Abstract:Taking polytetrahydrofuran (PTMG) as soft segment, 4,4′-diphenylmethane diisocyanate (MDI), chain extender 2,2-dimethylolpropionic acid (DMPA) and blocking agent 4-(2-(pyridin-4-yl)vinyl)phenol as hard segment, shape memory polyurethanes (PTMGUs) were synthesized by two-step method. The structures of PTMGUs were characterized by Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. After the polyurethanes were made into films, the effects of different hard segment contents on the thermal performance and shape memory properties were investigated by thermogravimetric analysis, differential scanning calorimetry and cyclic tensile dynamic thermomechanical test. Shape recovery processes were recorded via videos, and the results show that PTMGUs with different hard segment contents exhibit good shape memory performance. Both average fixed rates and recovery rates of PTMGUs are up to 90%. Among them, PTMGU32 (mass fraction of 35%) has the best shape memory performance, the average fixed rate is up to 96.9%, and the average recovery rate is up to 99.5%.