Synthesis of Bio-Derived Polyesters

Ring opening copolymerisation of epoxides and anhydrides (ROCOP) shows promise as a greener method of synthesising polyesters with wide ranging functionality, but it is understood that all studies have been conducted in extreme anhydrous conditions. Herein is reported the use of ROCOP under bench-top conditions to prepare polyesters from a range of monomers, including some entirely bio-derived, with molecular weights up to 11.7 kDa and narrow dispersities. Organoinitiator N-N’-dicyclohexylurea (DCU), a cheap by-product of peptide synthesis, was found to be comparably efficient to traditional organometallic initiator salph-Al, and was used to synthesise bio-derived copolymers of epichlorohydrin (ECH) and itaconic anhydride (IA) with two targets for post-polymerisation modification. These were cross-linked with multifunctional diamines and polythiols by aza- and thio-Michael addition and nucleophilic substitution to form high molecular weight insoluble thermoset polymeric resins. It has also been shown that bio-derived monomers with multiple active sites can also be reacted using ROCOP, creating high molecular weight crosslinked product from two polyunsaturated oils.