Condensed tannins from grape pomace: Characterization by FTIR and MALDI TOF and production of environment friendly wood adhesive

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• 作者：Lan Ping^a ; ^b ; Antonio Pizzi^b ; Zhou Ding Guo^a ; Nicolas Brosse^b ; ^{nicolas.brosse@lermab.uhp-nancy.fr}
• 关键词：Grape pomace ; Tannin-based adhesives ; MALDI-TOF spectrometry ; Formaldehyde emission ; Wood particleboard
• 刊名：Industrial Crops and Products
• 出版年：2012
• 出版时间：November, 2012
• 年：2012
• 卷：40
• 期：Complete
• 页码：13-20
• 全文大小：524 K

文摘

Condensed tannins were extracted from grape pomace using a water medium in presence of three different bases as catalyst (NaOH, Na₂CO₃ or NaHCO₃) and were characterized by FT-IR and MALDI-TOF spectrometry. It was demonstrated that the tannin extracts contained oligomers up to 6 repeating flavonoid units, with dominant procyanidin with a minor amount of prodelphinidin units. The structure of grape pomace tannin extracted did not present noticeable discrepancy exception of the ratio of the opening pyran ring which was different as a function of the catalyst used. Two different formulations (nonfortified tannin adhesive and fortified with addition of 20 % of polymeric 4,4?diphenyl methane diisocyanate (pMDI)) were used to press one layer particle board. It has been proved that the extraction processes largely affect the adhesive properties of the extracts obtained from the same raw material. Especially the particleboards prepared from tannins extracted using Na₂CO₃ as catalyst and without pMDI, give a high internal bonding value (IB = 0.45 MPa), which was good enough to pass relevant international standard specifications for interior grade panels. Formaldehyde emission of these panels is very low, well under the European Norm requirements (?.5 mg/100 g panel).