Fibras de carbono a partir de lignina: Uma revisão da literatura

Abstract

The most applied precursors to obtain carbon fiber are polyacrylonitrile, pitch and rayon. With the increased demand of lightweight composites and high strength, carbon fiber manufacting has increased exponentially and new precursors are been request. Lignin, a natural organic material, has been studied as possible candi-date. Besides being an industrial and biorrefinary waste, lignin-based carbon fibers have a lower cost com-pared to other commercial precursors. Because of the biodiversity of plants in nature, lignin can present dif-ferent structures. The lignin extraction method can directly influence the composition. As thermic extrusion properties are hardly dependent on this and other properties, many researches have been reported using pure lignin from different sources, modified lignin and plasticizers addiction. Steps of pretreatment, thermostabili-zation and carbonization/graphitization have also been evaluated to give better mechanical properties to the final product. Nevertheless many conditions required to manufacture lignin-based carbon fiber, promising results have been achieved. The set of mechanical properties inherent to the fiber allows its application to different areas. Lignin-based carbon comes to collaborate on cheapening its production, minimizing the de-pendence of fossil materials and making its manufacture process ecologically sustainable.