Fig. 7
From: A critical review of fibrous polyurethane-based vascular tissue engineering scaffolds
Schematic hydrolysis of poly ester-urethane which water reacts with a carboxylic ester link. The reaction breaks the polymer chain at the point of attack, producing two shorter chains. One of these chains ends in a hydroxyl group (−OH). The other ends in a carboxyl group (−CO2H) are acidic. This acidic carboxyl group speeds up the further hydrolysis of the polyester segments in the poly (ester-urethane), and the degradation becomes autocatalytic