Role of β-O-4 glycosidic bond on thermal degradation of cellulose

The pyrolytic characteristics of cellulose, cellobiose and glucose were examined by TG-FTIR combined with Py-GC-MS, in order to gain the effect of β-O-4 glycosidic bond on the pyrolysis process. In TG-FTIR analysis, two mass loss peaks were observed for cellobiose and glucose, indicating dehydration in low temperature stage and consequently intensive cracking of glycosidic bond and fragments for cellobiose. The samples were tested in Py-GC-MS at the temperature of 300, 500 and 900 °C according to their mass loss characteristics from TG-FTIR. Formation of furans from cellobiose, which involved the cracking of β-O-4 glycosidic bond, was prominent over other products, compared to that of cellulose and glucose. Four possible chemical pathways for the cleavage of β-O-4 glycosidic bond have been proposed with regard to the formation of furans and anhydrosugars from cellulose. Besides, another two reaction pathways leading to the formation of levoglucosan were also suggested.