Targeted Polyurethane Enzymatic Degradation via High-Throughput Assay

Presenter: Maria Rose Colombo

Faculty Sponsor: Melody Morris

School: UMass Amherst

Research Area: Chemical and Biomolecular Engineering

Session: Poster Session 4, 2:15 PM - 3:00 PM, Auditorium, A50

ABSTRACT

Polyurethanes are polymers used in planes, construction, and other critical applications. These polymers vary in crystallinity, molecular weight, composition, segmentation, and use, making a "one size fits all" approach to recycling and enzymatic degradation impossible. Chemically, a polyurethane is defined by its urethane linkage, which connects hard and soft segments, increasing tensile strength, thermal stability, and elasticity through microphase separation. Hard segments result from the reaction of diisocyanates and diols (urethanes), which are best degraded by urethanases and proteases. Soft segments are composed of short polyesters or polyethers terminated by alcohol groups or polyols that can be hydrolyzed by esterases. We lack understanding of how polymer architecture and microphase separation affect the degradation of different sections of thermoplastic polyurethane elastomers, and we seek to further this understanding by synthesizing a library of tagged polyurethanes and utilizing a previously developed high-throughput assay analysis to quantify enzymatic degradation. We will synthesize polycaprolactone polyols because the chain-growth polymerization mechanism provides greater control over molecular weight. Polyurethanes will be prepared using polyols and methylene diphenyl diisocyanate at multiple hard-to-soft segment ratios, and subsequently tagged with pendant galactose moieties. Upon degradation of the polymer matrix, monomers bearing a pendant galactose analog are released, triggering the quantitative expression of a fluorescent protein. The galactose moieties are selectively attached to the hard or soft segments of the polyurethane elastomer to track segmental degradation. With quantitative characterization, this project will provide a deeper understanding of how polyurethane elastomer microstructure and composition affect enzymatic degradation throughout diverse conditions.

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