Sanat Kumar

Polymer Recycling/Upcycling

Sanat K Kumar
Department of Chemical Engineering at Columbia University

Abstract: Polymer waste in the environment is a central concern to humanity. Currently, only ~10% of all plastics produced from hydrocarbon feedstocks are recycled, while 30% are dumped into the environment, 40% land filled and 14% are burned (into CO2 another environmental concern). Why it is so hard to recycle polymers is the first topic we shall consider. Then, we shall show that current protocols, which generally involve deconstructing a polymer into its building block monomers and then subsequent reconstruction, is not a productive strategy for many commercially relevant materials. Other strategies need to be developed and we discuss a particularly facile one, where mixed plastics can be reused through the process of mechanical recycling (e.g., simple reprocessing by extruding the polymer waste). The underpinning physics and chemistry of this process will be discussed. Time permitting, we shall also discuss how the 30% of polymers put into the environment degrade to form micro and nanoplastics. We shall also examine means to mitigate the formation of these environmental pollutants that could adversely affect lifeforms, especially in the marine milieu.

Bio: Undergrad education BTEch, Chem Eng., IIT Madras; SM and ScD, MIT, Chemical Engineering, 1987; Post-doc, IBM; Penn State 1989-2002; Rensselaer Polytechnic Institute, 2002-2006; Columbia 2006-; Brookhaven National Labs 2021-; IIT Madras Chevron Visiting Prof, 2018-; IIT Mumbai, Distinguished Visiting Prof., 2022-; Editor Soft Matter; Department chair, Chem Eng., Columbia 2010-2016; Polymer Physics Prize, APS, 2022.