Hydroxypropyl MethylCellulose is a non-ionic cellulose ether, in the appearance of white powder, odorless and tasteless. It is soluble in water, most polar organic solvents, and the appropriate proportion of ethanol/water, propanol /water, and dichloroethane, but insoluble in diethyl ether, acetone, and anhydrous alcohol. In cold water, it will swell into a clear or slightly turbid colloidal solution.
The product is soluble in water and part of solvents such as alcohol-water and propyl alcohol-water solvents in an appropriate proportion. The aqueous solution owns surface activity, high transparency, and stable properties. Products of different specifications have different gelation temperatures and the solubility changes with the viscosity. The lower the viscosity is, the higher the solubility will be. HydroxyPropyl MethylCellulose products with different specifications also have differences in properties and the dissolution of HydroxyPropyl MethylCellulose in water won’t get affected by the pH value.
Because Hydroxypropyl Methylcellulose (HPMC) does not dissolve in hot water, in the initial stage, Hydroxypropyl Methylcellulose can be evenly dispersed in hot water, and then it rapidly dissolves when cooled. And we usually use this property to dissolve non-surface treated HPMC
notices when you dissolve HPMC in cold water
Instant products can quickly disperse in contact with cold water and disappear in the water. The Hydroxypropyl Methylcellulose liquid has no viscosity, because Hydroxypropyl Methylcellulose is only dispersed in the water but not really dissolved. In about 2 minutes, the viscosity of the liquid gradually becomes large, and then a transparent as well as viscous gel will be formed.
Hot-dissolving products may coagulate or condense in contact with cold water, but can quickly disperse and then disappear in hot water. When the temperature drops to a certain temperature (58-65℃ for our products), the viscosity will slowly emerge, until the formation of a transparent viscous gel.
The reason for the coagulation in contact with cold water:
The outer cellulose powder can immediately produce viscosity in contact with cold water, and thicken to form a transparent gel. But the cellulose inside Hydroxypropyl Methylcellulose will be surrounded inside by the gel before contact with water. The solubility of Hydroxypropyl Methylcellulose is still powdery, but will slowly melt away.
