Hydroxypropyl methylcellulose (HPMC for short) is an important mixed ether, which is a non-ionic water-soluble polymer, and is widely used in food, medicine, daily chemical industry, coating, polymerization reaction and construction as a dispersion suspension , thickening, emulsifying, stabilizing and adhesives, etc., and there is a large gap in the domestic market.
Because HPMC has excellent properties such as thickening, emulsification, film forming, protective colloid, moisture retention, adhesion, enzyme resistance and metabolic inertness, it is widely used in coatings, polymerization reactions, building materials, oil production, textiles, food, medicine, Daily-use ceramics, electronic devices and agricultural seeds and other departments.
Building materials
In building materials, HPMC or MC is usually added to cement, mortar, and mortar to improve construction and water retention properties.
HPMC can be used on:
1). Adhesive and caulking agent for gypsum-based adhesive tape;
2). Bonding of cement-based bricks, tiles and foundations;
3). Plasterboard-based stucco;
4). Cement-based structural plaster;
5). In the formula of paint and paint remover.
Adhesive for ceramic tiles
HPMC 15.3 parts
Perlite 19.1 parts
Fatty amides and cyclic thio compounds 2.0 parts
Clay 95.4 parts
Silica seasoning (22μ) 420 parts
450.4 parts of water
Used in cement bonded with inorganic bricks, tiles, stones or cement:
HPMC (degree of dispersion 1.3) 0.3 parts
Cattelan cement 100 parts
Silica sand 50 parts
50 parts of water
Used as a high-strength cement building material additive:
Cattelan cement 100 parts
Asbestos 5 parts
Polyvinyl alcohol repair 1 part
Calcium silicate 15 parts
Clay 0.5 parts
32 parts of water
HPMC 0.8 parts
Paint industry
In the paint industry, HPMC is mostly used in latex paint and water-soluble resin paint components as a film-forming agent, thickener, emulsifier and stabilizer.
Suspension Polymerization of PVC
The field with the largest consumption of HPMC products in my country is the suspension polymerization of vinyl chloride. In the suspension polymerization of vinyl chloride, the dispersion system directly affects the quality of the product PVC resin and its processing and products; it can improve the thermal stability of the resin and control the particle size distribution (that is, adjust the density of PVC). The amount of HPMC accounts for 0.025%~0.03% of the PVC output .
The PVC resin prepared by high-quality HPMC, in addition to ensuring that the performance meets the national standard, also has good physical properties, excellent particle characteristics and excellent melt rheological behavior.
Other industry
Other industries mainly include cosmetics, oil production, detergents, household ceramics and other industries.
Water soluble
HPMC is one of the water-soluble polymers, and its water solubility is related to the content of methoxyl group. When the content of methoxyl group is low, it can be dissolved in strong alkali and has no thermodynamic gelation point. With the increase of methoxyl content, it is more sensitive to water swelling and soluble in dilute alkali and weak alkali. When the methoxyl content is >38C, it can be dissolved in water, and can also be dissolved in halogenated hydrocarbons. If periodic acid is added to HPMC, HPMC will quickly disperse in water without producing insoluble caking substances. This is mainly due to the fact that periodic acid has dihydroxyl groups in the ortho position on the dispersed glycogen.
Post time: Dec-07-2022