Room temperature vulcanized silicone rubber

Room temperature vulcanized silicone rubber

Silicone rubber is a linear high molecular weight polysiloxane with a molecular weight generally above 150,000. Its structure is similar to that of silicone oil. According to the different organic groups linked to the silicon atom, silicone rubber includes dimethyl silicone rubber, methyl vinyl silicone rubber, methyl phenyl silicone rubber, fluorosilicone rubber, nitrile silicone rubber, ethyl silicone rubber, ethyl phenylene silicone rubber and many other varieties.

According to the different vulcanization methods, silicone rubber can be divided into two categories: high temperature vulcanized (hot vulcanized) silicone rubber and room temperature vulcanized (including low temperature vulcanized) silicone rubber. Regardless of the type of silicone rubber, no heat release occurs during vulcanization. High temperature vulcanized silicone rubber is a high molecular weight polysiloxane (molecular weight is generally 400,000 to 800,000), while room temperature vulcanized silicone rubber generally has a lower molecular weight (30,000 to 60,000).

Room temperature vulcanized silicone rubber (RTV) has one or two functional groups at each end of the molecular chain (sometimes in the middle). Under certain conditions (moisture in the air or appropriate catalysts), these functional groups can react to form a high molecular weight cross-linked structure.

According to its vulcanization mechanism, it can be divided into condensation type and addition type; according to its packaging method, it can be divided into two types: two-component and one-component.

Room temperature vulcanized silicone rubber is widely used as potting and molding materials. Various electronic and electrical components are coated and potted with room temperature vulcanized silicone rubber, and are widely used in sealing in the automotive and mechanical industries, anti-seismic materials, rubber roller materials in the textile, plastic, and printing industries, and caulking sealing materials in the construction industry. At the same time, it can be used to make soft molds for casting molds of epoxy resin, polyester resin, polystyrene, polyurethane, vinyl plastic, paraffin, low melting point alloys, etc. In addition, the high simulation performance of two-component room temperature vulcanized silicone rubber can be used to reproduce various exquisite patterns on cultural relics.