Abstract:

This article analyzes the application of four different coupling agents in silicafilled natural rubber (NR) namely KH-560, KH-570, Si-69 and C800, and discusses effects of different types and dosages of coupling agents on the properties of NR vulcanizates. The results show that curing time is shortened with dosage increase of coupling agents, among which coupling agent C800 mixing with silica enhances antiscorch property of NR vulcanizates and improves its processability. Mechanical properties of NR vulcanizates are enhanced in varied degrees by different coupling agents, among which KH-560 mixing with silica is most effective in enhancing NR vulcanizate, and the optimum loading is 2 phr.

Key words: coupling agent; silica; natural rubber (NR); vulcanization characteristics