Hydroxypropyl methylcellulose,Hydroxypropyl methyl cellulose,Hypromellose,HPMC
What is Hydroxypropyl Methyl Cellulose?
synonym: HPMC; E464; MHPC; Hydroxypropyl methylcellulose. Hydroxypropyl methyl cellulose,Hypromellose.
CAS no. : 9004-65-3
Molecular weight: 86000.00000
HPMC Physical properties:
Appearance and properties: white or white fibrous or granular powder.
Density: 1.39 g/cm3.
Solubility: almost insoluble in anhydrous ethanol, ethyl ether and acetone; Swelling in cold water to clarify or slightly turbid colloidal solution.
Stability: solids are flammable and incompatible with strong oxidizing agents.
HPMC chemical properties
1.Appearance: white or white powder.
2.Granularity;98.5% pass 100 mesh; 100% pass 80 mesh . special sizes 40 ~ 60.
3. carbonization temperature: 280-300 ℃
4.Visual density: 0.25-0.70g/cm(usually around 0.5g/cm), with weight 1.26-1.31.
5.color temperature: 190-200 ℃
6.Surface tension: 2% water solution 42-56dyn/cm.
7.Solubility: soluble in water and partial solvents, such as ethanol/water, propanol/water etc. Aqueous solution has surface activity. High transparency, stable performance, different specifications of products different gel temperature and solubility with viscosity change, lower viscosity, the greater the solubility, different specifications HPMC its performance has a certain difference, HPMC dissolved in the water is not affected by pH.
8.The content of HPMC decreased with the content of methoxy, increased gel point, decreased water solubility, and decreased surface activity.
9.HPMC also has characteristics of thickening ability, salt tolerance low ash powder, pH stability, water retention, dimensional stability, excellent film forming, and extensive resistance to enzyme, dispersibility and adhesion.
HPMC Production method:
Crush refined cotton and treated with alkali liquor in 35-40 ℃ for half an hour, crushing, smash cellulose, in 35 ℃ suitable for aging, make base fiber average degree of polymerization in required range. And put alkali fiber into etherification kettle, add epoxy propane and methyl chloride and 50-80 ℃ in etherification 5 h, highest pressure 1.8 MPa. Then in 90 ℃ hot water adding suitable amount of hydrochloric acid and oxalic acid washing materials, volume expansion. Dehydrate with centrifuge. Washing to neutral, when material in water content below 60%, at 130 ℃ hot air flow drying to contain less than 5%. At last, finished product was smashed through 20 mesh.
HPMC Solution dissolving method:
- All HPMC grades can be added to material by dry mixing method;
- When you need to directly add to normal temperature water solution, it is better to use the cold water dispersive type, and after the addition, it can be thickened after 10 to 90 minutes.
- After mixing ordinary model with hot water, add cold water and stir to cool.
- If there is clumping phenomenon in the solution, it is because agitation is not sufficient or ordinary model is directly added to the cold water, and reason should be quickly stirred.
- If bubbles are produced when dissolved, it can be left for 2-12 hours (depending on consistency of solution) or vacuum, pressure and other methods to remove them, and the appropriate amount of defoaming agent can be added.
Hydroxypropyl methylcellulose,Hydroxypropyl methyl cellulose,Hypromellose,HPMC