Advances in thermo-responsive polymers exhibiting upper critical solution temperature (UCST)

Abstract

Immense work has been conducted in the field of thermoresponsive polymers specifically of lower critical solution temperature (LCST) type, but upper critical solution temperature (UCST) type polymers remain a significantly unexplored domain. However, in recent years, UCST polymers have attracted increased attention as evidenced by the rise in publications in the same domain, and therefore, this review is an attempt to compile the reported UCST-type polymers. Unlike LCST, UCST polymers are insoluble at low temperature but solubilize in a given solvent as the temperature increases. The synthesis approaches and applications of reported UCST polymers are discussed in this article. Emphasis has been given to the polymers exhibiting UCST behavior in aqueous medium, due to the obvious advantage of their wide applicability. It is quite apparent from this study that the attempts to synthesize novel polymers and copolymers exhibiting UCST has faced an upsurge, but their application part still requires considerable attention.

Keywords

• Smart polymers
• Thermoresponsive polymers
• Tailor-made polymers
• UCST
• Nanomaterials