Hydroxyethyl Cellulose Physical and Chemical Properties
Appearance properties This product is white to light yellow fibrous or powdery solid, non-toxic and tasteless
Melting point 288-290 °C (dec.)
Density 0.75 g/mL at 25 °C(lit.)
Solubility Soluble in water. Insoluble in common organic solvents. It is soluble in cold water and hot water, and generally insoluble in most organic solvents. The viscosity changes slightly in the range of PH value 2-12, but the viscosity decreases beyond this range. It has the functions of thickening, suspending, binding, emulsifying, dispersing, and maintaining moisture. Solutions in different viscosity ranges can be prepared. Has exceptionally good salt solubility for electrolytes.
As a non-ionic surfactant, hydroxyethyl cellulose has the following properties in addition to thickening, suspending, binding, floating, film-forming, dispersing, water-retaining and providing protective colloids:
1. HEC is soluble in hot water or cold water, high temperature or boiling without precipitation, so that it has a wide range of solubility and viscosity characteristics, and non-thermal gelation;
2. It is non-ionic and can coexist with a wide range of other water-soluble polymers, surfactants, and salts. It is an excellent colloidal thickener for high-concentration electrolyte solutions;
3. The water retention capacity is twice as high as that of methyl cellulose, and it has better flow regulation.
4. Compared with the recognized methyl cellulose and hydroxypropyl methyl cellulose, the dispersing ability of HEC is the worst, but the protective colloid ability is the strongest.
Technical requirements and quality standards for hydroxyethyl cellulose
Items: Index molar substitution (M.S) 2.0-2.5 Moisture (%) ≤5 Water insoluble (%) ≤0.5 PH value 6.0-8.5 Heavy metal (ug/g) ≤20 Ash (%) ≤5 Viscosity (mpa. s) 2% 20 ℃ aqueous solution 5-60000 lead (%) ≤0.001
Uses of hydroxyethyl cellulose
【Use 1】Used as surfactant, latex thickener, colloidal protective agent, oil exploration fracturing fluid, polystyrene and polyvinyl chloride dispersant, etc.
[Use 2] Used as a thickener and fluid loss reducer for water-based drilling fluids and completion fluids, and has an obvious thickening effect in brine drilling fluids. It can also be used as fluid loss reducer for oil well cement. It can be cross-linked with polyvalent metal ions to form a gel.
[Use 3] This product is used as a polymeric dispersant for water-based gel fracturing fluid, polystyrene and polyvinyl chloride in fracturing mining. It can also be used as an emulsion thickener in the paint industry, a hygrostat in the electronics industry, a cement anticoagulant and a moisture retention agent in the construction industry. Ceramic industry glazing and toothpaste binder. It is also widely used in printing and dyeing, textiles, papermaking, medicine, hygiene, food, cigarettes, pesticides and fire extinguishing agents.
[Use 4] Used as surfactant, colloidal protective agent, emulsification stabilizer for vinyl chloride, vinyl acetate and other emulsions, as well as viscosifier, dispersant, and dispersion stabilizer for latex. Widely used in coatings, fibers, dyeing, papermaking, cosmetics, medicine, pesticides, etc. It also has many uses in oil exploration and machinery industry.
【Use 5】Hydroxyethyl cellulose has the functions of surface activity, thickening, suspending, binding, emulsifying, film forming, dispersing, water retention and providing protection in pharmaceutical solid and liquid preparations.
Applications of hydroxyethyl cellulose
Used in architectural coatings, cosmetics, toothpaste, surfactants, latex thickeners, colloidal protective agents, oil fracturing fluids, polystyrene and polyvinyl chloride dispersants, etc.
Hydroxyethyl Cellulose Material Safety Data Sheet (MSDS)
1. The product has the risk of dust explosion. When handling large quantities or in bulk, be careful to avoid dust deposition and suspension in the air, and keep away from heat, sparks, flames and static electricity. 2. Avoid methylcellulose powder from entering and contacting eyes, and wear filter masks and safety goggles during operation. 3. The product is very slippery when wet, and the spilled methylcellulose powder should be cleaned up in time and anti-slip treatment should be done.
Storage and transportation characteristics of hydroxyethyl cellulose
Packing: double-layer bags, outer composite paper bag, inner polyethylene film bag, net weight 20kg or 25kg per bag.
Storage and transportation: Store in a ventilated and dry place indoors, and pay attention to moisture. Rain and sun protection during transportation.
Preparation method of hydroxyethyl cellulose
Method 1: Soak raw cotton linters or refined pulp in 30% lye, take it out after half an hour, and press. Press until the ratio of alkali-water content reaches 1:2.8, and move to a crushing device for crushing. Put the crushed alkali fiber into the reaction kettle. Sealed and evacuated, filled with nitrogen. After replacing the air in the kettle with nitrogen, press into the precooled ethylene oxide liquid. React under cooling at 25°C for 2 h to obtain crude hydroxyethyl cellulose. Wash the crude product with alcohol and adjust the pH value to 4-6 by adding acetic acid. Add glyoxal for cross-linking and aging, quickly wash with water, and finally centrifuge, dry, and grind to obtain low-salt hydroxyethyl cellulose.
Method 2: Alkali cellulose is a natural polymer, each fiber base ring contains three hydroxyl groups, the most active hydroxyl group reacts to form hydroxyethyl cellulose. Soak raw cotton linters or refined pulp in 30% liquid caustic soda, take it out and press after half an hour. Squeeze until the ratio of alkaline water reaches 1:2.8, then crush. Put the pulverized alkali cellulose into the reaction kettle, seal it, vacuumize it, fill it with nitrogen, and repeat the vacuumization and nitrogen filling to completely replace the air in the kettle. Press into the pre-cooled ethylene oxide liquid, put cooling water into the jacket of the reaction kettle, and control the reaction at about 25°C for 2 hours to obtain crude hydroxyethyl cellulose. The crude product is washed with alcohol, neutralized to pH 4-6 by adding acetic acid, and cross-linked with glyoxal for aging. Then it is washed with water, dehydrated by centrifugation, dried and pulverized to obtain hydroxyethyl cellulose. Raw material consumption (kg/t) cotton linters or low pulp 730-780 liquid caustic soda (30%) 2400 ethylene oxide 900 alcohol (95%) 4500 acetic acid 240 glyoxal (40%) 100-300
Hydroxyethyl cellulose is a white or yellowish odorless, tasteless and easy-flowing powder, soluble in cold water and hot water, generally insoluble in most organic solvents.
Hydroxyethyl cellulose (HEC) is a white or light yellow, odorless, non-toxic fibrous or powdery solid, which is prepared by etherification reaction of alkaline cellulose and ethylene oxide (or chlorohydrin). Nonionic soluble cellulose ethers. Because HEC has good properties of thickening, suspending, dispersing, emulsifying, bonding, film-forming, protecting moisture and providing protective colloid, it has been widely used in oil exploration, coatings, construction, medicine, food, textile, paper and polymer Polymerization and other fields. 40 mesh sieving rate ≥ 99%; softening temperature: 135-140°C; apparent density: 0.35-0.61g/ml; decomposition temperature: 205-210°C; slow burning speed; equilibrium temperature: 23°C; 50% 6% at rh, 29% at 84% rh.
How to use hydroxyethyl cellulose
added directly at production time
1. Add clean water to a large bucket equipped with a high shear mixer. the
Hydroxyethyl cellulose
2. Start to stir continuously at low speed and slowly sieve the hydroxyethyl cellulose into the solution evenly. the
3. Continue to stir until all particles are soaked. the
4. Then add lightning protection agent, basic additives such as pigments, dispersion aids, ammonia water. the
5. Stir until all the hydroxyethyl cellulose is completely dissolved (the viscosity of the solution increases significantly) before adding other components in the formula, and grind until the finished product.
Equipped with mother liquor
This method is to prepare the mother liquor with higher concentration first, and then add it to the latex paint. The advantage of this method is that it has greater flexibility and can be directly added to the finished paint, but it should be properly stored. The steps are similar to Steps 1-4 in Method 1, the difference is that there is no need to stir until it completely dissolves into a viscous solution.
Porridge for phenology
Since organic solvents are poor solvents for hydroxyethyl cellulose, these organic solvents can be used to prepare the porridge. The most commonly used organic solvents are organic liquids such as ethylene glycol, propylene glycol and film formers (such as ethylene glycol or diethylene glycol butyl acetate) in paint formulations. Ice water is also a poor solvent, so ice water is often used together with organic liquids to prepare porridge. The hydroxyethyl cellulose of the porridge can be directly added to the paint, and the hydroxyethyl cellulose has been divided and swelled in the porridge. When added to the paint, it dissolves immediately and acts as a thickener. After adding, keep stirring until the hydroxyethyl cellulose is completely dissolved and uniform. Generally, porridge is made by mixing six parts of organic solvent or ice water with one part of hydroxyethyl cellulose. After about 6-30 minutes, the hydroxyethyl cellulose will be hydrolyzed and swell obviously. In summer, the water temperature is generally too high, so it is not suitable to use porridge.
Precautions for hydroxyethyl cellulose
Since the surface-treated hydroxyethyl cellulose is powder or cellulose solid, it is easy to handle and dissolve it in water as long as the following items are paid attention to. the
1. Before and after adding hydroxyethyl cellulose, it must be stirred continuously until the solution is completely transparent and clear. the
2. It must be slowly sieved into the mixing tank, do not directly add a large amount of hydroxyethyl cellulose or hydroxyethyl cellulose that has formed lumps and balls into the mixing tank. 3. Water temperature and PH value in water have obvious relationship to the dissolution of hydroxyethyl cellulose, so special attention must be paid. the
4. Do not add some alkaline substances to the mixture before the hydroxyethyl cellulose powder is warmed through the water. Raising the pH value after warming up will help dissolve. the
5. As far as possible, add anti-fungal agent as early as possible. the
6. When using high-viscosity hydroxyethyl cellulose, the concentration of the mother liquor should not be higher than 2.5-3%, otherwise the mother liquor will be difficult to handle. The post-treated hydroxyethyl cellulose is generally not easy to form lumps or spheres, nor will it form insoluble spherical colloids after adding water.
It is generally used as a thickener, protective agent, adhesive, stabilizer and additive for the preparation of emulsion, jelly, ointment, lotion, eye cleanser, suppository and tablet, and also used as hydrophilic gel and skeleton material 1. Preparation of skeleton-type sustained-release preparations. It can also be used as a stabilizer in food.
Post time: Feb-02-2023