Upgrading melamine–urea–formaldehyde polycondensation resins with buffering additives. I. The effect of hexamine sulfate and its limits

Kamoun, C.; Pizzi, A.; Zanetti, Michela

doi:10.1002/app.12634

Cited by 77 publications

(53 citation statements)

References 34 publications

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“…13 C-NMR has confirmed (Kamoun et al, 2003;Pichelin et al, 1999) that in the presence of chemical species with very reactive nucleophilic sites, such as condensed flavonoid tannins, hexamine is not at all a formaldehyde-yielding compound. The very reactive imines and iminoaminomethylene intermediates initially formed in its decomposition do react with the phenolic species present without ever passing through the formation of formaldehyde (Kamoun et al, 2003;Pizzi and Tekely, 1995;Pizzi et al, 1996).…”

Section: Introductionmentioning

confidence: 96%

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Évaluation de la durabilité des produits en bois imprégnés avec du borax et collés avec un adhésif naturel à base d’amidon de maïs et de tannin

Moubarik

Charrier

et al. 2009

Ann. For. Sci.

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Abstract• At present, the production of wood composites mainly relies on the petrochemical-based and formaldehyde-based adhesives such as phenol-formaldehyde (PF) resins and urea-formaldehyde (UF) resins, which are non-renewable and therefore ultimately limited in supply.• This paper concerns the decay resistance of wood products bonded with a new, environmentfriendly adhesive derived from abundant and renewable cornstarch and tannin. To improve the total resistance of the composite against both Coriolus versicolor and Coniophora puteana rot fungi, borax (di-sodium tetraborate) was added in proportions of 0.5%, 1% and 2% (w/w) to the cornstarch-tannin adhesives.• The results show that increasing the concentration of borax in the adhesive decreased the mechanical properties of the composite. The best way to avoid this problem was to use wood impregnated with borax.• Biodegradation studies were conducted on new composites, first without any treatment, followed by borax at 0.5% aqueous solution treatment. The results show that wood impregnated with borax, in the presence of tannin and sodium hydroxide in the adhesive improves the total resistance of the wood composite against both Coriolus versicolor and Coniophora puteana rot fungi. Mots-clés :borax / amidon de maïs / durabilité / tannin / adhésif Résumé -Évaluation de la durabilité des produits en bois imprégnés avec du borax et collés avec un adhésif naturel à base d'amidon de maïs et de tannin.• Actuellement, la production des composites à base de bois nécessite l'utilisation d'adhésifs d'origine pétrochimique et à base de formaldéhyde, tels que le phénol-formaldéhyde (PF) et l'urée-formaldéhyde (UF), qui sont non renouvelables et limités dans l'approvisionnement.• Ce travail a pour objectif d'étudier la durabilité du bois collé avec une nouvelle colle naturelle à base d'amidon et tannin. Pour améliorer la résistance des composites vis-à-vis des deux types principaux de dégradation fongique, Coriolus versicolor et Coniophora puteana, nous avons ajouté à l'adhésif, différentes concentrations de borax (di-sodium tetraborate) 0,5 %, 1 % et 2 % (m/m).• Les résultats obtenus montrent que l'augmentation de la concentration du borax dans l'adhésif diminue les performances mécaniques des composites. La meilleure façon d'éviter ce problème est de traiter le bois avec du borax, avant collage.• L'étude de la biodégradation a été réalisée sur les nouveaux composites, d'abord sans traitement, et après traitement à 0,5 % (m/m) avec du borax. Les résultats montrent que le bois traité au borax associé à la présence des tannins et de NaOH dans l'adhésif améliore la résistance totale des composites vis-à-vis de Coriolus

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Section: Introductionmentioning

confidence: 96%

“…The very reactive imines and iminoaminomethylene intermediates initially formed in its decomposition do react with the phenolic species present without ever passing through the formation of formaldehyde (Kamoun et al, 2003;Pizzi and Tekely, 1995;Pizzi et al, 1996).…”

Section: Introductionmentioning

confidence: 99%

Évaluation de la durabilité des produits en bois imprégnés avec du borax et collés avec un adhésif naturel à base d’amidon de maïs et de tannin

Moubarik

Charrier

et al. 2009

Ann. For. Sci.

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“…Formaldehyde-based adhesives have been widely used in the wood processing industry because of their good bonding strength, water resistance, heat resistance, and low cost (Boquillon et al 2004;Kamoun et al 2003). However, in recent years, limited petroleum resources and the pollution caused by formaldehyde-based adhesives have spurred many efforts to develop environmentally friendly adhesives from renewable materials (Huang and Li 2008;Li et al 2009b;Liu and Li 2007;Wang et al 2009;Wang et al 2008b).…”

Section: Introductionmentioning

confidence: 99%

Preparation of Wood Adhesives Based on Soybean Meal Modified with PEGDA as a Crosslinker and Viscosity Reducer

Gao

Qin

et al. 2013

BioResources

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To increase the water resistance and reduce the viscosity of soybean meal (SM)-based non-formaldehyde wood adhesives, polyethyleneglycol diacrylate (PEGDA) used as crosslinker and viscosity reducer was introduced into the SM adhesive system. The apparent viscosity was evaluated by rheological measurements; gel content and water absorption of adhesives, the wet shear strength of plywood bonded with these modified adhesives were tested to evaluate their water resistance. In addition, the crosslink structures of modified adhesives were characterized by Fourier transform infrared (FTIR) spectroscopy and solid-state 13 C NMR analysis. The results indicated that all of the SM adhesives were pseudoplastic fluids with the property of shear-thinning. The viscosity of modified SM adhesives effectively decreased by 35% compared with the addition of PEGDA, and the wet shear strength of their bonded plywood increased; the wet shear strength of plywood bonded with 4% PEGDA-modified SM adhesive increased 114.2% compared to SM adhesive. FTIR spectroscopy and solid-state 13 C NMR analysis demonstrated that the crosslinking reaction of the PEGDA occurred successfully during the curing process of PEGDA modified SM adhesive, and no crosslinking reaction between the PEGDA and soy meal adhesive appeared to have occurred. Interpenetrating networks (IPNs) might be formed between the cured PEGDA and SM adhesive system.

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“…9A). Also this can improve water and weather resistance (Kamoun et al 2003, Zanetti & Pizzi 2003a. In industrial productions, star coolers are applied for postcuring of MUF-bonded panels .…”

Section: Melamine-formaldehyde Resinsmentioning

confidence: 99%

Wood production, wood technology, and biotechnological impacts

Kües¹

2007

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Upgrading melamine–urea–formaldehyde polycondensation resins with buffering additives. I. The effect of hexamine sulfate and its limits

Cited by 77 publications

References 34 publications

Évaluation de la durabilité des produits en bois imprégnés avec du borax et collés avec un adhésif naturel à base d’amidon de maïs et de tannin

Évaluation de la durabilité des produits en bois imprégnés avec du borax et collés avec un adhésif naturel à base d’amidon de maïs et de tannin

Preparation of Wood Adhesives Based on Soybean Meal Modified with PEGDA as a Crosslinker and Viscosity Reducer

Wood production, wood technology, and biotechnological impacts

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