Molecular formula: TiO2, molecular weight: 79.88
Crystalline type: anatase
Appearance: milky white sol
Average particle size: 10-20nm
Titanium dioxide content: 20%
The current industrial production method of cellulose ether is generally to first swell the cellulose with NaOH aqueous solution to prepare alkali cellulose, and then perform etherification reaction with an etherifying agent to induce substituents to obtain the product. Its properties depend on the type, number and distribution of substituents. The degree of substitution (DS) or molar degree of substitution (MS) is usually used to express the degree of etherification reaction. The degree of substitution refers to the average number of substituents per glucose residue in the cellulose molecule. Since there are only three free hydroxyl groups available for substitution on each glucose residue, when all of them are substituted, the DS value is the largest, that is, DS=3, and the DS value is generally between 0 and 3. The molar substitution is defined as the average number of moles of substitution reagent bound to each glucose residue in the cellulose molecule. Because there is a type of substituents (such as hydroxyalkyl) that can continue to react to form longer side chains, in theory MS can be infinite, that is, 0≤MS≤oo, DS≤MS, and MS/DS can indicate the length of the side chain. The HEC sold on the market has MS=1.5~3.0, and Natr osol 250 has MS=2.5L7J.
Thickening and rheology are not only related to molecular weight, but also to the degree of substitution (MS and DS). The higher the molecular weight, the better the thickening effect and the lower eaa emulsion for sale the formulation cost, but the greater the shear thinning, and the more splashing during roll coating.
Increasing the degree of substitution and uniform substitution can shield the glycoside bond from corrosion by bacteria, thereby facilitating the resistance to biodegradation. The anti-fermentation cellulose thickener is produced according to this principle. For example, the letter B in Aqua-lon products means this.
Cellulose ether tends to agglomerate when exposed to water. To prevent this, the cellulose ether is often treated with glyoxal to reduce its hydration at low pH. The treated HEC can be quickly dispersed in water and dissolve quickly when the pH value is alkaline. For example, the letter R in the A qual on product represents this function.
HEC can also be used as a protective colloid for vinyl acetate emulsion polymerization.
Leave a message
We’ll get back to you soon