*2.2.2.6 Eco-friendly preservatives*

Generally, condensed tannins preserve lignocellulosic materials naturally. Therefore, condensed tannins can be used as potential wood preservatives and biocides [46].

## *2.2.2.7 Medical science*

*Tannins - Structural Properties, Biological Properties and Current Knowledge*

*Comparison of the adsorption capacity of pesticides on cationic tannin adsorbent [45].*

**16**

*2.2.2.4 Metal protective agents*

**Figure 15.**

**Figure 14.**

coating for wood [11].

*2.2.2.5 Building construction purpose*

and architectural bricks [11].

Tannins have been used as a corrosion inhibitor for carbon steel and copper in oil and gas facilities with treated *Rhizopora mucronata* tannin. Sulfonated tannins can be used to remove scale-forming cooling water pipes and boilers. In the protective coating industry, tannins have been used for protecting metal surfaces as a primer/undercoat/topcoat. In Chile, pine tannin has been used as a commercial anticorrosive product. Black wattle extract has been used as a polyurethane-type

*Comparison of the adsorption capacity of pharmaceuticals on cationic tannin adsorbent [45].*

Tannins are used as a viscosity modifier of mud for the production of residential

Tannins have antiviral, anticancer, antibacterial, anti-inflammatory, and antioxidant properties, and these are the driving forces to be a potential source of medicinal products. A large amount of research is being undertaken currently to develop medicine from tannin [11].
