Fabrication of oil- andwater-resistantpaper without creating microplastics on disposal

The proliferation of microplastics in the ocean and other water bodies is becoming an alarming issue. The development of plastic-free water- and oil-resistant paper can contribute toward mitigating this problem. Herein we report a plastic-free paper coating derived from chitosan and sunflower oil. Chitosan grafted sunflower oil paper coatings were prepared via the ring opening of the partially epoxidized sunflower oil with chitosan. The product of these reactions was characterized by nuclear magnetic resonance and infrared spectroscopy techniques. The sunflower oil grafted chitosan solution was coated onto a Kraft paper. The Cobb 60 and kit rating values were determined to be 8.00 g/m(2)and 7.66, respectively, for the optimal formulations. Meanwhile, the water contact angle was found to be 94.0 +/- 1.6 degrees after 30 s. Scanning electron microscopy analysis was employed to gain insight regarding the changes that occurred on the paper surface at the microscopic level.

Automated summary

The study developed a plastic-free paper coating derived from chitosan and sunflower oil, which can help alleviate the proliferation of microplastics in the ocean and other water bodies. The findings demonstrate that the paper coating performs well in reducing water and oil permeation and has microscopic changes on the paper surface.