Natural fiber-reinforced polymers come back

Plant fibers are now increasingly often used to reinforce polymers. The accessibility, renew ability, low price and low density of the fibers make them a competitive counterpart of glass fibers in reinforcing of polymers. Composites reinforced with natural fibers are less burdensome to the environment than those reinforced with glass fibers. The chemical structure and physical structure of natural fibers and the techniques to make polymer composites with natural fibers are described. Modification (especially chemical) is described, intended to improve natural fiber-reinforced composites, primarily to reduce water regain, to improve adhesion to polymer matrix (with adhesion promoters like silanes or grafted polypropylene-maleic anhydride copolymers) and to improve impact strength.