¹³C NMR studies of polymorphy in isotactic polystyrene

The authors investigated the ¹³C spectrum of a dried gel and of an iPS specimen exposed to cyclooctane vapor. They wanted to see if the iPS spectra would display characteristic features related to the extended chain conformation; also we hoped to obtain information about the morphological distribution of the solvent molecules. It is shown that the appearance of spectral features associated with the CVI crystal lattice at the earliest spin diffusion times means that cyclooctane is incorporated into the crystal lattice; however these results do not imply that cyclooctane is limited to the crystal lattice. Similar spin diffusion experiments were attempted on the dried gel but the results were not definitive.