Tribochemical Degradation of Polytetrafluoroethylene in Water and Generation of Nanoplastics

Polytetrafluoroethylene (PTFE) is probably the most extensively used chemically inert and thermally stable polymer. We report the degradation of PTFE in water in the presence of common metals and carbohydrates resulting in polymeric fragments. About 53 mg of solid materials consisting of polymeric fragments and copper was separated from a copper vessel in 15 days when a PTFE pellet of about 920 mg was stirred with 1000 ppm glucose in 70 mL of water at 70 °C. Degradation produced fluorocarbon species in water were detected by high-resolution electrospray ionization mass spectrometry. Triboelectric charging of the PTFE surface during stirring and consequent interaction of the charged surface with the metal ions, brought to solution by carbohydrate-induced corrosion, is attributed to this phenomenon. We show that such a process can be extended to other polymers such as polypropylene. The study suggests important consequences of nanoplastics to environment and health, including impact of such chemistry to cooking.