Biobased Derivatives From Olive Oil for Tuning Physically Crosslinked Poly(Vinyl Alcohol) Hydrogel Properties

Vegetable oils, commonly discarded by kitchens and restaurants, comprise unsaturated triglycerides, and the double bonds present in triglyceride units can be readily converted into interesting precursors through various synthetic methods. In this contribution, we present a straightforward chemical methodology for the revalorization of cooking oil, towards using waste vegetable oil as a source to produce new building blocks for various applications. Specifically, the epoxidation of olive oil primarily yields an epoxidized oil derivative. This same epoxidation pathway can be applied to generate hydroxylated derivatives, such as diols.

These oil-based derivatives were then incorporated into the formulation of physically crosslinked PVA hydrogels. Notably, hydrogels containing a 5 wt% diol derivative exhibited the highest compressive Young's modulus, suggesting a significant interaction between PVA and the diol.

Although no apparent changes were observed in the spectroscopic response of the PVA-based hydrogels, molecular dynamics simulations indicated a profound interaction between PVA and diol molecules. Additionally, all synthesized PVA-based hydrogels demonstrated a bacteriostatic effect against L. monocytogenes, compared to pristine PVA hydrogel. This suggests that PVA-based hydrogels containing olive oil derivatives could have promising applications in various fields, including the tailored control of diol structures to modulate not only the mechanical properties of the hydrogels but also their antibacterial properties