A comparative study of the mechanical properties of hemp fiber with virgin and recycled high density polyethylene matrix

Abstract

Hemp reinforced composites were prepared using both recycled high density polyethylene (rHDPE) and virgin high density polyethylene (vHDPE). The effects of fiber loading and the different type of matrix on the composites’ mechanical and thermo-mechanical properties were studied. Prior to composite fabrication, hemp fibers were treated with 5wt% NaOH. The change in surface morphology and chemical composition of hemp fibers after treatment was analyzed by scanning electron microscope and Fourier transform infrared spectroscopy. Findings indicate that a 5wt% NaOH treatment effectively improved the fiber–matrix interface resulting in improved mechanical properties. With respect to both, mechanical and thermo-mechanical properties, hemp fiber composites with rHDPE matrix performed better than composites with vHDPE matrix. The optimized fiber loading of hemp–rHDPE was 40% volume fraction while achieving the highest tensile strength of 60.2MPa and flexural strength of 44.6MPa. The hemp–rHDPE composites with 30% of fiber loading demonstrated the best impact strength of 51.1KJ/m2.