Product description

The so-called foaming agent is a substance that makes the target substance pores. It can be divided into three categories: chemical foaming agent, physical foaming agent and surfactant. Chemical foaming agents are those compounds that can release carbon dioxide and nitrogen gas after being decomposed by heating, and form pores in the polymer composition; physical foaming agents are the changes in the physical form of the foam pores through a certain substance , Which is formed by the expansion of compressed gas, the volatilization of liquids or the dissolution of solids; foaming agents have high surface activity, can effectively reduce the surface tension of the liquid, and arrange the double electron layer on the surface of the liquid film to surround the air , To form bubbles, and then a single bubble forms a foam.

Inorganic foaming agents mainly include the following categories

Carbonate: an inorganic foaming agent, mainly calcium carbonate, magnesium carbonate, sodium bicarbonate. Among them, sodium bicarbonate is a white powder with a specific gravity of 2.16. The decomposition temperature is about 100-140℃, and part of CO2 will be released, and all CO2 will be lost when it reaches 270℃. Soluble in water but not in alcohol.

Water glass: Sodium silicate, when mixed with glass powder and heated to about 850°C, it reacts with the glass and emits a large amount of gas. At the same time, it can strengthen the material's compressive and tensile strength. It is mainly used as a foaming agent for preparing foam glass. .

Silicon carbide: The main foaming agent used in the current industrial production of foam glass, which emits a large amount of gas during sintering at 800-900°C.

Carbon black: It is also a very useful foaming agent. It emits CO2 when heated and has a good foaming effect, but the disadvantage is that the price is higher.

Commonly used physical blowing agents are low boiling point alkanes and fluorocarbons. Physical foaming agent is a compound physical foaming agent, which not only has the advantages of high foaming ratio, good foam stability, low bleeding, etc., but also has a certain modification effect on magnesite cement and reduces product halogenation. Probability of frost. Physical foaming agents have been widely used in the production of foamed magnesite products such as fire-resistant panels and lightweight partition panels, and in some products (magnesite fire-resistant door cores, etc.), they have a critical role in success.