Coconut Shell Derived Carbon Reinforced Polymer Composite Films for Packaging Applications

With the advancement toward global sustainability, there is a widespread demand for sustainable materials that can be used for various applications. Carbon has gained much attention in the past few decades due to its scope of utilization in energy and environment related applications. Biomass resources are considered a prominent precursor for the synthesis of carbon-based materials due to their availability and economic viability. In this study, high-quality graphitic carbon is synthesized from Coconut Shell Powder (CSP) by pyrolysis and reinforced into a low-density polyethylene (LDPE) matrix for fabricating films for packaging applications. A custom-built high-temperature autogenic pressure reactor was used for conducting the pyrolysis to synthesize carbon from the coconut shell powder and a blown film extruder was used for fabricating composite films. For preparing the films, coconut shell powder-derived carbon was added to the LDPE matrix at various weight percent loadings of 0.25, 0.5, and 1 wt.%, respectively. Various analytical techniques such as scanning electron microscopy, X-ray diffraction, Raman spectroscopy, thermogravimetric analysis, tensile test, and differential scanning calorimetry were used for studying the properties of carbon and LDPE/carbon composite films. Upon adding carbon as fillers, there were significant improvements in the tensile and thermal degradation properties of the polymer carbon composite films. Upon the incorporation of carbon into the LDPE matrix, the crystallinity and tensile strength were found to improve by a maximum of 29% and 13%, respectively.

Keywords: Biochar, Blow Films, Coconut Shell Powder, Film Extrusion, Food Packaging, LDPE, Low-density polyethylene, Raman, SEM, XRD.