1. Introduction to silicone rubber
Silicone rubber is the largest category of silicone products. It is an elemental organic elastomer obtained by hydrolysis and polycondensation of various dichlorosilanes. It is divided into thermal vulcanization type (high temperature vulcanization silicone HTV) and room temperature vulcanization type (RTV). The room temperature vulcanization type is divided into polycondensation reaction type and addition reaction type. High-temperature silicone rubber is mainly used to manufacture various silicone rubber products, while room-temperature silicone rubber is mainly used as an adhesive, potting material or mold. The thermal vulcanization type has the largest dosage, and the thermal vulcanization type is divided into methyl silicone rubber (MQ), methyl vinyl silicone rubber (VMQ, with the largest dosage and product brand), methyl vinyl phenyl silicone rubber PVMQ (low temperature resistance, radiation resistance ), others include fluorosilicone rubber, etc.
1.Characteristics of silicone rubber
The molecular structure of organosilicon (polydimethylsiloxane) is mainly composed of siloxane bonds, and the structure is very stable. Therefore, compared with ordinary organic rubber, organosilicon compounds have many beneficial properties, such as heat resistance, electrical properties, etc. Insulation, chemical stability, etc.
Because organic silicon has a spiral structure and the intermolecular force is very small, organic silicon has good elasticity, stretchability, cold resistance, etc. In addition, because the methyl groups located outside the spiral structure can rotate freely, silicone can exert many unique surface properties, such as waterproofness, mold release, etc.
2. Silicone rubber processing process
The mixed rubber is repeatedly refined by adding silicone rubber raw rubber to a two-roller rubber mixing machine or a closed kneader and gradually adding white carbon black, silicone oil, etc. and other additives. Depending on the added fillers and additives, the properties of silica gel also vary.