Effect of Rubber Modification on the Fracture Properties of GM Filled Epoxy Resin
Mitsugu TODO, Shinsuke KOMEDA and Kazuo ARAKAWA
Abstract:Glass microballoon filled epoxy resin (GM/EP) has widely been used as an encapsulant for aerospace engineering; however, distributed GM particles generally reduce the toughness of the matrix epoxy resin. It is well-known that the toughness of epoxy resins can be improved by blending CTBN rubber, therefore, in the present study, CTBN modification of GM/EP was attempted to improve its toughness. GM filled neat epoxy 828 (828G) and GM filled rubber-toughened 828 (828RG) were fabricated, and fracture toughness, bending strength and fracture absorbed energy were evaluated at quasi-static and impact loading-rates to assess the effects of rubber modification on these fracture properties. The results exhibited that the fracture properties were dramatically improved by rubber modification. SEM observation of fracture surfaces was also performed to characterize fracture mechanism, and it was found that interfacial debonding and shear band formation play important roles in the toughening of GM/EP by rubber modification. Key Words:Epoxy encapsulant, Rubber toughening, Fracture toughness, Impact fracture