Factors Affecting Water Retention of HPMC
1. Cellulose ether HPMC uniformity
HPMC, which is uniformly reacted, has even distribution of methoxy and hydroxypropoxy groups and high water retention.
2. Cellulose ether HPMC thermal gel temperature
The temperature of the thermogel is high, and the water retention rate is high; otherwise, the water retention rate is low.
3.Viscosity of cellulose ether HPMC
When the viscosity of HPMC rises, the water retention rate also increases; when the viscosity reaches a certain level, the increase in water retention rate tends to be gentle.
4. Cellulose ether HPMC added amount
The larger amount of cellulose ether HPMC added, the higher water retention rate and the better water retention effect. In the range of 0.25-0.6%, the water retention rate increases quickly with the increase of the amount added; when the amount is further increased, the increase of the water retention rate becomes slower.
The broad prospects of hydroxypropyl methylcellulose in the construction industry can’t be questioned.
Its excellent thickening properties and water retention properties make its application in the construction industry not to be ignored. But how much do we want to know about its excellence? Now let’s talk about the viscosity characteristics of an aqueous solution of hydroxypropyl methylcellulose.
A brief introduction of hydroxypropyl methylcellulose aqueous solution: The English abbreviation HPMC is a non-ionic, water-soluble cellulose ether with a white or light yellow powder or granular substance.
It’s odorless, odorless, non-toxic, and has stable chemical properties. It forms a smooth, slightly transparent, viscous liquid in water.
What’s the factor that affecting the viscosity of hydroxypropyl methylcellulose aqueous solution?
1. Relation with polymer: The viscosity of hydroxypropyl methylcellulose aqueous solution is directly proportional to the polymer or molecular weight. It increases with the increase of the degree of polymerization. This effect is lower in the case of polymerization than in the case of high polymerization More obvious.
2. The relationship between viscosity and concentration: The viscosity of hydroxypropyl methylcellulose in
the aqueous solution increases with the concentration of the aqueous solution. Even small changes in concentration can cause large changes in viscosity.
3. Relationship between viscosity and shear rate: Tests show that hydroxypropyl methylcellulose doesn’t change significantly at low shear rates, and the viscosity decreases with increasing shear rate.
4. Relationship between viscosity and temperature: Hydroxypropyl methylcellulose is greatly affected by temperature. As the temperature increases, the viscosity decreases.
5. Other factors affect: the viscosity of hydroxypropyl methylcellulose and various additives, solutions, PH value also have an effect.