Valorization of Banana Peel Waste Used as Filler in Castor Oil Polyurethane Foam for Vegetal Oil Sorption

This research describes the influence of fiber content from the banana peel waste used as a filler in castor oil polyurethane foam (PU), obtaining eco-sorbent for vegetal oil sorption. Biocomposites were prepared with banana peel waste (BP) in different content: 0, 5, 10, 15, and 20 wt.%, to improve the oil sorption capacity (system PU/BP-oil). Results indicated that banana peel waste was hydrogen-bonded to PU chains, increasing the foams' density and decreasing the pore size with an increase in fiber content, from 444 to 123 mu m. The addition of fibers from banana peel to PU maintained the foams' hydrophobicity and decreased the foams' crystallinity. Compared to pure PU, the biocomposites showed greater thermal stability (Tonset from 247.6 to 264 degrees C). All modified foams improved vegetal oil sorption capacity, but PU/BP20% presented better sorption capacity due to high pore size, which directly influenced the oil sorption. The response surface methodology (RSM) technique confirmed the influence of content fibers and oil sorption time.