A Novel Polytetrahydrofuran-Based Shape Memory Polyurethane Enhanced by Polyglycolide-Block-Polytetrahydrofuran-Block-Polyglycolide Copolymer

A series of polyurethanes (PU-GT) were prepared using polyglycolide-block-polytetrahydrofuran-block-polyglycolide (PGA-PTHF-PGA), polytetrahydrofuran homopolymer (PTHF), glycerol, and hexamethylene diisocyanate (HDI) by a one-pot synthesis method. The non-isothermal crystallization and subsequent heating curves showed that the PTHF component in these polyurethanes could crystallize in a temperature range of -11.5~2.6 °C during the cooling process, and the melting temperatures of PTHF crystallites were in the range of 24.0~26.9 °C. The WAXD results implied that a small content of PGA could crystallize in the membranes of PU-GT polyurethanes. And compared with PU-GT-100, which did not contain the PGA-PTHF-PGA block polymer, other PU-GT polyurethanes showed excellent mechanical properties because of the existence of the PGA component. Moreover, these polyurethanes had temperature-responsive shape memory properties due to the PTHF crystallites. The temporary shape could be fixed at -20 °C and recovered to the permanent shape at 37 °C. We conducted two kinds of conceptual experiments using PU-GT-50 polyurethane, which showed its great potential for medical applications in vascular and wound repair.