Polyether modified silicone is a polyether siloxane copolymer (referred to as silicone ether copolymer) by introducing polyether chain into siloxane molecule. Polyether modified silicone defoamer is a new and efficient defoamer which combines the advantages of the two. It is a defoamer composed of polyether with strong foam inhibition ability and dimethylsilicone oil with strong hydrophobicity and rapid foam breaking as main components, and emulsifier, stabilizer and other components that can organically combine silicone oil and polyether. It has the characteristics of low surface tension, rapid defoaming, long foam suppression time, low cost, less dosage and wide application. The polyether modification of organosilicon makes it have the advantages of the second kind of defoamer. It becomes a kind of defoamer with excellent performance and wide application prospect.
In the molecular structure of silicone ether copolymer, siloxane segment is lipophilic group, polyether segment is hydrophilic group. In polyether chain, the energy-saving polyethylene oxide chain provides hydrophilicity and foaming property, while the energy-saving polyethylene oxide chain provides hydrophobicity and permeability, which has a strong effect on reducing surface tension. The group at the end of polyether chain also has a great influence on the properties of the copolymer. The common end groups are hydroxyl group and aChinaoxy group. By adjusting the relative molecular weight of siloxane segment in copolymer, the properties of silicone can be highlighted or weakened. Similarly, changing the relative molecular weight of Polyether Segment will increase or decrease the proportion of silicone in the molecule, and also affect the properties of the copolymer. Polyether modified silicone defoamer is easy to emulsify in water, also known as "self emulsifying defoamer". Above the cloud point temperature, it loses water solubility and mechanical stability, and is resistant to acid, aChinaali and inorganic salts. It can be used for defoaming under harsh conditions.
In order to improve the lipophilic properties of water-based inks, coatings and cutting fluids, some methyl groups in polyether modified organosilicon copolymers are replaced by long chain aChinayl groups, which can play a more effective role in defoaming. In order to have good defoaming property below cloud point temperature, commercial self emulsifying defoamers are usually equipped with dimethyl silicone oil silica paste. At this time, polyether modified silicone surfactant can also be used as emulsifier of dimethylsilicone oil to disperse and emulsify at cloud point temperature.