Effects of liquid accelerant on the pyrolysis behaviors and kinetics of PMMA, a noncharring polymer

Thermal decomposition of solid combustibles infiltrated with combustible liquids (liquid accelerants) is one typical fire behavior in arsons. In the present study, thermogravimetric and kinetic analyses are used to investigate the pyrolysis of one typical noncharring polymer namely polymethyl methacrylate (PMMA) infiltrated with different contents of one representative liquid accelerant namely kerosene. Results indicate that the thermal decomposition process of pure PMMA and PMMA infiltrated with kerosene show a one-stage and a three-stage process, respectively. Furthermore, the first and third stages for PMMA infiltrated with kerosene can be both regarded as one-step reaction. With the increase of kerosene content, the conversion rate ranges of the first and third stages for PMMA infiltrated with kerosene are shortened. The peak and average reaction rates of the first and second stages increase, while the peak and average reaction rates of the third stage decrease. The maximum and average reaction rates for the entire decomposition process also decrease. The average activation energy values for the whole and one certain stage both increase. Moreover, the calculated kinetic parameters can be used to accurately predict the thermal decomposition behavior of PMMA infiltrated with kerosene.

Automated summary

This study investigates the thermal decomposition of polymethyl methacrylate (PMMA) infiltrated with kerosene using thermogravimetric and kinetic analyses. The results show that the thermal decomposition process of PMMA infiltrated with kerosene exhibits three stages, while pure PMMA only has one stage. As the kerosene content increases, the thermal decomposition rates of PMMA infiltrated with kerosene decrease.