Utilizing Benzyl Methacrylate Derivatives for Bulk Depolymerization of Methacrylate Polymers

Lauren Bishop, Kevin Stewart, Krisada Auepattana-Aumrung, Jared Bowman, Blanch Khouri Sader, Madison Ross, Jacqueline Anatot, Brent Sumerlin

University of Florida

Although poly(methyl methacrylate) (PMMA) is not the most common commodity plastic, it is still a large contributor to plastic waste. The recycling of PMMA is has previously been overlooked due to its rarity compared to other commodity plastics and the challenge of breaking down its stable all-carbon backbone. Current recycling methods involve reprocessing, degradation, and depolymerization. Specifically, depolymerization, a truly circular approach, involves various methods including the introduction of  labile bonds adjacent to the backbone,  lowering the temperature of the onset of depolymerization. Previous methods have exploited decarboxylation of phthalimide esters to initiate bulk depolymerization both at the chain ends and as pendent groups. Our work, inspired by phthalimide ester decarboxylation, investigates the efficiency of the decarboxylation of benzyl methacrylate derived pendent groups for initiating bulk depolymerization.  A broad scope of derivatives will be analyzed to understand the effects of induction, hyperconjugation, and resonance on the extent of depolymerization of PMMA. Thermogravimetric analysis (TGA) has been used to determine the onset temperature of depolymerization and extent of depolymerization. Preliminary bulk depolymerizations have shown methyl methacrylate monomer recovery at temperatures lower than pure PMMA ceiling temperature.