Impact of Chitosan Incorporation on <scp>PBAT</scp> Composite: Thermal, Viscoelastic, Mechanical, and Morphological Properties

ABSTRACT This study examines the effect of chitosan loadings of 10, 20, 30 wt.% on the thermal, viscoelastic, mechanical, and morphological properties of polybutylene adipate terephthalate (PBAT) composites produced via melt mixing and compression moulding. Tensile, Dynamic Mechanical Analysis (DMA), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Scanning Electron Microscopy (SEM), and Fourier transform infrared spectroscopy analyses (FTIR) were conducted according to ASTM standards. The tensile modulus increased significantly from 102.76 MPa for neat PBAT to 325.17 MPa for the 30 wt.% PBAT/Chitosan composite, indicating improved stiffness due to rigid filler incorporation. However, tensile strength and elongation at break decreased from 8.26 MPa and 172.37% for neat PBAT to 3.84 MPa and 20.02%, respectively, for the 30 wt.% composite because of poor interfacial compatibility and stress concentration effects. DMA demonstrated increased storage modulus with increasing chitosan content, suggesting enhanced rigidity and restricted molecular mobility. TGA analysis revealed a reduction in onset degradation temperature after chitosan addition, attributed to the lower thermal stability and hygroscopic nature of chitosan. SEM observations showed relatively uniform filler dispersion with evidence of particle pull‐out and microvoid formation at higher filler loadings. FTIR analysis suggested intermolecular interactions between PBAT and chitosan through hydroxyl and carbonyl functional groups.