Electrospun Fibers Containing Bio-Based Ricinoleic Acid: Effect of Amount and Distribution of Ricinoleic Acid Unit on Antibacterial Properties

Novel bio-based and biodegradable electrospun membranes, containing ricinoleic acid (RA), are prepared. RA units are either randomly copolymerized with butylene succinate (BS) units or introduced in the polymeric systems by blending poly(ricinoleic acid) (PRA) with poly(butylene succinate) (PBS). The chemical, physical and mechanical properties of the membranes are characterized. The Escherichia coli and Staphylococcus aureus mortality rate increases with the PRA amount in the blends,whereas the copolymer shows lower antibacterial activity with respect to the blend with similar composition. X-ray Photoelectron Spectroscopy (XPS) analyses show that the blends are characterized by an enrichment of RA units at the fiber surface occurredduring electrospinning, while in the copolymer RA units are homogeneously dispersed along fiber cross-section. Moreover, the17 surface concentration of units decreases in the blends after repeated cycles with bacteria due to macromolecular rearrangement and mixing of PBS and PRA components. The obtained antibacterial membranes can find useful environmental applications.