Polyether modified silicone is a new efficient defoaming agent which combines the advantages of polyether - siloxane copolymer in siloxane molecule.It is a defoaming agent composed of emulsifier and stabilizer which can make silicone oil and polyether organically combined by selecting polyether with strong foaming inhibition ability and dimethyl silicone oil with strong hydrophobicity and rapid foaming breaking.It has the characteristics of low surface tension, rapid defoaming, long foam suppression time, low cost, less dosage, wide application and so on.Organosilicon was modified with polyether to make it have the advantages of second-class defoaming agent, and become a defoaming agent with excellent performance and wide application prospect.

    The siloxane segment is the hydrophilic group and the polyether segment is the hydrophilic group.In the polyether chain segment, the poly (ethylene oxide) chain provides hydrophilicity and foaming property, while the poly (propylene oxide) chain provides hydrophobicity and permeability, which has a strong effect on reducing surface tension.The groups at the end of the polyether chain also have great influence on the properties of the silicon ether copolymer.Common end groups are hydroxyl, alkoxy and so on.Adjusting the relative molecular weight of siloxane segment in copolymer can make copolymer highlight or weaken the characteristics of silicone.Similarly, changing the relative molecular weight of polyether segment will increase or decrease the proportion of organic silicon in the molecule, which will also affect the performance of copolymer.

    It has been reported that organosilicon is used as a dye defoamer.The old dyeing process, generally using dimethylpolysiloxane defoaming agent, can achieve satisfactory effect of defoaming agent, and ensure the uniformity of dyeing.But the new dyeing process, the use of high temperature and high pressure machinery, in this kind of machinery, dyed by the dye liquid jet and movement, at the same time dyeing.Although the foam can be defoamed by ordinary silicone defoaming agent, but under high temperature and high pressure, the general siloxane defoaming agent will produce thin film precipitate and stain the matter.The use of block copolymers can overcome the above shortcomings, because these antifoaming agent components are soluble in cold water, but not in hot water, so they can play an antifoaming role.However, the defoaming effect of the copolymer defoaming agent is not satisfactory. If a certain amount of gas-phase SiO2 is added to the copolymer, satisfactory defoaming effect can be achieved, and uniform dyed fabrics can be produced.

    Polyether modified silicone defoamer is easy to emulsify in water, also known as "self emulsifying defoamer".When the temperature is above the turbidity point, it loses the solubility of water and mechanical stability, and is resistant to acid, alkali and inorganic salt. It can be used for defoaming under harsh conditions, and is widely used for defoaming in high temperature dyeing process and fermentation process of polyester fabric.In addition, can also be used for diethanolamine desulfurization system of defoaming and a variety of oil, cutting fluid, non-freezing liquid, water-based ink system of defoaming, also suitable for printing industry photosensitive resin plate making, washing off the uncured resin defoaming, is a very representative, excellent performance, a wide range of uses of silicone defoaming agent.

    In order to improve the lipophilicity used in water-based ink, coating and cutting fluid, part of methyl group in the copolymer of polyether modified silicone is replaced by long chain alkyl group, which can play the defoaming effect more effectively.In order to make the following turbidity point temperature can also have better defoaming, commercial self-emulsifying defoaming agent is usually equipped with dimethyl silicone oil - white carbon paste, then at the turbidity point temperature polyether modified silicone surfactant can be used as the emulsifier of dimethyl silicone oil and play the role of dispersion, emulsification.