An Investigation of Wool Hydrolysis in Conventional Carbonizing

Abstract

We have investigated the extent of wool hydrolysis in the carbonizing steps of acid izing, delay between acidizing and drying, baking, and delay between baking and neutralizing. We have also examined the roles played by oxygen and sorbed water. We found that wool was hydrolyzed by 5% (w/v) sulfuric acid solution even at room temperature during the delay time between the acidizing and drying steps. The drying of acidized wool can be divided into two stages. In the first stage of drying, the rate of wool hydrolysis changes with drying time, but remains constant in the second stage of drying. We observed critical temperature points at 70°C in drying and at 120°C in baking, above which wool hydrolysis increases significantly. The results suggest that in the absence of water, virtually no wool hydrolysis will occur under acid conditions; however, no amount of drying will curtail wool hydrolysis because of powerful water retention by the sulfuric acid. Oxygen does not appear to play any significant role in wool hydrolysis during carbonizing.