| Abstract: | Oxidation of poly(vinyl alcohol) (PVA) with 1-oxo-4-methoxy-2,2,6,6-tetramethylpiperidinium chloride (oxoammonium salt, 1 ) prepared by a one-electron oxidation of the corresponding nitroxyl radical ( 2 ) was carried out. PVA with a degree of polymerization (DP) of 300 and a degree of saponification (DS) of 88 mol-% was oxidized with 1 in the presence of magnesium perchlorate in N-methyl-2-pyrrolidone (NMP) to obtain a polymer containing 66 mol-% of ketone units. The oxidation was found to be dependent on solvent and additive and further, independent of DP but dependent on DS of PVA. In the case of PVA with extremely low (10 mol-%) or high (98,5 mol-%) DS, no or little oxidation took place. The highest ketone content was obtained in a polymer with a DS of 88 mol-%. Moreover, the ketone content of the oxidized PVA could be controlled by the amount of 1 . |
