作者机构：
[李新功; 吴义强; 符彬; 袁光明; 陈卫民] School of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha, China;[陈卫民] College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, China
通讯机构：
[Li, X.] S;School of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha, China
摘要：
Microwave pretreatment can increase the transverse permeability of wood. The effects of impregnation on microwave-pretreated wood with low-molecular weight phenol formaldehyde resin was investigated. The results showed that the improved transverse permeability of poplar wood that had received microwave pretreatment resulted in a positive influence on the effect of the impregnation. The maximum impregnation weight gain rate was 51.08%, with the average being approximately 40%. The average density of the specimens impregnated for 1.50 h at 0.8 MPa was 584.8 kg•m-3. During the course of the study, the resin present in the wood became distributed evenly in the vessel elements, wood fiber lumens, and intercellular spaces. Finally, the chromogenic reaction area accounted for 78.11% of the total area in the fluorescent staining diagram of the cross section.
摘要：
Phyllostachys heterocycla is mainly used for pulping. But water and other chemical aids are severely wasted because the content of extractives is high. What's worse, water pollution from the extractives is very serious in South China. Therefore, the acetone extractives of Phyllostachys heterocycla chips were identified by Py-GC/MS. The acetone extractives contains 80 compounds namely lupan-3-one (8.27%), benzofuran, 2,3-dihydro- (8.08%), 2-furancarboxaldehyde, 5-(hydroxymethyl)-(5.97%), lup-20(29)-en-3-one (5.89%), phenol, 2,6-dimethoxy-(5.71%), trimethylamine (5.2%), olean-12-ene (3.79%), ethanone, 1-(3-methoxyphenyl)- (3.6%), nonadecane (3.46%), carbon dioxide (2.98%), phenol, 2-methoxy- (2.97%), acetic acid (2.88%), .beta.-sitosterol (2.22%), 9,12-octadecadienoic acid (Z,Z)- (1.99%), phenanthrene, 9,10-dihydro- (1.86%), hexadecanoic acid (1.85%), 2-propanone, 1-hydroxy- (1.67%), heptadecane (1.55%), 4H-pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl- (1.55%), phenol (1.52%), phenol, 2,6-dimethoxy-4-(2-propenyl)- (1.46%), stigmasterol (1.36%), phenol, 2-methoxy-4-(1-propenyl)- (1.33%), 2(1H)-phenanthrenone, ,4,4a,4b,5,6,7,8,10,10a-decahydro-1,1,4a,7,7-pentamethyl- (1.23%), .alpha.-amyrin (1.12%), 2-pentanone, 4-hydroxy-4-methyl- (1.1%), 1-butanone, 1-(2,4,6-trihydroxy-3-methylphenyl)- (1.1%), etc. So the acetone extractives can be used as biomedicine, bioenergy, and so on.
作者机构：
[杨亿; 向洁琼; 吴义强] School of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China;[李文芳] School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China;[陈志彦] School of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China, School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China
通讯机构：
[Chen, Z.-Y.] S;School of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China
摘要：
Flame retardancy and thermal degradation of wood treated with magnesium chloride (MgCl2 center dot 6H(2)O) were investigated. Results showed that MgCl2 center dot 6H(2)O decreased flame intensity and heat release rate, and reduced smoke concentration and gas yield. From ambient temperature to 250 degrees C, MgCl2 center dot 6H(2)O reduced wood combustibility by gas dilution mechanism. The chemical started to decompose at 350 degrees C and produced MgOHCl, in which -Cl and -Mg free radicals were generated and intervened the chain reactions of wood combustion. Hydrogen chloride gas generated promoted wood charring. MgCl2 center dot 6H(2)O gradually converted to MgOHCl and MgO compounds at higher temperatures, and MgO suppressed wood combustion by the wall effect mechanism. (C) 2013 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.
作者机构：
[夏燎原; 吴义强] College of Material Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China;[胡云楚; 田梁材] College of Science, Central South University of Forestry and Technology, Changsha 410004, China
通讯机构：
College of Material Science and Engineering, Central South University of Forestry and Technology, China
作者机构：
[李新功; 卿彦; 吴义强; 杨守禄; 田翠花; 姚春花] School of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China
通讯机构：
[Wu, Y.-Q.] S;School of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China
关键词：
溶胶-凝胶法;APP-SiO_2凝胶;杨木;复合材料;阻燃抑烟
摘要：
采用溶胶-凝胶法制备聚磷酸铵(APP)-Si O 2凝胶/杨木阻燃复合材料,表征其微观形貌、结构组成、物理力学性能,并研究其阻燃抑烟作用机理。结果表明,APP-SiO_2凝胶主要分布在木材导管、木射线及细胞间隙中,凝胶体系与木材纤维素形成氢键紧密结合。复合材料在700℃的失重率仅为素材的71.9%,残炭量由5.4%上升到31.9%,热稳定性改善。复合材料的热释放速率、总热释放量、烟生成速率、总烟释放量较未处理木材均明显降低,当 APP 浓度为18%时,复合材料的总烟释放量仅为素材的4.9%,表现出高效的阻燃抑烟特性。尽管复合材料的静曲强度略微降低,但其弹性模量明显上升,增幅高达35.8%。
作者机构：
[Chi, Kai; Wu, Qinglin] Louisiana State Univ, Ctr Agr, Sch Renewable Nat Resources, Baton Rouge, LA 70803 USA.;[Wu, Yiqiang] Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha, Hunan, Peoples R China.;[Lee, Sunyoung] Korea Forest Res Inst, Seoul 130712, South Korea.
通讯机构：
[Wu, Qinglin] L;Louisiana State Univ, Ctr Agr, Sch Renewable Nat Resources, Baton Rouge, LA 70803 USA.
摘要：
Thermomechanical pulp (TMP) is used for fiber production in binderless boards industries. Milled wood lignin (MWL) and enzymatic mild acidolysis lignin (EMAL) isolated from raw material and from binderless boards (BB) were comparatively analyzed to investigate the effects of chemical changes on the bonding performance in BB. The results showed that acid-insoluble lignin of the BB were increased during the sodium silicate solution pretreatment after hot-pressing. The lignin fractions obtained were characterized by gel permeation chromatography (GPC), Fourier transform infrared (FT-IR) spectroscopy, and 1H-13C correlation heteronuclear single-quantum coherence (HSQC) nuclear magnetic resonance (NMR) spectroscopy. Results showed that 31.1% of EMAL (based on Klason lignin) with low molecular weight (Mw=1630 g/mol) was isolated from the BB. The increased total phenolic OH groups (3.97 mmol/g) of EMAL from sodium silicate solution pretreated BB indicated that there was degradation of lignin and cleavage of lignin-carbohydrate linkages during hot-pressing. In addition, the content of β-O-4' aryl ether linkages of EMAL from the BB increased to 69.2%, which was higher than that of the untreated sample (60.1%). It was found that S units (syringyl-like lignin structures) were preferentially condensed by hot pressing over G (guaiacyl-like lignin structures) units, and the S/G ratio increased after the hot-pressing process.
作者机构：
[王正良; 罗卫华; 袁彩霞; 吴义强; 唐忠荣] College of Material Science and Engineering, Central South University of Forestry and Technology, Changsha;410004, China;[王正良; 罗卫华; 袁彩霞; 吴义强; 唐忠荣] 410004, China
通讯机构：
[Luo, W.] C;College of Material Science and Engineering, Central South University of Forestry and Technology, Changsha, China
