Infrared spectroscopic evidence of structural defects in the crystalline regions of trans‐1,4‐polychloroprene

Infrared spectra have been obtained for the crystalline regions of samples of predominantly trans ‐1,4‐polychloroprenes polymerized at −20, 0, and 40°C. Spectral differences among the polychloroprenes are interpreted in terms of the increase in structural irregularities that occur as the polymerization temperature is increased. Results of this study indicate that crystallization occurs with random inclusion of these structural irregularities into the crystalline domains. The conclusion is supported by the spectra of the crystalline regions of a chloroprene copolymer containing known impurities in the form of 2,3‐dichloro‐2‐butenylene units in addition to the normal 2‐chloro‐2‐butenylene units.