Composition and Characteristics of Elastomeric Sealant

Elastomeric sealant is mainly composed of base sealant, filler, crosslinking agent, catalyst and other additives. Base adhesive is the basic material of elastomeric sealant, which determines the performance of sealant.

The base gum is 107 RSP silicone rubber, and its chemical structure is hydroxyl terminated polydimethylsiloxane, and the filler is some inorganic powder,such as white carbon black, calcium carbonate, heavy calcium, etc. The function of fillers is to provide strength, hardness, rheological properties, etc. Crosslinking agent and catalyst are the curing system of sealant. Sealants change from liquid state to elastomer by reaction of base glue with crosslinking agent, catalyst and moisture in air.

The production process of elastomeric sealant is the process of mixing all components of the sealant evenly. The usual production method is to mix the base material with the filler by kneading machine and to grind by grinding machine if necessary, Then the crosslinking agent, catalyst and other auxiliaries are mixed uniformly in vacuum state by planetary machine.

Compared with other kinds of sealants, elastomeric sealant has good elasticity, good resistance to high temperature and low temperature flexibility, good resistance to climate, ozone and ultraviolet, long service life and relatively low cost. In addition, the hardness of the elastic sealant is high and the surface sealant is rigid , with insufficient elasticity and flexibility. On the contrary, elastic sealant with small hardness has good elasticity and flexibility, insufficient rigidity. Therefore, sealant is neither the harder the better, nor the softer the better, but according to the actual needs of a certain range of requirements.

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