Phenolic monomers in aromatic syntans: the influence on leather

November 2021 – by Prasad Muppa

Aromatic syntans are widely used in the (re)tanning of leathers. Phenolic monomers such as phenol, phenolsulfonic acid, bisphenol S, and bisphenol F are common compounds in aromatic syntans. These compounds are unreacted molecules that are either starting materials or intermediate molecules formed during the manufacturing process. Due to the toxic nature of these compounds, both the regulatory authorities and the leather industry are displaying an increasing interest in these residual phenolic monomers.

The research study consist of 3 different parts:
1) Amount of monomers: This part discusses the number of phenolic monomers in different aromatic syntans across the market.
2) Model study: A research study has been conducted to determine the effect of each specific monomer in a specific syntan on the leather. In this study, several model syntan samples were repared by addition of different loadings of each monomer, in order to determine the effect of each
monomer separately.
3) Effects of monomers: In this part, an attempt has been made to correlate the combined effects in different syntans across the market to the number of monomers present in them.