Thermal stability and degradation kinetics of PVC/PEO nanocomposites incorporating CoFe2O4 nanoparticles

Abstract The thermal stability of PVC/PEO blends critically determines their utility in flexible electronics and sustainable packaging, yet their degradation pathways remain challenging to control. To address this, CoFe 2 O 4 nanoparticles were synthesized via an auto-combustion method and incorporated (1 wt%) into a PVC/PEO (75:25) matrix using the casting method. Structural characterization by XRD confirmed the formation of pure spinel-phase CoFe 2 O 4 nanoparticles with an average crystallite size of ~ 24.6 nm. Optical analysis revealed that nanoparticle incorporation reduced the band gap from 4.22 to 3.75 eV, suggesting localized state formation at the polymer–nanoparticle interface. FTIR spectroscopy confirmed strong molecular interactions between PVC and PEO, further modified by nanofiller incorporation. Contrary to most conventional nanofillers, CoFe 2 O 4 decreased thermal stability in the 200–350 °C range. Kinetic analysis using the KAS, FWO, and Friedman methods showed slightly lower activation energies for the nanocomposite. Master plot analysis revealed a mechanistic shift from diffusion-controlled (D2) degradation in the pure blend to (D2/L2) of diffusion and random scission in the nanocomposite, highlighting the role of CoFe 2 O 4 in altering degradation pathways.