| One of the key challenges for wood polymer composites (WPC) is the inadequate toughness partly due to the incompatibility of the natural fibres and polymer (e.g., polypropylene or PP) matrix. In this work, the toughening of wood fibre reinforced PP has been the main focus. Two approaches of improving the toughness of PP-based WPC were developed. The surface modification of the natural fibre by either in-situ grafting polymerization of butyl acrylate in the presence of CAN (cerium-and-ammonium nitrate) as an initiator or adsorbing matrix-compatible cationic poly(butyl acrylate) (PBA) latex on the fibre surfaces was used to enhance the toughness of the polypropylene composites. The similar trend in improving mechanical properties of fibre-reinforced PP composites was observed, regardless of the fibres being grafted with PBA via in-situ polymerization or treated by cationic PBA latex. With the increasing of PBA content up to 2%, impact strength increased significantly. The structure and property relationship for the toughened WPC was also revealed via comprehensive characterization using SEM, AFM and DSC. |
