Abstract

Combination tanning using vegetable tannins and oxazolidine Ehas been proved to be a preferred alternative to chrome tanning. But this kind of tannage has not been widely applied partly owing to the high price of oxazolidine E. In this study, a new oxazolidine tanning agent, oxazolidine SCU, was synthesized by using cheap and readily obtained raw materials, and its tanning properties both alone and in combination with vegetable tannins, were investigated. Oxazolidine SCU possesses high reactivity with skin collagen. Tanned by 5% oxazolidine SCU under room temperature at pH8.0, the shrinkage temperature of goatskin leather was around 83°C. In vegetable combination tanning, oxazolidine SCU exhibited a good synergistic tanning effect with condensed tannins. Among condensed tannins, mimosa is the preferred one in consideration of achieving high shrinkage temperature of leather. Tanning the depickled pelt with 10-15% vegetable tannin at first, and then retanning with 4-6% oxazolidine SCU for 4 hours at 60°C in the pH range 5.5-6.0, the shrinkage temperature of leather was 114-120°C.