Analysis of phenol-formaldehyde resols by gel permeation chromatography

✍ Scribed by M. Duval; B. Bloch; S. Kohn

• Publisher: John Wiley and Sons
• Year: 1972
• Tongue: English
• Weight: 755 KB
• Volume: 16
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.1972.070160701

✦ Synopsis

The chromatographic analysis of resol solutions in tetrahydrofuran solvent, by means of a set of columns packed with crosslinked polystyrene gels, has been carried out with adequate resolving power for a clear-cut qualitative or semiquantitative difierentiation between various types of resols to be practicable. The resulting chromatograms, which show the distribution of different constituents by molecular size, could be interpreted by the use of reference substance and by calibrating the system with a number of compounds of known structures. The method has been used to investigate the way in which various reaction parameters (nature of catalysts, proportion of starting material, treatments undergone by the resols) affect the composition of resols. Different commercial products have been thus characterized. It has also afforded an insight into the progress of the polycondensation reaction as a function of time and helped to state the reactivity of different groups and unblocked ring positions. Thus, an hydroxymethyl group appears to be more reactive in the para than in the ortho position. Otherwise the reactivity of unblocked ring positions would be enhanced by an hydroxymethyl group in the ortho rather than para position.