The invention discloses a thermotropic crosslinking type shape memory
polyurethane material obtained by thermal crosslinking of
thermoplastic polyurethane with a side-chain
double bond, a
bifunctional crosslinking agent and an initiator; in a bending mode, the shape fixed rate is more than or equal to 95%, and the shape
recovery rate is more than or equal to 90%; in a
dynamic mechanical analysis tensile mode, the shape fixed rate is more than or equal to 95%, and the shape
recovery rate is more than or equal to 90%. A preparation method disclosed by the invention is a second-
step method and comprises the steps: firstly preparing the
thermoplastic polyurethane with the side-chain
double bond, then carrying out melting mixing or solution mixing with the
bifunctional crosslinking agent under a condition with addition of the initiator, and carrying out thermal crosslinking to prepare the product. The polyurethane material disclosed by the invention has excellent shape memory properties and mechanical properties, the
transition temperature is close to a body temperature, and the raw materials have good biological compatibility and no
toxicity and can be degraded; the polyurethane material can be used as in-vivo
implant materials and clinical surgical materials, also can be used for wire and cable casings and building
pipe connecting sleeves, moreover, can be used for buffer sole protection devices, deformation toys and the like, and is suitable for large-scale industrialized production.