Your search resulted in 60 documents. Displaying 25 entries per page.
Smart hydrogels from low molecular weight amphiphilic compounds: toward a solution to decrease leachability and increase efficacy of boron preservatives?
2012 - IRG/WP 12-30589
A new catanionic system associating amphiphilic carnosine (AlaHisC8) and lauric acid forms supramolecular hydrogel at very low concentration. This gel was investigated and we have checked the validity of the concept of hydrogels utilization to reduce boron leachability and to develop new wood protection treatments. Impregnation with 5% aqueous borax solution (w/w) and 0.3% gelator agent (...
F Obounou Akong, P Gérardin, C Gérardin-Charbonnier
Hydrogels: a solution to reduce boron leachability without reduction of its biodisponibility to wood decaying fungi?
2012 - IRG/WP 12-30602
Products used today for wood protection must fulfill to more and more environmental constraints, such as being of low toxicity in answer to the Biocidal Product Directory, but also to involve waterborne treatments to limit rejection of volatile organic compounds in the atmosphere. Boron preservatives have been described as valuable alternatives for wood protection for non-ground contact applicatio...
F Obounou Akong, P Gérardin, M-F Thévenon, S Parant, C Gérardin-Charbonnier
State of progress of utilisation of supramolecular gels for formulations of water-soluble wood preservation salts
2013 - IRG/WP 13-30630
This article is a compilation of the work done so far concerning the utilization of supramolecular hydrogels, built on low-molecular-weight amphiphilic molecules and containing boron salts conferring fungicidal properties. Mixing boron with thermoreversible hydrogels allows the formation of a supra molecular network incorporating boron and important amount of water upon gelification of the solutio...
F Obounou Akong, P Gérardin, M-F Thévenon, C Gérardin-Charbonnier
Chemical composition of extractives of different wood compartments of Pinus merkusii and their potential implication in wood durability
2015 - IRG/WP 15-10841
Amounts and nature of extractives differ strongly according to the compartment of wood and to the nature of the wood species. Previous studies reported that knotwood of several European Pinus sp. contains extractives contents much higher than stemwood consisting mainly of lignans which may find valuable applications in cosmetic, nutraceutic or pharmaceutic sectors. Different explanations have been...
A Wijayanto, S Dumarçay, R Kartika Sari, W Syafii, P Gérardin, C Gérardin-Charbonnier
Environmentally Friendly Wood Modification based on Tannin-Furfuryl alcohol - Effect on stabilisation, mechanical properties and decay durability
2022 - IRG/WP 22-40929
Furfurylation is a well-known wood modification technology. This paper studied the effect of tannin addition on the wood furfurylation. Three kinds of dicarboxylic acids, adipic acid, succinic acid, and tartaric acid, as well as glyoxal as a comparing agent, were used to catalyse the polymerisation of furanic or tannin-furanic solutions during wood modification. Impregnation of furanic or tannin-f...
M Mubarok, E Azadeh, F O Akong, S Dumarçay, A Pizzi, C Charbonnier-Gérardin, P Gérardin
Novel bio-based tannin/furfurylic alcohol thermosets: application to wood preservation
2022 - IRG/WP 22-40959
This project is integrated within the overall context of sustainable development and targets the valorization the wood industry by-products such as polyphenolic extractives, and in particular tannins. The objective targets the use of the same polymer used for production of tannin-furanic foams, but here for wood preservation to avoid the utilization of biocides. The aims is to the design of copoly...
C Gérardin-Charbonnier, E Azadeh, A Pizzi, P Gerardin
Structure bioactivity relationships of softwood knot extracts
2023 - IRG/WP 23-11026
Antibacterial, antifungal and radical scavenging activities of knots of three softwood species have been investigated to evaluate the role of higher amounts of extractives present in knots. The results showed than Douglas fir presented higher scavenging activity than fir and spruce, which present more or less the same activities. Fir and spruce extracts presented higher antibacterial activities th...
P Gérardin, P Gérardin, D Hentges, S Dumarçay, C Audouin, C Gérardin-Charbonnier
Optimization of furfurylic alcohol/tannin ratio to improve the performance of biosourced thermoset resins for wood protection
2023 - IRG/WP 23-40994
This study concerns the chemical modification of wood with different ratios of tannin and furfuryl alcohol (FA) in the presence of maleic acid as catalyst. Tannins were used not only as cross-linking agents, but also as co-monomers to improve wood durability, while reducing the amount of FA used. Different aqueous formulations were prepared containing decreasing amount of FA (from 45.45% to 0%) an...
E Azadeh, A Pizzi, P Gérardin, C Gérardin-Charbonnier
Synergistic effects between 2-HPNO, Irganox 1076 and EDTA on the inhibition of wood degradation by Coriolus versicolor
2004 - IRG/WP 04-30331
The efficiency of 2-hydroxypyridine-N-oxide (2-HPNO) as wood preservative has been investigated. As shown using classical experiments as well as using response surface methodology, the efficiency of 2-HPNO as wood preservative is strongly improved in presence a chelator like EDTA and/or of Irganox 1076 an industrial antioxidant. In these conditions, wood preservative efficiency of the mixture the ...
A Mabicka, S Dumarçay, N Rouhier, M Linder, J P Jacquot, P Gérardin, E Gelhaye
Evaluation of tropolone as a wood preservative : activity and mode of action
2002 - IRG/WP 02-30282
The fungicidal activity of 2-hydroxy cyclohepta-2,4,6-trienone (tropolone) analogue of b-thujaplicin a natural product responsible for the durability of heart wood of several
cupressaceous trees was investigated in vitro on growth of white and brown rot fungi. Results obtained show that tropolone, easily prepared from commercially available products,
possesses strong fungicidal activity similar ...
P Gérardin, M Baya, N Delbarre, P N Diouf, D Perrin, P Soulounganga, E Gelhaye,
J P Jacquot, C Rapin
Evaluation of hydroxamates as wood preservatives
2004 - IRG/WP 04-30330
Fungicidal activity of different hydroxamates was investigated by laboratory malt-agar block tests to evaluate their potential as wood preservatives. Results obtained indicate that benzohydroxamic acids substituted or not on the aromatic nuclei were unable to protect wood blocks against the white rot fungus Coriolus versicolor while 2-hydroxypyridine-N-oxide (2-HPNO) possesses an interesting activ...
P Gérardin, S Dumarçay, E Gelhaye, A Mbamba, V Mussavu
Investigation on a Wood Decay Biomarker
2006 - IRG/WP 06-20336
HPLC evolution of beech wood extractives was investigated with or without exposure to Coriolus versicolor during one month. The nature and the quantity of extracts depends on the extraction conditions, but were also strongly influenced by the wood drying temperature and time leading to an important modification for higher drying temperature. After two weeks of exposure to Coriolus versicolor, resu...
S Mounguengui, S Dumarçay, P Gérardin
Investigation of new wood preservation formulations based on synergies between antioxidant, 2-HPNO and Propiconazole
2006 - IRG/WP 06-30401
Wood degradation by fungi is a complex phenomenon taking place in part through oxidative reactions involving many oxidizing agents like free radicals and hydroperoxide. In order to develop novel and more environmentally benign preservative systems, mixtures of Propiconazole and antioxidants with different stabilization mechanisms were investigated to detect possible synergies allowing to reduce th...
B Bakhsous, S Dumarçay, E Gelhaye, P Gérardin
Improvement of Grevillea robusta durability using heat treatment
2006 - IRG/WP 06-40333
Heat treatment of Grevillea robusta was carried-out under inert conditions to improve its durability. Resistance of heat treated samples was evaluated by malt agar block tests after three months of exposure to several wood rotting fungi. Results showed that the fungal durability was greatly improved after treatment. There was a good correlation between fungal resistance and mass loss which is a fa...
F Mburu, S Dumarçay, F Huber, M Petrissans, P Gérardin
On the reasons of Prunus africana natural durability
2007 - IRG/WP 07-10611
Analysis of Prunus africana heartwood extractives was studied with the aim of understanding the reasons for its high natural durability. Soxhlet extractions of wood powder using different solvents were carried out. Effect of each extracts at different concentrations was evaluated on the growth of several fungi among which Coriolus versicolor, Poria placenta, and Aureobasidium pullulans. Results sh...
F Mburu, S Dumarçay, M F Thévenon, P Gérardin
Effects of caffeine on growth of wood-decaying fungi
2007 - IRG/WP 07-30427
The wide-used triazoles alter the biosynthesis of ergosterol leading to a disruption of fungal membrane functions. The aim of this study was to investigate the effects of another cell wall perturbing agent, caffeine, in combination with propiconazole on the growth of wood-decaying fungi. 10 mM caffeine inhibits totally the growth of five fungal species. The obtained results showed that caffeine ha...
S Lekounougou, J P Ondo, J P Jacquot, G Nevers, P Gérardin, E Gelhaye
Effect of amphiphilic antioxidant alkyl ammonium ascorbate on inhibition of fungal growth: Application to wood preservatives formulation
2008 - IRG/WP 08-30466
Amphiphilic surfactants were synthesized from ascorbic acid and different fatty amines and evaluated for formulation of wood preservation products. Characterization of physicochemical properties of the new compounds indicated classical behavior of cationic surfactants. Antioxidant properties, estimated using methyl linoleate oxidation inhibition method, were similar to that of ascorbic acid teste...
C Gérardin , T Koumbi Mounanga, P Gérardin
Effect of wood polymers degradation during heat treatment on extracellular enzymatic activities involved in beech degradation by Trametes versicolor
2008 - IRG/WP 08-40392
Effect of heat treatment on extracellular enzymes involved in wood degradation by Trametes versicolor was investigated. Heat-treated and untreated beech blocks were exposed to T. versicolor on malt agar medium and extracellular enzymatic activities investigated. A strong ABTS oxidizing activity has been detected during the first stage of colonization in both cases, while cellulase activities are m...
S Lekounougou, G Nguila Inari, M Pétrissans, S Dumarçay, J P Jacquot, E Gelhaye, P Gérardin
Effects of new fixative additives on leachability of boron wood preservatives
2009 - IRG/WP 09-30507
Borates are well known with their protective capacity against both fungi and insects with low mammalian toxicity and environmental acceptable. However, boron itself does not ensure the appropriate protection for wood in the exterior applications because of their easily depletion from the treated wood under wet conditions. In this study, the potential use of monoglyceride and polyvinyl alcohol prod...
A Mohareb, J Henry, E Wozniak, P Gérardin
Effect of extractives on durability of Prosopis juliflora heartwood
2009 - IRG/WP 09-30518
The heartwood of Prosopis juliflora is resistant to fungal attack caused by different brown and white rot fungi. This durability due to the presence of high amounts of extractives decreases after extraction of these latter ones with different solvents. Heartwood extractives were effective in inhibiting the growth of the fungi. Depending on the concentration used, development of the fungal mycelium...
P Sirmah, K Iaych, B Poaty, S Dumarçay, P Gérardin
Influence of extractives on durability of Cupressus lusitanica heartwood
2010 - IRG/WP 10-10716
Identification of extractives present in Cupressus lusitanica heartwood has been conducted using GC-MS analyses. The chromatogram of toluene/ethanol extracts indicated the presence of high amounts of benzaldehyde and numerous of terpenic compounds such as cedrol, agathadiol, epimanool, bornyl acetate, -cedrene and -cedrene. Effect of extractives on cypress natural durability has be...
A Mohareb, P Sirmah, L Desharnais, S Dumarçay, M Pétrissans, P Gérardin
Effects of polyvinyl alcohol on leachability and efficacy of boron wood preservatives against fungal decay and termites attack
2010 - IRG/WP 10-30526
In this study, the use of polyvinyl alcohol (PVA) as boron fixative agent was investigated. Two levels of PVA (2.5 and 4%) were evaluated with disodium octaborate tetrahydrate (DOT) at three concentrations (1, 2 and 4% boric acid equivalent (BAE) using a double vacuum impregnation processes on Scots pine sapwood specimens. Leaching was performed according to a laboratory leaching procedure. Boron ...
A Mohareb, M F Thévenon, E Wozniak, P Gérardin
Development of markers to predict decay durability of heat treated wood
2010 - IRG/WP 10-40496
Effect of heat treatment temperature on elemental composition of Scots pine sapwood (Pinus sylvestris) has been investigated in the range of temperatures between 220 and 250°C. Results revealed an important increase of carbon content, while oxygen content significantly decreases. Independently of the heat treatment temperature, elemental composition is strongly correlated with the mass losses due...
Ž Šušteršic, A Mohareb, M Chaouch, M Pétrissans, M Petric, P Gérardin
Utilization of thermodesorption coupled to GC-MS to study kinetics of thermodegradation of different wood species
2011 - IRG/WP 11-40559
Thermdesorption coupled to Gas Chromatography coupled to Mass Spectroscopy (TD-GC-MS) has been investigated to identify volatile degradation products generated during wood heat treatment by mild pyrolysis. For this purpose, wood samples of different softwood and hardwood species have been heat treated under nitrogen for different temperatures comprised between 180 and 230°C during 15 min. in the ...
K Candelier, M Chaouch, S Dumarçay, A Pétrissans, M Pétrissans, P Gérardin
Utilization of thermodesorption coupled to GC-MS to characterize volatiles formation kinetics during wood thermodegradation
2012 - IRG/WP 12-40587
Identification of volatile degradation products produced during wood mild pyrolysis is important to have better insight on thermodegradation mechanisms. Previous studies have shown that thermodesorption coupled to GC-MS is an attractive tool to characterize and quantify products formed during wood thermodegradation indicating an higher susceptibility of hardwoods to thermodegradation compare to so...
K Candelier, S Dumarçay, A Pétrissans, M Pétrissans, P Kamdem, P Gérardin