A Triple Shape Memory Material of Trans-Polyisoprene/Polycaprolactone with Customizable Response Temperature Controlled by Crosslinking Density

Body-temperature responsive shape memory polymers (SMPs) attract a lot of attention with the application in biomedicine. Multiple SMPs regulate the response temperature through the proportion of their stationary and reversible phases by changing the molecular weight of the polymer or the components of the composite. Herein, a crosslinking reaction of trans-polyisoprene (TPI) and polycaprolactone (PCL) initiated by benzoyl peroxide gave a SMP of TPI/PCL, whose shape memory property is realized by stage-division crystallization zone. Under the fixed ratio of TPI:PCL, the crystallization performance of TPI/PCL is controlled by the crosslinking density. The response temperatures of the components in TPI/PCL are selected for the stage-division crystallization zone, making excellent shape memory performance at corresponding response temperatures. For the further achievement in controllable response temperature within a certain range, the relationship model between crosslinking density and response temperature is established, obtaining the customizable response temperature ranging 37–55 °C. The presented facile regulation method for response temperature will provide a new idea for the SMPs development.