Thermal Degradation and Combustion of Polycarbonate Blended with Small Amounts of Ultra Strong Acid Salts

Abstract

The effect of very small amounts of ultra strong acid salts on the flame retardancy of polycarbonate PC has been studied. The experiments were planned with emphasis on the reproducibility as the concentration of the additives were in the range of 100 ppm to 10000 ppm. The addition of ultra strong acid salts as low as 100 ppm resulted in the retardancy of the PC combustion. The self-extinguishing time was 5 seconds or shorter, which is useful for industrial application. Thermogravimetry, pyrolysis-gas chromatography-mass spectrometry, and elemental analysis showed that the thermal degradation is accelerated by adding the acid salts. The 5! and 50! weight loss temperatures decreased and the amount of the carbonaceous residue at 700c C also decreased. The results did not coincide with the general relationship between the flame retardancy of polymeric materials and thermal degradation nor with the general effect of the amount of additives.