Reaction Behavior of Cellulose in the Homogeneous Esterification of Bagasse Modified with Phthalic Anhydride in Ionic Liquid 1-Allyl-3-methylimidazium Chloride

Abstract EN

In order to elucidate the reaction behavior of cellulose component in bagasse, the homogeneous phthalation of bagasse was investigated comparatively with the isolated cellulose in 1-allyl-3-methylimidazium chloride (AmimCl) with phthalic anhydride (PA) at the dosage of 10–50 mmol/g.

The phthalation degrees of bagasse and the isolated cellulose were in the range of 5.66% to 22.71% and 11.61% to 44.11%, respectively.

A phthalation degree increase of cellulose was proportional to phthalic anhydride dosage due to its regular macromolecular structure and followed the equation y PDI = 0.004 x - 0.02 .

FT-IR and 2D HSQC NMR analyses confirmed the attachment of phthaloyl group.

The phthalation reactivity of the three hydroxyls in the isolated cellulose followed the order of C-6 > C-2 > C-3, and the more selective phthalation to C-6 position was found in the cellulose component in bagasse.

These results provide detailed understanding of the homogenous modification mechanism of lignocellulose.