Shape Memory Polymers from Elastomer/Fatty Acid Blends

Shape memory polymers (SMPs) were prepared by blending elastomers and fatty acids. Blending was accomplished by the swelling of a natural rubber band with molten fatty acid. By this method a SMPs with excellent shape fixity and recovery can be obtained during free recovery after uniaxial deformation to large strain. At higher loading the crystalline fatty acid is able to form a three-dimensional solid network that gels the elastomer and enables shape memory behavior. This route inverts the typically processing steps by crosslinking the permanent network prior to blending of the fatty acid. This offers a means to potentially generate a SMP from any preformed elastomeric article.