METHOD OF SYNTHESIS OF AMORPHOUZED POLYVINYL ALCOHOL Russian patent published in 2003 - IPC

FIELD: chemical technology. SUBSTANCE: invention relates to method of synthesis of novel amorphouzed polyvinyl alcohol that swells rapidly in cold water and suitable for preparing gels and spinning solution. Method goals also exclusion of toxic alcohol methanol from components, utilization of the parent polymer polyvinyl acetate in any form: granule, powder, latex, i. e it shows good technological effectiveness. Method of synthesis of polyvinyl alcohol as powder involves saponification of polyvinyl acetate in the presence of alkali and medium consisting of water and alcohol including ethyl, propyl and isopropyl alcohol. Then the end product is isolated by conventional procedures. The ratio alcohol to water is from 90:10 to 40;60 in alkali content from 0.4 to 1 mole per vinyl acetate link. Process is carried out in the range of temperatures from 0 C to the solvent boiling point. Crystallinity degree of the prepared polyvinyl alcohol is 5%, not above. EFFECT: improved method of synthesis. 7 cl, 2 tbl