Utilizing transition-metal catalysis for the development of novel aliphatic polyesters from bio-derived and waste feedstocks

Abstract

Polyesters have emerged as an attractive alternative to industrial olefins due to their multiple end-of-life options and potential to be derived from biomass and waste feedstocks. This thesis will focus on investigating new degradable polyester synthesis via two methods: hydroesterification and ring-opening polymerization. Chapter 2 aims to expand the applications of hydroesterificative polymerization by first tuning polymer microstructure through catalyst design and then increasing the hydroesterification monomer library by a two-step carbonylation and condensation approach. Chapter 3 describes the synthesis and ring opening polymerization of lactones derived from isoprene, 1,3-butadiene, and CO2. Copolymers with varying ratios of isoprene incorporation were isolated and characterized. Through stepwise synthesis and individual reactivity studies, the inhibitory effect of one lactone was identified. Finally, chapter 4 investigates copolymerizations of CO2 and butadiene derived δ-lactones with commercially available lactones, L-lactide and ε-caprolactone. Based on monomer feed ratios and the type of addition employed, a wide range of polymer thermal and mechanical properties were achieved, thus expanding the potential applications of CO2-derived polyesters.