Premium
Induced accelerated autocondensation of polyflavonoid tannins for phenolic polycondensates. II. Cellulose effect and application
Author(s) -
Pizzi A.,
Meikleham N.,
Stephanou A.
Publication year - 1995
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1995.070550611
Subject(s) - cellulose , tannin , chemistry , cellulosic ethanol , condensed tannin , cleavage (geology) , bond cleavage , reaction mechanism , lignin , branching (polymer chemistry) , organic chemistry , substrate (aquarium) , polymer chemistry , stereochemistry , proanthocyanidin , polyphenol , materials science , catalysis , food science , oceanography , fracture (geology) , composite material , antioxidant , geology
Abstract Polyflavonoid tannin autocondensation was found to be facilitated by the reaction occurring on cellulose and lignocellulosic substrates. Although the mechanism of polyflavonoid autocondensation induced by cellulose differs from that induced by the action of Lewis acids, the subsequent reaction of autocondensation appears to be similar. The determining step of tannin rearrangement pathways under alkaline conditions in cellulose‐induced highertemperature autocondensation is the favoring of the heterocycle pyran ring opening over the normal interflavonoid bond cleavage and catechinic acid rearrangement. This is caused by relevant bond weakening and easier cleavage induced by strong attractive forces between flavonoid and cellulosic substrate. Applied bonding of cellulosic substrates by polyflavonoid tannin autocondensation reaction appear to be feasible and to occur as predicted from theoretical predictions. © 1995 John Wiley & Sons, Inc.