01. Hydroxyethyl Cellulose
As a non-ionic surfactant, hydroxyethyl cellulose not only has the functions of suspending, thickening, dispersing, flotation, bonding, film-forming, water retention and providing protective colloid, but also has the following properties:
1. HEC is soluble in hot or cold water, and does not precipitate at high temperature or boiling, so that it has a wide range of solubility and viscosity characteristics, and non-thermal gelation;
2. Compared with the recognized methyl cellulose and hydroxypropyl methyl cellulose, the dispersing ability of HEC is the worst, but the protective colloid has the strongest ability.
3. The water retention capacity is twice as high as that of methyl cellulose, and it has better flow regulation.
Precautions when using:
Since the surface-treated hydroxyethyl cellulose is powder or cellulose solid, it is easy to handle and dissolve in water as long as the following matters are noted.
1. Before and after adding hydroxyethyl cellulose, it must be continuously stirred until the solution is completely transparent and clear.
2. It must be sieved into the mixing barrel slowly. Do not directly add the hydroxyethyl cellulose that has been formed into lumps or balls into the mixing barrel in large quantities or directly.
3. The water temperature and the pH value of the water have a significant relationship with the dissolution of hydroxyethyl cellulose, so special attention should be paid to it.
4. Never add some alkaline substances to the mixture before the hydroxyethyl cellulose powder is warmed by water. Raising the PH value after warming is helpful for dissolution.
HEC use:
1. Generally used as thickening agent, protective agent, adhesive, stabilizer and additive for preparing emulsion, gel, ointment, lotion, eye clearing agent, suppository and tablet, also used as hydrophilic gel, skeleton materials, preparation of skeleton sustained-release preparations, and can also be used as a stabilizer in food.
2. It is used as sizing agent in textile industry, bonding, thickening, emulsifying, stabilizing and other auxiliaries in electronics and light industry sectors.
3. Used as thickener and filtrate reducer for water-based drilling fluid and completion fluid, and has obvious thickening effect in saltwater drilling fluid. It can also be used as a fluid loss control agent for oil well cement. It can be cross-linked with polyvalent metal ions to form gels.
5. This product is used as a dispersant for water-based gel fracturing fluids, polystyrene and polyvinyl chloride in oil fracturing production. It can also be used as emulsion thickener in paint industry, humidity sensitive resistor in electronic industry, cement coagulation inhibitor and moisture retaining agent in construction industry. Glazing and toothpaste adhesives for the ceramic industry. It is also widely used in printing and dyeing, textile, papermaking, medicine, hygiene, food, cigarettes, pesticides and fire extinguishing agents.
02.Hydroxypropyl Methyl Cellulose
1. Coating industry: As a thickener, dispersant and stabilizer in the coating industry, it has good compatibility in water or organic solvents. as a paint remover.
2. Ceramic manufacturing: widely used as a binder in the manufacture of ceramic products.
3. Others: This product is also widely used in leather, paper product industry, fruit and vegetable preservation and textile industry, etc.
4. Ink printing: as a thickener, dispersant and stabilizer in the ink industry, it has good compatibility in water or organic solvents.
5. Plastic: used as molding release agent, softener, lubricant, etc.
6. Polyvinyl chloride: It is used as a dispersant in the production of polyvinyl chloride, and it is the main auxiliary agent for the preparation of PVC by suspension polymerization.
7. Construction industry: As a water-retaining agent and retarder for cement mortar, the mortar has pumpability. Used as a binder in plastering paste, gypsum, putty powder or other building materials to improve spreadability and prolong operation time. It is used as a paste for ceramic tile, marble, plastic decoration, as a paste enhancer, and it can also reduce the amount of cement. The water retention of hydroxypropyl methylcellulose HPMC can prevent the slurry from cracking due to drying too fast after application, and enhance the strength after hardening.
8. Pharmaceutical industry: coating materials; film materials; rate-controlling polymer materials for sustained-release preparations; stabilizers; suspending agents; tablet binders; tackifiers.
Nature:
1. Appearance: white or off-white powder.
2. Particle size; 100 mesh pass rate is greater than 98.5%; 80 mesh pass rate is 100%. The particle size of special specification is 40~60 mesh.
3. Carbonization temperature: 280-300℃
4. Apparent density: 0.25-0.70g/cm (usually around 0.5g/cm), specific gravity 1.26-1.31.
5. Discoloration temperature: 190-200℃
6. Surface tension: 2% aqueous solution is 42-56dyn/cm.
7. Solubility: soluble in water and some solvents, such as appropriate proportion of ethanol/water, propanol/water, etc. Aqueous solutions are surface active. High transparency and stable performance. Different specifications of products have different gel temperatures, and solubility changes with viscosity. The lower the viscosity, the greater the solubility. Different specifications of HPMC have different properties. The dissolution of HPMC in water is not affected by pH value.
8. With the decrease of methoxy group content, the gel point increases, the water solubility decreases, and the surface activity of HPMC decreases.
9. HPMC also has the characteristics of thickening ability, salt resistance, low ash powder, pH stability, water retention, dimensional stability, excellent film-forming properties, and a wide range of enzyme resistance, dispersibility and cohesiveness.
Post time: Apr-26-2024