Effects of salt on homogeneous succinoylation of lignocellulosic fibers in dimethyl sulfoxide/tetraethylammonium chloride under mild condition

Abstract

ABSTRACTEffects of salt in the homogeneous succinoylation of ball milled mulberry wood in dimethyl sulfoxide (DMSO)/tetraethylammonium chloride (TEACl) was investigated using viscometry and two‐dimensional nuclear overhauser effect NMR spectroscopy (2D NOESY). The intrinsic viscosity of mulberry wood solution strongly depends on the TEACl dosage indicating that the change in hydrodynamic size of polymers caused by the interactions between salt and polymers in solution. 2D NOESY spectra reveal that TEA+ cations bind to the cellobiose in DMSO by the interactions between methenyl of TEA+ and C(1)/C(1′) group of cellobiose and the intensities of the crosspeaks increased with an increase in TEACl dosage. Taking cellobiose as a model compound for cellulose, it can be expected that TEA+ cations and cellulose forms a polyelectrolyte‐like complex. The yields of homogeneous succinoylation of mulberry wood in DMSO/TEACl benefits from the interactions between TEA+ cations and cellulose evidenced by weight percent gain, Fourier transform infrared spectra as well as CP/MAS 13C‐NMR spectra. © VC 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41912.