Effects of fiber content and its chemical treatment on the mechanical properties of screw pine fiber reinforced vinyl ester composite

Abstract

Natural fiber-reinforced polymer composites have several advantages over traditional composites. The chemical modification of natural fibers helps to develop polymer composites with better mechanical properties. In the present work, mechanical properties such as tensile, flexural, and impact strength of chopped Screw pine fiber reinforced vinyl ester composites have been evaluated under-treated conditions based on the volume fractions of Screw pine fibers. The fibers have been treated with 5% of NaOH solution for 1 h at room temperature. The hand lay-up method has been used to prepare composite plates at room temperature. The results revealed that mechanical properties of composites increased with the increase of the fiber content up to 35.57 vol% at both the untreated and treated conditions and then dropped. However, the modulus values have been increased continuously from the fiber content of 8.43 to 45.3 vol%. It was identified that the critical or optimum fiber content for better mechanical properties is 35.57 vol% for both the untreated and treated conditions. The percentage of improvement at every combination was obtained by comparing the composites prepared with the untreated and treated fibers. The fractured surface of the treated fiber composites was examined by scanning electron microscopy. Moreover, the tensile properties are predicted using the Hirsch and Modified Bowyer and Bader model and compared with experimental values. The predicted results revealed that the Modified Bowyer and Bader model shows better conformity.

Keywords

• screw pine fiber
• vinyl ester
• fiber content
• alkali treatment
• mechanical properties
• scanning electron microscopy