Green Nanocomposites of <scp>PLA</scp> / <scp>PBAT</scp> Reinforced With Fe ₃ O ₄ and <scp>GNP</scp> : <scp>EMI</scp> Shielding, Mechanical, Thermal, and Morphological Analysis

ABSTRACT This study focuses on the bio‐based green nanocomposites formed by melt‐mixing PLA and PBAT in a 70/30 weight ratio, with Fe 3 O 4 and Graphene Nanoplatelets (GNP) as the nanoparticles. Reinforcement with Fe 3 O 4 (3, 5, and 7 phr), GNP (3, 5, and 7 phr), and their hybrid was used to evaluate improvements in electromagnetic interference shielding effectiveness (EMI SE), thermal, mechanical, and morphological properties of the PLA/PBAT system. GNP 7 phr and hybrid 7 phr show high SE, primarily from absorption due to magnetic dipoles in Fe 3 O 4 based and interfacial polarization in GNP based nanocomposites. The 70/30 blend shows a tensile strength of 31 MPa and elongation of 4.6%, while the nanocomposites range from 22 to 30 MPa and 2%–3.2%, respectively—except for 3 phr Fe 3 O 4 , which reaches 35 MPa and 2.7%. However, in fracture toughness, the critical stress intensity factor (K IC ) increased from 1.56 to 5.7 MPa.m 0.5 and strain energy release rate per unit area (G IC ) increased from 1.68 to 18.39 kJ/m 2 for the 70/30 to 3 phr hybrid. XRD confirms Fe 3 O 4 phase retention in nanocomposites. TGA shows improved thermal stability for GNP and the hybrid composition. SEM evaluated PBAT dispersion in PLA, and FTIR showed no chemical interaction between the materials.