Preparation of Oxidized Tapioca Starch and its Application for Tanning with Titanyl Sulfate

Chrome-free tanning agent is of great significance because it can eliminate the notable environmental pollution of chrome tanning. Tapioca is a non-grain crop, and oxidized starch is widely used in leather tanning. Titanium tanning agent is also considered as a potential tanning agent. However, the tanning effect of titanium tanning agent is not ideal. In this study, dialdehyde tapioca (DAS) with different dialdehyde contents have been prepared by sodium periodate oxidation. DAS has been further considered to be degraded by acid to obtain degradation products. The combination tanning effects of DAS and its degradation products with titanyl sulfate have been studied by using Fourier Transform Infrared spectroscopy (FT-IR), X-Ray Diffraction (XRD), Nuclear Magnetic Resonance (NMR) and Scanning Electron Microscopy (SEM). The results have shown that the combination tanning would significantly increase the shrinkage temperature of the tanned leather.