酸化セルロースの研究

第2報　クロム酸第三ブチルによるセルロースの酸化

抄録

Purified linter was oxidized with tert-butyl chromate in benzene with AcOH and Ac₂O, and both crystalline cellulose I and amorphous cellulose II were oxidized with this neutral oxidant in CCl₄. Acidic oxidation produced mainly carboxyl group to 150m moles, and 50m moles of aldehyde and 4-5m moles of ketone per 100g linter. This reaction was too drastic to investigate the oxidation of crystalline and amorphous cellulose at an early stage. In crystalline cellulose I, neutral oxidation produced 16m moles of aldehyde group, 7.5m moles of carboxyl and little ketone and it produced no change in crystal lattice and crystallinity obtained by means of X-ray diffraction, while in amorphous cellulose II, oxidation occurred even at 0°C, and 9m moles of ketone group which was not seen in cellulose I, 6m moles of aldehyde, and little carboxyl were produced, and besides appreciable degradation was observed from the figures of yield and X-ray diffraction. Alcohol group in C₂ and C₃ were oxidized to ketone, too.
In general, neutral tert-butyl chromate oxidizes cellulose heterogeneously; in crystal region oxidation of primary alcohol group to aldehyde in C₆, successively followed by the oxidation to carboxyl, mainly occurs, and in addition oxidation of secondary alcohol in C₂ and C₃ to ketone and considerable amounts of oxidative degradation of molecules in amorphous region occur. Acidic oxidation is so drastic that many oxidized groups are produced.