NMR study of photochemical initiation of cationic polymerization of propylene oxide

Photolysis of triphenylsulfonium hexafluorophosphate (TSHP) in various solvents and cationic polymerization of propylene oxide initiated with the Bronsted acid formed as a result of photolysis of this salt have been studied. The reduction of TSHP does not proceed, and the precipitate formed on the finite stage of the process is a photoinitiator not decomposed under the action of light. An increase of polarity of the medium and decrease of the TSHP concentration results in enhancing of the rate of its photolysis and decrease of the rate of polymerization of propylene oxide. Interpretation of the 1H NMR spectra shows that both for polymer and monomer gauche-conformation is presumable.