POLYMER BIOCOMPOSITES BASED ON AGRO WASTE: PART I. SOURCE, CLASSIFICATION, CHEMICAL COMPOSITION AND TREATMENT METHODS OF LIGNOCELLULOSIC NATURAL FIBERS

Abstract

At present, the depletion of natural resources and environmental problems have generated great interest in finding a sustainable alternative to create new materials that are environmentally friendly. In recent years, many researchers have focused on investigations related to agricultural waste products to solve environmental problems associated with the disposal of agro waste. Thanks to their annual renewability and biodegradability, over the past two decades, agricultural waste has become an environmentally friendly alternative to synthetic fibers. In this regard, this review gives a general idea of new lignocellulosic polymer composite materials in which various natural fibers are used as fillers and reinforcing additives. The sources, classification and chemical composition of lignocellulosic natural fibers have been also given. Natural fibers include a hydroxyl functional group that makes the fibers hydrophilic. Hydrophilic natural fibers and hydrophobic polymer matrix lead to incompatibility and weak interfacial bonds between them. To resolve the problem of incompatibility of plant fibers with non-polar polymer matrices, various methods of surface treatment of natural fibers, including physical, chemical and biological processing, have been considered. From this perspective, in our opinion, the data presented in this article can be used as a database for further study of agricultural waste as fillers or reinforcing additives in polymer composites in order to accelerate the development and stimulate the commercial production of these new materials.