@article {1847, title = { Characterization and 3D printability of poly (lactic acid)/acetylated tannin composites }, journal = { INDUSTRIAL CROPS AND PRODUCTS }, volume = {149}, year = {2020}, abstract = {

In this study, a three-dimensional (3D) printing filament prepared from poly (lactic acid) (PLA) and acetylated tannin via a twin-screw extruder was reported. The impact of acetylated tannin loading content on the final properties of the resulting composite materials and their 3D printability were investigated. The experimental results indicate that PLA can be compounded with up to 20 wt\% acetylated tannin without any obvious deterioration in the tensile property. The resulting composites acquired better degradation rate in aquatic system compared with neat PLA, especially in alkaline medium. Moreover, all composites are printable and showed generally good printing quality with brown color, however, this is limited to temperatures reasonably below 220 degrees C to avoid printing defects, especially at high loadings of acetylated tannin.

}, url = {https://hal.univ-lorraine.fr/LERMAB-UL/hal-02508080}, author = {J.J. LIAO and N. BROSSE and A. PIZZI and S. HOPPE and X.J. ZHOU and G.B. DU} } @article {1871, title = { Characterization and Preparation of Furanic-Glyoxal Foams }, journal = {POLYMERS}, volume = {12}, year = {2020}, pages = {692}, abstract = {

Synthetic foams have become an essential industrial product for a great variety of applications. Furfuryl alcohol, as a biomass chemical, was reacted with glyoxal at room temperature to prepare furanic-glyoxal rigid foams, and p-toluenesulfonic acid was used as a catalyst to initiate the reaction. Foams with different molar ratios (furfuryl alcohol/glyoxal) were prepared in this work, and uniform cells foams have been obtained. Their compression resistance, 24-h water absorption, density, and other basic properties were tested. Scanning electron microscopy (SEM) was used to observe the cellular morphology of the foams prepared, thermogravimetric analysis (TGA) helped to understand their thermal and combustion properties, and FTIR and Matrix Assisted Laser Desorption Ionisation Time of Flight (MALDI ToF) mass spectroscopy to explain the structure of the resulting foams to clarify the reactions occurring during foaming. The results show that the compression resistance of furanic-glyoxal foams declined as the furfuryl alcohol/glyoxal ratio decreases also. SEM observations revealed that foams with open-cell were obtained when furfuryl alcohol was added in greater amounts, and more closed cell structures were formed as the proportion of glyoxal increased. TGA results showed that the initial ignition temperature of furanic-glyoxal foams is similar to 200 degrees C higher than that of wood, and the smaller comprehensive combustion index S (about 0.15 x 10(-7) (\%2 K-3 min(-2))) indicates that the foam burns slowly and has poor flammability, that is, it is not easy to burn.

}, author = {X.D. XI and A. PIZZI and H. LEI and G.B. DU and X.J. ZHOU and Y.Y. LIN} } @article {1861, title = { Condensed tannin-glucose-based NIPU bio-foams of improved fire retardancy }, journal = { POLYMER DEGRADATION AND STABILITY }, volume = {175}, year = {2020}, abstract = {

Glucose-based self-blowing non-isocyanate polyurethanes foams were prepared in our previous work. They showed excellent properties comparable to commercial foams by just using a simple preparation procedure. These foams, nevertheless, present a critical drawback that is their flammability. In the research presented here a natural phenolic compound, condensed tannin, was tested as a flame-retardant to improve the fire resistance of glucose-based NIPU foams. A number of tannin-substituted glucose-based NIPU foams (mimosa tannin replacing glucose at 0\%, 25\% and 50\%, respectively) were prepared and characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), Thermogravimetric analysis (TG), ignition experiment and limiting oxygen index (LOI). Other physical and mechanical properties, such as foaming processes, density, compression strength, etc. were also investigated. The results indicated that the tannin-modified glucose-based NIPU foams (T/G (1/3)-Fs and (T/G (1/1)-Fs)) exhibit smaller mean cell size, improved compression strength and higher density than (T/G (0/4)-Fs). The FT-IR analysis showed that urethane linkages were formed, the chemical structure of glucose-based NIPU foam being nonetheless preserved even if the glucose was partially replaced by the condensed tannin. Thermogravimetric analysis showed that the presence of condensed tannin decreased the thermal stability of the tannin-glucose NIPU foam composites slightly. In addition, ignition experiments were also carried out in which the glucose-based NIPU foams with a condensed tannin showed longer burning time than neat (T/G (0/4)-Fs). Finally, limiting oxygen index (LOI) values from 17.5\% to 25.5\%, show a higher value with the increasing condensed tannin substitution.

}, author = {X.Y. CHEN and J.X. LI and X.D. XI and A. PIZZI and X.J. ZHOU and E. FREDON and G.B. DU and C. GERARDIN} } @article {1850, title = { One-step compatibilization of poly(lactic acid) and tannin via reactive extrusion }, journal = { MATERIALS \& DESIGN }, volume = {191}, year = {2020}, abstract = {

The compatibility issue between poly(lactic acid) (PLA) and tannin is a big challenge for preparing PLA/tannin biocomposites with enhanced properties. In this work, composites with enhanced properties have been accomplished using an efficient one-step reactive extrusion method with the help of methylene diphenyl diisocyanate (p-MDI) or 3-aminopropytriethoxysilane (APS). The extent of compatibility achieved via the one-step was evaluated by tensile, morphological, rheological, and thermal properties. The obtained results indicated that the adhesion promoters, especially p-MDI, contributed efficiently to an improved tensile behavior of the resulting composites with a tough tensile-fracture surface compared with incompatibilized PLA/tannin composite. Moreover, these composites displayed a plateau-like rheological behavior, enhanced complex viscosity, higher melting and thermal degradation temperature. This approach can be potentially adapted to other PLA/biopolymers composite systems.

}, url = {https://hal.inria.fr/hal-02495239/}, author = {J.J. LIAO and N. BROSSE and S. HOPPE and G. DU and X.J. ZHOU and A. PIZZI} } @article {1865, title = { Preparation and Characterization of Condensed Tannin Non-Isocyanate Polyurethane (NIPU) Rigid Foams by Ambient Temperature Blowing }, journal = {POLYMERS}, volume = {12}, year = {2020}, abstract = {

Ambient temperature self-blowing mimosa tannin-based non-isocyanate polyurethane (NIPU) rigid foam was produced, based on a formulation of tannin-based non-isocyanate polyurethane (NIPU) resin. A citric acid and glutaraldehyde mixture served as a blowing agent used to provide foaming energy and cross-link the tannin-derived products to synthesize the NIPU foams. Series of tannin-based NIPU foams containing a different amount of citric acid and glutaraldehyde were prepared. The reaction mechanism of tannin-based NIPU foams were investigated by Fourier Trasform InfraRed (FT-IR), Matrix Assisted Laser Desorption Ionization (MALDI-TOF) mass spectrometry, and C-13 Nuclear Magnetic Resonance (C-13 NMR). The results indicated that urethane linkages were formed. The Tannin-based NIPU foams morphology including physical and mechanical properties were characterized by mechanical compression, by scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). All the foams prepared showed a similar open-cell morphology. Nevertheless, the number of cell-wall pores decreased with increasing additions of glutaraldehyde, while bigger foam cells were obtained with increasing additions of citric acid. The compressive mechanical properties improved with the higher level of crosslinking at the higher amount of glutaraldehyde. Moreover, the TGA results showed that the tannin-based NIPU foams prepared had similar thermal stability, although one of them (T-Fs-7) presented the highest char production and residual matter, approaching 18.7\% at 790 degrees C.

}, author = {X.Y. CHEN and X.D. XI and A. PIZZI and E. FREDON and X.J. ZHOU and J.X. LI and C. GERARDIN and G.B. DU} } @article {1837, title = { DEVELOPMENT OF MIMOSA TANNIN-BASED ADHESIVE CROSS-LINKED BY FURFURYL ALCOHOL- FORMALDEHYDE AND EPOXY RESINS }, journal = { WOOD RESEARCH }, volume = {64}, year = {2019}, pages = {847-858}, abstract = {

A furfuryl alcohol-formaldehyde resin was synthesized as a crosslinker in our laboratory to develop a mimosa tannin-based adhesive with good water resistance. C-13 nuclear magnetic resonance and matrix-assisted laser desorption ionization time-of-flight mass spectroscopy indicated that furfuryl alcohol reacted with formaldehyde under acidic conditions and that-CH (-OH) - groups to be the ones involved in the crosslinking of mimosa tannin-furfuryl alcohol-formaldehyde adhesive (TFF). The wet shear strength of TFF-bonded plywood suggested that the cured TFF adhesive was better than mimosa tannin-furfuryl alcohol (TF) adhesive. The water resistance of TFF adhesive cross-linked with 9\% epoxy resin was also higher than those of TFF and TF adhesives.

}, author = {J. ZHANG and L.H. XIONG and X.J. ZHOU and G.B. DU and J.K. LIANG and X.D. XI} } @article {1805, title = { Polypropylene Blend with Polyphenols through Dynamic Vulcanization: Mechanical, Rheological, Crystalline, Thermal, and UV Protective Property }, journal = {POLYMERS}, volume = {11}, year = {2019}, abstract = {

Tannin and lignin were blended with polypropylene (PP) through dynamic vulcanization technique. Their influence of mechanical property, crystallinity, thermal stability, as well as ultraviolet (UV) protection property on the PP matrix was investigated and compared with native tannin and lignin. According to our experimental results, tannin and lignin undergo dynamic vulcanization and were more compatible with the PP matrix. Besides, tannin and vulcanized tannin can perform as nucleating agents of PP because of their relatively small particle size. Moreover, vulcanized tannin/lignin have a better performance on the thermal stability of PP compared with native tannin/lignin, especially PP/vulcanized lignin blend. Furthermore, vulcanized tannin/lignin present better UV protective performance, concluded from fewer changes on surface morphology, carbonyl index, crystallinity, viscosity, and tensile property.

}, url = {https://hal.univ-lorraine.fr/LERMAB-UL/hal-02196798}, author = {J.J. LIAO and N. BROSSE and A. PIZZI and S. HOPPE and X.D. XI and X.J. ZHOU} } @article {1815, title = { SYNTHESIS AND CHARACTERIZATION OF LIGNIN-BASED ADHESIVE CROSS-LINKED WITH FURFURYL ALCOHOL-FORMALDEHYDE AND EPOXY RESINS }, journal = { CELLULOSE CHEMISTRY AND TECHNOLOGY }, volume = {53}, year = {2019}, pages = {449-458}, abstract = {

Lignin extracted from corn stalk was cross-linked with furfuryl alcohol-formaldehyde (FF) resin in the laboratory to prepare a bio-based adhesive, with good water resistance, for producing particleboard. The results of matrix-assisted laser desorption-ionization time-of-flight mass spectroscopy and C-13 nuclear magnetic resonance spectroscopy indicated that furfuryl alcohol reacted with formaldehyde under acidic conditions. The -CH-(OH)- groups were involved in the cross-linking of the lignin-furfuryl-formaldehyde (LFF) adhesive. The internal bond strength of the LFF-bonded particleboard showed that the cured LFF was improved and had higher performance compared to the lignin-furfuryl alcohol (LF) adhesive. The LFF with 9\% epoxy resin adhesive had an excellent modulus of elasticity, which was higher than those of PF and LF adhesives.

}, author = {J. ZHANG and X.D. XI and X.J. ZHOU and J.K. LIANG and G.B. DU and J. CAI} }