Hardblock-free Termoplastic Polyurethanes (TPUs) Exhibiting Shape Memory

摘要

Shape-memory polymers (SMPs) are stimuli-responsive materials which possess the ability to memorize permanent shapes that differ substantially from their temporary shapes. With an external stimulus, they change shapes to temporary ones which can be recovered by heating up to their transition temperatures. Nowadays, SMPs have drawn much attention because they possess a lot of advantages over shape memory alloys such as high-shape recovery, easy processing, and low manufacturing cost. Many kinds of shape-memory polymers have been investigated, including trans-polyisoprene, styrene-butadiene copolymers, and segmented polyurethanes. Biocompatible, and biodegradable shape-memory polymers with appropriate thermal and mechanical properties are expected as a unique approach to medical devices such as surgical sutures and catheters. Recently, such biodegradable shape memory polyurethanes based on poly(ε-caprolactone) (PCL) diols have been reported by Lendlein and Langer.