Magnesium oxide is an inorganic compound with the molecular formula MgO. It is a white loose powder at room temperature, with a relative density of 3.20-3.23. It is odorless, tasteless, non-toxic, insoluble in water and ethanol, and soluble in acid.
Magnesium oxide is widely used in the rubber industry, mainly including the following:
① Vulcanizing agent: In rubber such as chloroprene rubber, fluororubber, chlorosulfonated polyethylene rubber, magnesium oxide can be used together with vulcanizing agents such as zinc oxide to increase the vulcanization speed and degree of rubber.
② Activator: Magnesium oxide can react with sulfur in rubber to generate vulcanized rubber particles and improve the vulcanization degree of rubber.
③ Filler: Magnesium oxide can be used as a filler in rubber to increase the strength, hardness and wear resistance of rubber.
④ Acid absorber: Magnesium oxide can absorb the acidic substances produced during the vulcanization process of rubber to prevent rubber degradation.
⑤ Anti-scorch agent: Magnesium oxide can absorb the heat generated during the rubber vulcanization process and prevent the rubber from scorching.
Specifically, the applications of magnesium oxide in different rubbers are as follows:
① In chloroprene rubber, magnesium oxide can be used together with zinc oxide as a vulcanizing agent, and can also be used as an active agent and inorganic accelerator of chloroprene rubber, and is suitable for almost all types of chloroprene rubber. Activated magnesium oxide can also improve the scorch performance of the rubber compound and improve the mixing and storage safety of the rubber compound.
② In fluorine rubber, magnesium oxide can be used as an acceptor of hydrogen fluoride, which can improve the vulcanization degree of fluorine rubber, improve the scorch performance of fluorine rubber and improve the thermal stability of vulcanized rubber, but its acid resistance is poor.
③ In chlorosulfonated polyethylene rubber, cross-linking with activated magnesium oxide will obtain good physical and mechanical properties, especially low permanent deformation, and is suitable for light-colored vulcanized rubber, but has poor water resistance.
④ In nitrile rubber, magnesium oxide can be used as a reinforcing agent for heat-resistant rubber to improve the heat resistance, wear resistance and tensile strength of the rubber.
⑤ In natural rubber, magnesium oxide can be used as a filler to increase the strength, hardness and wear resistance of the rubber.
In short, magnesium oxide plays an important role in the rubber industry and is an indispensable raw material in rubber production.