Abstract

The investigation enables us to draw a conclusion that THPS has very good stabilising properties, which allows its use for intensifying the process of chromium tanning by decreasing the consumption of chromium and, at the same time, increasing the shrinkage temperature of the leather. The treatment of pelt with THPS instead of chromium before vegetable-aluminium tanning allows it to reach a shrinkage temperature up to 115°C using half as much tannin. IR-spectroscopy has shown that phosphonium compounds react with amino groups of collagen forming hydrogen and covalent bonds, and this is the reason for the growth in thermal stability of collagen. The closely similar thermal characteristics which were obtained by DTA for phosphonium-vegetable- Al tanned leather and conventionally tanned leather allow us to suppose that the use of phosphonium compounds instead chromium compounds for pelt treatment before vegetable tanning provides the dermal structure with properties analogous to those of chrome.