Cerium phenylphosphonate and decabromodiphenyl oxide for flame retardancy of glass fiber reinforced poly(ethylene terephthalate) composites

The combinations of cerium phenylphosphonate (CeHPP) and decabromodiphenyl oxide (DBDPO) were used for flame retardancy of glass fiber reinforced poly(ethylene terephthalate)(GF/PET) composites by using melt blending. Thermograviment analysis(TGA) was employed to investigate the thermal decomposition behavior of the flame retardant DBDPO-CeHPP-GF/PET composites. The combustion properties of DBDPO-CeHPP-GF/PET composites were measured by using limiting oxygen index (LOI), underwriters laboratories 94 (UL-94) and microscale combustion calorimeter (MCC). SEM was used to investigate the microtopography of char residues of DBDPO-CeHPP-GF/PET composites. The thermal properties and flame retardance of DBDPO-CeHPP-GF/PET composites are significantly improved by the incorporation of the combinations of CeHPP and DBDPO. For DBDPO-CeHPP-GF/PET composite with mass ratio of GF/PET composites:DBDPO:CeHPP of 91:6:3, the UL-94 V-0 classification and high LOI (29.5%) are achieved. The total heat release (THR), peak heat release rate (PHRR) and heat release capacity (HRC) of DBDPO-CeHPP-GF/PET composites at this ratio are respectively reduced by 10.2%, 13.1% and 12.8% comparing with the pure GF/PET composites. And the flame retardant mechanism of DBDPO-CeHPP-GF/PET composites was analyzed based on the SEM results of char residues.