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Bai T.,Beijing Forestry University | Chang J.,Beijing Forestry University | Ren X.,Beijing Forestry University | Wang W.,Beijing Forestry University | And 3 more authors.
Journal of Biobased Materials and Bioenergy | Year: 2015

As one of the most important components in bio-oil, pyrolytic lignin has a close relationship with the property of bio-oil, which also be considered as a potential source to produce value-added chemicals due to its aromatic structure. To improve the stability and increase the economic value of bio-oil, three types of pyrolytic lignin extracted from different kind of bio-oils were studied in this paper. Thermo-gravimetry coupled with FTIR analysis was applied to determine the thermal decomposition behavior and real-time analysis of gases generated during the pyrolysis process. The results were compared with that of the raw alkali lignin, which indicated that PL is more sensitive to temperature and has a lower decomposition temperature range. The analysis on gases generation indicated pyrolytic lignin had less ether bonds, methoxy and hydroxyl groups than alkali lignin. The TG analysis indicated that pyrolytic lignin extracted from larch bio-oil had the lowest residue yields among the three types of PL. The yields of gases from PLs pyrolysis were lower than alkali lignin. Copyright © 2015 American Scientific Publishers All rights reserved.

Li Q.,Planning and Design Institute of Forest Products Industry | Wen-Ji Y.,Chinese Academy of Forestry | Yang-Lun Y.,Chinese Academy of Forestry
Forest Products Journal | Year: 2012

Untreated and 160°C, 180°C, and 200°C thermo-treated bamboo bundle curtains were reconstructed to make high-density board by impregnation with phenol-formaldehyde resin. The physical and mechanical properties of the boards were examined to evaluate the effect of temperature on their qualities. The modulus of rupture decreased with the increase in thermo-treatment temperature and was reduced by nearly 50 percent after 200°C treatment; however, the modulus of elasticity and bonding shear strength did not change much between untreated and thermo-treated specimens. Thermo-treatment improved the dimensional stability of the boards. Thickness swelling atler water immersion and wet-dry cyclic testing decreased with increasing thermo-treatment temperature. Compared 'With the control specimens, the total color difference (ΔE*) changed greatly as the thermo-treatment temperature increased. The chemical and Fourier transform infrared spectroscopy results showed that the major component content and functional groups in the major components changed after thermo-treatment. ©Forest Products Society 2012.

Xia X.-H.,Hunan University | Zhang D.-S.,Planning and Design Institute of Forest Products Industry | Liu H.-B.,Hunan University | He Y.-D.,Hunan University
Gongneng Cailiao/Journal of Functional Materials | Year: 2010

High specific surface area activated carbons used for supercapacitors were prepared from bamboo char and petroleum coke by activation with KOH. The influences of the ratio of KOH to carbon on pore structure, adsorption behavior and capacity performance were investigated. Particular pore structure was showed in activated carbon when different carbon precurcor was used. Abundant micropores (< 2 nm) were discovered in bamboo char-based AC, whereas a relative high mesoporosity was exhibited in petroleum coke based AC when at the same ratio of KOH to carbon. The KOH-activated bamboo char and petroleum coke carbons presented high BET surface area up to 2610.7 and 2597.9 m2/g, respectively. When used for the electrodes of supercapacitors, they exhibited excellent capacitance characteristics in 30 wt% H2SO4 aqueous electrolytes and showed high specific capacitances of 206 and 213 F/g, respectively.

Ren X.-Y.,Beijing Forestry University | Zhang Z.-T.,Beijing Forestry University | Zhang Z.-T.,Planning and Design Institute of Forest Products Industry | Wang W.-L.,Beijing Forestry University | And 3 more authors.
BioResources | Year: 2013

Transformation and products distribution of moso bamboo (Phyllostachys edulis) and its derived components during pyrolysis were investigated by thermogravimetric analyzer coupled with Fourier transform infrared spectrometry (TG-FTIR) and analytical pyrolysis coupled with gas chromatography/mass spectrometry (Py-GC/MS) techniques. The pyrolysis of moso bamboo was generally an integrated result of the decomposition of its several derived components by examining the degradation process parameters and pyrolysis kinetics. The main peaks of the infrared (IR) spectrum for gases released at the highest intensity were assigned to be CO2, CO, CH4, H2O, acids, aldehydes, aromatics, ethers, and alcohols. Pyrolysis temperature played an important role in the products distribution of moso bamboo by affecting the products' yield and secondary cracking of heavy compounds. 500°C was an inflection point for product release during moso bamboo pyrolysis. Further cracking of aromatic compounds and furans into lighter products was observed with increasing pyrolysis temperature.

Yan M.,Northeast Forestry University | Li S.,Northeast Forestry University | Zhang M.,Northeast Forestry University | Li C.,Northeast Forestry University | And 3 more authors.
BioResources | Year: 2013

Surface acetylated nanocrystalline cellulose (NCC) was prepared from cotton fiber by a single-step method under mild conditions using anhydrous phosphoric acid as the solvent. The absorbance peak of O-H was reduced, and the absorbance peaks of C=O and CH3 appeared in the Fourier transform infrared (FTIR) spectrum of the acetylated NCC with respect to that of the unmodified NCC. The roughly estimated degree of substitution was a little greater than 1.5 by FTIR analyses, implying that most of the free hydroxyl groups on the NCC surface were acetylated at 40 °C for 3 h. The carbons of the acetyl groups were clearly identified in the 13C cross polarization-magic angle spinning (CP-MAS) nuclear magnetic resonance (NMR) spectrum. The zeta potential was reduced from-32.12 mV to-20.57 mV after acetylation. Transmission electron microscope (TEM) and field-emission scanning electron microscope (FESEM) images showed that they were thread-like nano-crystals with a diameter less than 5 nm. Crystal structure analysis using X-ray diffraction (XRD) demonstrated that the acetylated NCC had the typical Cellulose'structure. The PLA film reinforced with 3 wt% acetylated NCC content exhibited the highest tensile strength, which was increased by 117% compared to the control. SEM observation demonstrated good interfacial interaction between the acetylated NCC and the matrix.

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