In-situ High Resolution NMR Investigation on Polymerization Mechanism. II. Comparison between BF3·Bu2O and CI-N2PF6as Catalysts in Homopolymerization of Trioxane and Copolymerization with Ethylene Oxide

Abstract

Abstract A comparison of BF3 ·Bu2O and Cl-N2PF6 as catalysts for cationic homopolymerization and copolymerization of trioxane has been made by employing high resolution nuclear magnetic resonance techniques. While no substantial difference was detected for the homopolymerization, two important differences were observed for the copolymerization with ethylene oxide; viz., 1) with Cl-NPF6 there is a lower build-up of formaldehyde concentration; 2) with Cl[sbnd]N2PF6, a lesser amount of cyclic compounds containing ethylene oxide units is formed (e.g., 1,3-dioxolane). Both observations suggest that depolymerization occurs to a lesser extent with the cl-N2PF6 catalyst.