Hydroxypropyl methylcellulose is a non-ionic cellulose ether processed from refined cotton through a series of chemical reactions. It is an odorless, non-toxic white powdery substance that dissolves in water and presents Clear or slightly cloudy colloidal solution. It has the characteristics of thickening, water retention and easy construction. The aqueous solution of hydroxypropyl methylcellulose HPMC is relatively stable in the range of HP3.0-10.0, and when it is less than 3 or greater than 10, the viscosity will be greatly reduced.
The main function of hydroxypropyl methylcellulose in cement mortar and putty powder is water retention and thickening, which can effectively improve the cohesion and sag resistance of materials.
Factors such as temperature and wind speed will affect the volatilization rate of moisture in mortar, putty and other products, so in different seasons, the water retention effect of products with the same amount of cellulose added will also have some differences. In the specific construction, the water retention effect of the slurry can be adjusted by increasing or decreasing the amount of HPMC added. The water retention of hydroxypropyl methylcellulose HPMC at high temperature is an important indicator to distinguish the quality of HPMC. Excellent HPMC can effectively solve the problem of water retention under high temperature conditions. In dry seasons and areas with high temperature and high wind speed, it is necessary to use high-quality HPMC to improve the water retention performance of the slurry.
Therefore, in high temperature summer construction, in order to achieve the water retention effect, it is necessary to add a sufficient amount of high-quality HPMC according to the formula, otherwise there will be quality problems such as insufficient hydration, reduced strength, cracking, hollowing and shedding caused by too fast drying, and at the same time Also increased the difficulty of worker’s construction. As the temperature drops, the amount of HPMC added can be gradually reduced, and the same water retention effect can be achieved.
In the production of building materials, hydroxypropyl methylcellulose is an indispensable additive. After adding HPMC, the following properties can be improved:
1. Water retention: Enhance water retention, improve cement mortar, dry powder putty too fast drying and insufficient hydration caused poor hardening, cracking and other phenomena.
2. Adhesiveness: Due to the improved plasticity of the mortar, it can better bond the substrate and the adherend.
3. Anti-sagging: Due to its thickening effect, it can prevent the slippage of mortar and adhered objects during construction.
4. Workability: Increase the plasticity of the mortar, improve the industriality of the construction and improve the work efficiency.
Post time: Apr-12-2023