Synergistic effects of terpolymer and its oleic modified nano-bentonite nanocomposite for cold flow enhancement for diesel fuel

Abstract

Abstract The defect in the properties of diesel fuel at low temperatures, caused by wax crystallization and agglomeration, negatively impacts engine performance at these temperatures. This work synthesizes and evaluates modified new terpolymeric additives, hexadecylacrylate-octyoleate-hexadecene (TPO), and its nanonentonite (NTPO), as depressants for the pour point of the diesel fuel (PPDs) and cold flow improvers. These polymers were synthesized using the prepared esters of hexadecylacrylate and octyoleate with 1-hexadecene by adding 1% modified nano-bentonite with oleic acid (NB-OL) for NTPO. The additives were characterized using FT-IR, 1 H NMR, GPC, TEM, EDX, and DLS to analyze their structural and morphological properties. The thermal degradation was also studied through TGA and DSC to prove the synergistic effect of the NTPO, while a polarized optical microscope was used to analyze wax crystal shape to show tiny and dispersant wax at NTPO. Diesel fuel treated with TPO and NTPO was tested for pour point, viscosity, and cold flow behavior using ASTM standard methods. Results demonstrated that TPO reduced the pour point by up to 24 °C, while NTPO achieved a 30 °C reduction, significantly improving low-temperature flow performance compared to conventional PPDs. The Viscosity index was increased from 116 to 120.3 and 126.85 for both TPO and NTPO. The enhanced efficiency of NTPO was attributed to the synergistic effect between the polymer matrix and nanobentonite (NB-OL), which effectively inhibited wax crystal growth and modified crystal morphology. This study presents a promising approach for developing high-performance, cost-effective additives to enhance diesel fuel operability in cold environments.