Structure of polypiperylene chain segments according to high-resolution 13C NMR spectra

The microstructure of stereoregular 1,4-trans-and 1,4-cis-polypiperylenes, as well as polymers prepared from the trans-and cis-piperylene isomers via cationic polymerization in the presence of TiCl₄, was studied by high-resolution ¹³C NMR spectroscopy. Polypiperylene synthesized through the cationic polymerization of the cis isomer had a more diversified morphology of the macromolecular chain, i.e., had higher relative amounts of 1,2-cis-units and combinations of irregular-addition 1,4-trans-units. It was shown that ¹³C NMR spectra give the most comprehensive and independent information on the details of structure of the piperylene macromolecular chain.