Kinetics of Polymerization of 1,3-Dioxolan Initiated by C6H5COSbF,and (C6H5)3C+SbF8 Salts

Polymerizations of 1,3-dioxolan initiated by oxycarbenium salt CeHsCO⁺SbFe^? and triphenylmethylium salt (C6H₅)₃C⁺SbF₆ ^? proceed with induction periods. C₆H₅CO⁺SbF6 initiates polymerization by a direct addition, while initiation with (C₆H₅CO⁺SbFe^?proceeds through the intermediately formed 1,3-dioxolan-2-ylium salt. Kinetic analysis of polymerization of 1,3-dioxolan, initiated by oxycarbenium salt or triphenylmethylium salt revealed that, in spite of different chemisty of initiation, both processes proceed with a slow initiation on monomer and fast initiation on polymer. The pertinent kinetic equations were derived and it was found, that the rate constant of propagation (k) does not depend on the structure of initiator used, being equal to 25 ± 5 liter/mole-sec (0°C, CH₂Cl₂ or CH₃NO₂).