Focus on Cellulose ethers

High Viscosity CMC

High viscosity CMC is white or milky white fibrous powder or granules, with a density of 0.5-0.7 g/cm3, almost odorless, tasteless, and hygroscopic. Easily dispersed in water to form a transparent colloidal solution, insoluble in organic solvents such as ethanol. The pH of 1% aqueous solution is 6.5 to 8.5. When the pH is >10 or <5, the viscosity of the glue will be significantly reduced, and the performance will be the best when the pH is 7. The degree of CMC substitution directly affects the solubility, emulsification, and enhancement of CMC. Consistency, stability, acid resistance and salt resistance and other properties.

It is generally believed that when the degree of substitution is around 0.6-0.7, the emulsifying performance is better, and with the increase of the degree of substitution, other properties are improved accordingly. When the degree of substitution is greater than 0.8, its acid resistance and salt resistance are significantly enhanced. .

The main indicators to measure the quality of CMC are degree of substitution (DS) and purity. Generally, the properties of CMC are different if the DS is different; the higher the degree of substitution, the stronger the solubility, and the better the transparency and stability of the solution. According to reports, the transparency of CMC is better when the degree of substitution is 0.7-1.2, and the viscosity of its aqueous solution is the largest when the pH value is 6-9.

The quality of CMC finished products mainly depends on the solution of the product. If the solution of the product is clear, there are few gel particles, free fibers, and black spots of impurities, it is basically confirmed that the quality of CMC is good. If the solution is left for a few days, the solution does not appear. White or turbid, but still very clear, that is a better product!

1. Brief introduction of high-viscosity technical grade CMC and low-viscosity technical grade CMC for oil drilling fluid

1. CMC mud can make the well wall form a thin and firm filter cake with low permeability, reducing the water loss.

2. After adding CMC to the mud, the drilling rig can get a low initial shear force, so that the mud can easily release the gas wrapped in it, and at the same time, the debris can be quickly discarded in the mud pit.

3. Drilling mud, like other suspensions and dispersions, has a certain shelf life. Adding CMC can make it stable and prolong the shelf life.

4. The mud containing CMC is rarely affected by mold, so it is not necessary to maintain a high pH value and use preservatives.

5. Contains CMC as a treatment agent for drilling mud flushing fluid, which can resist the pollution of various soluble salts.

6. CMC-containing mud has good stability and can reduce water loss even if the temperature is above 150°C.

Remarks: CMC with high viscosity and high degree of substitution is suitable for mud with low density, and CMC with low viscosity and high degree of substitution is suitable for mud with high density. The choice of CMC should be determined according to different conditions such as mud type, region, and well depth.

Main application: MB-CMC3 plays the role of lifting and lowering water loss and viscosity raising in drilling fluid, cementing fluid and fracturing fluid, so as to achieve the functions of protecting wall, carrying cuttings, protecting drill bit, preventing mud loss and increasing drilling speed. Add it directly or make it into glue and add it to the mud, add 0.1-0.3% to the fresh water slurry, and add 0.5-0.8% to the salt water slurry.

2. Application of CMC in coating industry

The main purpose:

As a stabilizer, it can prevent the coating from separating due to sharp changes in temperature.

As a tackifier, it can make the state of the coating uniform, achieve the ideal storage and construction viscosity, and avoid serious delamination during the storage period

Protects against drips and sags during use.

ST, SR series instant CMC can be completely dissolved in 30 minutes, forming a clear, transparent, uniform colloidal solution, without long-term soaking and vigorous stirring.

Coating grade CMC technical indicators:

3. Application of CMC in ceramic industry

Main application: MB-CMC3 is used in ceramics as retarder, water retention agent, thickener and stabilizer. In the ceramic production process, it is used in the ceramic body, glaze slurry and printing to significantly improve the flexural strength of the body and improve the stability of the glaze slurry.

4. Application of CMC in washing industry

Detergent grade MB-CMC3: used in detergents to prevent dirt from re-deposition. The principle is that there is mutual electrostatic repulsion between negatively charged dirt and charged CMC molecules adsorbed on the fabric. In addition, CMC can also Effectively thicken the washed slurry or soap solution and stabilize the structure of the composition.

5. Application of CMC in the daily chemical toothpaste industry

Main application: MB-CMC3 is mainly suspended in daily chemicals, preventing impurities from re-precipitating again, maintaining moisture, stabilizing, and thickening. It has the advantages of fast dissolution and convenient use. The addition amount is 0.3%-1.0%. Toothpaste mainly plays the role of shaping and bonding. Through its excellent compatibility, the toothpaste remains stable and does not separate water. Generally, the recommended dosage is 0.5-1.5%.

Six, the stability of CMC glue viscosity over time, instructions for use

1. Due to the high molecular weight of this product, when preparing MB-CMC3 glue, the dissolution time is about half an hour longer than that of ordinary CMC;

2. Due to the high viscosity of the glue above 1.2%, it is not suitable to use a concentration of more than 1.2% when CMC is glued. Generally, it is more appropriate to choose a glue with a concentration of about 1.0%;

3. In selecting the addition ratio of CMC, it should be determined according to the type of graphite, the specific surface area and the amount of carbon black (conductive agent) submitted, and the general addition ratio range is 0.5%^1.0%;

4. The viscosity of the slurry is controlled at about 2500mPa.s, the smoothing and leveling of the slurry will be better, which is conducive to the uniformity of coating.

Seven, product features and advantages

1. It has a high molecular weight, which can significantly reduce the amount of CMC added, and at the same time ensure the viscosity and stability of the slurry;

2. The amount of CMC added in the formula is reduced by about 1%, which can increase the content of active substances and increase the qualified rate of product capacity;


Post time: Jan-05-2023
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