PVA
Poly(vinyl alcohol) (PVOH, PVA, or PVAl) is a water-soluble synthetic polymer. It has the idealized formula [CH2CH(OH)]n. It is used in papermaking, textiles, and a variety of coatings. It is colourless (white) and odorless. It is sometimes supplied as beads or as solutions in water. PVA is used in a variety of medical applications because of its biocompatibility, low tendency for protein adhesion, and low toxicity. Specific uses include cartilage replacements, contact lenses, and eye drops.[5] Polyvinyl alcohol is used as an aid in suspension polymerizations. Its largest application in China is its use as a protective colloid to make polyvinyl acetate dispersions. In Japan its major use is the production of vinylon fiber.[6] Another application is photographic film.
| Chemical formula | C2H4O |
| Density | 1.19-1.31 g/cm3 |
| Melting point | 200 °C (392 °F; 473 K) |
| Boiling point | 181.7 °C (359.1 °F; 454.8 K) |
| log P | 0.26 |
| Vapor pressure | 0.4 mmHg (20 °C)[3] |
| Refractive index | 1.477 @ 632 nm |
