Comparing monolayer versus bilayer rotational molded polyethylene storage tanks for long-term biodiesel storage

The present work compared the year-long ageing at 23°C of roto-molded fuel tanks prepared with crosslmked polyethylene versus similar tanks with a polyamide-11 inner liner for their compatibility with biodiesel at different concentrations blended with low sulfur diesel. Analysis of the fuel itself showed few peroxides formed, even after a year. Mechanical properties based on tensile testing found no evidence of oxidative damage occurring with these tanks; however, reducing material stiffness was attributed to fuel absorption. The barrier properties of the polyamide layer meant to resist fuel absorption were not apparent due to sub-micron pores being evident from incomplete sintering.