The effect of overload current on the thermo-oxidative decomposition behavior of polyvinyl chloride insulated wires investigated by TG-FTIR technique
摘要
Via thermogravimetry combined with Fourier transform infrared spectrometry, this work aims to investigate the differences in the thermal decomposition characteristics and reaction mechanisms in wires carrying 1.5, 2.5, and 3.5 times the rated current (Ie). The whole thermo-oxidative decomposition process mainly occurred in the 2nd and 3rd stages, and overload wire with more than 2.5 Ie overcurrent was a more serious occur fire hazard. Nevertheless, the polyvinyl chloride (PVC) insulation of 3.5 Ie overload wire exhibited great lower entire activation energies than the PVC insulation of 2.5 Ie and 1.5 Ie overload wires in both stages of the thermo-oxidative decomposition process. Moreover, a reaction model corresponding to each stage showed a significant difference for the 3.5 Ie overload wire insulation compared to the other two overload wire insulations. The maximum release temperature of CO2 was different depending on the current overload, with a significant advance in the maximum CO2 release temperature for the 3.5 Ie PVC material.