Oil-palm fiber reinforced phenolformaldehyde composites were prepared and then tested for their thermal properties. Thermal conductivity and diffusivity were measured using the transient plane source (TPS) technique. The composites were then treated using different methods (alkali, silane and acetic acid treatments) and the thermal conductivity and diffusivity were measured again to see how the treatment affected the thermal properties of the composite. It was found that thermal conductivity increased varying ...