Effect of Barium stearate on the thermal stability of polyvinyl chloride

Thermal degradation reaction kinetics of PVC stabilized by barium stearate were studied by means of the non-isothermal weight-loss technique under a nitrogen atmosphere. The results show that the lowest decomposition temperature is greater than 203.6 degrees C and 217.2 degrees C in the conversion rate of 5% and 10% respectively. When the heating rate beta is 10 degrees C /min, at 200 degrees C and 225 degrees C the remaining mass from the sample with barium stearate was 99.1% and 95.3%, respectively. The thermal decomposition process occurred in three stages, the results calculated by various methods show that the average apparent activation energy in first, second and third phase is 79.88kJ/mol, 89.37kJ/mol and 187.34kJ/mol respectively. In the initial reaction (alpha< 18%), as heating rate is 20 degrees C /min, the decomposition reaction is controlled by the (A1.5) mechanism.