Stereocontrolled Cationic Copolymerization of Vinyl Ethers

Polymer tacticity has a profound influence on macroscopic material properties, including the thermal, mechanical, and optical behavior of a material. Despite advancements in coordination-insertion polymerization methods used for the synthesis of stereoregular poly(alpha-olefin)s, polar isotactic polymers have remained a challenging synthetic target. Previously, the Leibfarth group developed a method using the principles of asymmetric ion pairing catalysis to perform the stereoselective cationic polymerization of alkyl vinyl ethers. Homopolymerization of these initial monomers with a chiral BINOL-based phosphoric acid in combination with a titanium Lewis acid proved the promise of this approach to synthesize a unique class of polar, semi-crystalline thermoplastics. Herein, we provide a further expansion of this method through copolymerization, enabling the systematic tuning of both glass transition (Tg) and melting temperature (Tm). Key structure-reactivity relationships for this catalyst system were also established when copolymerizing an alkyl vinyl ether with a variety of functional group rich vinyl ether monomers.Bachelor of Scienc