Hyperbranched Polycoumarates with Photofunctional Multiple Shape Memory

Abstract

In good shape: The films of hyperbranched polycoumarate derivatives can undergo a reversible [2+2] cycloaddition under irradiation of UV light and behave like photomechanical elastomers. From a predetermined original shape A the photonically and thermally memorized shapes B and C were obtained. The original shape was recovered by photoirradiation (see picture; Tg =glass transition temperature).