Degradation mechanisms of curaua, hemp, and sisal fibers exposed to elevated temperatures

Abstract

The influence of elevated temperatures on mechanical behavior was studied for curaua, hemp, and sisal natural fibers. Tensile tests were performed on fibers heated at 100 °C, 150 °C, and 200 °C for 24 h, and reference samples were maintained without thermal treatment for comparisons. The cross sectional area of the fibers was measured using a scanning electron microscope (SEM), and the image analysis was performed using the open source software Fiji/ImageJ. These data allowed the computation of the tensile stresses and the correlation of the fiber morphology with its macro-mechanical behavior. The thermal degradation behavior of the natural fibers was measured via thermo-gravimetric analysis (TGA) and X-ray diffraction (XRD). The morphological and mechanical characteristics were described and discussed on a microstructural basis. The results showed that the loss of moisture leads to a significant increase in tensile strength before reaching the limits of the degradation range.

Physical-Chemical and Mechanical Characterization of the Bast Fibers of <i>Triumfetta cordifolia</i> A.Rich. from the Equatorial Region of Cameroon

“…The results of the thermogravimetric analysis (TGA) of the fiber under study give us the TG-DTG curves in Figure 4. and is the locus of thermal stability of the fiber [33]. A further loss of mass will occur above 235˚C (46.02%), due to the decomposition of the less thermally stable elements such as non-structural hemicelluloses [21] [32] [34], fats and waxes [35].…”

“…A further loss of mass will occur above 235˚C (46.02%), due to the decomposition of the less thermally stable elements such as non-structural hemicelluloses [21] [32] [34], fats and waxes [35]. The inflection point observed at about 336˚C, (loss of mass of about 43%), would correspond to the destruction of part of the constituents (cellulose in particular and the oxidative degradation of carbonized residues) [33].…”

Drilling of natural fiber-reinforced based polyurethane foam composite

“…Although the mechanical properties may vary according to factors such as plant origin and production process, sisal fibers are more resistant to shearing than pine fibers. 32,33 According to Rodrigues Pereira de Paula et al, 28 the best accommodation and occupation of empty spaces of the pine sawdust during the expansion of the foam are due to their smaller dimensions and lighter weight. The larger sisal fibers interfered with the homogeneous distribution in the material and remain accumulated and with loose ends inside the foam bubbles.…”

“…39 Pinus taeda and sisal fibers start their degradation around 100°C, depending on fiber composition and origin. 32,40 The maximum temperature measured during the drilling tests did not exceed 40°C; therefore, the material properties were not compromised and there was no adhesion of the workpiece on the cutting tool. Ref.…”

On the mechanical properties and crack pattern analysis of a strain-hardening cement-based composite reinforced by natural sisal fibers

“…The fibers were received in bundles, measuring approximately one meter in length, and were manually brushed to detangle them. Different from the other authors that also used natural fibers [30,32,43,50], the sisal fibers were not washed in warm water. In this experiment, just brushing and cutting in the demanded length were executed.…”