Types of Cellulose Ethers

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Types of Cellulose Ethers

In the ready-mixed mortar, the addition amount of cellulose ether is very low, but it can significantly improve the performance of wet mortar, and it is a main additive that affects the construction performance of mortar. Reasonable selection of different varieties, different viscosity, different particle size, different degree of viscosity and addition of cellulose ether, dry mortar performance and play a positive impact. At present, many masonry and plastering mortar water retention performance is not good, a little static a few minutes will appear water slurry separation. Water retention is an important performance of methyl cellulose ether, and it is also the performance of many domestic dry mortar manufacturers, especially those in the southern regions with higher temperatures. The factors that affect the water retention effect of dry powder mortar include the amount of cellulose, the viscosity of cellulose, the fineness of the particles and the temperature of the environment.

Cellulose ether is a synthetic polymer made from natural cellulose by chemical modification. Cellulose ether is a derivative of natural cellulose, cellulose ether production is different from synthetic polymers, its basic material is cellulose, natural polymer compounds. Due to the particularity of the structure of natural cellulose, cellulose itself does not have the ability to react with etherifying agents. However, after the treatment of swelling agent, the strong hydrogen bonds between and within the molecular chains are destroyed, and the active release of hydroxyl groups becomes alkali cellulose with reactive ability, and cellulose ether is obtained by converting-OH group into-OR group after etherification agent reaction.

The properties of cellulose ethers depend on the type, number and distribution of substituents. The classification of cellulose ethers is also classified according to the type of substituents, the degree of etherification, solubility properties and related application properties. According to the type of substituent on the molecular chain, it can be divided into single ether and mixed ether. The cellulose we usually use is single ether, while HP cellulose is mixed ether. Methyl cellulose ether cellulose is the product of the structural formula of [COH7O2(OH)3-h(OCH3)h ]x after the hydroxyl group on the glucose unit of natural cellulose is replaced by methoxy group. Hydroxypropyl methyl cellulose ether HP cellulose is the product of the hydroxyl group on the unit is partially replaced by methoxy group and the other part is replaced by hydroxypropyl group, the structural formula is [C6H7O2(OH)3-m-n(OCH3)m[OCH2CH(OH)CH3] n]x In addition, hydroxyethyl methyl cellulose ether HE cellulose is widely used and sold on the market. The main varieties.

From the solubility can be divided into ionic and non-ionic. Water-soluble nonionic cellulose ethers are mainly composed of two series of alkyl ethers and hydroxyalkyl ethers. Ionic C cellulose is mainly used in synthetic detergent textile printing and dyeing food and oil exploitation. Non-ionic cellulose, HP cellulose, HE cellulose, etc. are mainly used in building materials, latex coatings, medicine, daily chemistry, etc. Used as thickener, water retention agent, stabilizer, dispersant, film forming agent.

Key words:

Mortar additive