TITLE:
Characterization of Tannin-Based Resins from the Barks of Ficus platyphylla and of Vitellaria paradoxa: Composites’ Performances and Applications
AUTHORS:
Richard Ntenga, Frederic Djoda Pagore, Antonio Pizzi, Etienne Mfoumou, Louis-Max Ayina Ohandja
KEYWORDS:
Wood Condensed Tannins, Fibre/Matrix Bond, Mechanical Properties, Active Correlated Transmission Electron Microscopy (ACTEM), Matrix Assisted Laser Desorption/Ionization Time-Of-Flight (MALDI-TOF)
JOURNAL NAME:
Materials Sciences and Applications,
Vol.8 No.12,
November
20,
2017
ABSTRACT: This
work investigates the physico-chemical and mechanical properties of tannins
extracted from wood for composite materials manufacturing. Sustainable
knowledge (in terms of physico-chemical properties and behaviours) of the material
is needed to further enhance its applications. The condensed tannins extracted
from the Bark of Ficus platyphylla (BFP)
and the Bark of Vitellaria paradoxa (BVP)
were analyzed using Matrix Assisted Laser Desorption/Ionization Time-Of-Flight
(MALDI-TOF), Mass Spectroscopy and Attenuated Total Reflectance Fourier
Transform Mid-InfraRed (ATR-FT MIR) spectra
in the ranges 1800 cm-1 and
600 cm-1, as well as using CP MAS 13C-NMR. It
was found that, these two tannins are procyanidin/prodelphinidin and made up
of catechin/epicatechin, gallocatechin/epigallocatechin units, fisetinidin,
galloyl and
carbohydrates residues. Furthermore, BFP and BVP tannin bonded particleboard
densities lie in the range recommended by NF EN 326-1994 standard. The resins
also yielded good internal bond strength results of the panels, above relevant
international standard specifications minimum requirements for interior-grade
panels. The Transmission Electron Microscopy with Energy Dispersive X-ray
Spectroscopy Analysis (TEM/ EDXA)
are showing the ultrastructure and reveal that most of the resin material appears to be in an amorphous phase mainly composed of
carbon/oxygen with small amounts of K, Ca and Mg. These particles have a very
irregular morphology.