Core-shell structure antioxidant microencapsulated piperazine pyrophosphate towards improving service performance and fire safety of styrenic thermoplastic elastomer

Core-shell structure antioxidant microencapsulated piperazine pyrophosphate are designed to enhance the mechanical property, aging resistance and flame retardant of styrenic thermoplastic elastomer composites. In this study, the PAPP was wrapped with silica and then grafted with primary antioxidant 3-(3, 5-di-tert-butyl-4 hydroxyphenyl) (AO) for preparing double-shell wrapped flame retardants (MCPAPP). Because MCPAPP was well compatible with TPE matrix, the tensile strength and elongation at break of TPE/MCPAPP improved to 12.7 MPa and 437%. Moreover, the Retention rate of elongation at break for TPE/MCPAPP composite reached 66.5%, significantly higher than the pure TPE (22.2%) at 135 °C after aging for 14 d. Compared with pure TPE, the maximum smoke density and the peak heat release rate were reduced by 41.0% and 80.6%. Thus, the core–shell antioxidant strategy gives an excellent approach to obtain high-performance TPE composites.