The Polymer Society of Korea

Abstract

Phase transition-induced mechanical dissipation allows materials to absorb impact energy without permanent damage, based on their structural and mechanical properties. Specifically, viscoelastic materials with high loss factors are promising for applications like ballistic protection and crash absorbers. This presentation introduces three composite systems using such dissipation. First, a liquid crystal elastomer (LCE)-based fiber composite achieves a damping coefficient two orders of magnitude higher than typical composites, via the combined effects of LCE dissipation and composite damage. Second, strain rate-dependent stiffening in boric acid-based polymer gels is tuned through nanomaterial hybridization to meet low-velocity automotive impact demands. Lastly, a method is presented in which polymers, though not viscoelastic, generate hybrid supraparticles under high-speed nanoparticle impacts, enabled by and impact-induced phase transition from local thermal degradation.