The buyer How to test HPMC?

The buyer How to test HPMC ?

1. Take 1 g of this HPMC, heat water (80~90 ° C) 100 ml, stir to form a paste, cool in an ice bath, and form a viscous liquid; Take 2 ml of sulfuric acid solution of 0.035% anthrone and put it in a test tube, slowly add 1 ml of sulfuric acid solution of 0.035% anthrone along the tube wall, and place it for 5 minutes, and the blue-green ring appears at the interface between the two liquids.

2. Take an appropriate amount of viscous liquid under identification (1), pour it on the glass plate, and form a tough film after the water evaporates.

3. Take 0 5g HPMC, evenly dispersed in 50ml of boiling water, stirred by electromagnetic stirring to form insoluble slurry; Under electromagnetic stirring, the slurry is cooled to 1CTC to form a clear or slightly turbid solution. 50ml of water is added, electromagnetic stirring and heating are conducted at the same time, and the temperature is raised at the rate of 2-5X per minute. The flocculation temperature that produces turbidity should not be less than 50 ° C.