Thermal degradation of PVC cable insulation studied by simultaneous TG-FTIR and TG-EGA methods

Thermogravimetry (TG/DTG) coupled with evolved gas analysis ( MS detection) of volatiles was used to characterize the thermal behavior of commercial PVC cable insulation material during heating in the range 20-800degreesC in air and nitrogen, respectively. In addition, simultaneous TG/FTIR was used to elucidate chemical processes that caused the thermal degradation of the sample. A good agreement between results of the methods was found. The thermal degradation of the sample took place in three temperature ranges, namely 200-340, 360-530 and 530-770degreesC. The degradation of PVC backbone started in the range 200-340degreesC accompanied by the release of HCl, H2O, CO2 and benzene. The non-isothermal kinetics of thermal degradation of the PVC cable insulation in the temperature range 200-340degreesC was determined from TG results measured at heating rates of 1.5, 5, 10, 15 and 20 K min(-1) in nitrogen and air, respectively. The activation energy values of the thermal degradation process in the range 200-340degreesC of the PVC cable insulation sample were determined from TG results by ASTM method.