Abstract: The pyrolysis processes of polyethylene (PE) insulating and polyvinyl chloride (PVC) sheath materials in nitrogen at different heating rates were studied. The results showed that the thermo-loss (TG) curves of the two materials are basically the same pattern when the effect of the heating rate is neglected. The kinetic parameters of the single-component pyrolysis process were investigated. The average activation energies of the PVC and PE pyrolysis processes were obtained by 2 kinds methods as 163.77, 269.5 kJ/mol and 119.456, 251.449 kJ/mol, respectively. The pyrolysis products of PVC sheath materials included water, hydrogen chloride, chlorinated hydrocarbons and other hydrocarbons. The pyrolysis process of PE insulation materials was dominated by alkane functional groups in the first half of the process, and different kinds of olefin functional groups as well as other hydrocarbon functional groups were generated in the second half.

Key words: flame-retardant cable; pyrolysis kinetics; TG-FTIR; pyrolysis products