Antagonistic flame retardancy between hexakis(4-nitrophenoxy) cyclotriphosphazene and potassium diphenylsulfone sulfonate in the PC system

摘要

Hexakis(4-nitrophenoxy) cyclotriphosphazene (HNTP) was added to polycarbonate (PC) as intumescent flame retardant. In order to get high-flame-retardant PC composite with a small quantity of addition, potassium diphenylsulfone sulfonate (KSS) was added to PC as synergetic flame retardant. The flame retardancy and thermal degradation behavior of composites was investigated with limiting oxygen index (LOI), UL-94 vertical burning test, microscale combustion calorimeter (MCC), and thermogravimetric analysis (TG). TG coupled with FTIR (TG/FTIR) was used to research their gaseous products. Scanning electron microscopy analyses and FTIR spectrophotometer were used to study the structure of residual char. But the flammability properties of PC systems indicated the synergistic was instead of antagonistic effects. The antagonistic behaviors between HNTP and KSS were further researched by MCC, TG, and FTIR. The antagonism of KSS was quantified by Lewin M's synergistic effectiveness parameter, calculated from sample LOI data.