How much do organosilicon know about its application in defoamer field


Introduction: in modern industrial production, bubbles are everywhere: machine grooves of all kinds of processing fluids; various industrial cleaning pools; various industrial and agricultural products and preparations; water treatment and other aspects of petrochemical production. Foam brings many problems to industrial production: in order to prevent bubbles from overflowing, the feeding coefficient is forced to reduce 30%~ 50%; the spillover causes the waste of raw materials; the bubble occupies space, affects the reaction speed, and the production cycle is forced to prolong; the foam will affect the quality of products, such as coatings and plastic products; the emergence of foam will have an impact on the stability of industrial production, resulting in fluctuations in operation and quality. Instable. The most direct solution to the bubble problem is the use of defoamer.


The mechanism of organosilicon defoamer is that organosilicon has low surface tension. Silicone compounds (silicone oil) interfere with the surface tension of the gas-liquid boundary, resulting in defoaming effect.


When silicone is added to the foam medium, the small particles of silicone oil fall onto the surface of the bubble, while effectively reducing the surface tension of the contact point, causing a thin weakness in the outer skin, resulting in bubble breaking.


The optimum defoaming activity criterion can be described as follows: free silicone oil particles must be completely, quickly and effectively dispersed into the active region. The silicone oil is very small and has a very large proportion of SiO2 filler. It is dispersed rapidly and causes demulsification and bursting outside the contact point of SiO2 particles. Due to the burst of foam near the foam, the foam is unstable, accelerating the continuous bubble breaking effect, and finally reaching a stable state. If it is emulsion defoamer, the emulsion is too stable, which will reduce the defoaming effect. When the stability is poor, it has greater activity. Therefore, it is necessary to balance the stability and activity, and choose organosilicon compounds with low solubility and high activity in water and oil phases.