Recycling polycarbonate wastes to prepare hydrophobic and super mechanically robust aerogels with excellent oil–water and emulsion separation performance

Abstract

With the development of our society, plastic pollution is becoming more and more prominent. It is attractive and challenging to recycle plastic wastes to prepare valuable products at low cost. In this study, we report a unique strategy to obtain hydrophobic and super robust aerogels from polycarbonate wastes: (1) 4,4-diaminodibenzomethane is used to decompose polycarbonate (PC) waste, (2) the degradation product is compounded with organically modified montmorillonite (OMMT) to gel up through sol–gel transition, (3) solvent exchange and ambient-drying are performed to obtain the final aerogel samples. The addition of OMMT not only promotes the ring opening of the oxazine rings in the polymer matrix and the gelation rate of the system, but also strengthen the prepared aerogels due to the formation of stronger honeycomb network structure as a result of hydrogen bonding between OMMT and polymer matrix. The resulting aerogels can withstand up to 46,000 times its own weight and exhibits superb hydrophobic properties with contact angle up to 146.2°, as well as being suitable for use in a wide range of pH values. Besides, the aerogels possess good capacity for continuous oil–water separation, whose oil absorption performance does not deteriorate perceptibly after 50 cycles of oil absorption and degreasing. The aerogel obtained by this simple method not only has superb mechanical properties, hydrophobic properties, and oil–water emulsion separation, but also has many potential industrial applications and, most importantly, solves the waste disposal dilemma.