Stereoselective Cationic Polymerization of Cycloaliphatic Vinyl Ethers (2023)
Undergraduate: Mason Chapman
Faculty Advisor: Frank Leibfarth
Department: Chemistry
The stereoselective polymerization of isotactic polyvinyl ethers (iPVEs) presents an exciting avenue for the development of renewable and sustainable polymers with thermomechanical properties rivaling that of petrochemically-derived polymers such as polypropylene. In this project, non-stereoselective triflic acid catalyst was used as a control in the polymerization of various cycloaliphatic vinyl ether monomers. The resultant polymers were fully atactic with % m ranging from 50-70%, as expected for a non-stereoselective catalyst. On the other hand, when polymerized with the stereoselective Brønsted acid catalyst IDPi (imidodiphosphorimidate), the polyvinyl ethers reached near-full tacticity and were measured to have excellent thermomechanical properties1. Thus, the polymerization of cycloaliphatic vinyl ethers with triflic acid serves to illustrates the ability of IDPi to control tacticity in polyvinyl ethers with a wide range of substituents. Not only this, IDPi is metal-free (vs. previously studied stereoselective ligated Titanium Lewis acid catalysts), works efficiently in milder reaction conditions, and can be derived from relatively inexpensive feedstocks. Future work can explore post-polymerization functionalization and the use of other monomers, making this research area promising for the development of new and exciting polymeric materials.
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