Facile control of high temperature shape memory polymers

Glass transition temperature (T-g) is crucial in determining application areas of high temperature shape memory polymers (SMPs), but some T(g)s are difficult or uneconomic to be obtained. Here we introduce a facile way to prepare high temperature SMPs with controllable T(g)s from 183 to 230 degrees C by copolymerization of polyimides, and relationships between T(g)s and diamine components of the shape memory copolyimides agree with Fox Equation. These copolyimides can fix temporary shape and return to original shape nicely, and the possible mechanisms of their high shape fixity and shape recovery are analyzed on the basis of thermomechanical properties and molecular structures. The copolymerization of shape memory polyimides has offered an effective way to obtain high temperature SMPs with desired properties. (C) 2017 Wiley Periodicals, Inc. J. Appl. Polym.