Thermal Decomposition Kinetics of Poly(propylene carbonate maleate)

Abstract

The thermal decomposition kinetics of the novel terpolymer, poly (propylene carbonate maleate) (PPCMA), was investigated using thermogravimetric (TG) analysis at different heating rates. A new computational method called nonlinear approximation (NLA) is introduced in this work. The Flynn-Wall-Ozawa (FWO), Tang, Kissinger-Akahira Sunose (KAS), and NLA methods were used to calculate the apparent activation energy (E(subscript a)). The results show that the NLA method is ideal for E(subscript a) calculations because of its simpler and more appropriate analysis process. It does, however, give slightly higher average relative errors for E(subscript a) compared to the other typical model-free methods. Calculations using the solid-state reaction model-fitting method indicated that the thermal decomposition process was composed of multiple mechanisms. For the whole decomposition process, the values of E(subscript a) were between 70 and 135 kJ•mol^(-1), and the pre-exponential factor (A) varied from 5.24×10^4 to 9.89×10^7 min^(-1). The differences in E(subscript a) also explain the differences in decomposition temperature between poly(propylene carbonate) (PPC) and PPCMA.