(3io) Catalysts with Increased Surface Affinity for Acid Hydrolysis of Plastic Waste

Chemical recycling is a potential alternative for recycling of plastic wastes that can handle mixed waste dirty waste streams. There are challenges to broad commercial use of chemical recycling methods including slow rates of reaction at polymer-solution interface which require high temperatures for reaction. This work focuses on use of acid catalysts for hydrolysis of poly(ethylene terephthalate) that target improved reactivity at the polymer surface. Specifically, poly (4-styrenesulfonic acid) (PSSA), 2- naphthalenesulfonic acid (NDA-1 proton), and 1,5- naphthalenedisulfonic acid (NDA-2 proton) were applied as acid catalysts to hydrolyze PET to terephthalic acid (TPA) and ethylene glycol. The impact of temperature, catalyst concentration, and structure on hydrolysis kinetics were compared with baseline sulfuric acid. In all cases, the more hydrophobic catalysts (i.e. NDA-1 proton and PSSA) exhibited much faster reaction kinetics than sulfuric acid. The increased kinetics was attributed to improved surface wetting of PET by catalyst solution, along with, preferential distribution of more hydrophobic catalysts to the PET surface. The PSSA maintained catalytic activity after use and recovery for five reaction cycles at 150C.

Research Interests: Recycling, Sustainability, Materials Science, Polymer, and Chemical Engineering

Teaching Interests: Transport Phenomena, Engineering Mathematics, Polymers, Thermodynamics, Fluid Mechanics