▎ 摘　　要

This work experimentally and numerically studies pyrolysis and combustion performances of high impact polystyrene and its three composites containing modified ammonium polyphosphate and graphene. Both microscale thermogravimetric analysis (TGA) and mesoscale cone calorimeter experiments were carried out to develop and parameterize the complete pyrolysis model. A 1D numerical solver capable of involving multicomponent and multistep high order reactions and multilayer physical structure of solid was developed to simulate the experimental data. Total content of the added components served as flame retardant was remained unchanged at 15 mass%, but the ratio between the two additives varied. TGA tests were performed at three heating rates to establish the pyrolysis reaction scheme and attain the kinetics by Genetic Algorithm (GA). Pyrolysis mechanisms of individual neat materials were obtained first and then combined together to predict the experimental measurements of the synthesized composites. Additional interactions among intermediate products were invoked to better fit the experimental results. After parameterization, another composite with different component ratio was used to verify the extrapolation capability of the pyrolysis model. Subsequently, thermodynamics of the materials, including reaction heat, specific heat capacity and thermal conductivity, were further obtained by optimization using the measured mass loss rate in cone calorimeter tests. Effective combustion heats of the composites were calculated based on the measured mass loss and total heat released. Meanwhile, the effective combustion heat of each gaseous product in the pyrolysis model was quantitatively estimated by numerically fitting the measured heat release rate. Reliability of the attained thermodynamics was further verified by simulating the experimental results of the composite designed for validation, and acceptable agreement was found.