Environment-friendly flame retardants,cyclotriphosphazene derivatives,were synthesized and characterized by IR spectra and31P-NMR,and proved that the cyclotriphosphazene( HCCP) was substituted with pentaerythritol( PER). The influence of ratio of raw materials,solvent and reaction time were systematically investigated.The optimal reaction conditions were determined as n( HCCP) ∶ n( PER) = 1∶5,tetrahydrofuran as solvent,reaction for 24 h,and the yield was up to 76. 45%. Vertical combustion method was used to...