Now that there are more and more markets for hydroxypropyl carboxymethyl cellulose and the prices are uneven, how to easily and quickly determine the quality of hydroxypropyl carboxymethyl cellulose has become a crucial issue! So how to judge the quality of hydroxypropyl methylcellulose? The first thing to look at is the whiteness of hydroxypropyl cellulose; although the whiteness cannot determine whether HPMC is suitable for use, some unscrupulous manufacturers will add a whitening agent during processing, which will affect its quality. But generally speaking, most of the excellent cellulose ethers have better whiteness.
Secondly, it depends on the fineness of hydroxypropyl methylcellulose: the particle size of hydroxypropyl carboxymethyl cellulose is 80-100 mesh, less than 120 mesh, and hydroxyethyl cellulose HECHPMC is about 100 mesh. Most of the hpmc is 60-80 mesh. Generally, the softer the methyl cellulose, the better the dispersion.
The clarity of cellulose ether in the solution: put HPMC into water to produce a transparent colloidal solution, the higher the clarity, the higher the clarity, the lower the insoluble substances.
When the commodity is warmed, it gels or pools and then melts. It is hydrophobic and soluble. Concrete is the key bonding and demulsifying raw material for water-resistant putty powder. The principle of water resistance is as follows: when the redispersible latex powder and cement are mixed with water, the latex powder will continue to return to the original emulsion form, and the latex particles Disperse evenly into the cement slurry. After the cement encounters water, the hydration reaction begins, and the Ca(OH)2 solution reaches saturation and crystals are precipitated. At the same time, ettringite crystals and calcium silicate hydrate colloids are formed, and the latex particles are deposited on the On the gel and the unhydrated cement particles, as the hydration reaction proceeds, the hydration products continue to increase, and the latex particles gradually gather in the voids of inorganic materials such as cement, and form a densely packed layer on the surface of the cement gel. , due to the gradual reduction of dry moisture, the closely packed redispersed latex particles in the gel and voids coagulate to form a continuous film, forming a mixture with the interpenetrating matrix of the cement paste, and making the cement paste and other powders The aggregates are glued to each other.
Post time: May-11-2023