Development of aldehyde and similar-to-aldehyde tanning agents

Aldehyde and similar-to-aldehyde tanning agents were used in oil tanning and smoke tanning in ancient times. The aldehyde group reacts with the protein amino group in electrophilic form to obtain the preservation stability and practical function of fur and leather. The results showed that aldehyde-tanned leather can promote the hydrothermal stability of skin collagen and has better water and sweat resistance properties than chrome tanning. However, aldehyde tanning agents always lack sufficient coulombic attraction to penetrate well into skin collagen, and some aldehydes have biotoxicity and color, are not easy to dissolve and have high manufacturing costs. In this paper, the structure and application characteristics of some aldehydes are reviewed. According to prior theory and practice, the development of new aldehyde tanning agents and additives has good prospects and significance for providing substitutes for chrome tanning agents.