【Frontiers in HaiChuan Technology】Shandong University of Technology has developed modified polyurethane foam based on lignin polyols, which exhibits superior oil absorption compared to standard foam

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Polyurethane foam can be used to clean up crude oil spills without the need for on-site burning or the use of dispersant chemicals. Now, scientists at Shandong University of Technology have developed a modified polyurethane foam based on lignin polyols, which has an improved oil-absorbing capacity compared to standard foams. First, they prepared lignin-based polyurethane foam using a one-pot method, and then modified the foam by using octadecyltrimethoxysilane (OTMS) to enhance its superhydrophobic and photothermal properties. This reduces the surface energy of the foam, thereby producing a foam with superhydrophobic properties. It has been proven that this foam is highly effective at adsorbing several different organic solvents, with a maximum adsorption capacity of 20 grams per gram, and an oil-water separation efficiency of over 97%. They found that sunlight can raise the surface temperature very rapidly—a intensity of 1 kilowatt per square meter can raise the temperature to nearly 80°C within six minutes. This significantly reduced the viscosity of the crude oil on the foam surface, increasing the adsorption rate. Another favorable finding is that lignin-based polyurethane foam possesses self-cleaning properties, as it can be completely degraded after being immersed in an alkaline solution for five hours. This foam also exhibits good elastic recovery properties; after 10 cycles of adsorption and desorption, its adsorption capacity decreased by only 1.5%. Therefore, this foam can be reused multiple times. Researchers believe this new type of foam has the potential to become an effective oil removal tool. It can also provide new ways to use cheap renewable resources—lignin waste—to replace petroleum-based raw materials. They are currently researching how to reduce costs by lowering energy consumption in the manufacturing process.