and core-shell particles for toughening epoxy

Simultaneously improving toughness and strength without sacrificing thermal resistance and maintaining the viscosity of an epoxy resin for application in Liquid Composite Molding (LCM) process has been challenging. This paper reported such a high performance epoxy system modified by a hybrid of toughening agents, block copolymer particle (BCP) and core-shell particle (CSP), was successfully prepared via a two-step processing method. The viscosity, thermal stability and mechanical property of the resulting modified epoxy, BCP\CSP\epoxy, were studied. The results showed that the BCP\CSP\epoxy maintained the viscosity and thermal stability of the epoxy resin, while its flexural strength and fracture toughness (K-IC) were significantly increased in comparison with the neat epoxy, BCP\epoxy and CSP\epoxy. Based on the morphology analysis, a ladybug mechanism responsible for these impressive synergistic enhancement effects was proposed. It is believed that this study provides a new pathway for the toughening of epoxy matrix materials for making advanced LCM composites. (C) 2018 Elsevier Ltd. All rights reserved.