Toughness Properties of Lightly Crosslinked Epoxies Using Block Copolymers

Abstract Summary: In this work is discussed an alternative approach to the toughening of epoxy networks by the addition of acrylic block copolymers, composed of rigid and rubbery blocks. Once the reaction is completed, the initial self‐assembly of block copolymers in epoxy thermoset precursors produces rubbery domains: depending on the block copolymer structure and composition, these domains are of the micrometer or the nanometer size. Nanostructures are obtained when the rigid block is a random copolymer of methylmethacrylate and N,N ‐dimethylacrylamide. The rubbery domains prevent rapid crack propagation and the highest toughness is obtained with filament‐like microparticles or wormlike micelles.