
Figure 1:ATR-FT MIR spectrum of Monopetalanthus durandii tannin
Figure 1:ATR-FT MIR spectrum of Monopetalanthus durandii tannin
Figure 2: Maldi-Tof spectrum of the tannin of Monopetalanthus durandii
Figure 3: Some flavonoid structures
Figure 4:Gel time of the different resins: a) resin + 6% Hexamine b) resin + 5% Paraformaldehyde
Figure 5: thermomechanical analysis of resins
Figure 6: microscopic view (OLYMPUS SZX12) of the biocomposite a) after pressing, b) microscopic view of the structure, c) longitudinal view, d) transverse view
Figure 7: biocomposites tensile test characteristic curves
Figure 8
Tannin solution |
Hardener (%) |
pH |
|
F1 |
40% Monopetalanthus durandii |
15% V. nilotica |
6,3 |
F2 |
40% Monopetalanthus durandii |
6% Hexamine (at 30% w/w) |
|
F3 |
40% Monopetalanthus durandii |
5% Paraformaldéhyde |
Table 1:Different resin formulation
Cycle |
Pressure (MPa) |
Duration (min) |
C1 (8 min) |
2 |
4 |
1 |
2 |
|
0,5 |
2 |
Table 2:Biocomposites pressing cycle
Peak (cm-1) |
Meaning |
3187 |
O-H of the flavonoid |
1602, 1507 |
B-ring catechol-like vibrations occurring in Fisetinidin and Catechins |
1448 |
C-O attributed to the gallic / pyrogalic ring and to the vibrations of the Gallocatechin |
Vibratory movement of the C=C group attached to the aromatic ring is confirmed by the presence of the peak |
Table 3: Summary of the results of MIR ATR-FT
M+Na+ (exp.) |
Monomers and oligomers |
Observation |
248,8 |
Chalcon + Na+ (+OH) |
Monomer |
273,1 |
Fisetinidin deprotonated without Na+ |
Monomer |
296,1 |
Fisetinidin deprotonated + Na+ |
Monomer |
304 |
Gallocatechin without Na+(-2H) |
Monomer |
Catechin + Na+ |
Monomer |
|
Gallocatechin +Na+ |
Monomer |
|
Gallocatechin triprotonated +Na+ |
Monomer |
|
Myricetin +Na+ (-H) |
Monomer |
|
Myricetin +Na+ (+H2O) |
Monomer |
|
Myricetin deprotonated + 2 Na+ |
Monomer |
|
368,0 |
Gallocatechin protonated +2Na+ (+H2O) |
Monomer |
chalcon-gallic acid without Na+ (-4H) |
Dimer |
|
chalcon-gallic acid without Na+ (-2H) |
Dimer |
|
chalcon - gallic acid without Na+ (+OH) |
Dimer |
|
chalcon - gallic acid without Na+ (-4H) |
Trimer |
|
chalcon - gallic acid + Na+ (-3H) |
Dimer |
|
418,6 |
chalcon- chalcon without Na+ |
Dimer |
433,8 |
glucose- Chrysin protonated without Na+ |
Dimer |
Catechin gallate without Na+, deprotonted (-1H) |
Monomer |
|
Gallocatechin gallate without Na+ (-2H) |
Monomer |
|
463,9 |
Catechin gallate + Na+ (-2H) |
Monomer |
480,8 |
Gallocatechin gallate + Na+ (-H) |
Monomer |
chalcon triprotonated- Chrysin + Na+ |
Dimer |
|
Catechin triprotonated- chalcon + Na+ |
Dimer |
|
525,0 |
Fisetinidin-Chrysine without Na+ |
Dimer |
550,1 |
Chalcon triprotonated- Myricetin + Na+ |
Dimer |
568,6 |
Fisetinidin -Fisetinidin +Na+ |
Dimer |
Catechin-Fisetinidin +Na+, protonated |
Dimer |
|
Fisetinidin - Gallocatechin +Na+ (-H) |
Dimer |
|
619,4 |
Gallocatechin-Catechin+ Na+ |
Dimer |
649,5 |
Catechin gallate-Chrysine+ Na+ |
Dimer |
673,6 |
Chrysin-chrysin- gallic acid without Na+ (-H) |
Trimer |
698,2 |
Catechin gallate-Chrysin triprotonated without Na+ |
Dimer |
711,7 |
Gallocatechin gallate -Chrysin without Na+ |
Dimer |
743,3 |
Chrysin-chrysin-Chrysin without Na+ |
Trimer |
773,5 |
Chrysin-Fisetinidin-Chrysin without Na+ |
Trimer |
805,2 |
Fisetinidin - Fisetinidin - Fisetinidin without Na+ (-OH) |
Trimer |
824,2 |
Fisetinidin-Chrysin-Fisetinidin + Na+ |
Trimer |
840,3 |
Catechin-fisetinidin-chrysin +Na+ |
Trimer |
856,3 |
Catechin-catechin-chrysin +Na+ |
Trimer |
872,3 |
Gallocatechin-catechin-chrysin+ Na+ |
Trimer |
888,2 |
Gallocatechin-gallocatechin-chrysin + Na+ |
Trimer |
Gallocatechin-gallocatechin-catechin+ Na+ (-H) |
Trimer |
|
Fisetinidin gallate–chrysin-chrysin + Na+ |
Trimer |
|
Gallocatechin gallate-chrysin-chrysin + Na+ |
Trimer |
|
990,9 |
Chrysine-chrysin -chrysin -chrysin- chrysin+ Na+ |
Tetramer |
1021,0 |
Catechin-fisetinidin-gallocatechin gallate without Na+, protonated |
Tetramer |
1052,8 |
Gallocatehin-catechin-Gallocatechin gallate without Na+ |
Trimer |
1083,1 |
Catechin - Myricetin -Gallocatechin gallate + Na+ (-2H) |
Trimer |
1112,2 |
Myricetin - Myricetin -Gallocatechin gallate + Na+ (-H) |
Trimer |
1128,3 |
Myricetin protonated - Fisetinidin -Chrysin -Chrysin without Na+ |
Tetramer |
1144,7 |
Gallocatechin gallate protonated- Gallocatechin gallate-chalcon + Na+ |
Trimer |
1160,3 |
Myricetin - Myricetin -Chrysin -Chrysin + Na+ (-H) |
Tetramer |
1207,0 |
Myricetin - Myricetin -catechin - catechin + Na+ (-3H) |
Tetramer |
1269,2 |
Myricetin - Myricetin -Myricetin -Myricetin triprotonated + Na+ |
Tetramer |
1331,2 |
Catechin gallate – catechin diprotonated - catechin -catechin +Na+ |
Tetramer |
1352,1 |
Gallocatechin gallate - Gallocatechin gallate - catechin gallate without Na+ (-2H) |
Trimer |
1384,6 |
Chrysin diprotonated-Chrysin- catechin gallate- chalcon- chalcon+ Na+ |
Pentamer |
1416,5 |
Chrysin-Chrysin- catechin- Myricetin - Fisetinidin without Na+, protonated |
Pentamer |
1454,9 |
Chrysin-Chrysin- catechin -Myricetin - Myricetin + Na+, tetraprotonated |
Pentamer |
1517,1 |
Chrysin- Chrysin- Chrysin- Chrysin- Chrysin- Chrysin diprotonated without Na+ |
Hexamer |
1579,3 |
Chrysin-Chrysin -Fisetinidin-catechin - Gallocatechin gallate protonated + Na+ |
Pentamer |
1641,0 |
Chrysin – catechin-Fisetinidin -Gallocatechin gallate- Myricetin + Na+ (-H) |
Pentamer |
1703,5 |
Chrysin protonated-Chrysin- Chrysin- catechin -Myricetin -Myricetin + Na+ |
Hexamer |
Table 4:Monomers and oligomers present in the tannin of Monopetalanthus durandii
Method |
Tannin |
Duration |
Site |
Yield (%) |
Stiasny (%) |
Auteur |
Hot Water |
A. mangium |
3h |
Lembah |
11.2 |
89.1 |
[31] |
A. mangium |
3h |
Tawau |
15.4 |
95.6 |
[31] |
|
Kudat |
3h |
|
|
70.1 |
[14] |
|
M. durandii |
3h |
Littoral |
8,6 |
74,2 |
|
|
Recommended value |
|
≥ 65% |
[30] |
Table 5: Number of Stiasny of tannins at different extract duration, growing location and duration
Formulation |
%Hardener |
pH |
Viscosity (MPa.s) |
ρ (g/cm3) |
MOE (MPa) |
F1 |
15 % V. Nilotica |
6,3 |
252 |
1,16 |
6608,65 |
F2 |
6 % Hexamine (at 30% w/w) |
64 |
1,14 |
6374,07 |
|
F3 |
5 % Paraformaldehyde |
180 |
1.15 |
5962,77 |
Table 6:Resin viscosity
Figures at a glance