Defoamer is a chemical additive used to eliminate or inhibit foam in liquids, which is widely used in industrial production. The types of defoamers mainly include the following:
GP type defoamer: It is synthesized by polymerized propylene oxide and ethylene oxide or propylene oxide and glycerin, and its foam inhibition ability is higher than that of defoaming, and is often used in the production of biological pesticides and yeast.
GPE defoamer: On the basis of GP defoamer, ethylene oxide is added at the end of the polypropylene glycol segment to form a hydrophilic polyoxyethylene oxypropylene glycerin chain end, which has strong defoaming ability but large solubility and poor foam inhibition performance, which is suitable for the pharmaceutical industry.
GPES defoamer: Esterification with stearic acid at the end of the GPE defoamer chain to obtain a polyether defoamer, which has high defoaming efficiency.
Silicone-type defoamer: the main ingredient is polydimethylsiloxane (silicone oil), which is suitable for water-based and oil-based foaming systems, and has the advantages of stable chemical properties, wide range of use, low volatility and non-toxicity, but poor foam inhibition performance.
Polyether modified silicone defoamer: combining the advantages of polyether and polysiloxane, it has the characteristics of good dispersion, strong foam inhibition ability, stability, non-toxicity, low volatility and strong defoaming effect.
Mineral oils, amides, lower alcohols, fatty acids, fatty acid esters, phosphate esters and other organic defoamers: belong to the first generation of defoamers, raw materials are easy to obtain, high environmental performance, low production costs, but low defoaming efficiency, strong specificity, harsh use conditions.
Polyether defoamer: It is the second generation of defoamer, which has excellent properties such as strong foam inhibition ability, high temperature resistance, strong acid and alkali resistance, but the use conditions are limited by temperature, the use field is narrow, the defoaming ability is poor, and the foaming rate is low.
Polysiloxane defoamer: It has the characteristics of rapid defoaming, long foaming inhibition time, safety and non-toxicity, but it is insoluble in water, high temperature resistance, and poor alkali resistance.
Polyether defoamer: good water solubility, high temperature resistance, strong alkali resistance, but the defoaming speed and foam inhibition time may not be as good as polysiloxanes.
Each defoamer has its own specific application scenarios and advantages and disadvantages, and the choice of the right defoamer needs to be determined based on the specific industrial needs and the characteristics of the foaming system.
