Characterization of Cassava Fiber of Different Genotypes as a Potential Reinforcement Biomaterial for Possible Tissue Engineering Composite Scaffold Application

摘要

Cassava bagasse contains considerable amount of natural single elementary cellulose fibers and white thick root fiber (thick-core fiber) that has seen frequent application in the packaging industry as reinforcement for plastic composite development. However, a review of the literature was unable to find any study that characterized the material properties (such as tensile properties) of both the single elementary and white thick-core cassava cellulose fibers), and their application as potential reinforced filler in tissue engineering scaffold development. In this study, the tensile properties, morphology, crystallinity and thermal degradation profile of non-chemically treated single elementary cellulose fibers and thick-core fibers of different cassava genotypes were investigated. Fibers were tested according to ASTM C1557 under direct tension in a standard mechanical testing system and the cross-sectional area of the fractured regions of the fibers were determined using a 3D optical microscopy method. Cassava fibers of different genotypes did not show any significant difference in tensile properties, with average tensile strength ranging from (5.1-7.3 MPa), Young's modulus (258-333 MPa) and failure strain (3.4-4.2 %). Tensile test conducted for several gage lengths did not influence the tensile strength and Young's modulus of the fibers, however, strain-at-break depended on gage length. Single elementary and thick-core fibers showed similar surface morphology, degree of crystallinity (ranging from 21-40 %) and tensile properties with some variation in elastic modulus. Cassava fibers are thermally stable around 100-200 oC, where processing could be performed. Preliminary results showed an improvement in the mechanical properties of a gelatin scaffold when cassava cellulose microfibers were used as reinforcing fillers. The current findings show that cassava fiber has a reasonable mechanical strength, stiffness and thermal stability, and could be considered as a reinforced biomaterial to improve the mechanical integrity of tissue engineering scaffolds.