Natural fi ber-reinforced bio-based polymer composites: A bright perspective of eco-friendliness, cost reduction and broader utilization

Bioplastic, polymers that are biodegradable or based on bio-feedstocks, are considered as potential alternatives to conventional petroleum-based polymers since the latter have triggered concerns in terms of environmental contamination and greenhouse gas emissions. Due to increasing restricted availability of petrochemical resources, bioplastics have become strongly interesting for the public, research and plastic industries. Biodegradable polymers have many other desirable properties such as biocompatibility, chemical inertness and low toxicity. In this regard, polylactic acid (PLA) has been the frontrunner among many commercially biopolymers because of its outstanding physical and mechanical properties, good transparency, glossy appearance and high rigidity (for isomer of poly D-lactic acid). Its processing possibilities are very wide ranging from injection molding and extrusion over cast film extrusion to blow molding and thermoforming. It has some shortcomings as well, for example inherent brittleness, high rate of crystallization, sensitivity to thermal degradation, low-impact strength and poor toughness. By blending bio-based polymers with both synthetic and natural fibers as well as nanoparticles to create a composite, the overall mechanical and degradation properties can be improved. However, the natural fibers (such as wood fiber) serve as good reinforcements and fillers in biocomposites for several reasons including low cost, fewer health hazards during processing, less abrasiveness to processing equipment, and good thermal properties. There is an increasing attention in research and development of fully biodegradable composites with the combination of PLA and natural plant fibers due to their good processability, renewability, recyclability, sustainability, reduced processing costs and reduced costs of waste disposal after service. This will guarantee a viable future for a variety of applications of the natural fiber-reinforced PLA composites.

Biopolymer, fiber, composite, eco-friendliness