Kenaf (Hibiscus cannnabinus) is a fast growing annual growth plant tha
t is harvested for its bast fibers. These fibers have excellent specif
ic properties and have potential to be outstanding reinforcing fillers
in plastics. In our experiments, the fibers and polypropylene (PP) we
re blended in a thermokinetic mixer and then injection molded, with th
e fiber weight fractions varying to 60%. A maleated polypropylene was
used to improve the interaction and adhesion between the nonpolar matr
ix and the polar lignocellulosic fibers. The specific tensile and flex
ural moduli of a 50% by weight (39% by volume) of kenaf-PP composite c
ompare favorably with a 40% by weight of glass fiber-PP injection-mold
ed composite. These results suggest that kenaf fibers are a viable alt
ernative to inorganic/mineral-based reinforcing fibers as long as the
right processing conditions are used and they are used in applications
where the higher water absorption is not critical.