Kinetics Study on the Oxidative Degradation of Cellotriose and Cellotetraose by Hydrogen Peroxide

摘要

Cellulose is one of the main components of renewable lignocellulosic biomass. Functional cellooligosaccharides obtained from the hydrolysate of cellulose could be used as model compounds to study the chemical reactivity of cellulose. HPLC, ~1H NMR and ~(13)C NMR techniques were used to analyze the degradation products of cellotriose and cellotetraose oxided by hydrogen peroxide. Results demonstrated that the main degradation products were oligosaccharides with lower degree of polymerization (DP), glucose, and other products including polyhydroxy acid and ketone. The degradation rate declined with the increment of DP. The degradation of cellotriose and cellotetraose at 60 °C followed a pseudo-first-order rate law, the degradation reaction rates were k_3=0.25 h~(-1) and k_4=0.15 h~(-1). Cellooligosaccharides could be degraded completely at higher temperature and for longer reaction time. Degradation products were also degraded at higher temperature and for longer time. The concentration of degradation products went up with the increase of substrate concentration.