Morphological, Structural, Thermal and Mechanical Characterization of Piassava Fibers

Abstract

For the purpose of evaluating the suitability of piassava fiber as reinforcement of polymer matrix (recycled polyethylene), we carried out extensive characterization of morphological, structural, thermal, and mechanical properties of two species of piassava fibers, namely Leopoldinia piassaba (Amazon, Brazil) and Attalea funifera (Bahia, Brazil). Scanning electron microscopy images revealed that each fiber is essentially a composite in which rigid cellulose microfibrils are embedded in a soft lignin and hemicellulose matrix. In addition, the tubular microfibrils are helically wound along the fiber axis forming ultimate hollow cells. An irregularly dimensioned mass, composed mainly of silica, appears on the surface of each fiber. The crystallinity of L. piassaba is found to be inferior to that of A. funifera. On the other hand, thermal analysis shows that both species start to decompose at approximately similar temperature (∼265°C), and that the moisture content in each is approximately 4 to 5%. The mechanical properties correlate well with the fiber diameter. Finally, the L. piassaba, as compared with A. funifera, is softer and more ductile.