HPMC manufacturer-What is the effect of temperature on the water retention of hydroxypropyl methylcellulose HPMC
1. The water retention of hydroxypropyl methylcellulose HPMC product itself is affected by temperature and the following factors:
1. Cellulose ether HPMC thermogel temperature
The higher the thermal gel temperature, the higher the water retention rate; otherwise, the lower the water retention rate.
2. Cellulose ether HPMC viscosity
When the viscosity of HPMC increases, the water retention rate also increases; when the viscosity reaches a certain level, the increase of the water retention rate tends to be flat
3. Cellulose ether HPMC homogeneity
The uniformly reacted HPMC has uniform distribution of methoxy and hydroxypropoxy groups and high water retention.
2. The moisturizing effect and principle of hydroxypropyl methylcellulose HPMC:
High-quality cellulose HPMC can be uniformly and effectively dispersed in cement mortar and gypsum-based products, and encapsulates all solid particles, and forms a wetting film, and the moisture in the base is gradually released over a long period of time. The hydration reaction of the coagulating material occurs, thereby ensuring the bonding strength and compressive strength of the material. Therefore, in high-temperature summer construction, in order to achieve the effect of water retention, it is necessary to add high-quality HPMC products in sufficient quantities according to the formula, otherwise, there will be insufficient hydration, strength reduction, cracking, hollowing and falling off caused by too fast drying. It also increases the difficulty of construction for workers. As the temperature decreases, the addition amount of HPMC can be gradually reduced, and the same water retention effect can be achieved.
3. Factors such as air temperature, temperature and wind pressure speed will affect the volatilization speed of water in cement mortar and gypsum-based products. Therefore, there are some differences in the water retention effect of products with the same amount of HPMC added in different seasons. 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 methyl cellulose ether at high temperature is an important indicator to distinguish the quality of methyl cellulose ether. Excellent HPMC series products can effectively solve the problem of water retention under high temperature. In the high temperature season, 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, with 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.
4. The larger the amount of cellulose HPMC added, the higher the water retention rate and the better the water retention effect. In the range of 4-6 kg of addition, the water retention rate increases rapidly with the increase of the addition amount; when the addition amount further increases, the increasing trend of the water retention rate becomes slower.