A shape-memory poly(ε-caprolactone) hybridized TiO₂/poly(l-lactide) composite with antibacterial properties

Organic-inorganic composites as an efficient strategy to upgrade the structural and functional properties of synthetic polymers are attracting extensive attentions. However, there are few studies on the shape memory (SM) behavior of organic-inorganic composites. In the work, poly(ε-caprolactone) hybridized TiO₂ nanomaterial (PCL-TiO₂) is made as the switching phase and integrated into poly (l-lactide) (PLLA) to construct an SM composite. PCL-TiO₂/PLLA shows "sea-island" structure and better interfacial adhesion than PCL/PLLA, which facilitates the transmission of elastic power between the switching phase and the fixing phase. PCL-TiO₂ as switching phase exhibits lower enthalpy at 57 °C than PCL, and PCL-TiO₂ also acts as "heat dispersion pump station", which builds a dynamically responsive system and initiates shape change. The shape fixing and recovery ratio of PCL-TiO₂/PLLA are 93.9 % and 94.4 %, respectively, and go back to the original shape within 15 s at 57 °C. At the same time, PCL-TiO₂ endows SMP with good antibacterial properties. Then this work provides a well-placed way for developing SM materials with structure-function integration.