HPMC(hydroxypropyl methylcellulose)-INN name Hypromellose, it is used as the emulsifier, thickening and suspending agent, water retention agent in various applications. The key index of hpmc includes viscosity, D.S., M.S., Moisture and ash content. Normally, the viscosity is most important index in different application.
Regarding the viscosity:
-The viscosity test result will be different according to different test method.
-Same test method with different concentration of solution, the test result will be different also, for example, 1% solution and 2% solution tested by Brookfield, the result will be much different.
-In international market, there are many different viscosity test method: Ubelode, hoppler, Brookfield LV/RV, Roto, NDJ-1,NDJ-8S etc.
A comparison sheet as below will be helpful to check the relationship between different test method:
Brookfield LVT 2% solution, 20℃ | Brookfield RV 2% solution，20℃ | Hoppler | Roto |
60000 | 30000 | 60000 | 30000 |
75000 | 35000 | 75000 | 35000 |
100000 | 40000 | 100000 | 40000 |
150000 | 60000 | 150000 | 60000 |
200000 | 70000+ | 200000 | 70000+ |
HPMC viscosity test in lab:
It need to solve HPMC in water to make 1% or 2% solution, then, test the viscosity in specific equipment. Details are as below:
Step1:Get 8 g of the dried HPMC sample.
Step 2: Get 392g hot water(over 80℃ at least).
Step 3:Put the HPMC into hot water and stir.
Step 4: Keep stirring 10 minutes
Step 5: Put it into cold water and keep stirring for 40 mimutes.
Step 6: heat the temperature to 20℃
Step 7: Choose a viscosimeter to measure the viscosity.
The viscosity of HPMC related with the function in application, in order to reach the specific requirements need to choose the product with right viscosity.
Normally, in dry mix mortar industry, the viscosity is related with water retention. Under same dosage, the viscosity is higher, the water retention is higher. The different mainly shows when the viscosity below 100000cps. After the viscosity is over 100000cps. The difference is little. Meanwhile, the dosage will also effect on the water retention function.
On the other hand, the temperature will be also effected on the viscosity. The viscosity will reduce as the temperature increase. Normally, it will lost viscosity when the temperature in higher than 80 ℃.
It is very important to choose a reliable partner to recommend the right specifications accordingly to different applications.
Jinan maissen new material co.,ltd is HPMC/MHEC and RDP producer in China. Welcome to contact with us for more information.
