The main types of defoamers include silicone, polyether, fatty acid ester, mineral oil and biodegradable, etc. The specific classification depends on the composition and application scenario. The following is a detailed classification and characteristics:
1. Classification by chemical composition
Silicone defoamer
Core ingredient: polydimethylsiloxane (PDMS, i.e. silicone oil), which has extremely low surface tension (about 20 mN/m) and can quickly destroy the foam structure.
Features: High temperature resistance (-50℃~200℃), strong chemical stability, suitable for coatings, food, medicine and other fields.
Disadvantages: Excessive use may cause residues (such as clogging sewage treatment membranes).
Polyether defoamer
Core ingredient: ethylene oxide/propylene oxide copolymer, which adapts to different temperature conditions by adjusting the cloud point.
Features: Strong antifoaming ability and high temperature resistance, widely used in dynamic processes such as fermentation and circulating water systems.
Disadvantages: Poor defoaming durability and frequent replenishment are required.
Fatty acids and fatty acid esters
Core ingredients: palmitic acid, stearic acid and their esters, natural defoamers.
Features: Good biodegradability, commonly used in food processing and pharmaceutical industries.
Mineral oil defoamers
Core ingredients: white oil or hydrocarbon oil, compounded with hydrophobic particles (such as silica).
Features: low cost, low toxicity, suitable for scenes with low environmental protection requirements such as papermaking wastewater.
Polyether modified silicones
Core ingredients: silane ether copolymers, combining the advantages of polyether and silicone.
Features: good dispersibility, strong anti-foaming ability, suitable for complex systems (such as high-salt wastewater).
Biodegradable defoamers
Core ingredients: vegetable oil (such as castor oil) or degradable polyether.
Features: environmentally friendly, suitable for ecologically sensitive areas (such as natural water restoration).
2. Other classification methods
By form: emulsion type, oil type, solid particle type, etc.
By application area: special defoamers for textile, papermaking, coating, food, etc.