Proton Transfer Polymerization
Lecturer: Anzar Khan, Professor, Korea University
Time: 10:00a.m., Dec. 7th, 2018
Venue: Lecture Hall 441, Biological Science Building
Sponsors: Biomass Molecular Engineering Center, School of Forestry & Landscape
Profile to the Lecturer
Anzar Khan carried out his doctoral studies at the Free University Berlin (Germany). He then joined Prof. Craig Hawker's lab at the University of California at Santa Barbara (USA) as a post-doctoral scholar. He then moved to ETH-Zurich as a group leader. Since 2015, Anzar is with the Department of Biological and Chemical Engineering at Korea University as an assistant professor. Here, he is leading a research group with interests in the arena of polymer synthesis.
While an old reaction, the interest in thiol-epoxy reaction, especially as a polymerization process, is only recent. The power of this chemistry lies in its efficiency, operation under ambient conditions, commercial availability of a vast variety of thiol and epoxide carrying molecules that can be utilized as monomers, a long list of polymerization catalysts and associated solvent systems, and formation of a hydroxyl group upon completion. The amine-epoxy reaction bears similar hallmarks but is relatively simpler as a catalyst is not required for this process. Moreover, in comparing with the thiol-epoxy system that may sometimes give rise to disulfide defects through oxidative dimerization of thiols, the amine-epoxy system is comparatively more robust and insensitive to such a side reaction. The polymers resulting from thiol-epoxy and amine-epoxy reactions are termed as poly (ß-hydroxythio-ether)s and poly(ß-hydroxyl amine)s, respectively. The polymerization process itself is referred to as ‘proton transfer polymerization’. This is because quenching of the alkoxide anion, generated upon the nucleophilic attack of thiolate or amine moiety on the epoxide unit, through protonation is the critical step that ultimately decides the nature of propagation and the final structure of the polymer. It is understood that multiple proton-donors can exist within a polymerization system. Our attempt in this presentation would be to document the growing interest in the aforementioned chemistries as the polymerization process.