Polyether-Modified Silicone Oil: Reshaping the Efficiency and Convenience of Emulsion-Type Defoamers

Emulsion-type defoamers formulated using polyether-modified silicone oil with a specific structure as an emulsifier exhibit a more than 2-fold increase in particle size within 5 minutes in aqueous foaming solutions above 25°C, significantly improving the durability of defoaming ability. This particle size change phenomenon is unique to formulations using a specific proportion of polyether-modified silicone oil as an emulsifier.

This type of emulsion-type defoamer can be used at high concentrations and exhibits excellent dispersibility in foaming solutions, thus eliminating the need for the dilution step typically required for emulsion-type defoamers.

A specific structure of siloxane polyether block copolymer combined with silica to form a silicone paste, used as an active ingredient, results in an emulsion-type defoamer with better defoaming properties compared to general dimethyl silicone oil defoamers. It also avoids adverse effects on the target material, such as water repellency and non-stickiness. Suitable for use in dyeing, papermaking, water-based inks, emulsion polymerization, and latex industries.

The silicone paste formulated with siloxane block copolymer and silica can use emulsifiers commonly used in O/W type silicone oil emulsions, but polyether-modified silicone oil is preferred. The preparation method is as follows: 15 parts of fumed silica (Aerosil 200) with a surface treated with hexamethyldisiloxane for hydrophobicity and 0.7 parts of ammonium carbonate are mixed in a kneader at 155°C for 3 hours under a nitrogen atmosphere to prepare the silica silicone paste. 65 parts of silica silicone paste and 35 parts of polyether modified silicone oil were mixed and then slowly added to 900 parts of xanthan gum and sorbitol viscous aqueous solution under stirring. The mixture was then emulsified using a colloid mill to form an emulsion-type defoamer.