Mechanical properties of epoxy/ block-copolymer blends

Abstract

In this chapter, we summarized the recent progress in the studies of mechanical properties of epoxy/block copolymer blends. It is recognized that nanostructures can be formed in epoxy/block copolymer blends via either self-assembly or reaction-induced microphase separation mechanism. The formation of nanostructures in the epoxy thermosets can more effectively improve the tough-ness of the epoxy thermosets, which has been called "toughening by nanostructures." The toughening of nanostructured epoxy thermosets is quite dependent on type and shape of dispersed nanophases and the interactions between nanophases and epoxy matrix. In terms of the mechanism for energy dissipation, toughening mechanisms of the epoxy/block copolymer blends involve shear band, microcracking, crack pinning, and particle bridging. Depending on the inherent features of materials and operating conditions (e.g., applied loading), improvement of toughness can be achieved by the fonction of a single mechanism or through a complex combination of simultaneous and suc- cessive actions of different processes.