Octaphenyl polyhedral oligomeric silsesquioxanes( OPS) and a new novel flame rerardant of polyhedral oligomeric silsesquioxane containing 9,10 – dihydro-9-oxa-10-phoshaphenanthrene-10-oxide( DOPO-POSS) were synthesized in our lab. 4% DOPO-POSS and 6% OPS were mixed with polycarbonate( PC) by a twin-screw extruder to prepare the flame retardant composites. The analysis of pyrolysis product between PC / DOPO-POSS and PC / OPS composites were measured by pyrolysis chromatography-mass spectrometry( Py-GC / MS);...