Effect of chemical treatment of fibers on the mechanical properties of polyethylene-wood fiber composites

-Linear low-density polyethylene (LLDPE) was reinforced with chemithermomechanical (CTMP) aspen fiber, wood flour, and cellulose flour. Wood fibers were treated with isocyanate or a vinylsilane coupling agent to improve the adhesion between the fiber and polymer. Composites were made at different weight percentages of the fiber. Improvement in the tensile strength was achieved when vinylsilane- or isocyanate-treated fibers were incorporated in the polymer. The tensile modulus remained relatively unaffected by the fiber treatment. The Izod-impact strength (un-notched) decreased at higher concentrations of the wood fiber in the composite. The tensile properties of the LLDPE-wood fiber composites compared favorably with mica and glass fiber reinforcement.