How to improve the tear strength of liquid silicone?

How to improve the tear strength of liquid silicone?
Liquid silicone is widely used in many fields due to its good fluidity and formability. Improving its tear strength can start from raw materials, additives, processing technology, etc. The following is a detailed introduction:
Choose a suitable base polymer: a base polymer with a high relative molecular mass and a narrow distribution has a high degree of entanglement between molecular chains and can withstand greater external forces, thereby improving the tear strength.
Adding fumed silica: fumed silica is a commonly used reinforcing filler for liquid silicone. It has a large specific surface area, small particle size and high surface activity. It can form a strong interaction with silicone molecules and significantly improve the tear strength. The usual addition amount is between 10%-30%.
Use modified fillers: Surface modification of fillers, such as treating silica with a silane coupling agent, can enhance the interfacial bonding between the filler and the liquid silicone matrix, so that the filler is better dispersed in the matrix, thereby more effectively improving the tear strength.
Add additives reasonably
Toughening agent, cross-linking aid, improve processing technology
Vacuum degassing treatment: Generally, vacuum degassing is carried out multiple times after mixing. The time of each degassing is determined according to the amount of rubber and the performance of the equipment, usually 10-30 minutes.
Optimize molding process parameters: Control the temperature, pressure and time during the molding process. The appropriate temperature can ensure that the cross-linking reaction is fully carried out and a stable cross-linking structure is formed
Post-treatment: The liquid silicone product after molding is subjected to secondary vulcanization treatment, generally at a temperature between 150℃-200℃ and a time of 1-3 hours.