Functional modification of poly(vinyl alcohol) by copolymerization: 1. Modification with car☐ylic monomers

Autor: Tohei Moritani, Koichi Kajitani
Rok vydání: 1997
Předmět:
Zdroj: Polymer. 38:2933-2945
ISSN: 0032-3861
Popis: For the purpose of obtaining modified poly(vinyl alcohol-co-vinyl acetate), or partially hydrolysed poly(vinyl alcohol) (PVAL), containing sodium car☐ylate groups, -COONa, in polymer chains, ten car☐ylic monomers have been investigated for copolymerization with vinyl acetate, and the PVALs obtained by alcoholysis have been compared with each other. Dibasic acidic monomers, itaconic, fumaric and maleic acid, have been found useful for producing modified PVALs showing the functions targeted, reactivity to polyvalent inorganic salts like alum and increasing hydrophilic properties, without any risk of crosslinking. Among these dibasic monomers, itaconic acid has been regarded most practical. By using it, sodium γ,δ-hydroxycar☐ylate groups are formed directly in alcoholysis, and PVALs of lower degrees of hydrolysis, even less than 80 mol%, have become possible to be used as water soluble polymers. In contrast, maleic anhydride, or monomethyl maleate in methanol solution, cannot be applied to the production of partially hydrolysed PVAL modified thereof due to crosslinking problems; it can be explained by the ring-opening reaction of the δ-lactone formed in alcoholysis. Similar crosslinking has been observed in cases using other dibasic car☐ylic ester monomers. Properties and structures in cases using monobasic acidic monomers have also been investigated.
Databáze: OpenAIRE