Optimizing the conditions of quantitative 13C-NMR spectroscopy analysis for phenol–formaldehyde resol resins

✍ Scribed by Petra Luukko; Leila Alvila; Timo Holopainen; Jouni Rainio; Tuula T. Pakkanen

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 130 KB
• Volume: 69
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19980829)69:9<1805::aid-app15>3.0.co;2-k

✦ Synopsis

The experimental time of 13 C-NMR quantitative analysis of phenol-formaldehyde resins was reduced so that quantitativeness was maintained. The quantitative spectra of 14 model resins were obtained using a gated decoupling technique suppressing the NOE. The paramagnetic additive, Cr(acac) 3 , was used to shorten relaxation times of carbon atoms. The use of Cr(acac) 3 was optimized in two deuterated solvents, DMSO and acetone. To reach short relaxation times and further the measurement times, the concentration of relaxation reagent, the delay time, and the number of NMR scans were optimized. Quantitativeness was proved by analyzing the spectra of accurate mixture of model compounds, and the spectra of the condensed model resins.