Thesis (M.Sc.)--Chulalongkorn University, 2012

This research focuses on the improvement of compatibility between silica particles and NR matrix by modification of silica surface particles. The modifier containing MTES, VTES and APTMS were selected for investigation in this study. The preparations of modified silica filled NR compounds used two methods, i.e. direct and indirect methods. For direct method, all ingredients were mixed together with NR latex for silica particle generation and modification of their surface. For indirect method, the modified silica particles were first prepared and then directly mixed with NR latex. The optimum condition for both methods was carried out at 24 h under room temperature and the mole ratio of modifier to TEOS of 0.1. The modified silica particles were confirmed by using various techniques such as fourier transform infrared spectroscopy (FTIR), CHN analyzer and hydrophobic tester. The mechanical, thermal and dynamic properties of modified silica filled NR prepared by direct method were slightly enhanced when compared with indirect method. In addition, it is interesting to note that the modified silica filled NR vulcanizates of both direct and indirect methods were improved when compared with unmodified silica filled NR vulcanizates.