The Pyrolysis Characteristics and Kinetics Analysis on Typical Thermoplastic Artificial Green Plants

The flowers, leaves and stems of artificial green plants have been chosen as the study objects and the pyrolysis characteristics of these three parts have been analyzed in order to identify the fire characteristics of the typical thermoplastic artificial green plants. The pyrolysis activation energy distribution of the three parts of the sample has been studied through Starink method and Firedman method respectively and the accuracy of the two methods have been compared. The most probable mechanism functions of the primary pyrolysis stages of the three parts have been discussed through Malek method. The Coats-Redfern method has been used to verify the obtained most probable mechanism functions. The results of thermogravimetric experiments show that the pyrolysis of the flowers and leaves of the artificial green plants can be divided into two stages. The temperature at which these two parts reach the maximum heating rate is basically the same. The residual amount of the flower sample keeps decreasing with the increase of the heating rate while the residual amount of the leaves increases with the increasing heating rate. The pyrolysis of stems involves three stages, in which the second stage owns the highest mass loss rate, and the residual amount of stems decreases with the rising heating rate. The analysis results of the pyrolysis kinetics of artificial green plants show that the activation energy of stems is relatively low, most likely to be pyrolyzed in case of fire. The partial activation energy of the leaves is relatively high, contributing to high thermal stability in case of fire. As the reaction proceeds, the pyrolysis mechanisms of the artificial green plant flowers, leaves and stems transform from random nucleation to two-dimensional diffusion, from random nucleation to phase boundary reaction and from chemical reaction to three-dimensional diffusion respectively.