Impact of cellulose enrichment on castor oil polyurethane sheets: A path to greener materials.

Due to the growing concern over the depletion of the global crude oil stock and environmental issues, the replacement of petroleum‐based polymers with environmentally benign alternatives derived from renewable resource has attracted great attention. In the current study, four different polyurethane (PU) sheets were synthesized from unmodified castor oil (CO) and hexamethylene diisocyanate (HDI), incorporating cellulose nanofibers (CNF) as a filler. The mixture consisting molar ratio of CO, HDI, and CNF in a ratio of 1:5:0.8 yielded the best results. This formulation achieved a tensile strength of 22.55 MPa and an elongation at break of 55.9%. Additionally, the resulting PU sheets exhibited excellent thermal properties, with a glass transition temperature (Tg) and melting temperature (Tm) that were notably enhanced, further highlighting the effectiveness of this specific mixture in producing high‐performance, bio‐based PUs. Fourier‐transform infrared spectroscopy (FTIR), thermal, and mechanical characterizations indicated that both reinforced and unreinforced PU exhibited properties within acceptable ranges. Given the bio‐based origins of CO and cellulose, the synthesized polymers are biodegradable and suitable for biomaterial applications. The study confirms that the bio‐based origins of CO and cellulose render synthesized polymers biodegradable, suitable for various biomaterial applications. [ABSTRACT FROM AUTHOR]