| Synonyms | Vinyl alcohol polymer, PVOH |
| Definition | Polyvinyl alcohol is a synthetic resin prepared by the polymerisation of vinyl acetate, followed by partial hydrolysis of the ester in the presence of an alkaline catalyst. The physical characteristics of the product depend on the degree of polymerisation and the degree of hydrolysis. |
| Chemical name | Ethenol homopolymer |
| Chemical formula | (C2H3OR)n where R = H or COCH3 |
| Description | Odourless, tasteless, translucent, white or cream-coloured granular powder |
| Identification | |
|---|---|
| [F1Solubility | Soluble in water; Practically insoluble or insoluble in ethanol (≥ 99,8 %)] |
| Precipitation reaction | Dissolve 0,25 g of the sample in 5 ml of water with warming and let the solution cool to room temperature. The addition of 10 ml of ethanol to this solution leads to a white, turbid or flocculent precipitate. |
| Colour reaction | Dissolve 0,01 g of the sample in 100 ml of water with warming and let the solution cool to room temperature. A blue colour is produced when adding (to 5 ml solution) one drop of iodine test solution (TS) and a few drops of boric acid solution Dissolve 0,5 g of the sample in 10 ml of water with warming and let the solution cool to room temperature. A dark red to blue colour is produced after adding one drop of iodine TS to 5 ml of solution. |
| Viscosity | 4,8 to 5,8 mPa.s (4 % solution at 20 °C) corresponding to an average molecular weight of 26 000-30 000 Da |
| Purity | |
| Water insoluble matter | Not more than 0,1 % |
| Ester value | Between 125 and 153 mg KOH/g |
| Degree of hydrolysis | 86,5 to 89,0% |
| Acid value | Not more than 3,0 |
| Solvent residues | Not more than 1,0 % Methanol, 1,0 % Methyl acetate |
| pH | 5,0 to 6,5 (4 % solution) |
| Loss on drying | Not more than 5,0 % (105 °C, 3 hours) |
| Residue in ignition | Not more than 1,0 % |
| Lead | Not more than 2 mg/kg |
Textual Amendments
F1 Substituted by Commission Regulation (EU) 2015/463 of 19 March 2015 amending Annex to Regulation (EU) No 231/2012 laying down specifications for food additives listed in Annexes II and III to Regulation (EC) No 1333/2008 of the European Parliament and of the Council as regards specifications for polyvinyl alcohol (E 1203) (Text with EEA relevance).