The production of polymer composites comprising of lignocelluloses (LC) fibers will often result in fibers physically dispersed in the polymeric matrix. But in most of the cases, poor adhesion and consequently inadequate mechanical properties re­sult. Hence, surface treatment of the fibers will play a vital role. Generally surface treatment of LC fibers is not required to develop the bonding for the synthesis of biopolymer based composites, in view of the comparable chemical scenery of both the biofiber and biopolymer matrix, which have a hydrophilic nature, unlike the situation with commodity polymers, which have a tendency to be hydrophobic. To improve many specific aspects, such as providing greater adhesion and reduced moisture sensitivity, surface treatment can be useful even in the case of biodegrad­able composites. Although better adhesion between the biopolymers and fibers is contributed by the similar polarities of the two materials yet these results in an increase in water absorption of the composite. Hence, these fibers require suitable surface treatments.

Surface treatment normally involves one of four methods, namely chemical, physical, physical-chemical and physical-mechanical. Chemical methods involve treatment with silanes or other chemicals through chemical functionalization reac­tions and leaching of the surface through alkali or bleaching.109 Physical methods involve treatment by plasma, corona, laser or y-ray and subjected to steam explo­sion.110 Steam explosion process, a high pressure steaming, involves heating of LC materials at high temperatures and pressures followed by mechanical disruption of the pretreated material by violent discharge (explosion) into a collecting tank.111 Mechanical methods involve rolling or swaging and those may damage the fibers. Finally, physical-chemical methods involve solvent extraction of surface gums and other soluble components of the fibers. As an alternative to the methods described above, drying of LC fibers may be an effective process for surface modification, both in terms of cost and improvement in properties.112 It should be noted that all the above mentioned treatments of LC fibers have helped to improve their interac­tion with the matrix materials, increase adhesion of fibers with the matrix through surface roughness of fiber, leading to increased strength or other properties of com­posites through higher fiber incorporation and possibly providing greater durability of the composites.