Thermal decomposition kinetics of polymeric wastes using a nonisothermal thermogravimetric method

Nonisothermal kinetic experiments of polymeric wastes, such as polyethylene (PE), polypropylene (PP), polystyrene (PS) and polyethylene terephthalate (PET), were studied in nitrogen atmosphere, and kinetic parameters were analyzed by Flynn-Wall method. The mixture containing polymeric wastes, which were combined to the ratio of 2: 2: 2: 1 for PE, PP, PET and PS on the basis of weight fraction, was also studied and analyzed in the same way. Theoretical activation energies (En,) of mixtures were calculated and compared with experimental activation energy (E_a) obtained by Flynn-Wall method. The nonisothermal kinetic results of polymeric wastes showed that most of polymeric wastes had single step reactions and similar activation energies for observed conversion ranges respectively. In the result of kinetic parameter analysis of mixtures, Ea showed lower values than values of E,h for all observed conversion ranges. This means that lower activation energies are the result of interaction among polymeric wastes during thermal decomposition of mixtures.