Rheological study of polyurethane shape memory polymer

Abstract

There is an interesting group of shape changing materials in development or under consideration in laboratories around the world, known as shape memory materials. This group of materials comprises of Shape Memory Alloys (SMA) and Shape Memory Polymers (SMP) which can perform the shape changing features in different ways. Both types of materials can be programmed with a permanent shape which can be "remembered" by the material. After a shape change, the shape memory material can recover to their permanent shape. Most of the time, the recovery stimulant is the application of heat to bring the material back to its pre-set form. For the metal alloy, the mechanism for recovery is the change in crystal structure while the polymers control their forms at different temperatures by their chain movements.