Super-tough poly(lactic acid)/silicone rubber thermoplastic vulcanizates: The organic and inorganic synergistic...

Polymer modification using silicone rubber represents a promising avenue for enhancing physico-mechanical properties. However, achieving optimal performance through direct blending is hindered by the poor interface compatibility between silicone rubber and the matrix. In this study, we prepared super-tough thermoplastic vulcanizates (TPVs) of polylactic acid/silicone rubber through dynamic vulcanization with PLA, methyl vinyl silicone rubber (MVQ), glycidyl methacrylate grafted MVQ (MVQ-g-GMA), and fumed silica nanoparticles (SiO₂). The impact of the SiO₂ addition in MVQ on the morphology, mechanical properties, crystallization, and thermal properties of the TPVs was investigated. The results showed that MVQ-g-GMA and SiO₂ exhibited a synergistic compatibilization effect significantly improving the interfacial adhesion between PLA and MVQ. Therefore, the impact and tensile strength of the TPVs increased from 8.0 kJ/m² and 22.2 MPa to 62.6 kJ/m² and 36.7 MPa, respectively. Moreover, the TPVs also presented good low-temperature toughness with a maximum impact strength of 40.4 kJ/m² at -20 °C. Additionally, improvements in thermal stability and crystallization rate were also observed. Overall, combining organic and inorganic synergistic compatibilization is a feasible and effective method to fabricate outstanding low-temperature toughness to PLA.