Polymer–solvent interactions as a tool to engineer material properties

Abstract

Multi-dynamic polymers, materials with multiple reversible cross-linkers, exhibit improved and unexpected properties compared to materials with only one class of dynamic bond due to co-operative self-assembly. To tune the properties of multi-dynamic materials an understanding of the complex nature of these co-operative effects and their self-assembly is essential. As a model multi-dynamic system, we report a doubly dynamic amphiphilic random co-polymer, poly(methacrylate-co-anthracene methacrylate-co-oligoethylene glycol methacrylate), that harnesses π–π interactions, hydrogen bonding, and the hydrophobic effect. Using dynamic mechanical analysis, molecular dynamics simulations, and qualitative solution studies, we present a library of polymers with a remarkable range of elastic properties achieved by simple modification of the incorporated anthracene content and the polymer's environment. We further show that re-assembly due to solvent vapour exposure permanently alters the bulk properties of the material, akin to solvent vapour annealing in block co-polymers.