Controlling properties of thermogels by tuning critical solution behaviour of ternary copolymers

Thermoresponsive hydrogel materials show promise as biomaterials as their properties can be widely tuned to fit engineering requirements for an array of important applications. Here we show that the properties of thermogelling tri-block copolymers consisting of a central poly(ethylene glycol) block and pendant N -substituted polyacrylamides can be tuned by altering the random terpolymer compositions. The heterogeneity of the pendant terpolymer blocks is reflected in the concentration dependence of their critical solution behavior. The lower critical solution temperature (LCST) of the pendant blocks can be finely tuned, enabling controlled modulation of thermogel properties. Altering terpolymer composition to control LCST behaviour, therefore, provides a facile approach to design thermogel properties. Thermogelling tri-block terpolymers were made from a bifunctional PEG RAFT agent. The critical solution behavior was tunable by alteration of the terpolymer composition, enabling modulation of gelation temperatures and hydrogel viscoelasticity.