The UV spectra of cellulose and some model compounds

Abstract

AbstractComparison of the reflectance spectrum of cellulose with that of myoinositol, cycloheptaamylose, and other model compounds indicates that the acetal linkage does not contribute significantly to the absorption peak at 260 nm. The spectra of photolyzed and photo‐oxidized cellulose suggest that ketonic carbonyl groups are a more likely cause of this peak. Photolysis of cellulose and amylose under vacuum with 253.7 nm light increases the concentration of ketonic carbonyls and thus promotes yellowing. Photo‐oxidation with 253.7‐nm light bleaches both carbohydrates owing to the formation of carboxyl groups. Other investigators had previously reported that this last reaction yellows cellulose, but it appears that this was an effect caused by the 184.9‐nm component in the light of the lamp used. Comparison of the spectra of thermally and photolytically yellowed cellulose indicates that the end products of the two degradations are quite different.