@article {1734, title = { Acetyl Groups in Typha capensis: Fate of Acetates during Organosolv and Ionosolv Pulping }, journal = {POLYMERS}, volume = {10}, year = {2018}, abstract = {

During biomass fractionation, any native acetylation of lignin and heteropolysaccharide may affect the process and the resulting lignin structure. In this study, Typha capensis (TC) and its lignin isolated by milling (MWL), ionosolv (ILL) and organosolv (EOL) methods were investigated for acetyl group content using FT-Raman, H-1 NMR, 2D-NMR, back-titration, and Zemplen transesterification analytical methods. The study revealed that TC is a highly acetylated grass; extractive free TC (TCextr) and TC MWL exhibited similar values of acetyl content: 6 wt \% and 8 wt \% by Zemplen transesterification, respectively, and 11 wt \% by back-titration. In contrast, lignin extracted from organosolv and [EMIm][OAc] pulping lost 80\% of the original acetyl groups. With a high acetyl content in the natural state, TC could be an interesting raw material in biorefinery in which acetic acid could become an important by-product.

}, url = {https://hal.univ-lorraine.fr/LERMAB-UL/hal-02297011}, author = {I.G. AUDU and N. BROSSE and H. WINTER and A. HOFFMANN and M. BREMER and S. FISCHER and M.P. LABORIE} } @article {1623, title = { The chemical, kinetic and mechanical characterization of tannin-based adhesives with different crosslinking systems }, journal = { INTERNATIONAL JOURNAL OF ADHESION AND ADHESIVES }, volume = {68}, year = {2016}, pages = {1-8}, abstract = {

Network formation, cure characteristics and bonding performance of tannin-based resins were investigated in order to establish structure-property relationships between the stage B and stage C. Tannin-aldehyde and base-catalyzed autocondensed tannin resins were synthesized and characterized for molecular weight distribution, cure kinetics and cure chemistry by means of GPC, DMA and C-13 CP/MAS NMR spectroscopy and solvent stability tests. The resins performance as wood adhesives was further established from lap-shear tests and microscopic observation of the bondline. Resins prepared with highly reactive aldehydes, such as formaldehyde or glyoxal, exhibited a significant extent of hetero-condensation reactions, fast cure kinetics, a high storage modulus and good solvent stability of the stage C-resin. In contrast, resins prepared with bulky aldehydes of low reactivity, such as citral, were dominated by autocondensation reactions, and exhibited slower cure kinetics, a lower storage modulus and solvent-stability of the stage C-resin, alike those neat autocondensed tannin resins. However, all resin systems fulfilled the standard requirements for wood adhesive bonding for interior applications. Additionally, storage modulus increase during cure was found to be a good predictor of the stiffness of the wood-bonded assembly, useful to discriminate between the autocondensation and heterocondensation cure chemistries.

}, url = {https://hal.archives-ouvertes.fr/hal-01599534}, author = {R. BOHM and M. HAUPTMANN and A. PIZZI and C. FRIEDRICH and M.P. LABORIE} } @article {1653, title = { Modification of condensed tannins: from polyphenol chemistry to materials engineering }, journal = { NEW JOURNAL OF CHEMISTRY }, volume = {40}, year = {2016}, pages = {36-49}, abstract = {

Condensed tannins (CTs) are high molar mass polyphenolic bio-polymers based on flavonol units. CTs have been well-studied due to their respective biological activity. However, the application of CTs in several areas is limited because of their physicochemical properties. The objective of this review is to investigate the state of the art regarding the chemical modification of CTs, and to outline recent and potential applications of tannin derivatives. An overview of the most important reactions is given, and a comprehensive summary of the experimental parameters for modification (chemicals, time, temperature, solvent type, and yield) is presented. The impact of the modification on the physicochemical properties of derivatives in comparison to native tannin behavior is discussed. Finally, the applicability of modified or unmodified CTs is described, referring to academic articles and patents. Future research in terms of modification reaction type, as well as derivatizing agents, is discussed.

}, url = {https://hal.univ-lorraine.fr/hal-01599784}, author = {D.E. GARCIA and W.G. GLASSER and A. PIZZI and S.P. PACZKOWSKI and M.P. LABORIE} } @article {1549, title = { Biobased foams from condensed tannin extracts from Norway spruce (Picea abies) bark }, journal = { INDUSTRIAL CROPS AND PRODUCTS }, volume = {73}, year = {2015}, pages = {144-153}, abstract = {

Different kinds of tannin-based foams were developed in the recent past with fisetinidin/robetinidin-type tannins extracted from mimosa (Acacia mearnsii) or quebracho (Schinopsis lorentzi) bark; or procyanidin-type tannins from pine (Pious pinaster and Pinus radiata). These biobased porous products revealed excellent properties similar to their synthetic counterparts in many applications. Norway spruce (Picea abies) bark is another large potential source of procyanidin-type tannins. In this study rigid and homogeneous foams were produced from purified tannins containing at least 80\% of polyflavonoid condensed tannins. This paper deals with the study of spruce tannins reactivity for rigid foam formulations. Characterization results have point out their very good mechanical resistance (sigma \> 0.08 MPa), and low thermal conductivities (lambda \< 0.045 W/m/K) at low densities (d \< 50kg/m3).

}, url = {https://hal.archives-ouvertes.fr/hal-01294580}, author = {C. LACOSTE and M. COP and K. KEMPPAINEN and S. GIOVANDO and A. PIZZI and M.P. LABORIE and M. SERNEK and A. CELZARD} } @article {1560, title = { Characterization of the curing process of mixed pine and spruce tannin-based foams by different methods }, journal = { EUROPEAN POLYMER JOURNAL }, volume = {69}, year = {2015}, pages = {29-37}, abstract = {

Dielectric analysis, rheometry and differential scanning calorimetry were used in this study to analyse the curing process of tannin-based foams using mixture of maritime pine and Norway spruce tannins. The amounts of blowing agent (pentane) and catalyst (para-toluene sulphonic acid) were varied with the aim of monitoring the changes in the curing processes of foams.

A thermal analysis carried out by differential scanning calorimetry revealed an almost finished reaction at the time of the peak temperature, occurring from the reaction of foaming, whereas conversion results derived from dielectric analysis and rheological tests indicated that curing process began after the occurrence of maximum temperature. With increased catalyst concentration, the start of curing process was accelerated, while a raised amount of pentane delayed the curing process. The curing process of the tannin-based foams was divided into three characteristic phases: the induction phase, the expansion phase, and the structure-strengthening phase.

}, url = {https://hal.univ-lorraine.fr/hal-01598441}, author = {M. COP and B. GOSPODARIC and K. KEMPPAINEN and S. GIOVANDO and M.P. LABORIE and A. PIZZI and M. SERNEK} } @article {1542, title = {The effect of the composition of spruce and pine tannin-based foams on their physical, morphological and compression properties}, journal = {INDUSTRIAL CROPS AND PRODUCTS}, volume = {74}, year = {2015}, pages = {158-164}, abstract = {

Tannin-based foams were successfully prepared, using Norway spruce and maritime pine tannins. Various parameters, including the amount of procyanidins, were varied in order to observe the effect of changes in the density of the foam, on the structure its pores, and on the homogeneity, compressive strength, and compressive modulus of the foams. It was found that an optimum amount of spruce tannin exists, which results in a foam with the lowest density whereas the amount of cross-linker affects homogeneity, and the foam morphology is defined by the surfactant A partial replacement of pine tannin with spruce tannin decreased the foaming temperature and led to decreased compressive strength and a decreased compressive modulus of the foams. The main attribute affecting the reaction was the amount of polyphenols, or the amount of impurities (cellulosic sugars) present in the tannin extract.

}, url = {https://hal.univ-lorraine.fr/LERMAB-UL/hal-01599795}, author = {M. COP and C. LACOSTE and M. CONRADI and M.P. LABORIE and A. PIZZI and M. SERNEK} } @article {1565, title = { Hydroxypropyl tannin from Pinus pinaster bark as polyol source in urethane chemistry }, journal = { EUROPEAN POLYMER JOURNAL }, volume = {67}, year = {2015}, pages = {152-165}, abstract = {

Novel thermosetting polyphenol-based polyurethane (PU) films were prepared using condensed tannin (CTs) and hydroxypropyl tannin derivatives (HPTs) from Pinus pinaster bark and diisocyanates. Four HPTs with a degree of substitution (DS) rising stepwise from 1 to 4 were crosslinked with either an aromatic (polymeric methylene diphenyl diisocyanate (pMDI)) or an aliphatic isocyanate (hexamethylene diisocyanate (HDI)). Chemical structure, moisture sorption, thermal, and morphological properties of the films were studied. Properties varies with NCO:OH ratio (0.5-4.0), DS, diisocyanate type, and cross-link density (CD). Partial tannin hydroxypropylation (DS 2, 3) based/films showed a flexible-type character in term of Young\&$\#$39;s modulus, elongation and tensile strain. Significant relationships were established between CD and physicochemical properties. HPTs constitute suitable macro building-block polyols for urethane chemistry.

}, url = {https://hal.univ-lorraine.fr/hal-01598443}, author = {D.E. GARCIA and W.G. GLASSER and A. PIZZI and S. PACZKOWSKI and M.P. LABORIE} } @article {1548, title = { Natural albumin/tannin cellular foams }, journal = { INDUSTRIAL CROPS AND PRODUCTS }, volume = {73}, year = {2015}, pages = {41-48}, abstract = {

Albumin/tannin-based foams were prepared under alkaline or acid conditions by whipping up a water solution of a protein, egg albumin, mixed with a second water solution of condensed flavonoid tannins. Foam formulations with 4 different condensed tannin bark extracts and different relative proportions of protein and tannin were developed with a rapid foaming process where the protein has a double function: co-reagent and surfactant as well. Physical properties such as mechanical performance, thermal conductivity, and porous structure were characterised to identify the large potential of applications of these new cellular foams, fully bio-based and probable easier biodegradability. Moreover, some albumin-based foams were found to be completely flexible in certain conditions.

}, url = {https://hal.archives-ouvertes.fr/hal-01294576}, author = {C. LACOSTE and M.C. BASSO and A. PIZZI and A. CELZARD and M.P. LABORIE} } @article {1175, title = {Curing characterisation of spruce tannin-based foams using the advances isoconversional method}, journal = {BioRessources}, volume = {9}, year = {2014}, month = {2014}, chapter = {4643}, author = {M. COP and M.P. LABORIE and A. PIZZI and M. SERNEK} } @article {1173, title = {Pinus pinaster tannin/furanic foams : Part 2: physical properties.}, journal = {Ind. Crops \& Prod.}, year = {2014}, author = {C. LACOSTE and A. PIZZI and M.C. BASSO and M.P. LABORIE and A. CELZARD} } @article {1189, title = {Polyphenolic resins prepared with maritime pine bark tannin and natural bulky-aldehydes.}, journal = {Ind. Crops \& Prod.}, volume = {62}, year = {2014}, month = {2014}, chapter = {84}, author = {D.E. GARCIA and W.G. GLASSER and A. PIZZI and C. LACOSTE and M.P. LABORIE} } @article {1190, title = {Substitution pattern elucidation of hydroxypropyl Pinus pinaster (Ait.) bark polyflavonoids derivatives by ESI(-)-MS/MS. }, journal = {J. Mass Spectrometry}, volume = {49}, year = {2014}, month = {2014}, chapter = {1050}, author = {D.E. GARCIA and W.G. GLASSER and A. PIZZI and S. PACZKOWSKI and M.P. LABORIE} }