Raman Spectra of Polyacrylonitrile

The polarized Raman spectra of polyacrylonitrile have been obtained and compared with ir spectra. On the basis of the selection rules, various proposed structural models are compared with the experimental results. The spectra suggest a syndiotactic rich composition with a planar structure. The blocks of syndiotactic placements are disrupted by short sequences of isotactic or atactic placements.