Preparation and mechanical properties of epoxy resin filled with shaped hybrid nanobrushes

Abstract

Nanostructure formed through self-assembly of block copolymer has been used to modify epoxy resins and the shape of the nanobrushes has a significant effect on its properties. Through RAFT polymerization and bulk self-assembly of PMMA-b-PTEPM block copolymers, SiO2@PMMA hybrid nanobrushes was prepared with three different shapes, i.e., nanospheres, nanowires and nanosheets. According to the transmission electron microscope results, all three kinds of nanobrushes were well dispersed in the epoxy resins. The differential scanning calorimeter and thermogravimetric analysis tests showed that the addition of these nanobrushes has no significate effect on the curing behaviour and the glass transition temperature of epoxy resins. Their modification effects have been investigated through tensile, bending and impact tests. Compared with the neat epoxy resin, the bending and tensile strengths of 0.5 wt% nanosphere-filled epoxy resins were increased by 11.7% and 27.0%, and the impact strength of 0.5 wt% nanowire-modified epoxy resins was increased by 93.0%. And the nanosphere-modified epoxy resins showed a better comprehensive performance.