Sustainable and Cytocompatible Thermoplastic Vulcanizate Based on Silicone Rubber and Polycaprolactone

The development of advanced biomaterials that combine excellent mechanical properties, elasticity, processability, and biocompatibility remains a challenge. In this study, silicone rubber (SiR)/polycaprolactone (PCL) thermoplastic vulcanizate (TPV) was designed and prepared because of the good cytocompatibility of both phases, high elasticity of SiR, and good mechanical and rheological properties of PCL. By introducing 10 wt % polyurethane-polysiloxane copolymer (PU-co-PSi), the interfacial thickness increases from 75 to 223 nm, and the average size of dispersed SiR phase decreases from 2320 to 890 nm, indicating a good compatibilization effect of PU-co-PSi on SiR/PCL blend. By using dynamic vulcanization, the phase inversion of the PCL phase from dispersed phase to continuous phase was achieved, and the fine size of the SiR phase with an average size of less than 2 μm was obtained at a high ratio of SiR/PCL (60/40). The SiR/PCL TPVs exhibit good mechanical properties with tensile strength and elongation at break of 6.1 MPa and 458%, respectively, and high elasticity. SiR/PCL TPVs also exhibit good processability and recyclability. Their cytocompatibility is confirmed by supporting cell adhesion, proliferation, and spreading. This sustainable TPV material can be a highly versatile biomaterial with promising applications in tissue engineering and biomedical devices.