Organic defoamers, including mineral oils, amides, low alcohols, fatty acids, fatty acid esters, and phosphate esters, were studied and applied at an earlier stage. They belong to the first generation of defoamers. These defoamers have the advantages of easily available raw materials, good environmental performance, and low production costs. However, they also have drawbacks such as low defoaming efficiency, strong specificity, and strict usage conditions.
The polyether defoamer is the second generation of defoamers. It mainly consists of straight-chain polyethers, polyethers with alcohol or ammonia as the initiator, and polyether derivatives with end-group esterification. The most prominent advantage of polyether defoamers is their strong anti-foaming capacity. Moreover, some polyether defoamers possess excellent properties like high temperature resistance, strong resistance to acids and alkalis. Nevertheless, their usage conditions are restricted by temperature, their application fields are relatively narrow, their defoaming ability is not strong, and the bubble-breaking rate is low.
Silicone defoamers (the third generation of defoamers) have numerous advantages, such as strong defoaming performance, rapid defoaming ability, low volatility, no toxicity to the environment, no physiological inertia, and a wide range of applications. Therefore, they have broad application prospects and huge market potential. However, their foam suppression performance is not satisfactory.
Polyether-modified polysiloxane defoamers simultaneously possess the advantages of polyether defoamers and silicone defoamers, and they represent the development direction of defoamers. In some cases, they can even be reused based on their reverse solubility. However, there are only a few types of such defoamers, which are still in the research and development stage, and the production cost is relatively high.
Your message must be between 20-3,000 characters!
