Investigation of coconut-periwinkle shell bio-composites for alternate thermal insulation application

Periwinkle and coconut shells are becoming increasingly popular as dielectric materials with thermal insulation properties. Natural sources of synthesis could provide a cheaper and more ecologically friendly alternative to chemically synthesizing such compounds as thermal insulators or fillers in polymer composites. The utilization of a fine powder made from periwinkle shell and coconut shell composites as an alternative filler for composite materials and as a thermal insulation material was investigated in this study. Cleaning, oven drying, and milling of the components resulted in bio composite powder particles. X-ray fluorescence, scanning electron microscopy (SEM), X-ray diffraction (XRD), and thermal conductivity measurements were used to characterize the powders. CaO is the most abundant metallic oxide in the powder, accounting for 81.8 wt %, according to XRF. For coconut shell, periwinkle shell, and coconut-periwinkle shell composite materials, the average grain size from SEM examination is 4.88 µm, 6.37 µm, and 11.04 µm respectively. The creation of a polycrystalline film can be seen in the XRD patterns of periwinkle shell powder and composites of periwinkle and coconut shell powders, but the XRD pattern of coconut shell is amorphous. The thermal conductance of the composite material is 21.18 Wm^-1 k^-1, which is higher than TiO₂ and SiO₂, which are often employed as fillers in polymeric materials insulation. This shows that, in comparison to polymer composites containing TiO₂ and SiO₂, the composite material could yield insulating materials with improved thermal conductivity characteristics, enhancing the growing waste to wealth concept.