Poly(vinyl alcohol)
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| Names | |
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| Other names
PVOH; Poly(Ethenol), Ethenol, homopolymer; PVA; Polyviol; Vinol; Alvyl; Alcotex; Covol; Gelvatol; Lemol; Mowiol; Mowiflex, Alcotex, Elvanol, Gelvatol, Lemol, Mowiol, Nelfilcon A, Polyviol und Rhodoviol
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| Identifiers | |
| ChemSpider |
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| ECHA InfoCard | 100.121.648 |
| E number | E1203 (additional chemicals) |
| KEGG | |
| RTECS number | TR8100000 |
| Properties | |
| (C2H4O)x | |
| Density | 1.19-1.31 g/cm3 |
| Melting point | 200 °C (392 °F; 473 K) |
| Boiling point | 228 °C (442 °F; 501 K) |
| Hazards | |
| Safety data sheet | External MSDS |
| NFPA 704 | |
| Flash point | 79.44 °C (174.99 °F; 352.59 K) |
| Lethal dose or concentration (LD, LC): | |
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LD50 (median dose)
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14,700 mg/kg (Mouse) |
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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| Infobox references | |
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 white (colourless) and odorless. It is sometimes supplied as beads or as solutions in water.
Polyvinyl alcohol is used as an emulsion polymerization aid, as protective colloid, to make polyvinyl acetate dispersions. This is the largest market application in China. In Japan its major use is vinylon fiber production.
Other uses of polyvinyl alcohol include:
PVA is widely used in freshwater sport fishing. Small bags made from PVA are filled with dry or oil based bait and attached to the hook, or the baited hook is placed inside the bag and cast into the water. When the bag lands on the lake or river bottom it dissolves in water, leaving the hook bait surrounded by ground bait, pellets etc. This method helps attract fish to the hook bait.
Anglers also use string made of PVA for the purpose of making temporary attachments. For example, holding a length of line in a coil, that might otherwise tangle while the cast is made.
Unlike most vinyl polymers, PVA is not prepared by polymerization of the corresponding monomer. The monomer, vinyl alcohol, is unstable with respect to acetaldehyde. PVA instead is prepared by first polymerizing vinyl acetate, and the resulting polyvinylacetate is converted to the PVA. Other precursor polymers are sometimes used, with formate, chloroacetate groups instead of acetate. The conversion of the polyesters is usually conducted by base-catalysed transesterification with ethanol:
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