The Effect of Lignin and Surface Activation on the Mechanical Properties of Rubberwood-Polypropylene Composites

Lignin was employed in rubberwood-polypropylene (RW-PP) composites to serve as a bridging agent between polar wood filler and non-polar PP. Incorporation of lignin in the composites was able to improve the flexural and tensile properties of the composites. SEM showed evidence of improved adhesion as the result of the addition of lignin. Activation of the wood surface with sodium hydroxide (NaOH) improved the flexural and impact properties of the composites. The tensile modulus was improved, especially at 5% lignin loading. However, no improvement was detected in the tensile strength.