Green fabrication of flexible aerogels from polypropylene fibers for heat insulation and oil/water separation

For the first time, hydrophobic polymer-based aerogels have been developed from polypropylene fibers for heat insulation and oil spill treatments. By physically cross-linking polypropylene fibers with non-toxic polyvinyl alcohol and carboxymethyl cellulose, followed by eco-friendly freeze-drying method, the fabricated aerogels exhibit an extremely low density of 0.024-0.054 g/cm(3) and a high porosity of 94.71-97.82%. The developed polypropylene aerogels express excellent flexibility and good heat insulation with remarkably low compressive modulus and thermal conductivity of 27.54-58.58 kPa and 0.036-0.039 W/m.K, respectively. Experimental results have demonstrated that methyltrimethoxysilane-coated PP aerogels have great water repellency with a water contact angle of 123.5-133.8 degrees. Therefore, they show a good maximum absorption capacity of 12.9-27.3 g/g for fuel oil, 10.2-24.5 g/g for 5w30 motor oil, and 10.2-23.5 g/g for diesel oil; these good characteristics are attributed to their porous hollow structure. Moreover, the oil absorption of polypropylene aerogels in this work is 5 times better than that of the previous one and equivalent to that of commercial absorbents and other polymer aerogels from plastics.

Automated summary

Hydrophobic polymer-based aerogels were successfully developed from polypropylene fibers for heat insulation and oil spill treatments. These aerogels exhibit low density, high porosity, flexibility, good heat insulation, water repellency, and high oil absorption capacity, attributed to their porous hollow structure. The oil absorption of polypropylene aerogels in this study is significantly better than previous research and comparable to commercial absorbents and other polymer aerogels.