Triple Thermoresponsiveness of a TADDOL-Based Homopolymer through the Formation of Supramolecular Complexes with Chiral Guest Molecules at Variable Ratios

Multi-thermoresponsiveness which exhibits more than triple phase transitions has not been achieved yet. Current research studies have reported double thermoresponsive copolymers having two kinds of polymer chains. However, the molecular design strategy of triple thermoresponsiveness remains unclear. Herein, we report a triple thermoresponsive chiral homopolymer which exhibits UCST–LCST–UCST-type phase transitions. The polymer contains the α,α,α′,α′-tetraaryl-2,2-disubstituted 1,3-dioxolane-4,5-dimethanol moiety in the side chains, where multiple supramolecular complexes between the host polymer and guest molecules are formed. The formations and dynamic changes in the multiple complexes of model compounds were monitored by 1H NMR spectroscopy. We concluded that the key factor of the triple thermoresponsive behavior is the stoichiometric change in the multiple complexes. This work can extend the molecular design of the thermoresponsive polymer and lead to the next stage of functional polymer materials.