Lower‐frequency infrared spectra and structures of some typical aliphatic polyamides

Abstract

Abstract The Polarized lower‐frequency infrared spectra (800–33 cm ‐1 ) of nylon 66 (α form), nylon 77 (γ form), and nylon 6 (both α and γ form) have been examined. The spectral changes which occur on complex formation of the polyamides with iodine‐potassium iodide solution and on subsequent iodine desorption have been studied in relation to the changes in the polymer structures. On the basis of these results, most of the stronger bands have been reasonably assigned to the vibrations characteristic of the amide group and the methylene chain of the polyamides, and some new structure–frequency correlations have been established for the polymers.