The structural and thermal characteristics of wheat straw hemicellulose

摘要

The structural characteristics of hemicelluloses isolated from delignified wheat straw were investigated by ion chromatography, FT-IR and NMR. The pyrolytic characteristic and the products at different temperatures were studied by TG and pyrolysis gas chromatography and mass spectrometry (py-GC/MS). The results showed wheat straw hemicelluloses were mainly consisting of arabinoxylan and uronic acids, the typical structure of straw hemicelluloses. The TG and DTG curves suggested the mass loss of hemicelluloses mainly happened between 190 and 315 C and formed a 24 wt.% residue at 700 C. The result of py-GC/MS revealed that the volatile products at different temperatures varied greatly and the main products of hemicellulose pyrolysis were acetic acid, carbon oxide, 2-furaldehyde, cyclopenten-1-one derivatives and small amounts of aromatic compounds which were very useful chemicals.