MECHANICAL-PROPERTIES OF SISAL FIBER AT ELEVATED-TEMPERATURES

Sisal fibres extracted from the leaves of-Agava sisalana plants 3, 5, 7 and 9 years old were tested at different temperatures for tensile st rength, elongation, toughness and modulus. The tensile strength, modul us and toughness values of sisal fibre decreased with increase in temp erature. The effect of plant age on tensile strength, tensile modulus and toughness of sisal fibre became very much less at 100-degrees-C as compared to 30-degrees-C. Fractured fibres were observed by using a s canning electron microscope. The ends of fibres fractured at elevated temperature showed a failure similar to that of inorganic fibres. Elon gation values at all temperatures increased with age. Elongated capill aries were observed in fibres fractured at 80 and 100-degrees-C, due t o the removal of moisture and volatiles originally present in the fibr es. The fibrils are clearly observed in the form of hollow cylinders. Fractured surfaces are composed of brittle as well as ductile phases. The ductile portion increased with the increase of temperature.