Heat and solvent responsive polytriazole: shape recovery properties in different solvents

Abstract

Shape memory polytriazole actuatable by both heat and solvents is presented. Hydrogen bonding solvents exhibit strong influence on shape recovery. In this work, a dual-stimuli responsive (both temperature and solvents) polymer is synthesized from propargylated bisphenol-F (PF) and a tris azide (TA) monomer via an azide–alkyne polycycloaddition reaction in the presence of a copper catalyst. The polytriazole exhibits a trigger temperature at 103 °C and displays cyclic shape memory properties. The SMP shows a storage modulus >2 GPa with a cross-link density of 6.9 × 10³ mol m⁻³. The SMP possesses shape memory features in different solvents. Highly polar solvents lead to shape recovery with cracks whereas hydrogen bonding solvents like ethanol supported crack-free shape recovery. A two-step kinetic profile is seen in the shape recovery sequence of SMP in hydrogen bonding solvents. The SMP is hydrophobic and no recovery in water is observed.