Effects of Surface Treatment of Kraft Wood Fibers by Polymerization Compounding on Properties of Fiber Composites

Treatment of fibers through polymerization compounding not only increases the adhesion between polymer and fibers but also helps to disperse fibers into a viscous matrix with existing equipment. The rheological and mechanical properties of polyethylene composites containing treated wood fibers were studied. Polymerization compounding (PC) was used to graft polyethylene chains on the Kraft wood fibers. Composites containing 20 wt. % treated wood fibers were found to have a Young modulus 37 % larger than that of the polyethylene alone. Scanning electron micrographs suggest a strong interaction between the polymer and the fibers. The complex viscosity of composites containing up to 10 % treated fibers was found to be smaller than that of the polymer matrix and considerably smaller than that of composites containing untreated fibers. The elastic characteristic time based on the ratio of the storage and loss modulus was found be approximately independent of the fiber content and of surface treatment.