A phosphorous/nitrogen/silicon containing diphenylphosphoramide silicon oil toward effective flame retardancy for polycarbonate with comparable mechanical properties

A P/N/Si containing diphenylphosphoramide silicone oil (PASO) was synthesized using amino phenyl silicone oil and diphenylphosphinyl chloride as raw materials. The as-synthesized PASO displayed better flame retardancy toward polycarbonate (PC) meanwhile maintaining the mechanical performances of PC. At loading level of 1 wt% PASO, UL 94V-0 rating and a high limited oxygen index value of 31% were achieved for the flame retardant composite in the presence of 5 wt% talc as anti-dripping agent. Additionally, it gave a tensile strength of 65.5 MPa, elongation at break of 96.4%, and impact strength of 52.6 kJ/m(2), which were comparable to the pure PC. The analysis of the char residue after cone calorimeter test and the pyrolysis gaseous products demonstrated that PASO exhibited flame retardant mechanism of both gas and condensed phases.