X-ray photoelectron spectroscopy of maleated polypropylene treated wood fibers in a high-intensity thermokinetic mixer

An XPS (X-ray Photoelectron Spectroscopy), also known as ESCA (Electron Spectroscopy for Chemical Analysis) study of wood fiber treated with maleated polypropylene was performed to obtain information on the chemical nature of wood fiber before and after treatment. Wood fiber was treated in a high-intensity thermokinetic mixer with maleated polypropylene at different loading level (relative to wood fiber weight). The XPS results showed that the treatment of maleated polypropylene increased the hydrocarbon concentration of wood fiber, as indicated by the decrease in oxygen-carbon ratio, and the continuous increase of the relative intensity of the component C1 in C1s signal. Based on these values, higher molecular weight maleated polypropylene produced more hydrophobic wood fiber surface than lower molecular weight maleated polypropylene. The decrease in C4 carbon type in C1s signal after treatment suggested that the esterification reaction between wood fiber and maleated polypropylene had not ocurred under the experimental conditions used in this study.