Abstract

We have investigated the use of phosphonium compounds in combination tannages with vegetable tannins and aluminium. The phosphonium compounds -veg-Al tannage was applied to hide powder and pickled goatskin. The shrinkage temperature of the leather obtained by Complex Combination tannage with phosphonium compounds, vegetable tannins and aluminium tanning agent is 110°C which is much higher than that of combination tannages using vegetable tannins and aluminium tanning agents alone. The fibre weave is better separated in ternary combination tannage than those in single tannage or binary combination tannage as judged from SEM images. Based on Ts, contraction in length, tensile strength and tear strength of the leather after heat-aging, a satisfactory ternary combination tannage sequence is confirmed as phosphonium compounds, vegetable tannins, and aluminium tanning agent. The optimized offers of phosphonium compounds, vegetable tannins, and aluminium tanning agent are 3.5%, 7% and 3.5 % based on pickled goatskin pelt. The complex tannage was conducted in industrial scale and it gave a superior performance.