硅酸钠/硼酸处理增强杨木和辐射松阻燃性能  

Enhancement of wood flame retardancy by treatment with sodium silicate and boric acid

作　　者：肖泽芳 常野 程泽斌 李京潘 王永贵 谢延军[2] 徐子凡 XIAO Zefang;CHANG Ye;CHENG Zebin;LI Jingpan;WANG Yonggui;XIE Yanjun;XU Zifan(Engineering Research Center of Advanced Wooden Materials(Northeast Forestry University),Ministry of Education,Harbin 150040,China;College of Materials Science and Engineering,Northeast Forestry University,Harbin 150040,China;Dehua Tubao New Decoration Material Co.Ltd.,Huzhou 313200,China)

机构地区：[1]木质新型材料教育部工程研究中心(东北林业大学),哈尔滨150040 [2]东北林业大学材料科学与工程学院,哈尔滨150040 [3]德华兔宝宝装饰新材股份有限公司,湖州313200

出　　处：《林业工程学报》2022年第5期35-43,共9页Journal of Forestry Engineering

基　　金：中央高校基本科研业务费专项资金(2572014CB06);国家自然科学基金(31500469)。

摘　　要：先后采用质量分数为10%的硅酸钠(SS)水溶液和5%的硼酸(BA)水溶液,在真空加压辅助条件下通过两步法分别对人工速生林杨木和辐射松进行浸渍处理,制备阻燃杨木和阻燃辐射松木材(SS/BA处理)。未处理素材、10%SS处理材和5%BA处理材作为SS/BA处理材的对比试样。扫描电子显微镜分析显示,SS、BA或者SS/BA在木材中分别以纳米颗粒、微米薄片和微米块状体的形式分布于细胞腔等大孔隙中;SS/BA在细胞腔内的微米块状体表明SS与BA发生反应生成块状凝胶,阻塞了木材细胞腔通道。经SS或者SS/BA处理的杨木出现了一定程度的细胞皱缩现象,表明木材细胞壁组分如木质素和半纤维素经碱性的改性液处理后出现化学降解或物理溶出。X射线能谱分析显示,在细胞壁中存在大量的硅和硼元素,证明改性剂分子能够扩散进细胞壁内部。傅里叶红外变换光谱结果显示,SS与BA二者能够在木材细胞中反应生成凝胶,但缺乏与木材形成化学键的充分证据;经SS或SS/BA处理的木材,其位于1730 cm^(-1)处的羰基特征峰消失,进一步说明了半纤维素等组分的降解和溶出。热重分析表明,SS/BA两步处理的木材最大热降解速率降低,残炭率提高,表明二者协同催化低温成炭,保护木材表面;通过锥形量热仪对木材燃烧性能分析,与对照组相比,经SS/BA两步处理后的杨木和辐射松的点燃时间分别由35和36 s延长至55和53 s,放热速率分别降低了59.9%和51.5%,总热释放量分别降低了56.9%和51.4%,烟生成速率分别降低了83.1%和91.8%,总产烟量分别降低了90.9%和84.2%。上述结果表明,SS物理隔绝作用和BA催化木材成炭作用能够协同增强木材的阻燃性能。Two fast-growing wood species,poplar(Populus adenopoda)and radiata pine(Pinus radiata),were treated by two steps,with aqueous solutions of 10%sodium silicate(SS)firstly and then following with 5%boric acid(BA)through impregnation under vacuum and pressure processes.Wood samples untreated and treated with SS or BA alone were used as references for wood samples treated with SS/BA.The examination of the scanning electron microscopy showed that SS,BA or SS/BA widely distributed in the cell lumens and cavities in the form of nanoparticles,flakes,and bulk solids.The bulk solids in wood treated with SS/BA indicated that SS and BA were reacted to form gel for blocking the cell lumens.The poplar wood treated with SS or SS/BA exhibited cell wall shrinkage to some extent due to the degradation and dissolution of cell wall compositions such as lignin and hemicellulose in the alkaline solution.The energy dispersive X-ray spectroscopy results displayed plenty of elements of silicon and boron in the cell walls,suggesting that both SS and BA can diffuse into cell walls during treatments.The Fourier-transform infrared spectroscopy showed that the condensation of SS and BA in wood;however,the signals for chemical reaction between wood and SS/BA were weak.The characteristic peak at 1730 cm^(-1) disappeared after treatments with the solution containing SS evidenced the dissolution of hemicellulose.The thermogravimetric analysis showed that the SS/BA combinative treatment resulted in a lower pyrolysis temperature and higher residual char,suggesting that both SS and BA synergistically accelerate the formation of chars.The examination of the Cone calorimetry indicated that the treated wood samples are generally more difficult to ignite than the untreated control wood;the ignition times of the SS/BA-treated poplar and radiata pine were extended from 35 s and 36 s to 55 s and 53 s,respectively.Compared to the untreated control ones,poplar and radiata pine wood samples treated with SS/BA exhibited decreases in heat release rates by 59.9%a

关 键 词：硼酸 硅酸钠 杨木 辐射松 阻燃性能 

分 类 号：TS65[轻工技术与工程]