The role of magnesium oxide in nitrile rubber sheet and neoprene rubber sheet

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Issue Time: Dec 13,2019

Summary

The polymerized monomers of nitrile rubber sheet are butadiene and acrylonitrile, which are polar rubbers.

Main performance characteristics:

1. Advantages: (1) Because it contains polar AN groups, it has higher stability to non-polar or weakly polar animal and vegetable oils, liquid fuels and solvents. The higher the AN content, the better the oil resistance.

(2) Heat resistance is better than NR, SBR, CR. (3) Good air tightness. Second only to butyl rubber. (4) Poor cold resistance, the higher the AN content, the worse. (5) It is a non-crystalline rubber, which requires carbon black reinforcement

2. Disadvantages: Poor insulation and small volume resistance

Application areas: Used to make oil-resistant rubber products such as rubber hoses, rubber rollers, gaskets, tank linings, aircraft tank linings, large oil sacs, conveyor belts, and supports

Neoprene rubber sheet is an elastomer formed by the polymerization of 2-chloro-1,3-butadiene. The molecules are polar and easy to crystallize.

Main performance characteristics:

1. Advantages: (1) Excellent weather resistance, ozone resistance, heat aging resistance, oil resistance, solvent resistance (2) Affected by crystallization, good raw rubber strength

(3) Good adhesion (4) Excellent chemical resistance and excellent flame resistance

2. Disadvantages: (1) Poor storage of raw materials, hardening during storage, poor cold resistance (2) Relative density

Application areas: rubber rollers, tapes, wire covers, cable jackets, rubber sheets, gaskets, gaskets, seals, gaskets and adhesives

There is a difference between heavy and light magnesium oxide. The apparent density of light magnesium oxide is equal to or less than 0.5 g / ml, while the apparent density of heavy magnesium oxide is about three times that of light weight. Light weight is white amorphous powder, heavy weight is white or beige powder, but the relative density of both is 3.58, both are odorless and non-toxic; soluble in acid absorption and ammonium salt solution, but hardly soluble in water Ethanol overseas; melting point is 2800 ° C, with excellent thermal insulation and fire resistance. Placed in humid air for a long time, magnesium oxide will absorb water and carbon dioxide in the air, generate acidic magnesium carbonate and deteriorate. At the same time, light magnesium oxide and heavy magnesium oxide more easily absorb moisture and carbon dioxide.

Heavy magnesium oxide is mainly used in the manufacture of thermal insulation materials and refractory materials. Light magnesium oxide can be used as a reinforcing agent and filler for plastics and rubber. It can also be used as an inorganic accelerator and vulcanization active agent in the rubber industry. It can be used as an acid inhibitor in the pharmaceutical industry; as a catalyst in the chemical industry, or as a raw material for other magnesium compounds. At the same time, it is also a raw material for dyes, greases, enamels, ceramics, glass and other industries.

Among nitrile rubber sheets, magnesium oxide acts as a reinforcing agent for heat-resistant rubber. For example, the heat resistance of nitrile rubber with 100 parts of magnesia is 177 ° C. Chloroprene rubber with proper amount of magnesium oxide can improve the hardness, tensile strength and tensile strength of vulcanizate. It can also neutralize the small amount of hydrogen chloride produced by rubber during vulcanization or in the product under sunlight. Almost.

Qihang rubber special warm reminder:

Magnesium oxide should be packaged and sealed in polyethylene bags, and the protective bag should be protected. It should be protected from moisture and stored for less than 6-12 months.