New post modification route for styrene butadiene copolymers leading to supramolecular hydrogen bonded networks - Synthesis and thermodynamic analysis of complexation

Abstract

In this work we present a new and simple post modification route for styrene-butadiene copolymers using well established reactions including hydrochlorination and Steglich esterification to obtain alkyne functionalized styrene-butadiene copolymers. The alkyne linker allows the introduction of arbitrary azides into the styrene-butadiene copolymers via copper catalyzed azide alkyne cycloaddition and this leads to a toolbox of diverse functional polymers. This method gives new opportunities regarding modification strategies and is used in this work to obtain supramolecular styrene-butadiene copolymer networks by introduction of a benzoic acid derivative. This simple supramolecular motif forms temperature dependent hydrogen bonding complexes which can be quantitatively studied by FTIR spectroscopy. We found that the equilibrium constant, ΔH and ΔS are changing with temperature which can be attributed to a structural modification: the dissociation.