A 13C NMR study of polyflavonoid tannin adhesive intermediates. I. Noncolloidal performance determining rearrangements

Chemical and heat treatments introduce noticeable modifications on the structure of four different polyflavonoid tannin extracts during their modification for use as tannin‐form aldehyde polycondensates. Such modifications are performance determining and account for the profound differences in behaviour of the four tannin extracts when used as tanninformaldehyde adhesives. Such modifications are directly followed by 13 C NMR on the tannin...