The existence of foam may have many negative effects on product quality and production and construction process. In order to ensure the smooth progress of production and construction in the industry, appropriate defoamer is selected to eliminate potential risks, among which silicone defoamer plays an important role in the development of the industry.


Silicone defoamer is a kind of highly efficient chemical preparation, the main components include natural polymer, synthetic polymer and silicone oil. It achieves excellent defoaming effect by reducing the surface tension of the liquid and causing the bubble to burst.


According to relevant statistics, the global organic defoamer market has maintained steady growth in recent years. With the development of the global economy, the demand for organic defoamer in all walks of life continues to rise, and the market size is expected to further expand in the future. In China, with the rapid development of China's economy, chemical, food, pharmaceutical and other industries are growing rapidly, and the demand for organic defoamer is strong. At the same time, the Chinese government's attention to the environmental protection industry continues to increase, and the application of organic defoamer in the field of environmental protection will receive more attention.






01


Bubble formation






The bubble refers to the existence of a large number of insoluble gases (mainly air) in the form of tiny dispersions in the liquid, forming a heterogeneous system. There is a large interface between liquid and gas, and the liquid separates the gas molecules in a thin film. Its stability mechanism is as follows:





02


Action characteristics and types of organosilicon defoamer






1. The action characteristics of silicone defoamer are as follows:


① It has low surface tension and is therefore incompatible with most coating systems.


② In the coating industry, silicone defoamer is widely used.


③ The defoamer has high efficiency and low addition amount.


Even if the amount added is small, it is not enough to cause significant changes in the compatibility of the coating system, so it can be used for varnish.


(5) Silicone defoamer can quickly migrate to the surface, mainly to defoamer.






2. Types of silicone defoamer


① water-emulsion type defoamer


Polydimethylsiloxane (silicone) as the main body, combined with white carbon black complex, under the action of surfactants (emulsifiers), can be prepared into different concentrations of O/W type water-emulsion defoamer (suitable for water-based media defoamer scene), or transformed into high concentration silicon paste. When used, it can be applied by smearing method or after temporary dilution.


② oil system defoamer


The silicone oil is carried and dispersed into the foaming solution using a solvent. As the solvent diffuses, the silicone oil or droplets can effectively play a defoaming role (usually achieved by blending high and low viscosity silicone oil), or be prepared into a silicone oil/mineral oil dispersion.


③ Solid powder defoamer


A powder solid carrier containing 2%-5% silicone defoamer by mass fraction and 98%-50% by mass fraction.


④ Antifoam stick


Preparation of silicone oil, sodium sulfonate and wax.


⑤ Self-emulsifying self-dispersing defoamer


This type of defoamer is based on silicone surfactant copolymerized by polysiloxane and polyether. By introducing hydrophilic groups on the molecular chain of polysiloxane, it can significantly improve the dispersion performance of silicone in water and form a self-emulsification state, so it is specially used as a class of defoamer. This kind of defoamer has excellent defoaming effect above the cloud point, especially suitable for high temperature and high pressure jet dyeing and other scenes.


"Self-emulsifying" defoamer has good heat resistance, mechanical stability, and acid and alkaline resistance, and can achieve defoaming effect under harsh conditions, such as polyacetate fiber high temperature dyeing, diethanolamine aqueous desulfurization system, all kinds of oil cutting fluid, non-freezing fluid and other systems can play a defoaming role.