Syntan:
Synthetic tanning material. May be defined as any high molecular organic compound containing reactive groups or mixture of such compounds capable of converting raw animal hide/skin into leather.
Properties of Syntan:
- Syntan is highly water soluble.
- Like natural tannin they have no filling property, so leather produced with syntan are soft.
- Shorter the tanning period.
- Lighten the color of leather if mixed with vegetable tan liquor.
- Aqueous solution are highly acidic due to presence of HSO3 radical.
- It could dissolve sludge produced in natural tan liquor.
- pH is 1.3 to 2. It is detrimental to leather manufacture, so it can't be used alone.
Synthesis of Syntan:
Two steps involved in synthesis of syntan as they are-
1. Nerodol:
When sulphonation takes place before polymerization.
- contain high HSO3.
- Solubility is more attractive for collagen.
2. Novolac:
When sulphonation takes place after polymerization.
- contain less HSO3.
- Solubility is less attractive for collagen.
Classification of Syntan:
1. Auxiliary syntan
2. Combination syntan
3. Replacement syntan.