Development of biocomposites from coir fibre and poly (caprolactone) by solvent casting technique

In this study, blends of poly (caprolactone) (PCL) with different content of coir fibre (CF) (2, 2.5 and 5 wt%) were fabricated by solvent casting technique to obtain a biodegradable composite. The PCL/CF composites obtained have been characterised using the X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and Electrodynamic fatigue testing machines. According to XRD patterns, the intensity of the peak in the pure PCL spectrum was found to decrease by the addition of coir fibre which then disappears when the CF content is 5 wt% is indicating that coir fibre inhibited the diffusion and deposition of PCL molecules. The FTIR absorption spectra for the PCL/CF blends showed that there was no new peak to represent the chemical interaction between the functional groups of coir fibre and poly (caprolactone). The SEM micrographs of the composites indicate inadequate wetting of coir fibre as filler content increases due to poor dispersion and interfacial adhesion. The tensile strength of the composites samples was found to increase with an increase in the fibre content up to 2.5 wt% on addition of coir fibre but with a reduction from 16.79 N/mm² for the neat polymer to 5.08 N/mm² for the blend with 5 wt% coir fibre (a 69.74% decrease). The addition of coir fibre reduces the elongation at break of the composites, whereas the Young modulus value of composites goes on increasing up to 182 N/mm² for coir fibres volume fraction of 2.5 wt%. The behaviour of samples with high fibre content could be explained by insufficient fibre wetting and poor interfacial adhesion with no coupling agent in addition to the low aspect ratio of the coir particles.