Differences between three defoaming agents
一、 Polyether modified silicon defoamer
1. Composition characteristics of polyether-modified silicon defoamer. Polyether-modified silicon defoamer introduces polyether chains into polysiloxane chains through condensation technology, making it both a polyether and silicone defoamer. With its advantages, it has become a defoaming agent with excellent defoaming performance and wide application prospects. The polyethylene oxide chain segments in the polyether segment of polyether-modified silicone can provide hydrophilicity and foaming properties, while the polypropylene oxide chain segments can provide strong hydrophobicity and high permeability, which is important for reducing defoaming agents. The surface tension has a strong effect.
2. Excellent characteristics of polyether modified silicon defoamer. Since in the molecule of silicon ether copolymer, the siloxane segment is a lipophilic group and the polyether segment is a hydrophilic group, polyether modified silicon defoamer can be used. It is suitable for both oil-based and water-based foaming systems, and can quickly eliminate foam and exert its continuous foam suppression function for a long time. Among them, the Huashengyuan defoaming agent R&D team has upgraded its distribution, so it uses less additives, which helps customers save consumption costs to a certain extent. It can be said to be a cost-effective product. Soak product. And it is easy to emulsify in water, so it is also called “self-emulsifying defoamer”. It has stable chemical properties, strong high temperature resistance, is not easy to lose its solubility in water and mechanical stability, and is resistant to acids, alkali and inorganic Salt can be used for defoaming under harsh conditions.
二、Polyether defoamer.
Polyether defoamer is a non-ionic surfactant. It has excellent defoaming and anti-foaming functions. It is odorless, non-irritating and easily dispersed in water. It is one of several defoaming agent products. One of the most important varieties. It is widely used in fermentation and manufacturing of antibiotics, vitamins and defoaming treatment in food processing, papermaking, chemical industry, coatings, building materials, detergents and other fields.
1. The defoaming performance and foam control performance of polyether defoamer are not as good as those of silicone defoamer. However, polyether defoamer has very little toxicity, can be used for microbial fermentation, and can withstand high temperature, high alkalinity and high temperature. acidic.
2. Silicone defoaming agents have good defoaming and foam-suppressing properties, but are not resistant to high temperatures or acids. They are slightly resistant to alkali and can be used in water treatment and other fields. Polyethers are not effective when used alone and need to be used in combination with polyether-modified silicone defoaming agents. Therefore, polyethers and silicones have many things in common but also many differences.
The main components of polyether defoamer: Polyether defoamer contains special modified polyether and fluorine-containing raw materials, which are compounded through a special process. According to these different additives, polyether defoaming agents can be divided into polyols, fatty acid lipids and amine ethers. These three different types of polyether defoaming agents have their own characteristics: they are colorless and transparent, have fast defoaming and long-lasting foam suppression.
三、Silicone defoamer
The main component of silicone defoamer is silicone oil. Silicone oil is a non-volatile oily liquid at room temperature. It is insoluble in water, animal and vegetable oils and mineral oil, or has very little solubility. It can withstand both high temperature and low temperature. It is chemically inert, physically stable and has no biological activity.
Silicone defoamer is a white, viscous emulsion. It has been used in various industrial fields since the 1960s, but its large-scale and comprehensive rapid development began in the 1980s. As a silicone defoaming agent, its application fields are also very wide, and it has attracted more and more attention from all walks of life. In chemical, paper, coating, food, textile, pharmaceutical and other industrial sectors, silicone defoamer is an indispensable additive in the production process. It can not only remove foam on the liquid surface of the process medium during the production process, thereby improving filtration, The separation, gasification, liquid drainage and other effects of washing, extraction, distillation, evaporation, dehydration, drying and other processes ensure the capacity of various materials holding and processing containers.
Advantages:
(1) Wide range of applications: Due to the special chemical structure of silicone oil, it is neither compatible with water or substances containing polar groups, nor with hydrocarbons or organic substances containing hydrocarbon groups. Due to the insolubility of silicone oil to various substances, it has a wide range of applications. It can be used for defoaming in water systems and in oil systems.
(2) Small surface tension: The surface capacity of silicone oil is generally 20-21 dynes/cm, which is smaller than the surface tension of water (72 dynes/cm) and general foaming liquids, and has better defoaming efficiency.
(3) Good thermal stability: Taking commonly used dimethyl silicone oil as an example, it can withstand 150°C for a long time and more than 300°C for a short time, and its Si-O bond does not decompose. This ensures that the silicone defoamer can be used within a wide temperature range
(4) Good chemical stability: Since the Si-O bond is relatively stable, the chemical stability of silicone oil is very high and it is difficult to chemically react with other substances. Therefore, as long as the preparation is reasonable, silicone defoaming agents are allowed to be used in systems containing acids, alkalis, and salts.
(5) Physiologically inert: Silicone oil has been proven to be non-toxic to humans and animals, and its half-lethal dose is greater than 34 g/kg. Therefore, silicone defoaming agents (when combined with appropriate non-toxic emulsifiers, etc.) can be safely used in industries such as food, medical, pharmaceutical and cosmetics.
(6) Strong defoaming power: Silicone defoaming agents can not only effectively break the foam that has been generated, but also significantly inhibit foam and prevent the formation of foam. Its use is very small, as long as one millionth (1ppm) of the weight of the foaming medium is added, it can produce a defoaming effect. Its common range is 1 to 100ppm. Not only is the cost low, but it also does not pollute the defoamed material.
