Abstract

An investigation has been made of the reaction of chromium tanned modified collagen with myrobalans and mimosa extract. The results suggest that basic groups likely play an important role in the rapid absorption of vegetable tannin, and these sites seem more accessible after chromium pretannage. Irreversible fixation of tannin is mainly due to the coordination of vegetable tannin to the chromium/collagen complex through displacement of sulphate radicals or water, and to a very small extent by displacement of protein carboxyl groups.