Methylcellulose (MC)

technical requirement

Q/SJM003-2003 (in accordance with USP25/NF19, European Pharmacopoeia EP and Chinese Pharmacopoeia 2005)

Determination conditions: viscosity 2%, 20 ℃ aqueous solution
Physical and chemical properties:
1. Appearance: MC is white or almost white fibrous or granular powder, odorless.
2. Character: MC is almost insoluble in anhydrous ethanol, ether and acetone. It can disperse and swell rapidly in hot water of 80~90>℃, and dissolve rapidly after cooling. The aqueous solution is quite stable at room temperature, and can gel at high temperature, and this gel can transform with the solution with the temperature. It has excellent wettability, dispersibility, adhesiveness, thickening, emulsification, water retention and film-forming properties, as well as impermeability to oils and fats. The film has excellent toughness, flexibility and transparency. Because it is non-ionic, it can be compatible with other emulsifiers, but it is easy to salt out. The solution is stable in the range of PH2-12.
3. Apparent density: 0.30-0.70g/cm3, density about 1.3g/cm3
Dissolution method:
MC>If the product is directly added to the water, it will produce condensation and then dissolve, but this dissolution is slow and difficult. The following three dissolution methods are recommended, and users can choose the most convenient method according to the use situation:
Hot water method: MC cannot be dissolved in hot water, so MC can be uniformly dispersed in hot water at the initial stage. When cooling later, two typical methods are described as follows:
1). Put the required amount of hot water into the container and heat it to about 70 ℃. Gradually add MC under slow stirring. MC floats on the surface of water at first, and then gradually forms a slurry, which is cooled under stirring.
2). Add 1/3 or 2/3 of the required amount of water into the container, heat it to 70 ℃, disperse MC according to the method in 1), and prepare hot water slurry; Then add the remaining amount of cold water or ice water to the hot water slurry, stir and cool the mixture.
Powder mixing method: MC powder particles are fully dispersed by dry mixing with equal or more other powder ingredients, and then dissolved by adding water, then MC can be dissolved without agglomeration.
Organic solvent wetting method: MC is dispersed or wetted in advance with organic solvent, such as ethanol, ethylene glycol or oil, and then dissolved with water, then MC can be dissolved smoothly.
purpose:
This product is widely used in building construction, building materials, dispersible coatings, wallpaper pastes, polymerization aids, paint removers, leather, ink, paper making, etc., respectively as thickener, adhesive, water retaining agent, film-forming agent, excipient, etc. For example, it is used as adhesive, thickener and water retaining agent in building materials, film forming agent and thickener in coating industry, and also widely used in petroleum drilling, daily chemical industry and other fields.