Comportamento morfológico e mecânico de fibras de coco tratadas superficialmente e de mantas de fibra de coco

Abstract

Natural fibers has recently gained attention due to low environmental impact, low cost and easy availability. Morphological and mechanical investigations on Brazilian coconut fibers in four different surface conditions (as received; dried; chemically treated by NaOH; chemically treated by NaOH followed by heating) and coconut fiber mats manufactured by compression were used in this study. Scanning Electron Microscopy (SEM) were used to morphological analysis and in-situ mechanical testing uniaxial traction were used. SEM analysis showed the chemically treated coconut fibers have sharper external cell walls and circular particles with diameters of approximately 10 μm. Chemical treatment altered the external wall of coconut fibers; on one of the samples were seen microcracks order 7 to 60 μm due to the treatment followed by heating. The initial modulus (modulus of elasticity) and tensile strength decreased with increasing diameter for the four conditions of coconut fibers. The geometry and the weight of the coconut fiber mats influenced their mechanical behavior.