Environmentally beneficial composites can be made by replacing glass fibres with various types of cellulose fibres. Fibres from pine or
eucalyptus wood and also one-year crops such as coir, sisal, etc. are all good candidates. The poor resistance towards water absorption is one
of the drawbacks of natural fibres/polypropylene composites. New natural fibres/polypropylene composites were made and the water
absorption in them was studied by immersion of the composites in water at three different temperatures, 23, 50 and 70 8C. The process of
absorption of water was found to follow the kinetics and mechanisms described by Fick’s theory. In addition, the diffusivity coefficient was
dependent on the temperature as estimated by means of Arrhenius law. A decrease in tensile properties of the composites was demonstrated,
showing a great loss in mechanical properties of the water-saturated samples compared to the dry samples. The morphology change was
monitored by scanning electron microscopy studies of the samples before and after exposure to water and the devastating effect of water on
the fiber
structure was shown.