Hydroxypropyl Methyl Cellulose (HPMC)

Hydroxypropyl Methyl Cellulose (HPMC)

Designation: Hydroxypropyl Methyl Cellulose
Chemical structural formula:


Where: n is number of glucose units in cellulose molecule.
R is CH 3 or CH 2 CH(0H)CH 3 .

 

Product Specification

Specification

Industrial grade

PME

PMF

PMK

Appearance

White or off-white powder

Methoxy group ۲۸٫۰-۳۰٫۰% ۲۷٫۰-۲۹٫۰% ۱۹٫۰-۲۴٫۰%
Hydroxypropoxy group ۷٫۰-۱۲٫۰% ۴٫۰-۷٫۵% ۴٫۰-۱۲٫۰%
Gel temperature °C °C °C
pH

۵٫۰-۷٫۵

Viscosity ①

۱۰۰-۸۰۰۰۰mPa . s

Finesses

۴۰-۱۲۰mesh

Weight loss on drying

≤ ۵٫۰%

Residue on ignition ( Calculated as sulphate )

≤ ۱٫۵%

Arsenic

/

Heavy metals

/

Hygienics examine

Microbial quantity

/

Mildew quantity

/

Colibacillus

/

Note 1: The viscosity is measured by Brookfield viscometer on conditions of 2% neutral aqueous solution, Brookfied 20℃, ۲۰RPM.

The pharmaceutical grade complies with USP27 and Chinese Pharmacopoeia 2010.
Various viscosity products are available according to customer' requirements.

 

 Physical and Chemical Properties

۱٫Appearance: white or off-white powder

 

۲٫Particle size: about 95% through 100mesh ; 100% through 80mes.Special particle size is about 40 ~ 60 mesh;

 

۳٫Carbonation temperature: 280-300°C

 

۴٫Bulk density: 320-350kg/m 3 (generally about 0.5g/cm3 ) , specific gravity is 1.26-1.31

 

۵٫Temperature to change color: 190-200°C ;

 

۶٫Surface tension: 42-56dyn/cm,2% solution.

 

۷٫Dissolution properties: dissolve in water and some solvent. Such as, the suitable proportion of ethanol/ water, propanol/water. Its aqueous solution provides surface activity and high transparence and stable properties. Various products have different gel temperatures. Solubility changes with viscosity. Lower the viscosity is, higher the solubility is. Different types of HPMC have different properties. Its dissolution is not subject to PH.

 

۸٫ With the reduction of methoxyl content, gel point rises, solubility in water and surface activity decrease.

 

۹٫HPMC has the ability of thickening, anti-salt, water retention, good film-forming, anti-enzyme, dispersing, bonding, and low ash content.

 

 

 Application

Building

To provide excellent workability and water retention to spray and manual plasters, dry wall joint compounds,tile cements and grouts, extruded mortars, under water concretes, etc.

Adhesives

To thicken adhesives and glues and to form film in adhesive dispersions.

 

Paints & Coatings

To be used as thickeners,  protective colloids, pigment suspension aids.To improve the viscosity stability and dissolution of water based emulsion paints.

Personal Care

To be used as thickening, dispersing and emulsifying agents for the manufacturing of lotions, shampoos, toothpastes. Etc.

 

Pharmaceuticals

To be used as emulsifying and dispersing agents for ointment and creams as binders for plaster bondage and as a compression aid and coating agent for a tablet.

Ceramics

To provide water retention and lubricity in processing.

 

Dissolution Method

Non-surface treated powder:

To prevent lumping, put the powder into water (over 90℃)First, stir to disperse and then cool down the solution with stirring.

Hot Water(over 90℃)        Dispersion             Cool to Room Temp       Cooling in Water               Solution 

When non-surface treated powder is used in a dry-mixing application, lumping is not of  concern  because  each  particle of MEILOSE is distributed  throughout  the final product.

 

 

Surface treated powder:

Surface treated powder is specially developed to prevent lumping in the wet blending application such as paints and emulsion based ones. To make the solution with surface treated powder, place the powder directly into cold water. With time the viscosity fully developed-solution is prepared with continuous stirring.

Dispersion in           Stirring 1-2hr disperson        Adjust Water                    Solution                                             Cold Water                       at Room Temp                   Temp(20℃)

Each modified MEILOSE show different solubility properties. The  solubility of modified MEILOSE depends on the original property of the basic MEILOSE and its degree of modification.

 

Package, Storage and Transpotation

  • Package: Plastics-paper bag outside, lined with PVC bag.
  • Storage: Seal tightly. Exposing to the sun and rain is forbidden, to avoid absorption of moisture and contact with acid and alkali.
  • Transportation: As common moisture-proof chemicals.

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