Views: 1 Author: Site Editor Publish Time: 2020-11-02 Origin: Site
Redispersible latex powder is processed by spray drying of special polymer emulsion. In the process of processing, protective colloids and anti-hardening agents have become indispensable additives. The dried rubber powder is a group of 80~100mm spherical particles gathered together. These particles are soluble in water and form a stable dispersion that is slightly larger than the original emulsion particles. This dispersion will form a film after it loses water and dries. This kind of film is as irreversible as ordinary emulsions and will not disperse again when exposed to water. Dispersions.
Redispersible latex powder can be divided into: styrene-butadiene copolymer, tertiary carbonate ethylene copolymer, ethylene-acetic acid acetic acid copolymer, etc., and on this basis, grafting silicone, vinyl laurate, etc. to improve performance. Different modification measures make the redispersible rubber powder have different properties such as water resistance, alkali resistance, weather resistance and flexibility. Containing vinyl laurate and organic silicon, the rubber powder has good hydrophobicity. Highly branched ethylene tertiary carbonate has a low Tg value and good flexibility.
These kinds of latex powders are used in mortar, all have a delaying effect on the setting time of cement, but the delaying effect is less than that of directly applying similar emulsions. In contrast, styrene-butadiene has the greatest retardation effect, and ethylene-vinyl acetate has the least retardation effect. If the content is too small, the improvement effect of the mortar performance is not obvious.