Abstract
The exhaustion of petroleum oil has been concerned as the consumption of them increases. In response to the trend, biomass resources, in particular lignocellulosics, recently attracts a lot of attention as a substitute for petroleum oil. The phase-separation system accomplishes conversion and separation of lignocellulosics into both carbohydrates and lignin based polymers by the hydrolysis of carbohydrates and the phenolysis of lignin. Through the system under typical conditions, native lignin is converted into linear type polymer (lignophenol) with p-cresol. In this study, the phase-separation treatments with both p-coumaric acid (CA) and ferulic acid (FA) were carried out. The lignin derivatives with CA and FA were distributed into the organic and interface layers, termed L-CA/FA and I-CA/FA, respectively. Through the treatments with CA and FA, most part of native lignins were derived as I-CA or I-FA, having black color and poor solubility. The FT-IR spectra of these derivatives showed bands at 1715 and 1610 cm-1 assigned to unconjugated and conjugated carbonyl groups, respectively. These results suggested that lignin derivatives were derived by rearrangement of lignin polymer network with CA or FA.
