The difference between polyether modified silicon, polyether and silicone defoaming agent

The difference between polyether modified silicon, polyether defoamer and silicone defoamer is that polyether modified silicon combines the advantages of both polyether defoamer and silicone defoamer, which is non-toxic and harmless. It is harmless to bacteria and has very little added amount. It is a cost-effective product. Polyether-modified silicone is a polyether-siloxane copolymer (referred to as a silicone ether polymer) prepared in the siloxane molecule due to, for example, a polyether segment.

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Polysiloxane defoamer has the characteristics of rapid defoaming, long foam suppression time and safe five poisons, but it is difficult to dissolve in water, high temperature resistance, poor alkali resistance, polyether defoamer, high temperature resistance, resistance Strong alkalinity, but its defoaming speed and defoaming time are not ideal. The polyether chain is introduced into the polysiloxane chain by condensation technology, which makes it have the advantages of two types of defoamers and becomes a kind of defoamer. A defoamer with excellent performance and wide application prospects. In the molecule of the silicone ether copolymer, the siloxane segment is a lipophilic group, and the polyether segment is a hydrophilic group. The polyethylene oxide chain in the polyether segment provides energy saving and hydrophilicity, and the polypropylene oxide chain provides hydrophobicity and permeability, which has a strong effect on reducing surface tension. The groups of the polyether end groups also have a strong influence on the properties of the silicone ether copolymers.

Common end groups are hydroxyl, alkoxy and so on. Adjusting the relative molecular mass of the siloxane segment in the copolymer can make the copolymer highlight or weaken the properties of the silicone. Similarly, the relative molecular mass of the modified polyether segment will increase or decrease the ratio of the organosilicon in the molecule, and will also affect the performance of the copolymer. Polyether modified silicone defoamer is easy to emulsify in water, also known as “self-emulsifying defoamer”. When its cloud point temperature is above, it will lose its solubility to water and mechanical stability, and it is resistant to acid and alkali. And inorganic salts, can be used for defoaming of diethanolamine desulfurization system and defoaming of various oil agents, cutting fluids, non-freezing, water-based inks and other systems. It is also suitable for the printing industry to wash off uncured resin after plate making Defoaming agent, is a very representative, excellent performance, versatile silicone defoamer. Polysiloxane defoamer is usually composed of two main components: polydimethylsiloxane and silicon dioxide. The defoamer based on polydimethylsiloxane is one of the defoaming systems. An ideal type of defoamer is that it is insoluble in water and difficult to emulsify. Polydimethylsiloxane has lower surface properties than carbon chain hydrocarbons, and therefore has lower surface tension than surfactants commonly used in the textile industry.

Pure polydimethylsiloxane has poor foam suppression and is slow. The defoaming effect needs to be strengthened by silica particles. The silica particles are carried by the silicone oil to the air-water interface of the foam and enter the bubble liquid film due to its hydrophobicity The contact angle between the surfactant and the foaming droplets of the surfactant is greater than 90 ° C, thereby forcing the foaming liquid to be discharged from the surface of the solid hydrophobic particles, causing the foam to drain rapidly and cause rupture. This produces a good defoaming effect due to the synergistic effect of the two compositions.

 


Post time: Dec-11-2019