Optimization of tensile and water absorption properties of biosilica dispersed cardanol oil blended PLA/PCL biocomposite for packaging applications

Abstract

The present research study focuses on optimizing the formulation of (PLA/PCL) polycaprolactone/polylactic acid biocomposite films for durable packaging applications by incorporating cardanol oil and nanosilica. The materials used include PLA pellets (Mw = 207,000 g/mol) and PCL polymer (Mn = 95 kDa). Cardanol oil were utilized as compatibilization and reinforcing agents. Composite films were prepared using a film casting method with varying concentrations of PCL (8, 10, 12 wt.%), cardanol oil (5, 10, 15 wt.%), and nanosilica (1, 3, 5 wt.%) based on the L9 orthogonal design. The produced films, with thicknesses ranging from 85 to 100 microns, were conditioned at 50% relative humidity and 25 °C to stabilize their properties. The key findings reveal that the optimal combination of process parameters, A2B1C3 (10 wt.% PCL, 5 wt.% cardanol oil, and 5 wt.% nanosilica), significantly enhanced the mechanical properties, achieving a tensile strength of 91.47 MPa and hydrophobicity of 95.25°, showing a 2.57% improvement in Grey Relational Grade (GRG). These results underscore the effectiveness of using cardanol oil and nanosilica to improve the compatibility and performance of PLA/PCL blends, providing valuable insights for developing sustainable biocomposite films for packaging applications. The FTIR analysis demonstrated effective compatibility between PLA/PCL and the added components, with distinctive peaks at 2900 cm⁻¹ and 3300 cm⁻¹ indicating CH alkyl bonds and OH phenolic groups, respectively. Morphological analysis using SEM images confirmed a uniform distribution of nanosilica and cardanol oil within the PLA/PCL matrix, which enhanced the composite’s properties, although minor submicron gaps and pits were observed. Unlike previous studies, this did not explore the ideal amounts or combined effects of these additives. This work employs a systematic approach using the Taguchi L9 orthogonal array to determine optimal input process parameters. However, this study has certain limitations like requirement of raw material for mass production of biosilica, and limited properties are studied under optimization in this study. This can be overcome by upcoming research study on this background and more properties studies on this research. Moreover, the natural material influenced biofilm composite can potentially be applied in areas such as food packaging industry, pharmaceutical, biomedical field, etc.