Hydroxyethyl cellulose (HEC), a white or light yellow, odorless, non-toxic fibrous or powdery solid, prepared by etherification of alkaline cellulose and ethylene oxide (or chlorohydrin), belonging to the genus Nonionic soluble cellulose ethers. Because HEC has good properties of thickening, suspending, dispersing, emulsifying, bonding, film-forming, protecting moisture and providing protective colloids, it has been widely used in oil exploration, coatings, construction, medicine and food, textiles, papermaking and polymers. Polymerization and other fields.
After hydroxyethyl cellulose meets water-based paint?
As a non-ionic surfactant, hydroxyethyl cellulose has the following properties in addition to thickening, suspending, binding, flotation, film-forming, dispersing, water retention and providing protective colloids:
HEC is soluble in hot or cold water, and does not precipitate at high temperature or boiling, making it have a wide range of solubility and viscosity characteristics, as well as non-thermal gelling;
The water retention capacity is twice that of methyl cellulose, and it has better flow regulation;
Compared with the recognized methyl cellulose and hydroxypropyl methyl cellulose, the dispersing ability of HEC is the worst, but the protective colloid ability is the strongest;
It is non-ionic and can coexist with a wide range of other water-soluble polymers, surfactants, and salts. It is an excellent colloidal thickener for high-concentration electrolyte solutions.
How to use hydroxyethyl cellulose?
Add directly at the time of production – this method is the easiest and takes less time:
Begin stirring continuously at low speed and slowly sieve the hydroxyethyl cellulose evenly into the solution and continue stirring until all particles are soaked through. Then add preservatives and various additives. Such as pigments, dispersing aids, ammonia, etc. Stir until all the hydroxyethyl cellulose is completely dissolved (the viscosity of the solution increases significantly) before adding other components in the formula to carry out the reaction.
Equipped with mother liquor
It is to prepare a mother liquor with a higher concentration first, and then add it to the product. The advantage of this method is that it has greater flexibility and can be directly added to the finished product, but it must be properly stored. The steps of this method are similar to most of the steps in Method 1; the difference is that there is no need for a high-shear agitator, and only some agitators with sufficient power to keep the hydroxyethyl cellulose uniformly dispersed in the solution can be used, and continue to Stir until completely dissolved into a viscous solution. However, it must be noted that the antifungal agent must be added to the mother liquor as soon as possible.
Kind tips:
Since surface-treated hydroxyethyl cellulose is powdery or fibrous solid, when preparing hydroxyethyl cellulose mother liquor, remind you to pay attention to the following points:
Before and after adding hydroxyethyl cellulose, it must be kept stirring until the solution is completely transparent and clear;
It must be sieved into the mixing barrel slowly, and do not directly connect the lumps or spheroids and hydroxyethyl cellulose into the mixing barrel;
The water temperature and the pH value of the water have a significant relationship with the dissolution of hydroxyethyl cellulose, so special attention should be paid to it;
Do not add some alkaline substances to the mixture before the hydroxyethyl cellulose powder is soaked with water. Raising the pH value after soaking will help dissolve;
As far as possible, add antifungal agent in advance;
When using high-viscosity hydroxyethyl cellulose, the concentration of the mother liquor should not be higher than 2.5-3% (by weight), otherwise the mother liquor is difficult to handle.
Post time: Apr-28-2024