hydroxypropyl methylcellulose HPMC in Plastering MortarFebruary 2nd 2023
In the construction industry, hydroxypropyl methylcellulose HPMC is often placed in neutral water, SLEOCHEM HPMC products are dissolved separately to determine the dissolution rate. Separated into neutral water, quickly coalesced together, not dispersed products, not surface treatment products; separated into neutral water, can be dispersed non-holding products, is a surface treatment products.
When dissolving unmodified HPMC hydroxypropyl methyl cellulose alone, individual particles dissolve quickly and quickly into the film, resulting in water can not enter the other particles, resulting in aggregation, agglomeration, currently on the market is called slow dissolving products.
Surface-treated hydroxypropyl methylcellulose HPMC product particles in neutral water, individual particles can be dispersed without agglomeration, but does not immediately produce product viscosity. After a period of immersion, the chemical structure, surface treatment has been destroyed, water can be dissolved in HPMC particles, while the product particles have been fully dispersed and absorbed enough water, so the product dissolves without clumping and agglomeration.
Dispersion speed and dissolution speed depends on the degree of surface treatment, mild surface treatment, relatively slow dispersion speed glue; product surface treatment is deeper, high dispersion speed, slow gluing speed. If the product dissolves rapidly in this state, a small amount of alkali may drip out when dissolved alone. At present, the market is usually referred to as instant products. HPMC products surface treatment is characterized in aqueous solution, the particles can disperse each other, in the alkaline state can be quickly dissolved, in the neutral and acidic state slowly dissolved.
Untreated hydroxypropyl methylcellulose HPMC is characterized by the fact that individual particles dissolve quickly in the acidic, alkaline and neutral states, but the particles in the liquid cannot be dispersed from particle to particle, causing clumping and agglomeration. In practical application, the series products are physically dispersed with solid particles such as gum powder, cement, sand, etc.
The dissolution speed is very fast and there is no clumping and agglomeration. This series of products should be used with caution when dissolved HPMC products need to be separated and will agglomerate and clump. If the surface treated hydroxypropyl methyl cellulose HPMC products must be dissolved separately, they should be dispersed evenly at 95℃ and then cooled.
In the actual production process, this series of products are often dissolved under alkaline conditions, and other solid particles are dispersed, and their dissolution rate is no different from that of untreated products. It is also applicable to individual dissolved products without lumping and lumping. According to the dissolution degree of construction needs, choose the specific model of the product.
In the construction process, whether it is cement mortar or gypsum slurry, most of them are alkaline system, and the amount of HPMC is very little, it can be evenly dispersed in these particles, and HPMC dissolves quickly when adding water.
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