Mechanical properties of randomly oriented short Sansevieria cylindrica fibre/polyester composites

Abstract

The tensile, flexural and impact properties of randomly oriented short Sansevieria cylindrica fibre/polyester (SCFP) composites are described for the first time in this work. Composites were fabricated using raw S. cylindrica fibres (SCFs) with varying fibre lengths and weight percents of fibre. When the length of the SCFs was increased, the tensile, flexural and impact properties of the composite were increased up to a 30-mm fibre length, and then a curtailment in properties occurred for higher fibre length composites. SCFP composites showed a regular trend of an increase in properties with fibre weight percent until 40% and afterwards a decrease in properties for composites with greater fibre weight percent. Tensile tests revealed that the tensile strength was about 76MPa, the Young’s modulus was 1.1GPa and the elongation at break was between 7% and 8.3%. The flexural strength and modulus were estimated to be around 84MPa and 3GPa, respectively. Impact tests exhibited a strength of approximately 9.5J/cm2. The analysis of the tensile, flexural and impact properties of short SCFP composites displayed a critical fibre length and optimum fibre weight percent of 30mm and 40%, respectively. Scanning electron microscope (SEM) studies were carried out to evaluate the fibre/matrix interactions. The experimental tensile strengths were compared with the theoretical predictions and found to be in good agreement with Hirsch’s model. An X-ray diffraction (XRD) analysis of the composites exposed the presence of cellulose IV with a crystallinity index of 60% and crystallite size of 68nm.