Study on the Synthesis and Application in the Polycarbonat of Silicone- Cyclophosphazene Flame Retardant

Silicone-cyclophosphazene (SCP) as a flame retardant was synthesized using hydroxyl terminated polydime thylsiloxane(PDMS-OH) and hexa cyclophosphazene silicone oil and phosphonitrilic chloride trimer(HCCTP) as the precursors, The properties of SCP-modified polycarbonat(PC) such as thermal stability, flame retardant properties and carbon layer after combustion were analyzed. It was found that the target product was SCP, as evidenced by infra-red spectrum (IR)and nuclear magnetic resonance(31P-NMR) spectra results. The PC/SCP composite had higher thermal stability, with higher amount of carbon residue at both initial degradation temperature and 800 oC. When the addition of SCP was 10 wt.% in the PC/SCP composite, the oxygen index increased from 28 to 34%, and a V-0 level was achieved on UL – 94 test. Also, a compact structure of the residue carbon layer after combustion was observed.