Structure and properties of 2-methyl-5-ethynylpyridine polymers

The structure and some properties were investigated for poly-2-methyl-5-ethynylpyridine (PMEP) prepared by thermal polymerization of the monomer. It was found that PMEP is characterized by a relatively broad MWD. The results of IR and UV analyses show that the PMEP macromolecules have mainly a trans-S-cis conformation with a trans-positioning of substituents relative to double bonds in the polyene chain. A study was made of how the molecular weight of the fractions and of unfractionated influenced their UV spectra. It was found that the inhibiting activity of PMEP samples in reactions of initiated cumene oxidation increases with rising Mn of the samples, and depends on their MWD. The thermooxidative stability of PMEP is increased with increasing Mn, and is likewise dependent on MWD.