THE EFFECT OF HYDROGEN CHLORIDE ON THE INFRARED SPECTRUM OF NYLON

The effect of HCl on the infrared spectrum of nylon in the form of Zytel films was studied in the region 3600 cm.−1 to 600 cm.−1. The effect of partial deuteration of the films was also observed. Definite changes in the characteristic bands of the NH—CO group show that HCl interacts with this group. The results indicate that the two NH bands at 3300 cm.−1 and 3030 cm.−1 are associated with different NH bonds. The general effect of the HCl seems best explained by assuming a polar interaction with the peptide linkage. The behavior of several of the bands is readily explained on the basis of the picture given by Fraser and Price for the NH—CO vibration.