Morphological and physicomechanical characterization of synthetic and natural fibers.

Green and renewable materials are becoming promising worldwide. Here, we compared morphological and mechanical strength characteristics of natural plant-based bast fibers (flax, hemp and nettle) with those of synthesized fibers (glass, basalt, carbon, polyacrylonitrile (PAN), polycaproamide (PCA) and viscose). The industrial bast fibers from hemp and nettle were extracted by chemical treatment with a sodium carbonate solution. The natural fibers were comparable in size to the synthetic ones. The PCA fibers had the largest diameter of 23–28 µm. The carbon monofiber had the lowest diameter of 7–8 µm. The dimension of the natural elementary fibers was 10–25 µm. The natural fibers had a better interfacial bonding to an epoxy matrix than PCA. Moreover, the specific strength of the unimpregnated and epoxy-impregnated fibers was determined. The natural fibers were superior in strength performance to some of synthetic fibers (viscose), while the specific strength of the impregnated flax fiber was commensurate with that of the impregnated PAN and PCA fibers. The specific strength of the flax and hemp fibers once impregnated with the matrix increased four- and twofold, respectively. The impregnated flax fibers exhibited the best mechanical strength behavior among the hemp and nettle bast fibers. The natural fibers are biodegradable, have a low density, and are more eco-benign than the mineral fibers. The selected natural fibers can be used to fabricate composites therefrom. [ABSTRACT FROM AUTHOR]