A ¹³C‐NMR analysis method for phenol–formaldehyde resin strength and formaldehyde emission

Abstract

Abstract A method based on the use of 13 C‐NMR relative peak intensity ratios for different characteristic chemical groups, known or supposed to contribute to phenol–formaldehyde (PF) resin strength and formaldehyde emission is presented. The method relates results obtained by 13 C‐NMR analysis of liquid PF resins with the strength and formaldehyde emission in the resin‐hardened state. Correlation of differnt peak ratio with experimental results allows the proposal of equations relating the sum of different 13 C‐NMR peak ratios with the two mentioned physical properties of the same resins in their hardened state. The equations presented appear to have some applied value in predicting physical properties of hardened industrial‐type PF resins from a single 13 C‐NMR spectrum of the original liquid resin, as well as to render easier comparison between different PF resin formulations. © 1995 John Wiley & Sons, Inc.