Thermogravimetric-Mass Spectrometric Study of the Pyrolysis Behavior of PVC

• Published in: Journal of China University of Mining and Technology Vol. 17; no. 2; pp. 242 - 245
• Main Authors: SUN, Qing-lei, SHI, Xin-gang, LIN, Yun-liang, ZHU, He, WANG, Xiao, CHENG, Chuan-ge, LIU, Jian-hua
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2007; Shandong Analysis and Test Center, Shandong Academy of Science, Jinan, Shandong 250014, China
• Subjects: gas evolution; PVC; pyrolysis; TG-MS; TQ 20; TG-MS; pyrolysis; TQ 20; PVC; gas evolution
• ISSN: 1006-1266
• DOI: 10.1016/S1006-1266(07)60080-7

The pyrolysis characteristics of PVC were systematically investigated using a Netzschne TG thermo-balance coupled to a quadrupole mass spectrometer. The pyrolysis conditions were 0.1 MPa of Ar, a heating rate of 10 °C/min and a final temperature of 1000 °C. Both the thermogravimetric properties and the simultaneous evolution of gaseous products during pyrolysis were studied. The TG/DTG results showed that as the pyrolysis temperature increases the weight loss and weight loss rate of PVC increases. Near 412 °C the weight loss rate attained its peak value. At higher temperatures the rate of loss gradually decreases. The gases evolved during thermogravimetric analysis were analyzed by a mass spectrometer, monitoring the relative intensity of HCl, C 6H 6, light hydrocarbon and chlorine-containing gases. The evolution curves showed that HCl, C 6H 6, light hydrocarbon and chlorine-containing gases all peak at about 416 °C. This is consistent with the fact that the weight loss curves also peak at about 412 °C. The extensive HCl evolution is consistent with the high chlorine content of PVC. The formation of these gases can be explained by considering these reactions: dehydrochlorination, intramolecular cyclization and the addition of HCl to unsaturated hydrocarbons.