Application of Compound Formaldehyde Scavenger in Leather

Abstract

Different types of formaldehyde scavenger were used to remove free formaldehyde in aldehyde tanning leather. The results showed that: the formaldehyde removal effect of self-made aminated collagen (EAC) was the best, followed by hyperbranched polymer with active methylene (HPAM). Then the mixture of EAC and HPAM was used to remove free formaldehyde. The optimum conditions were obtained by single factor experiment. The weight ratio of EAC and HPAM was 1:1 and the processing time was 2h. Finally, EAC, the mixture of EAC with HPAM and chitosan were used to remove free formaldehyde in oxazolidine tanned sheep skin. The comparison results showed that the formaldehyde-removal rate of the mixture of EAC and HPAM reached to 75% which was better than that of EAC and chitosan, but also it had obvious thickening and assisting dyeing effects to leather.

Development of aldehyde and similar-to-aldehyde tanning agents

“…The aldehyde tanning mechanism is relatively simple, and the tanning effect is achieved through covalent crosslinking of the aldehyde group with amino or imino groups on collagen molecules. [11][12][13] Among the modern aldehyde tanning agents, only formaldehyde, glutaraldehyde, and oxazolidine have sufficient tanning power (T s 85 C) for use in the tanning of leather and fur. Aldehyde-tanned leather is white, has good resistance to sweat and washing and good antiseptic effects, and can be preserved for a long time.…”