Kinetic study of the thermal decomposition of castor oil based polyurethane

Abstract

Polyurethane is a class of polymer that presents as main feature the versatility in its physical and chemical properties. Knowing the kinetic parameters of the thermal degradation of these materials collaborates with the development of new applications. Therefore, this work had as objective to study of the kinetic parameters of the thermal decomposition of vegetable oil-based polyurethane (castor oil), through non - isothermal thermogravimetric method. The thermogravimetric curves of the samples showed two decomposition steps, and the kinetic parameters of each step were determined using the Flynn-Wall-Ozawa (FWO) method. The first stage of thermal decomposition presents characteristics of first-order reactions, the second stage of decomposition presented a behavior similar to that of the first stage until α equal to 0.4, in the conversion range between 0.4 and 0.9 a concave profile was observed, characteristic of complex processes, indicating parallel reactions and minimum lifetime of 1650 years old.