Mechanically mediated trithiocarbonate addition to commodity polymers for a more circular economy

Abstract

Mechanical recycling, while thought of as environmentally conscious, is not nearly as effective as it is lauded to be. Great levels of mechanical force cause chain-scission and lower product value while simultaneously only working once, maybe twice before the material is useless. Studies to harness the chain-scission with functional groups have proved possible but limited. This study shows the effect of adding bis(BTTC) and monomer to a mechanical recycling process to allow for post-recycling reactions with functionalized material. PMMA was shown to decrease in MW from 350 kDa down to ca. 15 kDa, then repolymerized back to 350 kDa. Other post-recycling reactions including block polymer synthesis and depolymerization are also possible and show promise. Expanding the scope outside of PMMA to other common plastics is studied as well, though it needs to be greatly expanded upon.