Multi-responsive (diethylene glycol)methyl ether methacrylate (DEGMA)-based copolymer systems

Abstract

Multi-responsive (diethylene glycol) methyl ether methacrylate–methacrylic acid (DEGMA–MAA) copolymers were synthesised for the first time via RAFT polymerisation, and the structure–activity interplay of statistical and block copolymers in solution was compared. In addition to MAA, DEGMA was also copolymerised with 2-(dimethylamino)ethyl methacrylate (DMAEMA) to generate two sets of well-defined weakly acidic or weakly basic copolymers, respectively. The temperature, pH and salt-responsive properties of all polymers was determined via UV-visible spectroscopy and dynamic light scattering, and their solution structures as a function of temperature were visualised via electron microscopy. Results from this study indicate that the DEGMA–MAA statistical and block copolymers display similar stimuli-responsive property trends to the well-characterised DEGMA–DMAEMA copolymers, and show similar lower critical solution temperature (LCST) modulations and aggregate structures in water.