Effect of Strain Rate and Temperature on the Tensile Failure of Pineapple Fiber Reinforced Polyethylene Composites

The dependence of temperature and strain rate on the mechanical properties of pineapple leaf fiber (PALF) reinforced polyethylene (LDPE) composites has been investigated. The effects of fiber loading, fiber orientation, and fiber treatment on the test properties were studied. The tensile strength of the composite was found to be decreased and elongation increased up to 40'C, decreasing thereafter as the temperature was increased from 40 to 80'C. Failure at low temperature and or high strain rate occurred due to brittle matrix fracture, which was evident from SEM micrographs. Activation energy of the failure was calculated using an Arrhenius equation. Failure envelope is generated in order to understand the effect of temperature and strain rate on composite properties. Composites with longitudinally oriented fibers showed higher retention of tensile properties at elevated temperatures. Fibers treated with poly(methylene) poly(phenyl) isocyanate (PMPPIC) showed maximum retention in strength at higher temperature.