For previous studies on the aging state of silicone rubber composite insulators, the second step of the thermogravimetric curve is usually considered to be the polydimethylsiloxane content, but there is no discussion on the decomposition products. In this study, thermogravimetric-IR coupling experiments were carried out on silicone rubber samples and filler components under a nitrogen atmosphere to qualitatively and quantitatively analyze the weight loss process of silicone rubber during thermogravimetric analysis and to relate the thermogravimetric curves and IR spectra by time variation. The infrared experimental data yielded products of silicone rubber during thermal decomposition that were different from the expected results. To verify the plausibility of the causes, single component experiments with silicone rubber fillers were carried out. The experimental results are analyzed and interpreted in terms of both temperature and the characteristic peaks of the infrared spectrum. Solutions to the causes of the experimental errors are also proposed, and the next step of the work is envisaged.

silicone rubber; thermogravimetric analysis; thermogravimetric-infrared