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1.
The technology of liquefying processed-waste bamboo with phenol is investigated by single factor trials and an orthogonal
design. We studied the preparation technology and properties of adhesives from this phenol-liquefied bamboo with formaldehyde
(BPF). The results show that temperature has a significant effect on liquefaction. The effect of the mass ratio of phenol
to bamboo comes second and the catalyst dosage within the range of 2%–4% is the least effective. The optimum conditions of
liquefaction are as follows: a mass ratio of phenol to bamboo 3.5, a catalyst dosage of 4%, liquefying temperature 145°C and
liquefying time 60 min. The liquefaction rate of bamboo reached 99.1%. For the preparation of the adhesive, a mass ratio of
liquefied bamboo products to formaldehyde (37%) is 100 to 164.8–199.5, while the ratio 100 to 108.2 is the best. This adhesive
has a lower curing temperature than that of normal PF resin. At a hot-press temperature of 130 or 140°C, this new adhesive
provides excellent bonding strength of plywood. The most favorable temperature for hot-pressing is 140°C.
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Translated from Chemistry and Industry of Forest Products, 2007, 27(6): 65–70 [译自: 林产化学与工业] 相似文献
2.
The objective of this study was to find an effective method for treating ma bamboo (Dendrocalamus latiflorus) and moso bamboo (Phyllostachys pubescens) using new water-based reagents containing copper. The effects of green-color protection using various treatments on bamboo
culms were examined in this study. Two methods were used: heating in a water bath and ultrasonic dipping. The results revealed
that excellent green-color protection (a* value of −6.2) was obtained when ma bamboo culms were treated with 0.25% ammoniacal copper quaternary compound-type B (ACQ-B)
in a water bath at 100°C for 2 h. It was also found that the wettability of bamboo epidermis increasedsignificantly after
pretreatment in a mixture of 1% KOH and surfactant in a water bath at 100°C for 30 min. Furthermore, pretreated moso bamboo
culms exhibited excellent green-color protection after they were treated with 0.25% ACQ-B at 100°C for 2 h (a* value of −8.2). This novel treatment method definitely endows the bamboo culms with a fascinating green skin color and consequently
could increase the economic value of bamboo products. No improvement in green-color protection was found when ultrasonic energy
was added to the water bath at ambient temperature. 相似文献
3.
Dynamic properties of bamboo, Phyllostachys pubescens, with moisture content (MC) ranging from −130 to 130°C, were studied by dynamic mechanical analysis (DMA). The results showed
that the hygrothermal effect on dynamic mechanical properties was negative. The storage modulus decreases with increasing
temperature and MC, and glass transition temperature decreases with increasing MC. The glass transition temperature and tan
delta of bamboo were 30.5°C, 0.02 and 10.61°C, 0.04, when MC was 10% and 34%, respectively.
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Translated from Journal of Nanjing Forestry University (Natural Sciences Edition), 2006, 30(1): 65–68 [译自: 南京林业大学学报(自然科学版), 2006, 30(1): 65–68] 相似文献
4.
This study investigated the liquefaction of bamboo in phenol, which involved the effects of weight ratios of phenol to bamboo,
amount of catalyst, temperature, etc. The study showed that liquefaction could be accomplished with a phenol to bamboo weight
ratio of 2–1: 1, a 5% catalyst of HCl or BF3, and a temperature of 115°C. Liquefied bamboo formaldehyde (BLF) resin adhesive for exterior use could be obtained with a
phenol to formaldehyde molar ratio of 1:1.6–2.0. The curing behavior of BLF resin adhesive, studied by TG-DSC and IR analyses,
showed that BLF resin adhesives had a lower curing temperature than PF adhesives but had the same characteristic trough in
IR spectra as PF adhesives.
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Translated from Chemistry and Industry of Forest Products, 2004, 24(3) [译自: 林产化学与工业, 2004, 24(3)] 相似文献
5.
Intercalation of wood charcoal with sulfuric acid (H2SO4) was investigated. Carbonized sugi (Japanese cedar) samples were prepared by heating at various temperatures in the range
1700°–2700°C. Electrochemical oxidization was carried out in H2SO4 and the feasibility of intercalation was determined. In potentiometric analysis, plateaus appeared for samples carbonized
at temperatures above 2300°C. In their X-ray diffraction profiles, the peak at around 26° was shifted to a smaller angle of
about 22.4°. These results can be considered as signs of intercalation with acid molecules. Fourier transform infrared analysis
of charcoal heated at 2700°C, following washing with water and drying of the sample, showed a band at 1220 cm−1 that was assigned to a sulfonate group. This band was not observed for samples heated at 1900°C. These observations suggest
the occurrence of intercalation in the former charcoal, but not in the latter. It is concluded that wood charcoal can undergo
intercalation when it has ordered stacking of hexagonal carbon layers.
Part of this article was presented at the 55th, 56th, and 57th Annual Meetings of the Japan Wood Research Society, Akita,
Hiroshima, and Tsukuba, August 2006, August 2007, and March 2008, respectively, and at the International Conference on Carbon
“CARBON 2008,” Nagano, July 2008 相似文献
6.
Vibrational properties and fine structural properties of wood were measured at high temperatures. Sitka spruce (Picea sitchensis Carr.) and Shioji (Japanese ash, Fraxinus spaethiana Lingelsh.) were used as specimens. The specimens, the system to support them, a magnetic driver, and a deflection sensor
were in an electric drying oven, where vibration tests were conducted. The heating temperatures ranged from room temperature
to 200 °C in 25 °C increments in both heating and cooling processes. X-ray diffractometry was carried out using positive sensitive
proportional counter (PSPC) at room temperature to 200 °C in 20 °C increments in both heating and cooling processes.
Received 13 December 1999 相似文献
7.
Thermal-softening properties and cooling set of water-saturated bamboo were investigated using stressrelaxation measurements
in heating and cooling processes, followed by residual deflection measurement. In the heating process, an obvious decrease
in relative relaxation modulus due to thermal-softening of lignin was found at around 60°C. On the other hand, no clear change
in the relative relaxation modulus was recognized in the cooling process. After the cooling process, about 65% and 75% of
residual set was measured when the specimen was loaded on the epidermis and endodermis side, respectively. Also, residual
set depended on the maximum temperature reached in the heating process and the unloaded temperature in the cooling process.
From these results, it was deduced that the glass transition of lignin from the rubbery to glassy state is important to fix
the deformation. Comparing thermal-softening behavior between bamboo and wood, the relative relaxation modulus of wood decreased
steeply at higher temperatures than for bamboo. On the other hand, while about 75% of residual set was also found for wood,
almost the same as for bamboo, the recovery of deformation with time was larger for wood than for bamboo.
Part of this article was presented at the 53rd Annual Meeting of the Japan Zairyou Society, Okayama, May 2004 相似文献
8.
Norway spruce (Picea abies) was heated for 2–8 h in the temperature range 180–225 °C, under a steam atmosphere. The chemical analyses of the treated
feedstock samples indicated that during heating (total mass loss 1.5–12.5% of the initial DS) carbohydrates (hemicelluloses
and cellulose) were clearly more amenable to various degradation reactions than lignin. In addition, major water-soluble products
released from the feedstock material during the treatments were classified into several compound groups and changes in the
relative mass portion of these groups were monitored by GC during a separate experiment.
Received 20 December 1998 相似文献
9.
Thermogravimetric and differential thermal analyses techniques have been applied to investigate the thermal degradation characteristics
and chemical kinetics of Japanese cedar, cypress, fir, and spruce. The decomposition of the components could be modeled by
an Arrhenius kinetic expression. The kinetic parameters were extracted from the thermogravimetric data using least-squares
techniques. The heating rates used for the analyses were 10°, 5°, and 0.33°C/min; and the activation energy and reaction order
of the above woods were 7.54, 8.39, 2.87, and 7.88 kJ/mol and 0.71, 0.64, 0.44, and 0.63, respectively. Finally, carbonization
was done to produce charcoal from these woods under various operating conditions, and the charcoal was characterized in respect
to yield, heating value, electrical conductivity, and X-ray diffraction. The quality of the charcoal from fir was the best
among the four types of wood. The charcoal produced is inferior to binchotan (white charcoal) in respect to electrical conductivity
and crystalline structure.
Received: February 13, 2002 / Accepted: July 12, 2002
Acknowledgment The authors express their gratitude to Professor Yoshida of Applied Chemistry in Tokyo Metropolitan University for performing
the TG/DTA in his laboratory and for his valuable suggestions about the analyses. 相似文献
10.
This study focuses on a novel, multipass, acoustically open photoacoustic detector designed for fast-response high-sensitivity
detection of formaldehyde adsorption by bamboo charcoal in an ambient atmosphere. The detection range, estimated from formaldehyde
measurements at a wavenumber of around 2805 cm−1, is 0–2.0 parts per million by volume. In this work, photoacoustic (PA) detection with various bamboo charcoals was analyzed
at our laboratory for the detection of a photoacoustic signal using a pulsed laser system and the comparative performances
of the charcoals were studied. The PA system is applicable to pollution monitoring and detection of hazardous gases in an
indoor environment. 相似文献
11.
Tsutomu Suzuki Kyoko Suzuki Yukio Takahashi Mitsuhiro Okimoto Tetsuo Yamada Noriyasu Okazaki Yuichi Shimizu Masashi Fujiwara 《Journal of Wood Science》2007,53(1):54-60
Japanese larch wood loaded with nickel (1%–4%) alone or with nickel and calcium (0.25%–1.5%) was carbonized at 800°–900°C
for 0–120min with a heating rate of 5°–20°C min−1 in a helium flow of 5.8−46.4 ml STP cm−2 min−1 to examine the influence of these variables on the crystallization of carbon (the formation of T component) and the development
of mesoporosity. From the obtained results, reaction conditions suitable for effective production of carbon with the dual
functions of adequate electroconductivity and adsorption capacity in liquid phase were established, thereby explaining the
factors that govern the process. It was also confirmed that mesopore having a diameter of about 4 nm was selectively produced
at the cost of specific (BET) surface area in parallel with the formation of T component. This result provided good insight
into how the simultaneous dual function could be realized. 相似文献
12.
Raw moso bamboo (Phyllostachys pubescens) was examined to optimize the carbonization and the consecutive air activation procedure. Influence of sample size, nitrogen
flow rate, heating rate and final temperature on the carbon yield and the pore structure was investigated for the raw bamboo.
The short length cutting along bamboo trunk and the increase in heating rate to 40°C/min and nitrogen flow rate up to 500
ml/min was found to be advantageous for the carbonization of raw bamboo at 500°C, resulting in a surface area of 230 m2/g with a bamboo char yield of 25% on dry base. In the next step, effects of air treatment temperature, ash content and its
composition on the pore development were studied for the prepared bamboo char in comparison with coconut shell char. Additional
increase in surface area by 200 m2/g with 97% yield could be achieved conducting the 2-hour air treatment at 280°C for the bamboo char, whereas only a 100 m2/g rise in surface area was attained for the coconut shell char, partly due to the difference in K2CO3 content in the char. 相似文献
13.
In order to improve the efficiency of softening bamboo block when manufacturing bamboo veneer, chemistry reagents such as
NaHCO3 are often adopted during bamboo softening treatment. But the results of Fourier transform infrared spectroscopy (FTIR) showed
that the band intensity at 1,733 cm−1, assigned to C=O stretching vibration in xylan, was reduced in the spectrum of softening-treated bamboo with NaHCO3 compared with that of not softening-treated bamboo and softening treatment of bamboo without NaHCO3. That is to say, that the hemicellulose of bamboo was destroyed after softening treatment with NaHCO3, which meant that softening treatment of bamboo with NaHCO3, is not a perfect softening treatment method. Thus, in this paper a softening technology at 120°C for 30 min in a closed
container was adopted. The results of FTIR show that there was almost no difference in FTIR spectra between no softening treatment
of bamboo and softening treatment of bamboo at 120°C for 30 min, which meant that softening treatment at 120°C for 30 min
had no effect on the composition of bamboo. The results of dynamic mechanical analysis (DMA) show that T
g of not softening-treated bamboo was 120°C, while T
g of softening-treated bamboo at 120°C for 30 min was 88°C. T
g of softening-treated bamboo at 120°C for 30 min decreased by 26.7% compared with that of not softening-treated bamboo. The
results of hardness show that the hardness of bamboo strip after a softening treatment for 30 min at 120°C decreased by 42.0–54.6%
compared with that of not softening-treated bamboo. The results of hardness and DMA show that the effect of softening treatment
of bamboo at 120°C for 30 min was resultful. 相似文献
14.
Carbonization mechanism of bamboo(phyllostachys) by means of Fourier Transform Infrared and elemental analysis 总被引:3,自引:0,他引:3
ZUOSong-lin GAOShang-yu YUANXi-gen XUBo-sen 《林业研究》2003,14(1):75-79
Bamboo was carbonized at different temperatures ranging from 200℃ to 600℃.The dependence of the change of hemicellulose,cellulose,and lignin on the temperature was investigated by means of elemental analysis and Fourier Transform Infrared (FTIR) spectra of the residual solid products.The results showed:(1)Below 200℃,hemicellulose in bamboo wasdecomposed and a large amount of hydroxyl groups are dislocated from hemicellulose and cellulose,accompanied by the evolution of water to escape.(2)200℃-250℃,cellulose in bamboo was brastically decomposed whereas the net structure of lignin keep stable,with the except of the dislocation of methoxyl groups from lignin.(3)250℃-400℃,the net structure of lignin collapse,up to 400℃,followed by that the more position in aryl groups are substituted.(4)For bamboo carbonization,the aromatization of residual carbon has approximately completed at the temperature as high as 600℃.But the fusion of aromatic rings possibly does not occur. 相似文献
15.
By means of the analysis of TG-DSC curves, we studied the effect of temperature and several additives, i.e., H2SO4, HCl, NaOH, H2O2 and H3PO4 on the performance of the thermal decomposition of bamboo. The results indicated that the weightlessness of pure bamboo powder
may be divided into three stages, up to 700°C. At each stage, the effect of each chemical additive on the weightlessness rate
of bamboo was different. In the end, we analyzed the function of additives in practical applications of the thermal decomposition
of bamboo.
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Translated from Journal of Bamboo Research, 2007, 26(1): 42–45 [译自: 竹子研究汇刊] 相似文献
16.
This study evaluated the protection effectiveness of alcohol-borne reagents for the green color of ma bamboo (Dendrocalamus latiflorus Munro) and moso bamboo (Phyllostachys pubescens Mazel). The results show that the types and concentrations of alcohol-borne reagents, the kinds of solvent, and the conditions
of treatment greatly affected the green color of these two bamboo species. Without alkali pretreatment, an excellent green
color protection (a* = −14.5) was obtained when the ma bamboo culms were treated with 0.5% methanol-borne copper chloride (CuCl2) at 60°C for 30 min. Similar results were also obtained when ma bamboo culms were treated with 0.5% methanol-borne copper
nitrate [Cu(NO3)2] at 60°C for 2 h (a* = −13.5). For moso bamboo, an attractive green color in the bamboo culms was achieved by treating the specimens with 1%
methanol-borne copper acetate [Cu(CH3COO)2] at 60°C for 30 min. The a* value of treated specimens was −13.3. In addition, results demonstrated that ultrasonic treatment was more effective on
green color protection than conventional water bath treatment. When moso bamboo was treated with 1% copper acetate at 60°C
in an ultrasonic bath for only 15 min, a remarkable green color with an a* value of −13.6 was obtained on the bamboo epidermis. 相似文献
17.
Tsuguyuki Saito Masayuki Hirota Naoyuki Tamura Akira Isogai 《Journal of Wood Science》2010,56(3):227-232
Oxidation of bleached wood pulp by the TEMPO/NaClO/NaClO2 system was carried out at pH 3.5–6.8 and 25°–60°C with different amounts of NaClO, and investigated in terms of effects of
the reaction conditions on carboxylate content and degree of polymerization (DP) of the oxidized pulp. Oxidation was accelerated
by the addition of NaClO, when carried out at pH 6.8 and 40°–60°C. Addition of NaClO of more than 0.5 mmol per gram of the
pulp was effective to accelerate the oxidation. Carboxylate content of pulp oxidized under such conditions increased to approximately
0.6 mmol/g within 6 h. Although DP of the oxidized pulp gradually decreased with oxidation time, no significant differences
in DP of oxidized pulps were found at oxidation temperatures between 25° and 60°C, and DP values of more than 900 were maintained
after oxidation for 54 h at 60°C. 相似文献
18.
Masamitsu Nakajima Yuzo Furuta Yutaka Ishimaru Makoto Ohkoshi 《Journal of Wood Science》2009,55(2):107-112
To clarify the effects of tissue and structure of bamboo on its bending properties and set by cooling (bent at 90°C and cooled
to 20°C with bending), the effects of set in bast-fiber-rich (Bfib) and parenchyma-cell-rich (Bpar) specimens were investigated with regard to their dynamic viscoelastic properties, chemical composition, and recovery from
deformation with time. The results are summarized as follows: (1) while no clear effect of the proportion of parenchyma cells
and bast fibers on residual set immediately after cooling was found, the relative recovery from the deformation with time
for Bfib was larger than that for Bpar. (2) Slightly higher lignin content and a-cellulose were seen in Bfib than in Bpar. (3) The peak temperature of loss modulus (E″) found for Bpar, which was attributable to micro-Brownian motion of lignin, was obviously lower than that for Bfib. This was considered to be due to differences in the degree of condensation of lignin or higher-order structure. From these
results, it was deduced that the bastfiber-rich specimen, which showed a higher peak temperature regarding thermal softening
of lignin allowing the induction of insufficient thermal-softening in the range of 20° to 90°C, caused a larger recovery from
deformation with time.
Part of this report was presented at the 56th Annual Meeting of the Japan Wood Research Society in Akita, August 2006 相似文献
19.
20.
Masamitsu Nakajima Yuzo Furuta Yutaka Ishimaru Makoto Ohkoshi 《Journal of Wood Science》2009,55(4):258-263
To clarify the effects of lignin on the fixation of bending deformation by cooling, cooling set for delignified woods with
various lignin residues were investigated to compare with mechanical and dynamic viscoelastic properties. Bending tests showed
that steep reductions occurred in the modulus of elasticity and modulus of rupture with delignification during the initial
stage of delignification. The dynamic viscoelastic measurements revealed that the peak temperature of tan δ due to micro-Brownian
motion of lignin was reduced with delignification, and the peak disappeared in the temperature range of 5°–100°C for the specimens
that had lost more than 21% of their weight. On the other hand, no clear change in residual set was found in the range of
0%–15% of weight loss in spite of a marked reduction in lignin content. Subsequently, set decreased steeply for the specimens
delignified beyond 15% of weight loss. It was suggested that cooling set is not determined solely by lignin content but is
influenced by changes in the quality of lignin due to delignification. Lignin quality affects the balance of the elastic potential
to recover from deformation and its viscosity, which is an indication of resistance against flow.
Part of this report was presented at the 57th Annual Meeting of the Japan Wood Research Society, Hiroshima, August 2007 相似文献