Toughening of epoxy by nanostructures with ABA triblock copolymers: An influence of organosilicon modification of block copolymer

In this work, we investigated the effect of organosilicon modification of an ABA triblock copolymer on the morphologies, thermal properties, and fracture toughness of epoxy thermosets. First, a poly(epsilon-caprolactone)-block-poly(butadiene) -block-poly(epsilon-caprolactone) triblock copolymer was synthesized through the ring-opening polymerization of epsilon-caprolactone by using an alpha,omega-dihydroxyl-terminated polybutadiene as the macromolecular initiator. Thereafter, the triblock was organosilicon-modified via the hydrosilylation of its midblock (viz. polybutadiene) with pentamethyldisiloxane. It was found that the organosilicon modification resulted in a switch of the nanostructure formation mechanism from reaction-induced microphase separation to self-assembly. As a consequence of the organosilicon modification, the morphological structures of the thermoset were significantly changed, and thus, the materials displayed different improvement in fracture toughness. In addition, the organosilicon modification further enhanced the surface hydrophobicity of the materials.

Automated summary

The study investigated the effect of organosilicon modification on an ABA triblock copolymer in epoxy thermosets, revealing that the modification changed the morphology and improved fracture toughness. Additionally, the organic silicon modification enhanced the surface hydrophobicity of the materials.