Shape memory materials based on adamantane-containing polyurethanes

In this contribution, a series of adamantane (AD)-containing polyurethanes were prepared from 1,3-adamantanediol, 1,4-butanediol and hexamethylene diisocyanate, and the influences of AD on the shape memory behavior of polyurethanes were systematically studied. Due to large steric hindrance, AD was able to disrupt the regular arrangement of polyurethane chains and contributed to forming an amorphous domain. It was found that moderate AD-containing polyurethanes had good mechanical properties and broad glass transition, and shape memory tests confirmed these polyurethanes possessed a shape fixation rate of 98% and shape recovery rate of 91% during a dual-shape memory procedure. Furthermore, they also exhibited a triple-shape memory effect. This work demonstrated a facile and feasible way to prepare polyurethane-based shape memory materials by using adamantane as a functional unit.