The Effect of Chemical Modification on Ultraviolet Absorption

Although, the ultraviolet spectroscopy of softwood lignin and guaiacyl model compounds has been thoroughly studied, the same cannot be said about hardwood lignins. It has been shown that the absorptivity of hardwood milled wood lignins at 280 nm decreases linearly with the methoxyl/carbon ratio (Sarkanen et al. 1967), but the effects of side chain structures on the ultraviolet absorption properties of hardwood lignins have yet to be determined. 

Adler E, Marton J (1959) Zur Kenntms der Carbonyl-gruppen in Lignin I Acta Chem Scand 

Braude EA (1955) Ultraviolet light absorption and the structure of organic compounds Ann Rep Prog Chem, Chem Soc Lond 17 105-130 Brauns FE (1952) The chemistry of lignin Academic Press New York, 217-230 Brauns FE, Brauns DA (1960) The chemistry of lignin, Suppl Vol Academic Press, New York, 199-219 

Brown W, Cowling EB, Falkehag SI (1968) Molecular size distributions of lignins liberated enzymatically from wood Sven Papperstidn 71 811-821 Browning BL (1967) Methods of wood chemistry, Vol 1 Interscience, New York, 179-180 Fengel D, Wegener G (1984) Wood, chemistry, ultrastructure, reactions Walter de Gruyter, Berlin, 157-160 

Fengel D, Wegener G, Feckl J (1981) Contribution to characterization of analytical and technical lignins (2) Physical-chemical and electron microscopical studies Holzforschung 35 111-118 

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