(585f) Interfacial Phenomena Facilitate Plastic Reuse and Recycling to Improve Environmental Sustainability

Polymers are highly versatile materials that constitute numerous products, ranging from the ubiquitous water bottles to personal protection equipment. 44 million tons of plastic waste were managed in the US in 2019, with 86 % of all that plastic landfilled, and only 5 % recycled. There is great interest nowadays in increasing the reuse and the recycling of plastic. Mechanical recycling is currently used to recycle plastic waste, however, this method is efficient only for homogeneous and non-contaminated plastic waste, and for easily identifiable objects such as bottles made of PET (polyethylene terephthalate) or HDPE (high density polyethylene). Ample room exists for improvement upon the current situation. Interfacial phenomena are critical in (i) enabling the reuse of plastic items, thus extending their useful life and reducing the need for virgin plastic, and (ii) increasing the recovery rate of plastic during mechanical recycling. Washing is a key step in both cases, aiming to (i) render the plastic objects acceptable for reuse, and (ii) remove surface contamination that adversely affects the reprocessing of post-consumer plastic. Another contribution of interfacial phenomena to increasing the recycling of plastic pollution is through flotation that can separate, on the basis of their surface properties, plastics that often have similar physical and chemical properties. The presentation will report on trends on plastic production, use and misuse, discuss recent developments in plastic waste management, and highlight interfacial phenomena in plastic cleaning and separation.