Study on the preparation of wheat bran carbon material (CM) and its preliminary tanning property in leather industry

Wheat bran is a massive by-product from agro-industry, which is a sustainable raw material to make carbon material (CM). This work addresses wheat bran as a possible source for leather tanning agents to enlarge its industrial applications. Firstly, wheat bran was extracted with water and further modified with a hydrothermal carbonization (HTC). The UV-vis spectra, the FTIR spectra and the fluorescence phenomena were recorded to speculate the effects of HTC on the components in the bran extract solutions in terms of the reaction time (1 h, 3 h, 5 h and 7 h) at 170 degrees C and the reaction temperature (150 degrees C, 170 degrees C and 190 degrees C) at 5 h. Secondly, the branbased CM was directly used to tan pickled pigskins without purification according to a normal leather processing procedure. The maximum rise in shrinkage temperatures of pigskins reached to 27 degrees C after tanning with bran CM. Scanning electron microscope images and atomic force microscope images revealed that bran-based CM penetrated into the collagen fibers to loosen and dilate fibers and then further provide stable crosslinking, resulting in firm and delicately grained surfaces. These results demonstrated that bran-based CM was an effective and environmentally-friendly tanning agent.

Automated summary

This study found that wheat bran can be used to make leather tanning agents, expanding its industrial applications. The bran-based CM, after hydrothermal carbonization treatment, was directly applied to tan pigskins, resulting in good effects and proving the effectiveness and environmental-friendliness of the bran-based CM as a tanning agent.