The important role of water-soluble hydroxypropyl methyl cellulose HPMC in mortar is important in three aspects, one is excellent water retention professional ability, two is the damage to the viscosity and compressibility of mortar, three is the interaction with cement. Poor water retention of mortar in the whole process of transportation is easy to separate water outflow, spread on the surface of porous material, most of the water is easy to be absorbed to digest, produce change feature of the mortar, mortar down the damage of all normal coagulation and small pieces of raw materials in the middle of bonding and so reduce the compressive strength of masonry wall. The water retention of mortar is explained by stratification.
The greater the viscosity of hydroxypropyl methyl cellulose HPMC, the better the water retention performance, the better the viscosity of polymer aqueous solution. The length and shape of the molecular chain also depend on the relative molecular mass of the polymer (glass transition temperature). The number of functional groups also affects the viscosity range.
Hydroxypropyl methyl cellulose HPMC own water retention performance from hydroxypropyl methyl cellulose own solubility and to water utility. It is well known that cellulose is insoluble in water because of its relatively high crystalline structure, although the molecular chain of the fiber contains many highly hydrated OH groups.
The superstrong covalent bonds and van der Waals forces between molecular structures cannot be paid for by the hydration ability of methyl groups alone. Therefore, it can be dissolved only in water. When substitutive molecules are introduced, not only the substitutive molecules destroy the hydrogen chain, but also the covalent bonds in the hydrogen chain are destroyed by substitutive molecules wedges in neighboring chains. The greater the substitution, the greater the molecular spacing. The greater the utility of breaking covalent bonds. When the fiber lattice constant expands, aqueous solution enters and hydroxypropyl methyl cellulose becomes water-soluble, resulting in a highly viscous aqueous solution.
As ambient temperatures rise, the polymer’s hydration becomes less effective and water is driven out of the middle of the chain. When enough water is removed, the molecular structure gradually gathers, producing a three-dimensional network of tissues that can be stretched. The viscosity, dosage, particle size and application temperature of hydroxypropyl methyl cellulose are the factors that harm the water retention performance of mortar.
Hydroxypropyl methyl cellulose viscosity is divided into: viscosity 100,000, viscosity 150,000, viscosity 200,000.
How to choose hydroxypropyl methyl cellulose?
100,000 viscosity hydroxypropyl methyl cellulose can be used as interior wall putty powder. Tile binder. Caulking agent. Bonded concrete mortar. High toughness non shrinkage grouting material.
Inorganic insulation insulation mortar specification is higher, viscosity of 150 thousand hydroxypropyl methyl cellulose or 200 thousand hydroxypropyl methyl cellulose. If choose the fresh fruit that viscosity is 100 thousand, produce flow to hang a phenomenon very easily.
The dominant role of methyl cellulose is water retention, followed by thickening. Be bored with child powder in inner wall, if it has better water dissolve and inferior viscosity (70000-80000), still can apply. When the viscosity exceeds 100,000, the viscosity is not harmful to water retention. In the manufacture and production of interior wall putty powder, there is no need to choose 200,000 viscosity. Because the viscosity is too large, it is difficult to scratch and scratch in large quantities.
Hydroxypropyl methyl cellulose uses a viscosity of 100,000.
1. Engineering project concrete mortar batch putty mortar.
High water solubility can make concrete sufficient condensation, adhesive tensile strength continued to increase. Similarly, the compressive strength and laser cutting compressive strength can be reasonably improved, and then improve the expected effect of building construction, improve efficiency.
2. Inner wall putty powder moisture resistance.
In the putty, moisturizing, bonding, lubrication is very important, to prevent the amount of water caused by cracks and dry conditions also improve the bonding of the inner wall putty powder, reduce the flow hanging phenomenon in construction, engineering construction relative smooth.
3. Plaster of Paris brushing series products.
In the plaster of Paris series products, it has the main effects of water retention, thickening and wetting. As such, it has a certain initial setting effect, which can increase the construction time and deal with the problems of cracking and original compressive strength in the construction operation process.
4. Waterproof putty.
As an important application of demulsifier, it can improve the tensile strength and laser cutting compressive strength, improve the surface coating, improve the adhesion and bonding compressive strength.
5. Ceramic tile adhesive.
High water soluble floor tiles and industrial bases do not need to be wet or wet in advance, which significantly improves the bonding compressive strength. The construction time is long, delicate and uniform, saving time and effort in construction. In addition, it also has high quality lubricity.
6. Caulking agent. Trench sealant.
HPMC fiber with high quality adhesion, low shrinkage and high wear resistance, maintenance of the basic raw materials from the destruction of industrial equipment, to prevent the infiltration of all construction projects.
7. Dc plain materials.
Smooth bonding ability ensures high quality circulation system of concrete and self-leveling ability of cement, adjusts moisture retention rate to make it solidify quickly and reduce cracking and closing.
8. Industrial paint wall latex paint.
In the industrial coating processing and manufacturing industry, methylpropyl methyl cellulose can be used as a film forming agent, demulsifier, demulsifier and adhesive, so that the film has better wear resistance, well-proportioned coating performance, adhesion and surface tension of pH is worth improving. The expected results are also good when mixed with organic solvents. It has high moisture retention and high quality paint performance.
Hydroxypropyl methyl cellulose 1500000 viscosity.
In the middle of 100,000 viscosity and 200,000 viscosity, 150,000 viscosity close to 100,000 viscosity.
Hydroxypropyl methyl cellulose 200,000 use.
In building materials, especially the use of inorganic insulating layer mortar, the most important thing is to improve the cohesivity, enhance the effect of tensile strength, make concrete mortar more easy to glue, improve efficiency. In addition, it has anti-vertical liquidity effect. High moisturizing performance can prolong the running time of concrete mortar, improve fracture resistance and anchoring, improve surface quality, improve adhesion.
(1) The water retention of methyl cellulose depends on its addition amount, viscosity, particle fineness and dissolution rate. Generally, the addition amount is large, the fineness is small, the viscosity is large, the water retention rate is high, among which the addition amount has the greatest influence on the water retention rate, the viscosity and the water retention rate is not lower than the relationship, the dissolution rate mainly depends on the surface modification degree and particle fineness of cellulose particles. Methyl cellulose and hydroxypropyl methyl cellulose in the above several cellulose ethers have higher water retention rate.
Post time: Jun-09-2022