Shape memory film

A shape memory polyurethane polymer consisting of a difunctional diisocyanate, difunctional polyol and difunctional chain-extender containing active hydrogen in the form of a film, said film having been formed into a first shape at a temperature higher than the glass transition point, and then having been formed into a second shape at a temperature above the glass transition point and maintained in said second shape and cooled to a temperature below the glass transition point whereby the film maintains said second shape, said film being capable of resuming said first shape upon heating at a temperature higher than the glass transition point wherein said polyurethane contains almost equal amounts of NCO groups and OH groups at the terminals of the polymer chains and has a glass transition point in the range of -50.degree. to 60.degree. C. and a crystallinity of 3 to 50 wt. %.