Effect of Solvent Type on Tannin Extractability from Three Tetrapleura Tetraptera (Schum. & Thonn.) Taubert Positions for Wood Composite Adhesive Formulation

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Journal of Emerging Trends in Engineering and Applied Sciences
Raw materials for adhesive production are conventionally from expensive petrochemicals, which affect synthetic resins relative to total costs of glued products. Phenol replacement with tannins (i.e., plant polyphenols) in Phenol-Formaldehyde resins is imperative since tannin adhesives are equally resistant to moisture and microbial degradation. Tannin was extracted from Tetrapleura tetraptera (i.e., bark, leaf and fruit) using distilled water and 1% NaOH through Soxhlet extraction. Tannin presence, Extract yield and polyphenol/tannin content (i.e., Stiasny numbers) were respectively determined from qualitative and quantitative analyses. The solvent type and plant part influenced the yield and tannin content. All the three parts, especially the bark, contained tannin. Extract yield was greater in 1% NaOH (39.54% [from leaf] to 77.05% [from fruit]) than in distilled water (12.96% [from fruit] to 18.16% [from leaf]). Conversely, Stiansy numbers for tannin, at all plant parts, were greater for the water-soluble extracts (i.e., 67.50, 68.96 and 87.50% from the leaf, fruit and bark respectively) than in 1% NaOH (i.e., 33.72, 21.94 and 37.42% correspondingly). The large extract yields (i.e., 39.54 - 77.05% for 1% NaOH) and high Stiasny numbers particularly for the water-soluble extracts (e.g. 87.50% for the bark) demonstrate the potential of T. tetraptera extracts as agents for tanning and adhesive formulation for leather, wood and related industries.
Article published in the Journal of Emerging Trends in Engineering and Applied Sciences (JETEAS, 2012
extract yield, polyphenol, quantitative test, sodium hydroxide, soxhlet extractor, tannin adhesive
Journal of Emerging Trends in Engineering and Applied Sciences (JETEAS) 3(3): 517-525