BJ-90 is a cross-linked polymer emulsion thickener made by copolymerization of acrylate and methacrylate.BJ-90 is an alkali-soluble thickener containing acidic groups, with low viscosity in acidic medium but high viscosity in alkaline medium.BJ-90 has high molecular weight, strong thickening ability, good anti-settling and anti-mildew properties, and easy to use. BJ-90 can effectively improve the low shear BJ-90 can effectively improve the low shear viscosity of coatings, improve splashing and sagging.
The coverage rate of the adsorbed polymer compound on the solid surface of the pigment increases sharply as the concentration rises, but the coverage rate is different in the flat-top area that seems to reach the adsorption isotherm. Some ratios are close to 1. Some are 0.5. If it is 0.5, oxidised pe wax it means that half of the solid phase surface is bare and there is no adsorbent.
The influence of solvent on adsorption For resins, there are good solvents and poor solvents. Solvents are measured by dissolution parameters. Good solvents with similar or equal dissolution parameters are good solvents with strong dissolving power. The big difference in dissolution parameters is poor solvent, poor dissolving power or immiscibility. To make the polymer dispersant better adsorb on the surface of the pigment, the solvent must be a good solvent. The high molecular polymer dispersant is used in coatings, and it must have good compatibility with the resin solution. Therefore, the solvent in the resin solution should not only be a good solvent for the resin, but also a good solvent for the dispersant.
Only in a good solvent can the extended chains of the dispersant unfold freely and form a sufficiently thick adsorption layer. In a poor solvent, the extended chains will curl up, and the thickness of the adsorption layer is not enough to better exert the steric hindrance effect. That is to say, high molecular polymer dispersant can only function fully in a solvent system better than 0. It is impossible to design a high molecular polymer dispersant that is effective in any dispersion system. , Any kind of high molecular polymer dispersant can only be effective in certain specific solvent systems.
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