| 1.
Molecular structure:
|
| n: degree of polymerization; R:-H,-CH3
or CH2CHOHCH3 |
2. Technical Index:
Quality index
| |
Type (gelatification
temperature) |
| 60 |
65 |
75 |
| Item |
Methoxyl |
28-30% |
27-30% |
19-24% |
| Hydroxypropyl |
7-12% |
4-7.5% |
4-12% |
| Gelatification temperature |
58-64 |
62-68 |
70-90 |
| Moisture |
 5% |
| Ash |
1% |
PH (1% solution, 25 ) |
4-8 |
Viscosity specification
| Type |
Specification |
Range, mpa.s |
| special
low viscosity |
5 |
3-7 |
10 |
8-12 |
15 |
13-18 |
| low viscosity |
25 |
20-30 |
50 |
40-60 |
100 |
80-120 |
| high viscosity |
4000 |
3500-5600 |
12000 |
10000-14000 |
| special
high viscosity |
20000 |
17000-22000 |
25000 |
22000-28000 |
30000 |
27000-32000 |
40000 |
37000-42000 |
50000 |
47000-52000 |
60000 |
57000-62000 |
75000 |
72000-78000 |
100000 |
80000-100000 |
| Note: 2% aqueous solution at 20; |
3. Property:
| (1) |
Appearance: white or off-white powder |
| (2) |
Particle size: throughput efficiency
of above 98.5% in 100 mesh, and 100% in 80 mesh. |
| (3) |
Carbonization temperature: 280-300 |
| (4) |
Apparent density: 0.25-0.70g.cm3(usually
about 0.5g/cm3), specific gravity: 1.26-1.31. |
| (5) |
Color degradation temperature: 190-200 |
| (6) |
Surface tension: 42-56dyn/cn(2% aqueous solution) |
| (7) |
Soluble in water and some organic solvents: its
aqueous solution is of surface tension, high transparency and
stable property. The solubility varies with the viscosity, the
lower the viscosity is, the higher solubility it has. The different
HPMC is different in some properties and its solubility in water
is not affected by pH |
| (8) |
The lower methoxyl content in HPMC,
the higher gelatification temperature, the lower solubility
in water and surface activity. |
| (9) |
HPMC has also other characteristic such as thickening
property, pH stability, water retention , excellent film-forming
property and good disperse and adhesion power. |
4. Usage:
HPMC is mainly used as dispersant in the production of PVC and as
thickener, stabilizer, emulsifier, excipient, water retention agent,
film-forming agent in petrochemical, building materials, agrochemical,
ink, printing and dyeing of textile, paper making, cosmetic, etc.
5. Dissolving method:
| (1) |
Heat the water to above 85
and slowly add HPMC under slow agitation to gradually form uniform
pulp, then cool under agitation to become transparent. |
| (2) |
Heat one third to two third of needed water to
above 85,
add HPMC to form heat pulp, then add residual water and remain
agitation, cool to about 20 . |
6. Package
and storage:
Sealed in the plastic-plated polypropylene woven
bag, net weight: 20kg, keeping away from sun, rain and moisture
during storage and transportation. |
Hydroxypropyl Methylcellulose
(HPMC)
