Supramolecular Templation of Trapped Entanglements in Polymer Networks

Polymer entanglements—topological constraints to chain motion—are fundamental features of polymers that have intrigued scientists for over 80 years. The presence of entanglements in polymers is believed to modify material properties, such as modulus and toughness, which are essential for most applications of soft materials. However, the precise examination of the relationship between how chains entangle and material properties has remained elusive due to both difficulty in synthesizing materials with controlled entanglement topologies and an inability to spectroscopically detect entanglements within the resulting polymer. Controlled installation of entanglements in polymer networks could allow for the direct study of the effects of entanglements on material properties and help to improve existing models for polymer elasticity. In this dissertation, I present my work in the pursuit of installing trapped entanglements in polymer networks and the resulting properties that arise from the inclusion of these mechanical bonds. Chapter 1 provides a background on entanglements, as well as an outline of current methods used to install and characterize entanglements in soft materials. Chapter 2 details an approach to install trapped entanglements in poly(ethylene glycol) (PEG) networks from supramolecular templates composed of phenanthroline-copper(I) complexes. Lastly, Chapter 3 outlines attempts to expand on the installation of trapped entanglements in gels through the creation of an “Olympic” gel (OG), named after its resemblance to the iconic interlocking Olympic rings. Altogether, my work aims to advance our understanding of entanglements in polymer networks by better establishing topology-property relationships in soft materials. Additionally, this work demonstrates a novel approach to tune mechanical properties of polymer networks through the design of a methodology allowing for the controlled installation of entanglements in a network.