Measures to improve yellowing of silicone rubber
1. Using modified silicone oil: On the one hand, it can inhibit the yellowing of silicone rubber after secondary vulcanization; On the other hand, it can improve the vulcanization speed and crosslinking density of silicone rubber, shorten the vulcanization time, and act as a crosslinking active additive. Experts have invented a paste like 2,5 vulcanizing agent that can resist yellowing. Due to the addition of high hydrogen silicone oil, the anti yellowing effect of the vulcanizing agent is greatly enhanced, making the appearance of silicone products more transparent, and preventing the splashing of the vulcanizing agent during processing, reducing safety hazards.
2. Experts have added organic surfactants to control the size of secondary particles during the treatment of white carbon black. After treatment with composite anti yellowing agents, the product has been applied to silicone rubber products and has a good anti yellowing effect. Experts such as Ge Jianfang from Zhongkai Agricultural Engineering College have enhanced the anti yellowing performance of the mixed rubber and expanded its usage environment by adding an anti yellowing additive, pyrophosphate, without reducing its physical and mechanical properties.
3. In terms of process, the main problems that cause the color of silicone rubber products to turn yellow after molding are: high mold temperature or long vulcanization time.