English Abstract

Interface and Adhesion of Composite
1. Toughening of Particle-Filled Epoxy Composite

Yoshinobu NAKAMURA
Tomoyasu HIRAI
Department of Applied Chemistry, Nanomaterials Microdevices Research Center, Osaka Institute of Technology, Asahi-ku, Osaka, Japan
Nippon Gomu Kyokaishi,(2020),93(1),17-20 General Review in Japanese

The effect of filler silica particle size on the flexural strength and the fracture toughness (KIC) of silica particle-filled epoxy composite was investigated. As the particle size increased the flexural strength decreased and the KIC increased. The large filler acts as the defect which causes fracture initiation for the flexural strength. On the other hand, the stress relaxation by the branching, the making a detour and the debonding of interface caused by the large filler developed the KIC. In order to raise both strength and KIC, the following interface of filler/resin considered to be ideal: the interface having the adhesion strength which is sufficient for the required mechanical strength of composite, whereas when the applied stress exceeds a threshold value, the debonding of the interface occurs and causes the stress relaxation.

Keywords: Composite, Filler, Interface, Mechanical strength, Fracture toughness