| abstract |
The invention provides a shape memory polyurethane composition, which comprises at least a bifunctional polyalcohol, a bifunctional diisocyanate, and a polyurethane obtained by polymerizing a chain extension agent having more than two functional groups. The diisocyanate / the polyalcohol / The chain extender has a molar ratio of 2 to 3/1/1 to 2 and an NCO / OH ratio in the range of 0.95 to 1.1. The weight average molecular weight of the polyurethane is in the range of 50,000 to 300,000. The polyurethane has a first phase The change temperature is in the range of 40 ° C to 60 ° C. The storage elastic modulus of the polyurethane at a temperature below the first phase change temperature is 10 9 Pa or more. |