Silica- and diatomite-modified fluorine rubber nanocomposites

To find the most suitable filler system for fluorine rubber, a simple and green method to introduce a limited content of silanol groups on the surfaces of silica and fluorine rubber was studied. Fluorine rubber nano-composites were prepared by using nano-silica, diatomite and carbon black as the reinforcement and filler and the coupling agents KH550, KH590 or Si69 as the compatibilizer between the filler and fluorine rubber. The structure and morphology of the composites were investigated by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The results showed that the most suitable filler system for fluorine rubber was the diatomite and silica compound (8:12 mass ratio), the best coupling agent was KH550 at 2 parts per hundred rubber (phr). The modified compound filler was silanized with the coupling agent KH550 for fluorine rubber by FTIR analysis, the compatibility between the filler and fluorine rubber was improved by SEM analysis and further confirmed by thermogravimetric analysis to improve the thermal properties of fluorine rubber with the filler compound system.