Silicone rubber refers to a rubber whose main chain is alternately composed of silicon and oxygen atoms, and the silicon atoms are usually connected with two organic groups.

Silica gel is a highly active adsorption material and is an amorphous substance. Introduction to silicone rubber

Silicon rubber refers to a rubber whose main chain is alternately composed of silicon and oxygen atoms, and the silicon atoms are usually connected with two organic groups. Ordinary silicone rubber is mainly composed of silicone links containing methyl groups and a small amount of vinyl groups. The introduction of phenyl groups can improve the high and low temperature resistance of silicone rubber, while the introduction of trifluoropropyl and cyano groups can improve the temperature resistance and oil resistance of silicone rubber. Silicone rubber has good low temperature resistance and can generally still work at -55°C. After the phenyl group is introduced, it can reach -73°C. The heat resistance of silicone rubber is also outstanding. It can work for a long time at 180°C, can withstand temperatures slightly higher than 200°C for several weeks or longer while still being elastic, and can instantly withstand high temperatures above 300°C. Silicone rubber has good air permeability, and its oxygen transmission rate is the highest among synthetic polymers. In addition, silicone rubber also has the outstanding characteristics of being physiologically inert and not causing coagulation, so it is widely used in the medical field.

Silicone rubber 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 condensation polymerization 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 silicone rubber, fluorosilicone rubber, etc. Introduction to silica gel

Basic information

Name: Silica gel

Alias: oxidized silica gel or silicic acid gel

English name: Silica gel; Silica

Molecular formula: xSiO2·yH2O

Molecular weight: 60.08

CAS registration number: CAS# 112926-00-8

EINECS login No.: 231-545-4

Word explanation

Chemical formula xSiO2·yH2O. Transparent or milky white granular solid. It has an open porous structure, strong adsorption, and can adsorb a variety of substances. Add dilute sulfuric acid (or hydrochloric acid) to the aqueous solution of water glass and let it stand to form a hydrous silicate gel and solidify. The electrolyte Na+ and SO4 2-(Cl-) ions dissolved in it are removed by washing with water, and silica gel is obtained after drying. If it absorbs water, some silica gel absorbs about 40% or even 300% of moisture. Used for gas drying, gas absorption, liquid dehydration, chromatography, etc., and also used as a catalyst. If cobalt chloride is added, it will turn blue when dry and red after absorbing water. Renewable and reusable.

Safety performance

The main component of silica gel is silica, which is chemically stable and does not burn. Silica gel is a kind of amorphous silica. The dust content in the workshop should be controlled to no more than 10 mg/cubic meter. Exhaust ventilation needs to be strengthened and a mask should be worn during operation.

Silica gel has strong adsorption capacity and can have a drying effect on human skin. Therefore, work clothes should be worn during operation. If silicone gets into your eyes, rinse with plenty of water and seek medical treatment as soon as possible.

Blue silica gel contains a small amount of cobalt chloride, which is potentially toxic. You should avoid contact with food and inhalation. If poisoning occurs, you should seek medical treatment immediately.

During use, silica gel absorbs water vapor or other organic substances in the medium, and its adsorption capacity decreases. It can be reused after regeneration.

Safety terms: S22 Do not breathe dust. Do not breathe dust.