1. HPMC is divided into instant type and fast dispersion type
The HPMC fast dispersion type is suffixed with the letter S, and glyoxal must be added during the production process.
HPMC instant type does not add any letters, such as “100000″ means “100000 viscosity fast dispersion type HPMC”.
2. With or without S, the characteristics are different
Rapidly dispersed HPMC disperses quickly when it encounters cold water and disappears into the water. At this time, the liquid has no viscosity, because HPMC is only dispersed in water without real dissolution. After about two minutes, the viscosity of the liquid gradually increases, forming a transparent viscous Thick colloid.
Instant HPMC can be quickly dispersed in hot water at about 70°C. When the temperature drops to a certain temperature, the viscosity will appear slowly until a transparent viscous colloid is formed.
3. With or without S, the purpose is different
Instant HPMC can only be used in putty powder and mortar. In liquid glue, paint and washing products, there will be grouping phenomenon and cannot be used.
Rapidly dispersed HPMC has a wide range of applications and can be used in putty powder, mortar, liquid glue, paint, and washing products without any contraindications.
Dissolving method
1. Take the required amount of hot water, put it into a container and heat it above 80°C, and gradually add this product under slow stirring. The cellulose floats on the water surface at first, but is gradually dispersed to form a uniform slurry. The solution was cooled while stirring.
2. Alternatively, heat 1/3 or 2/3 of the hot water to above 85°C, add cellulose to obtain a hot water slurry, then add the remaining amount of cold water, keep stirring, and cool the resulting mixture.
3. The mesh of cellulose is relatively fine, and it exists as individual small particles in the evenly stirred powder, and it dissolves quickly when it meets water to form the required viscosity.
4. Slowly and evenly add cellulose at room temperature, stirring continuously until a transparent solution is formed.
What factors affect the water retention of hydroxypropyl methylcellulose?
The water retention of hydroxypropyl methylcellulose HPMC product itself is often affected by the following factors:
1. Uniformity of cellulose ether HPMC
Evenly reacted HPMC, methoxyl and hydroxypropoxyl are evenly distributed, and the water retention rate is high.
2. Thermal gelation temperature of cellulose ether HPMC
The higher the thermal gel temperature, the higher the water retention rate; otherwise, the lower the water retention rate.
3. 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 in water retention rate tends to be flat.
Addition amount of cellulose ether HPMC
The greater the amount of cellulose ether HPMC added, the higher the water retention rate and the better the water retention effect.
In the range of 0.25-0.6% addition, the water retention rate increases rapidly with the increase of the addition amount; when the addition amount further increases, the increase trend of the water retention rate slows down.
Post time: Nov-17-2022