Temperature-duration effects on tensile properties of kenaf bast fiber bundles

This paper investigated heat and duration effects on the tensile properties of kenaf bast fiber bundles (KBFB) as potential reinforced fibers for polymer composites in automotive structural part applications. A complete two-factor factorial experiment performed in this study includes five temperature levels from 110 to 190 degrees C with an increment of 20 degrees C and three levels of heat duration times three, six, and 9 hours. Results of the analysis of variance of experimental data showed a significant temperature-duration interaction effect on tensile modulus and a marginally significant temperature-duration interaction effect oil tensile strength at the 10 percent significance level, while the only significant temperature effect was on failure strain. A significant decrease in tensile modulus occurred when temperature increased from 170 to 190 degrees C. The decline in tensile modulus was 39 percent, 47 percent, and 55 percent for three, six, and 9 hour duration respectively. There was no significant change in KBFB stiffness as the temperature increased from 110 to 170 degrees C. The tensile strength declined as the temperature increased, and different declining behaviors were among three heat durations. Significant drops in the KBFB tensile strength started at 190 degrees C, 190 degrees C, and 170 degrees C for each of three durations 3, 6, and 9 hours, respectively. The KBFB failure strain decreased as the temperature increased. Duration showed no significant effect on tensile properties of KBFBs at the temperature 130 degrees C and above.