Enhancement of Mechanical Properties of ABA Triblock Copolymer-Based Elastomers by Incorporating Partial Cross-Links on the Soft Bridge Chains

We propose a simple molecular design of glassy-b-soft-b-glassy ABA triblock copolymer-based elastomers with enhanced mechanical properties by blending a very small amount of photoreactive cross-linker polymers with small molecular weight. In the blend, the cross-linker polymer is selectively incorporated into the B block matrix, and UV irradiation locally forms cross-links on the network strands. The present design achieves mechanical property enhancement without sacrificing elongation ability and recyclability. Such enhancement is discussed in terms of the increase in the fraction of effective bridge chains connecting glassy cross-link domains and the enhanced deformation recovery of self-assembled nanostructures.