A new process for the esterification of wood by reaction with vinyl esters

A novel route to wood modification by transesterification of vinyl esters is developed in the current study. The reaction between varied saturated and unsaturated vinyl esters and the hydroxyl groups of maritime pine sapwood (Pinus pinaster Soland) was examined using potassium carbonate as a catalyst. The esterification of wood was investigated by weight percent gain calculations (WPG), Fourier-transform infrared spectroscopy (FTIR) and 13C cross-polarization with magic-angle spinning nuclear magnetic resonance spectroscopy (13C CP–MAS NMR). Differences in the rates of modification were noted, depending on the vinyl ester used, but relatively high yields were obtained in all cases. The infrared and NMR spectra of the different esterified samples were analysed in detail and the assignment of the signals corresponding to the grafted acyl groups confirmed that esterification occurred.