Low Molecular Weight Products from the Aqueous Alkaline Degradation of Cellulose

摘要

Low molecular weight products from the degradation of pure cellulose in 0.6 to 1.3 N alkali at 300 exp 0 C were identified by gas chromatography/mass spectrometry (GC/MS). Both the aqueous residual phase and the floating oil product phase were examined, and found to contain essentially the same compounds. Derivatization by trifluoroacetic anhydride was used as an ancillary method to aid identification of these compounds, which consisted primarily of unsaturated aliphatic and alicyclic hydrocarbons, aldehydes, ketones, alcohols, and furans. Many isomers were present. Specific compounds identified with a high level of confidence were cyclopentanone, cyclohexanone, phenol, cresols, 2-ethylcyclopentanone, 2- or 3-methylcyclopentanone, 2,5-dimethyl-2-cylopentenone, acrolein, 2,5-dimethyl-2,4-hexadiene, and octene. Compounds identified with a lower level of confidence include 2,4-dimethylfuran, 2,5-diethylfuran, ethylmethylfuran, 4-octyne, and decyne. The formation of these compounds from cellulose under alkaline conditions demonstrates not only the degradation of cellulose, but the resynthesis of molecules with carbon chain lengths greater than 6 atoms (the chain length of glucose). Such resynthesis must occur to a great extent in the formation of insoluble high molecular weight oils from cellulose by heating in aqueous alkali. (ERA citation 04:005410)