Dr Marc Behl
Head of Polymer Chemistry (commissarial) and Head of Active Polymers Departments, Center for Biomaterial Development, GKSS-Institute of Polymer Research, Teltow
Shape-memory polymers are an emerging class of active polymers, having the capability of changing their shape between distinctive shapes. When exposed to an appropriate stimulus they can change their shape in a predefined way from shape (A) to a shape (B). While shape (B) is given by the initial processing step, shape (A) is determined by applying a process called programming (Scheme 1, Figure 1) .
Within this presentation fundamental aspects of the molecular design of suitable polymer architectures, tailored programming and recovery processes of the shape-memory effect are presented.
Proceedings of the National Academy of Sciences of the United States of America , 2001, 98(3), 842 – 847.
Initially founded on the thermally-induced dual shape-effect the concept of shape-memory polymers has been extended to other stimuli by either indirect thermal actuation or direct actuation by addressing stimuli-sensitive groups on the molecular level. By the incorporation of reversibly photoreacting molecular switches, light-induced stimulation of shape-memory polymers has been realized .
Remote actuation of the thermally-induced shape-memory effect in magnetic fields was enabled by the incorporation of magnetic nanoparticles of iron(III)oxide cores in a silica matrix into shape-memory thermoplasts (figure 2). Here the sample temperature is increased by inductive heating of the nanoparticles in an alternating magnetic field .
1. Lendlein, A. and S. Kelch, Shape-memory polymers. Angewandte Chemie-International Edition, 2002. 41(12): p. 2034-2057.