Where n is the degree of polymerization, R is -H, -CH3 or -CH2CHOHCH3 According to the degree of substitution and modification of the substituent groups, they have different chemical properties
Gel temperature, ℃
Viscosity (2%, 20℃)
Physical And Chemical Properties
White or yellowish white powder
98% pass 80 mesh
Hydroxypropyl methyl cellulose (HPMC) is made from refined cotton after being pulverized, and then alkalized with sodium hydroxide (liquid caustic soda) solution, and then monochloromethane + propylene oxide is added for etherification to form crude HPMC , After neutralization (pH adjustment), filter press, drying, crushing and sieving, a pure HPMC product of certain fineness is obtained. The finished product has a slight smell, the smell of methane.
(1) Water solubility: it can be dissolved in water in any proportion, the highest concentration depends on the viscosity, and the dissolution is not affected by PH.
(2) Organic solubility: HPMC can be dissolved in some organic solvents or organic solvent aqueous solutions such as dichloroethane, ethanol solution, etc.
(3) Thermal gel characteristics: Reversible gel will appear when their aqueous solution is heated to a certain temperature, with controllable quick-setting performance.
(4) No ionic charge: HPMC is a non-ionic cellulose ether and will not complex with metal ions or organics to form insoluble precipitates.
(5) Thickening: Its aqueous solution system has thickening, and the thickening effect is related to its viscosity, concentration and system.
(6) Water retention: HPMC or its solution can absorb and retain water.
(7) Film formation: HPMC can be made into a smooth, tough, and elastic film, and has excellent grease and oxidation resistance.
(8) Enzyme resistance: HPMC's solution has excellent enzyme resistance and good viscosity stability.
(9) PH stability: HPMC is relatively stable to acid and alkali, and the pH is not affected in the range of 3-11. (10) Surface activity: HPMC provides surface activity in the solution to achieve the required emulsification and protective colloid effects.
(11) Anti-sagging property: HPMC adds system thixotropic properties to putty powder, mortar, tile glue and other products, and has excellent anti-sagging ability
(12) Dispersibility: HPMC can reduce the interfacial tension between the phases and make the dispersed phase uniformly dispersed into droplets of appropriate size.
(13) Adhesion: It can be used as a binder for pigment density: 370-380g/l³ paper, and can also be used in coatings and adhesives.
(14) Lubricity: It can be used in rubber, asbestos, cement and ceramic products to reduce friction and improve the pumpability of concrete slurry.
(15) Suspension: It can prevent the fixed particles from precipitation and inhibit the formation of precipitation.
(16) Emulsification: Because it can reduce the surface and interfacial tension, it can stabilize the emulsion.
(17) Protective colloid: A protective layer is formed on the surface of the dispersed droplets to prevent the droplets from merging and agglomerate to achieve a stable protective effect.
(1) In the field of building construction, HPMC is used in mechanized construction such as wall masonry, plastering, caulking, etc. It is suitable for centralized dry-mixing and pre-mixed mortar, which has thickening water retention and cohesiveness, and improves slurry pumping ；
(2) In the tile adhesive for pasting tiles, marbles, etc., HPMC can effectively improve the bonding strength and reduce the amount of cement;
(3) In products such as plaster plaster, water-resistant putty, bonding plaster, caulking plaster, etc., HPMC can significantly improve its key properties such as water retention and bonding strength, and has the characteristics of good workability and no cracking;
(4) HPMC is used as a thickener in the coating industry, which can make the coating bright and fine, without powdering, and improve its leveling performance;
(5) HPMC's excellent water retention capacity and emulsification performance in daily chemical detergents can significantly improve the suspension and consistency of the product, and prevent product deposition, etc.
(1) Quick dissolution: HPMC is soluble in water and some organic solvents under constant stirring. In case of rapid dissolution, the following methods are recommended: A. Heat the required water to above 85°C, stir continuously and gradually add the product, the cellulose is dispersed in the water, swelled into a slurry, and stirred and cooled until the solution is transparent, that is, it is completely dissolved. B. Heat about half of the required amount of water to above 85°C, keep stirring and add this product to obtain a slurry, then add the remaining cold water, and stir until it is transparent. C. Instant S type can be directly stirred in cold water for half an hour, and it can be completely dissolved
(2) Preparation of porridge-like mother liquor for use: First, HPMC is made into a higher-concentration porridge-like mother liquor (the method is the same as above to slurry), and when using it, add cold water and continue stirring until it is transparent.
(3) Dry mixed use: Because HPMC has excellent compatibility, it can be directly used in dry mixed with cement, gypsum powder, paint, etc., and achieve the desired effect.
Packaging, storage and transportation
HPMC can be packed in paper-plastic composite bags lined with polyethylene plastic bags, cardboard drums or plastic coated, etc., each with a net weight of 25KG. During storage and transportation, it should be protected from sun and rain, fire and moisture.