Poly(imidazoled glycidyl methacrylate-co-diethyleneglycol methyl ether methacrylate) – A new copolymer with tunable LCST and UCST behavior in water

Abstract

A series of poly (imidazoled glycidyl methacrylate-co-diethylene glycol methyl ether methacrylate) copolymers (denoted as P (iGMA-co-MEO2MA)) with different monomer compositions were synthesized and characterized. These copolymers exhibit lower critical solution temperature (LCST) behaviors as the mole ratio of iGMA to MEO2MA in the copolymers range from 0/100 to 1/1, and upper critical solution temperature (UCST) behaviors when this mole ratio ranges from 4/1 to 10/1. The thermoresponsive behaviors of these copolymers were also investigated in water at different pH values. The LCST of the copolymer increased with the iGMA content in the copolymer at pH 6.5, and changed little at pH 7.0, while it decreased with the iGMA content in the copolymer at pH 7.5. Meanwhile, the UCST of the copolymer increased with the iGMA content in the copolymer at pH 6.5 and 7.0. In addition, the thermoresponsive properties of P (iGMA-co-MEO2MA) were influenced by the presence of salt and by the copolymer concentration. This paper offers a facile approach toward thermoresponsive materials with tunable LCST and UCST behaviors.