When stretched, the crystal phase of poly(vinylidene fluoride), PVDF, exhibits a crystal to crystal alpha to beta phase transition [A. Lovinger, Poly(vinylidene fluoride), D.C. Basset (Ed.), Developments in Crystalline Polymers, vol. 1,1982, p. 195]. Typical DSC analysis of this film results in analyzing the relaxed film, which would not be representative of the starting material. This paper will focus on the just mentioned relaxation effect. (c) 2006 Published by Elsevier B.V.