We developed a novel aluminum-based initiator that facilitated polymerization of various epoxides (epichlorohydrin, propylene oxide, <i>etc.</i>) up to molecular weights of 100 kg/mol while maintaining relatively narrow polydispersity. The initiator was synthesized through a thiol ligand and trialkyl aluminum reaction, with the thiol ligand choice enabling polymer end group control. Copolymerization of epichlorohydrin and propylene oxide demonstrated the ability of this method to control polymer architecture. We further investigated catalyst concentration and initiator structure on the kinetics of epoxide polymerizations through <sup>1</sup>H NMR spectroscopy. Finally, we combined our polymerization method with another facile method, reversible addition-fragmentation with chain transfer (RAFT) polymerization, to synthesize block-co-polymers made from vinyl and epoxide monomers. To do this, we made a macroinitiator from polystyrene (PS) and poly(methyl methacrylate) (PMMA), synthesized by RAFT polymerization, and further polymerized epoxide from it. Therefore, this new synthetic tool allows for the facile and controlled polymerization of epoxides into well-defined, functional polyether materials.

Aluminum-based initiators from thiols for epoxide polymerizations

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.