Knowledge Bank

The infrared spectra of a number of high polymers have been recorded in the range between $20\mu$ and $110\mu$ in order to explore the possibilities of this region for structural work on such compounds. The number of bands found varies from none (polyethylene) to eight (Saran). It has been found that the spectra of some polymers in this region depend upon the state of orientation and crystallinity in the specimen (e.g., mylar and rubber). The spectra of a few selected compounds will be discussed in detail to illustrate how tentative assignments of the observed bands may be made to a) group vibrations, b) skeletal vibrations, and c) intermolecular vibrations. The last class of vibrations is of particular interest in relation to hydrogen bonding.