INVESTIGATIONS ON POLYVINYL-CHLORIDE) .4. EFFECTS OF METAL CHLORIDES ON THERMAL-DECOMPOSITION OF POLYVINYL-CHLORIDE)

In this work, 23 metal chlorides were investigated to determine their effects on the thermal decomposition of PVC by pyrolysis-gas chromatography at 500 degree C. Each metal chloride exhibits influences on the course of thermal decomposition of PVC almost similar to the corresponding metal oxide except for a few elements; the metal chlorides from acidic metal oxides accelerate the thermal decomposition of PVC, but the metal chlorides from basic metal oxides do not. On comparing the effects of metal oxidea and metal chlorides on the thermal decomposition of PVC, most the thermal chlorides were found to accelerate th decomposition of PVC more than the corresponding metal oxides, owing to ease of addition of the chlorine atoms released from metal chloride to the dehydrochlorinated chains. It is concluded from these results that the thermal decomposition of PVC containing metal salts is markedly influenced by the ease with which chlorine atoms are released from the corresponding metal chloride.