Mechanical, Thermal, and Barrier Property Studies of Polylactic Acid Composite Blown Films with Nanohydroxyapatite as a Filler Derived from Pink Perch Fish Scales

The present study focuses on improving the flexibility of PLA by reinforcing it with a nanohydroxyapatite (n-HAp) filler. The n-HAp was synthesized via pink perch fish scales (PPFS) using a simple and feasible pyrolysis method and was characterized using XRD, FTIR, Raman spectroscopy, TGA, SEM, and TEM. n-Hap of 0.25, 0.5, 0.75, and 1 wt % was used to reinforce the PLA matrix, and PLA_HAp composite blown films were extruded for further studies. The PLA_HAp composite blown films were characterized by using XRD, FTIR, Raman spectroscopy, and SEM to understand the interaction of the n-HAP in the PLA matrix. The thermal and mechanical analyses of the PLA_HAp blown films reveal that a low concentration of n-HAp can reduce the thermal stability and improve the flexibility of the films. The thermal characterizations infer that n-HAp in PLA acts as a nucleating center in the PLA backbone to improve the flexibility of films. Tensile results show that PLA_HAp 0.5 exhibited maximum flexibility with elongation at break of 20%, which is a 400% enhancement compared to neat PLA. The WVTR analysis of PLA-HAp composites, compared to neat PLA blown films, revealed a reduction in water permeability by 56% for PLA_HAp 0.5 and 66% for PLA_HAp 1 under ambient conditions, making them suitable for food packaging applications.