Syntheses and characterization of xylan esters

A series of low-molecular weight and high-molecular weight xylan esters with different alkyl chain lengths (C2–C12) were synthesized by heterogeneous and homogeneous reactions, respectively. Structure elucidation of these xylan esters was obtained by NMR analysis. The solubility of xylan in CHCl3 improved after esterification. DSC results did not show a melting peak for all samples. However, WAXD diffractograms show the presence of diffraction peaks. The proposed structural model for xylan ester films is presented. TGA suggested that the thermal stability of xylan increased after esterification. Xylan esters with longer alkyl chains had higher decomposition temperatures. The mechanical properties of the xylan esters were dependent on the alkyl chain length. The tensile strength and elongation at break of these xylan esters ranged from 8 to 29 MPa and from 19 to 44%, respectively. Xylan esters in HFIP can be electrospun into nanofibers.