Investigation On The Enzymatic Degradability Of Glycoloic Urthanes Via Fluorescence Assay

The continual rise of plastic production globally has placed a heightened focus on the end of life destination for this durable products.¹ Replacing current nondegradable commodity plastics with degradable alternatives, specifically those that are compostable, can help alleviate the disposal burden that these products present.² Through the application of a high-throughput fluorescence based enzymatic degradation screening method, we have produced a methodology for directing the synthesis of crosslinked polyurethanes to target degradability in an industrial composting setting. The base polymer composition poly(butylene glutarate-co-butylene succinate) (PBGS), was chosen based on its high level of enzymatic degradation determined using the fluorescence based assay. The impact of diisocyanate indexing using hexamethylene diisocyante (HDI) and content of three different crosslinking agents glycerol, sorbitan monooleate, and a mannose derivative on enzymatic degradation was then determined.  Directed by the enzymatic degradation assay and mechanical properties a final polyester polyurethane formulation with each cross-linker was determined. These materials were then subjected to respirometry studies under industrial composting conditions to further corroborate similarities in degradation profiles between the assay and respirometry for the polymer/crosslinker pairs.

1. Geyer, R.; Jambeck, J. R.; Law, K. L. Production, Use, and Fate of All Plastics Ever Made. Science Advances 2017, 3 (7).
2. S. B. Borrelle, J. Ringma, K. L. Law, C. C. Monnahan, L. Lebreton, A. McGivern, E. Murphy, J. Jambeck, G. H. Leonard, M. A. Hilleary, M. Eriksen, H. P. Possingham, H. De Frond, L. R. Gerber, B. Polidoro, A. Tahir, M. Bernard, N. Mallos, M. Barnes and C. M. Rochman, Science, 2020, 369, 1515–1518.