Thermal decomposition behavior of poly blend

• Published in: Journal of thermal analysis and calorimetry Vol. 135; no. 4; p. 2437
• Main Authors: Cui, Shaoying, Wei, Pingfu, Li, Li
• Format: Journal Article
• Language: English
• Published: Springer 01.02.2019
• Subjects: Carbonates; Hydroxides; Infrared spectroscopy; Propylene; Protons; Pyrolysis; Spectroscopy
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1007/s10973-018-7297-5

To provide guidance for the practical thermal processing and applications of poly(propylene carbonate)/poly(vinyl alcohol) (PPC/PVA) blend, an environmentally friendly material with wide potential applications, thermogravimetric analysis (TG) and thermogravimetric-Fourier transform infrared spectroscopy (TG-FTIR) were adopted to investigate the thermal decomposition behavior of PPC in PPC/PVA blend for its worse high-temperature thermal stability, and the decomposition processes were analyzed by Chang's method. Accordingly, the precise kinetic parameters of each thermal decomposition process were calculated by Flynn-Wall-Ozawa method. The results showed that neat PPC underwent three pyrolysis stages: unzipping, unzipping and chain random scission and unzipping. For PPC/PVA blend, the elimination reaction of the side-hydroxyl groups of PVA promoted the chain random scission of PPC, thus playing the dominant role in the thermal decomposition of PPC. The more the hydroxyl groups in PVA were, the lower the thermal stability of the blends would be. On the basis of above, a rational decomposition mechanism of PPC accelerated by PVA was proposed: With the increase in temperature, the elimination reaction of the hydroxyl groups of PVA occurred to release H.sup.+ protons; then, the H.sup.+ protons attacked the PPC backbone to release CO.sub.2 by chain random scission, leading to a rapid mass loss of PPC in PPC/PVA blend during 200-250 °C.