An innovative synergy between metal-free click reaction and electrospinning for the fabrication of sustainable castor oil-modified poly (vinyl chloride) cross-linked nanofiber scaffolds

In this study, we present a sustainable strategy to produce cross-linked poly (vinyl chloride) (PVC) nanofibers by combining azide-functionalized PVC (PVC-N, ) with castor oil-based alkyne compounds (CO-Al). A green, metal-free thermal azide-alkyne click reaction was used to create covalently cross-linked networks within electrospun nanofiber mats. Blends containing 5, 10, and 20wt% CO derivatives were successfully processed into uniform, bead-free fibers. Fourier-transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance (1H NMR) confirmed the chemical modifications and network formation. Scanning electron microscopy (SEM) imaging revealed structural uniformity, and solvent tests confirmed the successful cross-linking with complete insolubility. Hydrophilicity increased with higher CO content, and TGA/DSC analysis revealed enhanced thermal stability in cross-linked samples. TGA showed a ∼10 °C increase in thermal decomposition onset after cross-linking, while differential scanning DSC revealed a significant Tg increase from 65.30 °C (non-cross-linked) to 91.75 °C (cross-linked) for the 5wt% CO sample, demonstrating enhanced thermal resistance. Overall, the integration of green, metal-free click chemistry with electrospinning offers a tunable and sustainable route to engineer bio-based, plasticized PVC nanofibers with potential for use in advanced material applications such as filtration, biomedical scaffolds, and eco-friendly packaging.