¹H‐ and ¹³C‐NMR analyses of aqueous polyamideamine–epichlorohydrin resin solutions

More accurate signal assignment for 1 H‐ and 13 C‐NMR spectra of aqueous solutions of polyamideamine‐epichlorohydrin (PAE) resin and its related compounds was achieved by using distortionless enhancement of polarization transfer (DEPT) and C‐H correlation spectroscopy (COSY) methods. On the basis of the assignment, we developed new methods to determine the content of four‐membered azetidinium ring (AZR) and number‐average degree of polymerization (DP n ) of the repeating unit of PAE by using NMR. Degree of introduction of epichlorohydrin into polyamideamine chains at the initial stage was 75–80%, and the resultant AZR content per one repeating unit in the PAE sample prepared in this study was about 72%. DP n of the initial polyamideamine was 32, and this value decreased to about 18 during the PAE preparation process.