1. Overview
Hydroxypropyl Methyl Cellulose (HPMC) is a non-ionic cellulose ether made from natural polymer material – cellulose through a series of chemical processes. Hydroxypropyl methylcellulose (HPMC) is an odorless, tasteless, non-toxic self-coloring powder, which can be dissolved in cold water to form a transparent viscous solution, which has the functions of thickening, bonding, dispersing, emulsifying, film-forming, and suspending , adsorption, gelation, surface activity, moisture retention and protective colloid properties.
Hydroxypropyl methylcellulose (HPMC) can be used in building materials, coatings, synthetic resins, ceramics, medicine, food, textiles, agriculture, cosmetics and tobacco industries
2、Product specifications and classification Products are divided into cold water soluble type S and ordinary type
Common Specifications of Hydroxypropyl Methyl Cellulose
|
product |
MC |
HPMC |
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| E |
F |
J |
K |
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|
Methoxy |
content（%） |
27.0~32.0 |
28.0~30.0 |
27.0~30.0 |
16.5~20.0 |
19.0~24.0 |
|
Degree of substitutionDS |
1.7~1.9 |
1.7~1.9 |
1.8~2.0 |
1.1~1.6 |
1.1~1.6 |
|
|
Hydroxypropoxy |
content（%） |
7.0~12.0 |
4~7.5 |
23.0~32.0 |
4.0~12.0 |
|
|
Degree of substitutionDS |
0.1~0.2 |
0.2~0.3 |
0.7~1.0 |
0.1~0.3 |
||
|
Moisture（Wt%) |
≤5.0 |
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|
Ash(Wt%) |
≤1.0 |
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|
PHvalue |
5.0~8.5 |
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|
Exterior |
milky white granule powder or white granule powder |
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|
Fineness |
80head |
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|
viscosity（mPa.s) |
see viscosity specification |
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Viscosity specification
|
Specification |
Viscosity range(mpa.s) |
Specification |
Viscosity range(mpa.s) |
|
5 |
3~9 |
8000 |
7000~9000 |
|
15 |
10~20 |
10000 |
9000~11000 |
|
25 |
20~30 |
20000 |
15000~25000 |
|
50 |
40~60 |
40000 |
35000~45000 |
|
100 |
80~120 |
60000 |
46000~65000 |
|
400 |
300~500 |
80000 |
66000~84000 |
|
800 |
700~900 |
100000 |
85000~120000 |
|
1500 |
1200~2000 |
150000 |
130000~180000 |
|
4000 |
3500~4500 |
200000 |
≥180000 |
3、product nature
Properties: This product is a white or off-white powder, odorless, tasteless and non-toxic.
Water solubility and thickening ability: This product can be dissolved in cold water to form a transparent viscous solution.
Dissolution in organic solvents: Because it contains a certain amount of hydrophobic methoxyl groups, this product can be dissolved in some organic solvents, and can also be dissolved in solvents mixed with water and organic matter.
Salt resistance: Since this product is a non-ionic polymer, it is relatively stable in aqueous solutions of metal salts or organic electrolytes.
Surface activity: The aqueous solution of this product has surface activity, and has functions and properties such as emulsification, protective colloid and relative stability.
Thermal gelation: When the aqueous solution of this product is heated to a certain temperature, it becomes opaque until it forms a (poly) flocculation state, so that the solution loses its viscosity. But after cooling, it will turn into the original solution state again. The temperature at which gelation occurs depends on the type of product, the concentration of the solution and the rate of heating.
PH stability: The viscosity of the aqueous solution of this product is stable within the range of PH3.0-11.0.
Water-retaining effect: Since this product is hydrophilic, it can be added to mortar, gypsum, paint, etc. to maintain high water-retaining effect in the product.
Shape retention: Compared with other water-soluble polymers, the aqueous solution of this product has special viscoelastic properties. Its addition has the ability to keep the shape of extruded ceramic products unchanged.
Lubricity: Adding this product can reduce the friction coefficient and improve the lubricity of extruded ceramic products and cement products.
Film-forming properties: This product can form a flexible, transparent film with excellent mechanical properties, and has good oil and fat resistance
4. Physical and chemical properties
Particle size: 100 mesh pass rate is greater than 98.5%, 80 mesh pass rate is 100%
Carbonization temperature: 280~300℃
Apparent density: 0.25~0.70/cm specific gravity 1.26~1.31
Discoloration temperature: 190~200℃
Surface tension: 2% aqueous solution is 42~56dyn/cm
Solubility: Soluble in water and some solvents, the aqueous solution has surface activity. High transparency. Stable performance, solubility changes with viscosity, the lower the viscosity, the greater the solubility.
HPMC also has the characteristics of thickening ability, salt resistance, PH stability, water retention, dimensional stability, excellent film-forming property, and wide range of enzyme resistance, dispersibility and cohesiveness.
5, the main purpose
Industrial grade HPMC is mainly used as a dispersant in the production of polyvinyl chloride, and is the main auxiliary agent for preparing PVC by suspension polymerization. In addition, it can be used as a thickener, stabilizer, emulsifier, excipient, and water-retaining agent in the production of other petrochemicals, coatings, building materials, paint removers, agricultural chemicals, inks, textile printing and dyeing, ceramics, paper, cosmetics, etc. , film forming agent, etc. The application in synthetic resins can make the obtained products have the characteristics of regular and loose particles, suitable specific gravity and excellent processing performance, thus basically replacing gelatin and polyvinyl alcohol as dispersants.
Six dissolution methods:
（1）. Take the required amount of hot water, put it into a container and heat it to above 80°C, and gradually add this product under slow stirring. The cellulose floats on the water surface at first, but is gradually dispersed to form a uniform slurry. The solution was cooled while stirring.
（2）. Alternatively, heat 1/3 or 2/3 of the hot water to above 85°C, add cellulose to obtain a hot water slurry, then add the remaining amount of cold water, keep stirring, and cool the resulting mixture.
（3）. The mesh of cellulose is relatively fine, and it exists as individual small particles in the evenly stirred powder, and it dissolves quickly when it meets water to form the required viscosity.
（4）. Slowly and evenly add cellulose at room temperature, stirring continuously until a transparent solution is formed.