In depth analysis of water retention performance of hydroxypropyl methyl cellulose ether

Experimental analysis of Shandong chuangyao Biotechnology Co., Ltd. cellulose ether plays an irreplaceable role in the production of building materials, especially dry mixed mortar, especially in the production of special mortar. The important role of water-soluble hydroxypropyl methylcellulose ether in mortar mainly has three aspects: first, excellent water holding capacity, second, the influence on mortar consistency and thixotropy, and third, the interaction with cement.

The water retaining effect of hydroxypropyl methyl cellulose ether depends on the water absorption of the base, the composition of mortar, the layer thickness of mortar, the water demand of mortar and the setting time of setting material. The water retention of hydroxypropyl methylcellulose ether itself comes from the solubility and dehydration of cellulose ether itself. It is well known that although the molecular chain of hydroxypropyl methylcellulose contains a large number of OH groups with strong hydration, it is not soluble in water because the cellulose structure is highly crystalline. The hydration ability of hydroxyl group alone is not enough to pay for the strong intermolecular hydrogen bond and van der Waals force. Therefore, it only swells and does not dissolve in water. When a substituent is introduced into the molecular chain, not only the substituent destroys the hydrogen chain, but also the hydrogen bond between chains is destroyed due to the wedging of adjacent substituents. The larger the substituent, the greater the distance between molecules. The greater the hydrogen bond breaking effect, the solution enters after the cellulose lattice is expanded, and the cellulose ether becomes water-soluble to form a high viscosity solution. When the temperature increases, the hydration of polymer decreases, and the water between chains is expelled. When the water is fully used, the molecules begin to aggregate and form a three-dimensional network structure. The factors affecting the water retention of mortar include cellulose ether viscosity, addition amount, particle fineness and service temperature。

The higher the viscosity of hydroxypropyl methyl cellulose ether, the better the water retention performance and the viscosity of polymer solution. Depending on the molecular weight (degree of polymerization) of the polymer, it is also determined by the molecular structure, chain length and chain morphology. The type and quantity distribution of substituents also directly affects its viscosity range. The viscosity of polymer solution depends on the molecular weight of polymer. The viscosity and concentration of cellulose ether solution are related to the application in various fields. Therefore, each cellulose ether has many different viscosity specifications, and the adjustment of viscosity is mainly realized through the degradation of alkali cellulose, that is, the fracture of cellulose molecular chain.

Shandong chuangyao Biotechnology Co., Ltd. has been specialized in cellulose ether industry for many years. It has rich product scientific research achievements and technical support capacity. With complete product models and stable performance, it can meet the needs of customers at home and abroad for product performance indicators.