1. Basic Concept
•Name: Hydroxypropyl Methylcellulose (HPMC)
•Formula: C₁₀H₂₀O₆(C₁₀H₁₈O₆)ₓ
•Nature: A non-ionic cellulose ether derived from natural cellulose through chemical modification.
•Appearance: White or off-white powder, swells in water to form a transparent or translucent viscous solution.
•Features: Non-toxic, odorless, environmentally friendly; soluble in cold water; provides thickening, film-forming, emulsifying, water retention, and suspension properties.
2. Main Production Process
1.Alkalization: Natural cellulose (cotton linter or wood pulp) is treated with sodium hydroxide to produce alkali cellulose.
2.Etherification: In an organic solvent system (e.g., isopropanol), alkali cellulose reacts with methyl chloride (CH₃Cl) and propylene oxide (C₃H₆O), introducing methoxy (-OCH₃) and hydroxypropyl (-OCH₂CHOHCH₃) groups → yielding HPMC.
3.Post-treatment: Filtration, washing, drying, and milling → final HPMC product.
👉 By adjusting the substitution degree of methoxy and hydroxypropyl groups, properties such as solubility, gel temperature, and viscosity can be controlled.
3. Main Applications
•Construction industry: Water retention agent and thickener in cement mortar, tile adhesives, putty powder, and self-leveling materials. Improves workability and prevents cracking.
•Pharmaceuticals: Used as a binder, coating agent, and controlled-release material in tablets; capsule shells (vegetarian capsules); lubricant and film former in eye drops.
•Food industry: Approved food additive (E464); emulsifier, thickener, stabilizer; used in low-calorie foods as a fat substitute.
•Cosmetics and others: Thickener and stabilizer in creams, shampoos, toothpaste; dispersant in paints; dispersing agent in PVC polymerization.
✅ Summary:
HPMC is a functional polymer obtained through alkalization → etherification → post-treatment. With properties such as water retention, thickening, film-forming, and suspension, it is widely applied in construction, pharmaceuticals, food, cosmetics, and coatings industries.
