White oil has a great influence on the quality of silicone glue, please refuse to use it

As China's economy continues to grow rapidly, the curtain wall industry has also developed rapidly. Some new materials and new technologies have been widely used in curtain wall design, making curtain wall buildings higher and higher, and the forms also appear diversified. The main component of silicone sealant is hydroxy-terminated polydimethylsiloxane. The molecular structure is dominated by silicon-oxidation bonds. The breaking energy of the molecular chain is very high, which makes it have good UV resistance and It also has excellent high elasticity.

Silicone sealant mainly utilizes its high elasticity on the building curtain wall. When the displacement of the joint changes, it can withstand the stress change caused by the change of the joint size; at the same time, it can maintain the good air tightness and water tightness of the joint.

If the silicone sealant suffers from embrittlement and loses its high elasticity, it will cause great hidden dangers to the safety of the curtain wall. Silicone sealant uses dimethyl silicone oil as a plasticizer in the production process. Its main function is to weaken the force between polydimethylsiloxane molecules and increase the mobility of polymer molecular chains. Make it have good flexibility. During the use of the silicone sealant, the dimethyl silicone oil will not volatilize or ooze out over time, so that the high elasticity of the silicone sealant can always be maintained.

As the price of simethicone is relatively high, with the fierce market competition in the sealant industry, some manufacturers start with plasticizers in order to reduce costs and use white oil instead of simethicone as the plasticizer of silicone sealants. . When white oil is used as a plasticizer, it can not only increase the gloss of the silicone sealant, but also increase the extrusion speed of the silicone sealant. The cost is higher than that of the silicone sealant using dimethyl silicone oil as the plasticizer. low. However, white oil is composed of small-molecule saturated alkanes with relatively low molecular weight and is easy to volatilize. It is added to the silicone sealant as a plasticizer. As time goes by, it will be completely volatilized or exuded from the silicone sealant, and it will not function as a plasticizer. The final result will be the hardness of the silicone sealant. It will increase sharply, and will become brittle or even crack in severe cases. If white oil penetrates into the butyl sealant, it will also cause the dissolution of the butyl sealant, and in severe cases, it will cause oil flow. If silicone sealant containing white oil is used in the stone curtain wall, it will also cause the pollution of the stone curtain wall.

Therefore, the use of white oil-containing silicone structural sealant in engineering will cause the failure of the curtain wall, which not only affects the beauty of the curtain wall, but also reduces the energy-saving and thermal insulation effect of the curtain wall. If there is a problem with the sealant on the curtain wall of a high-rise building, the glass plate will be debonded, and it will also cause a great hidden danger to the personal safety of the pedestrians below. The country should increase the testing requirements for silicone sealants and further regulate the silicone sealant market.