What is the HPMC Hydroxypropyl methyl cellulose and cement ratio?
A waterproof engineering insulation mortar, its characteristics depend on the following net weight of raw materials made: Concrete 30-340, engineering construction waste brick powder 40-50, lignin fiber 20-24, calcium formate 4-6, hydroxypropyl methyl cellulose 7-9, silicon carbide powder 40-45, calcium hydroxide powder 10-20, brown corundum powder 10-12, dry big city silt powder 30-35, Datong city soil 40-45, aluminum sulfate 4-6, carboxymethyl Base starch 20-24, modified materials nanotechnology carbon powder 4-6, water 600-650; The waterproof engineering insulation mortar of this product has strong heat insulation, good fire resistance, strong bonding with the wall, compressive strength, tensile performance, good aging resistance, good environmental protection, excellent moistureproof, crack resistance, prevent falling down. Today we will talk about the viscosity of hydroxypropyl methyl cellulose aqueous solution is all in what aspects? Let’s actually study it.
1. The relative molecular weight, temperature of aqueous solution, cutting rate and experimental method of cellulose ether; 2. The higher the glass transition temperature, the greater the relative molecular weight, the viscosity of the solution is naturally higher; 3. The higher the content of cellulose ether, the higher the viscosity of the solution, so in the implementation of the application we should pay attention to the suitable amount of incorporation, prevent incorporation is too high, and directly affect the characteristics of cement mortar and cement concrete; 4. Like most of the solution, the viscosity will also decrease with the increase of temperature, plus the higher the content of cellulose ether, the greater the harm of the temperature; In addition, the actual thickening effect also varies according to the amount of water used for epoxy cement.
Hydroxypropyl methyl cellulose aqueous solution viscosity is also can serve as a key link for comments on characteristics of cellulose ether, the higher the viscosity of aqueous solution, its thick of epoxy cement materials are, the better, on the back of the plate gelling properties, but if the viscosity is too large, will harm the epoxy cement raw material immediately liquidity and enforceability. As for some self-leveling mortar with high fluidity, the viscosity of cellulose ether will be specified to be lower.
Cellulose ether aqueous solution is a pseudoplastic body, we in the later stage of the detection of the shear rate is greater, the viscosity is smaller.
Therefore, to sum up is: the cohesion of cement mortar will be reduced by external force, which is beneficial to the engineering construction behind, but cellulose ether aqueous solution in the case of a very low concentration value, will occur the characteristics of non-Newtonian liquid, on the contrary, when the concentration value is increased, the water solution will occur pseudoplastic liquid characteristics.
Water retention from hydroxypropyl methyl cellulose is one of the key properties of hydroxypropyl methyl cellulose. The evaporation rate of water content in mixed mortar and plaster based products is affected by gas temperature, temperature and pressure rate. Therefore, in different seasons, plus hydroxypropyl methyl cellulose the same amount of product water efficacy has some differences.
In general, the higher the viscosity of hydroxypropyl methyl cellulose is, the better the actual effect of water retention will be, but the harm of viscosity to water retention will be reduced after the viscosity exceeds 100,000 Mpa. s. When the viscosity of HYDROXYpropyl methyl cellulose exceeds 100,000, the water retention rate can be significantly improved by increasing the amount of hydroxypropyl methyl cellulose.
In the detailed construction process, the water retention effect of slurry can be adjusted by adjusting the amount of hydroxypropyl methyl cellulose. Hydroxypropyl methyl cellulose series products can effectively solve the problem of water retention under continuous high temperature. In the continuous high temperature season, especially in the hot and boring areas and the construction of the chromatography on the sunny side, high quality HYDROXYpropyl methyl cellulose is required to develop the water retention of the slurry.
High quality of hydroxypropyl methyl cellulose, it has a good balance, its tertiary butyl and hydroxypropyl oxygen functional groups along the fiber molecular chain structure joint distribution, it can develop methyl aldehyde group and the oxygen, and water quality of the digital form covalent bonds can, become bound water and water of the dispersion, then effectively control high temperature climate caused by water evaporation, high water retention.
High quality of hydroxypropyl methyl cellulose can fit loose and commercial land in mixed mortar and plaster products, and all the solid particles cyst, damp, cool, and form a layer of film, moisture in moderate long-term slowly release from base, with the onset of organic compound admixture of hydration reaction, then guarantee the coherence of raw materials compressive strength and tensile strength. In sustained high temperature summer construction process, therefore, to reach water effect, should be in accordance with the recipe for a certain amount and quality of hydroxypropyl methyl cellulose products, otherwise, will show the boring too fast and causing insufficient hydration, reduce the compressive strength, split, popped the qualities such as metope empty drum and doubt, also combined with the worker construction difficulty coefficient. As the temperature drops, the amount of hydroxypropyl methyl cellulose can be slowly reduced and the same water retention effect can be achieved.
If cellulose ether is not added, the chromatography of fresh cement mortar will quickly dry, making concrete can not be hydrated in a normal way, resulting in cement mortar can not be hard primed and get better adhesion. At the same time, the addition of cellulose ether makes cement mortar have good ductility and flexibility, and improves the bonding compressive strength of cement mortar.
1, hydroxypropyl methyl cellulose particle size
The particle size of cellulose ether harms its solubility. The finer cellulose ether is, the faster its decomposition rate in water and the higher its water-retention characteristics. Therefore, the particle size of cellulose ether should be included in the investigation of one of its characteristics. In general, cellulose ether particle size of 80 mesh based on.
2, hydroxypropyl methyl cellulose dry without gravity rate
Dry manic no gravity rate, refers to a certain temperature of dry manic cellulose ether, the loss of chemical quality accounted for the original sample quality percent of the composition. For a certain quality of cellulose ether in the dry without gravity rate is too high, will reduce the relevant components in cellulose ether, harm the actual effect of the use of downstream companies, but also improve the purchase cost. Usually the dry cellulose ether without gravity rate shall not exceed 5.0%.
3, hydroxypropyl methyl cellulose potassium thiocyanate ash
For a certain quality of cellulose ether in the ash content is too high, will reduce the cellulose ether in the relevant components, harm the actual effect of the use of downstream companies, cellulose ether potassium thiocyanate ash content is the main consideration of its own characteristics index value.
4, hydroxypropyl methyl cellulose viscosity
Hydroxypropyl methyl cellulose water retention and thickening effect is the key to add cement mortar cellulose ether in its own viscosity and incorporation.
5, hydroxypropyl methyl cellulose PH value
The viscosity of hydroxypropyl methyl cellulose products decreases gradually at higher temperature or after storage for a long time, especially for high viscosity products, so the pH value must be limited. It is generally stipulated that the PH value category of cellulose ether should be operated as 5-9.
6. Transmittance of hydroxypropyl methyl cellulose
The advantages and disadvantages of the transmittance of hydroxypropyl methyl cellulose can directly affect the actual effect of its use in building materials. The primary factors that harm the transmittance of cellulose ether are 1) the quality of raw materials; (2) the actual effect of deashing; (3) Processing technology preparation; (4) organic solvent preparation; (5) The actual effect of zhonghe.
According to the actual application effect, the transmittance of cellulose ether should not be less than 80%.
7, hydroxypropyl methyl cellulose suspected temperature
Hydroxypropyl methyl cellulose in cement components as the key to increase adhesives, viscosity and water retention agent, so viscosity and gel temperature is the key index value of hydroxypropyl methyl cellulose. The temperature is used to judge the type and specification of cellulose ether, and the degree of substitution of cellulose ether is related.
8. In addition, salt and residue will also harm the temperature of the glue. When the temperature of the aqueous solution rises, the fiber polymer gradually lacks water, and the viscosity of the aqueous solution decreases. When the adhesive point is reached, the polymer is completely dried and the adhesive is produced. Therefore, the operating temperature of cement members is usually below the original glue temperature. Under this standard, the lower the temperature, the higher the viscosity, and the more significant the actual effect of viscosification and water retention.
Post time: Jun-09-2022