Surface modification of natural fibers in polymer composites

Over the past few years, fibrous materials have found widespread applications in different technological areas including the automotive industry due to their versatile properties. Natural fibers, in particular, are cheap, abundant, biocompatible, and biodegradable, which has motivated many researchers worldwide to explore their potential applications in various industrial sectors. Nevertheless, these types of fibers show some limitations such as high moisture absorption and subsequent swelling and degradation, poor fire resistance, nonhomogeneity of their mechanical properties and poor interfacial interactions with polymeric or cementitious matrices. The fibers surface functionalization using different approaches like physical, chemical, or biological could be the solution to overcome most of the drawbacks related to the use of natural fibers, especially the compatibility between the fiber and the polymeric matrix. Herein, a detailed description of the techniques commonly employed in the modification of natural cellulose fibers will be presented. Several examples will also be shown regarding the application of these natural fibers in polymer composites for possible use in automotive applications.