Improving the tracking and erosion resistance performance of alumina trihydrate-free addition-cure liquid silicone rubber

Aiming to improve tracking and erosion resistance performance of addition-cure liquid silicone rubber (ALSR) without alumina trihydrate, A- and B-series ALSR samples with different fumed silica mass fraction and platinum catalyst concentration were prepared respectively. The tracking and erosion resistance performance of all the samples were evaluated. Also, the thermal decomposition products were detected. Basing on the comparative analysis of thermal decomposition characteristics, morphology, crystal structure, the improvement mechanism was discussed. Results showed that increasing the concentration of platinum catalyst and the mass fraction of fumed silica both can improve the tracking and erosion resistance performance, whereas the former was more effectively. Further analysis considered that platinum catalyst played a very important role in thermal decomposition process of ALSR, increasing the platinum catalyst content can not only promote the crosslinking reaction between the methyl groups, but also suppress backbone decomposition.