Synthesis of polymers with phosphorus containing side chains via modular conjugation

Abstract

Polystyrene-based copolymers synthesized by RAFT polymerization of 4-vinylbenzyl chloride (4-VBC) and styrene with subsequent azide transformation are used to prepare phosphorylated polymers via 1,3-dipolar cycloaddition with diphenyl prop-2-ynyl phosphoric ester (DPPP). To avoid metal salts in the reaction mixture of the 1,3-dipolar cycloaddition, a novel metal free approach was developed to synthesize DPPP. The successful conversion to phosphorylated polymers is confirmed by X-ray photoelectron spectroscopy (XPS), infrared (IR) spectroscopy as well as solid phase nuclear magnetic resonance (NMR) spectroscopy. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) are employed to determine the influence of the phosphoric ester on the thermal properties of the generated polymers. Through a series of TGA-MS measurements, the decomposition products of the phosphorylated polymers, e. g. styrene, phenyl, alkyne and diphenyl phosphite moieties, are determined