In cement mortar and gypsum-based slurry, hydroxypropyl methylcellulose mainly plays the role of water retention and thickening, and can effectively improve the adhesion and sag resistance of the slurry.
Factors such as air temperature, temperature and wind pressure speed will affect the volatilization rate of water in cement mortar and gypsum-based products. Therefore, in different seasons, there are some differences in the water retention effect of products with the same amount of hydroxypropyl methylcellulose added. In the specific construction, the water retention effect of the slurry can be adjusted by increasing or decreasing the amount of HPMC added. Water retention under high temperature conditions is an important indicator to distinguish the quality of hydroxypropyl methylcellulose ether.
Excellent hydroxypropyl methylcellulose series products can effectively solve the problem of water retention under high temperature. In high temperature seasons, especially in hot and dry areas and thin-layer construction on the sunny side, high-quality HPMC is required to improve the water retention of the slurry. High-quality HPMC has very good uniformity. Its methoxy and hydroxypropoxy groups are evenly distributed along the cellulose molecular chain, which can improve the ability of the oxygen atoms on the hydroxyl and ether bonds to associate with water to form hydrogen bonds. , so that free water becomes bound water, so as to effectively control the evaporation of water caused by high temperature weather, and achieve high water retention.
High-quality hydroxypropyl methylcellulose can be uniformly and effectively dispersed in cement mortar and gypsum-based products, and wrap all solid particles, and form a wetting film, and the moisture in the base is gradually released over a long period of time , and the hydration reaction with the inorganic gelling material to ensure the bonding strength and compressive strength of the material.
Therefore, in high-temperature summer construction, in order to achieve the water retention effect, it is necessary to add high-quality HPMC products in sufficient quantities according to the formula, otherwise, there will be insufficient hydration, reduced strength, cracking, hollowing and shedding caused by excessive drying. problems, but also increase the construction difficulty of workers. As the temperature drops, the amount of HPMC added can be gradually reduced, and the same water retention effect can be achieved.
Post time: Apr-13-2023