Reactivity ratio study for the cationic copolymerization of vinyl ethers with 2,3-dihydrofuran

To understand the monomer distribution in the copolymers from the cationic copolymerization of vinyl ethers (VEs) with 2,3-dihydrofuran (DHF), the reactivity ratios of VEs (<i>r</i>_VE) and DHF (<i>r</i>_DHF) were determined. The copolymer compositions were calculated from ¹H NMR spectroscopy, which were used to determine the reactivity ratios from the extended Kelen-Tüdós (extended K-T) method at high monomer conversion. Furthermore, the effect of solvent (hexane and toluene), temperature (0, −20, and −40 °C), Lewis acid (SnCl₄ and TiCl₄) and alkyl groups in VE monomers (<i>iso-</i>butyl vinyl ether (<i>i</i>BVE), propyl vinyl ether (PVE), and <i>n</i>-butyl vinyl ether (<i>n</i>BVE)) were studied in detail on the reactivity ratios of monomers during the cationic copolymerization of VEs with DHF. The two monomers in every case were randomly placed along the copolymer chain. This article demonstrates the scope of copolymer synthesis of VEs with DHF and their microstructure analysis.