Analysis of Among-Species Variability in Wood Fiber Surface Using DRIFTS
and XPS: Effects on Esterification Efficiency.
Hassine Bouafif, Ahmed Koubaa, Patrick Perré, Alain Cloutier, Bernard Riedl.
Variability in the chemical composition of surface properties of various wood
fibers (eastern white cedar, jack pine, black spruce, and bark) was investigated using
diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and X-ray photoelectron
spectroscopy (XPS). Both DRIFTS and XPS showed high variability in fiber
surface composition between species and between fiber types (sapwood, heartwood,
and bark). Fiber surface was modified by esterification reaction using a maleic anhydride
polyethylene (MAPE) treatment. DRIFTS failed to assess surface modification,
whereas XPS results showed that MAPE treatment increased the surface hydrocarbon
concentration of jack pine wood fiber, indicated by a decrease in oxygen–carbon ratio
and an increase in relative intensity of the C1 component in the C1s signal. Lignin
concentration variability on the fiber surface was determined as the major factor that
prevents esterification from taking place.