Tuning the gelation of thermoresponsive gels based on triblock terpolymers

Abstract

In need of new thermoresponsive gels, a novel combination of repeated units is reported in this study, with the best-performing polymer outperforming the commercial counterpart pluronic F127 by gelling at body temperatures at concentrations as low as 3 w/w%. These polymers are ABC triblock terpolymers of constant molar mass (MM), where A, B, and C blocks consist of hydrophilic oligo(ethylene glycol) methyl ether methacrylate with an average molar mass of 300 g mol–1 (OEGMA300), hydrophobic n-butyl methacrylate (BuMA), and the thermoresponsive di(ethylene glycol) methyl ether methacrylate (DEGMA), respectively. In total, 15 triblock terpolymers were synthesized via group transfer polymerization (GTP), and their composition was systematically varied. Key focus was the characterization of their gelation properties via visual tests and rheological measurements. It was concluded that achieving the optimum hydrophilicity/hydrophobicity ratio is critical to ensure a clear solution to gel transition and a wide gelation area that includes the body temperature.