Seminar 10-31-25: seminar by Prof. Brooks Abel (UC Berkeley)

Extensive efforts have been made to synthesize polymers derived from heterocyclic monomers including lactones, lactams, and epoxides among other monomers, and numerous synthetic routes have been developed for their controlled syntheses using anionic ring-opening polymerization (AROP) and coordination catalyst systems. Less explored but equally promising as sustainable materials are polymers derived from heterocyclic monomers that are best polymerized by cationic ring-opening polymerization (CROP). Polymers synthesized by CROP comprise a diverse range of functional groups including acetals, orthoesters, ethers, phosphates, and disulfides among others. Additionally, polymers synthesized by CROP have been explored for their biodegradability and chemical recycling to monomer. However, despite more than half a century of development, CROP of heterocyclic monomers has not yet reached the same level of control over molecular weight, microstructure, architecture, and stereochemistry as has been achieved for AROP systems. This is largely due to undesirable Lewis acid-base interactions between the CROP catalyst and heterocyclic monomer. This presentation will provide an overview of our recent efforts toward the development of organocatalysts for cationic ring-opening polymerizations