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, Δ H and Δ S are changing with temperature which can be attributed to a structural modification: the dissociation.