Physical and Chemical Properties of HPMC
1. Appearance: white or almost white powder.
2. Granularity; the pass rate of 100 mesh is greater than 98.5%; the pass rate of 80 mesh is 100%. Special specifications have a particle size of 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: 42-56dyn/cm for 2% aqueous solution.
7. Solubility: soluble in water and some solvents, such as ethanol/water, propanol/water in appropriate proportions. The aqueous solution has surface activity. 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 performances. The dissolution of HPMC in water is not affected by pH.
8. As the content of methoxy group decreases, the gel point of HPMC increases, the water solubility decreases, and the surface activity also decreases.
9. HPMC also has thickening ability, salt resistance, low ash powder, pH stability, water retention, dimensional stability, excellent film-forming properties, and wide range of enzyme resistance, dispersibility and adhesion.