Effect of fibre loading and Ca(OH)₂ treatment on thermal, mechanical, and physical properties of pineapple leaf fibre/polyester reinforced composites

This research work investigated the use of calcium hydroxide (Ca(OH)₂) as a fibre treatment technique for pineapple leaf fibre (PALF) and their effect on mechanical, physical, free vibration analysis, dynamic mechanical analysis, and morphological properties of PALF reinforced polyester (PE) composites at different fibre loading. Fibre treatment with 1 M Ca(OH)₂ solution led to the removal of hemicellulose and lignin as noted by the disappearance of the corresponding characteristic peaks from the Fourier-transform infrared analysis (FTIR) and increase in the degree of crystallinity from the x-ray diffraction (XRD) analysis. The treated fibre composites given the maximum impact strength of 59.27 J m^-1 observed for 35 wt% composite. The void content of treated composites decreased by 6.26% and 22.33% at 25 wt% and 35 wt% fibre loading, respectively. The dynamic mechanical properties such as storage modulus and loss modulus increased with the fibre loading from 25 wt%-45 wt% for the treated composites. Both the storage modulus and loss modulus were maximum for the treated composites at 45 wt%. Similarly, the lowest tan delta peak was recorded for the treated composites at 45 wt% followed by the 35 wt% and 25 wt%. The developed composites with Ca(OH)₂ treated fibres also possessed superior vibration damping characteristic.