Performance of castor oil polyurethane resin in composite with the piassava fibers residue from the Amazon.

Abstract

The intensive global environmental changes have motivated researchers to follow new routes to reuse or recycle waste. Castor oil for producing polyurethanes is one of the most viable routes for resin production. This study combined castor oil resin-based with the piassava fibers waste generated by the industry. Higher content of mercerized piassaba fibers (10 mm, 85 wt.%) reinforced polyurethane castor oil-based resin, resulting in composite boards. Characterizations included FTIR, TGA, DSC, FTIR, DMA, and SEM analyses. Piassaba fibers, after alkaline treatment, present excellent performance reported by physical characterization for all composites, highlighting the CP3 sample with higher density and lower swelling and water absorption percentage than other composites. FTIR results indicated NCO traces after the resin cured in the PU3, possibly contributing to the interaction with the fibers. DMA results reported relevant information about more flexibility to CP1 and CP3 than CP2. This study suggests that the proper combination with natural products must lead to composites with potential applications as engineering materials.