首页 | 本学科首页   官方微博 | 高级检索  
     检索      

基于FTIR和UV-Vis光谱表征蒸汽介质高温热改性对橡胶木颜色的影响
引用本文:李晓文,李彤彤,李冠君,李民,秦韶山,陆全济.基于FTIR和UV-Vis光谱表征蒸汽介质高温热改性对橡胶木颜色的影响[J].热带作物学报,2019,40(4):746-752.
作者姓名:李晓文  李彤彤  李冠君  李民  秦韶山  陆全济
作者单位:中国热带农业科学院橡胶研究所,国家重要热带作物工程技术研究中心橡胶分中心,海南儋州 571737
基金项目:海南省自然科学基金项目(317280);中国热带农业科学院基本科研业务费专项资金项目17CXTD-05(1630022017013)
摘    要:以水蒸汽作为保护气,将橡胶木分别置于155℃处理2、6 h,185℃处理2、6 h,215℃处理2 h,测定了热改性后的橡胶木颜色,并通过紫外-可见光谱(UV-Vis)和傅里叶变换红外光谱(FTIR)对木材热改性前后的化学结构进行了表征。结果表明,高温热改性处理使橡胶木的颜色从浅黄白色变为橙色然后转向深棕褐色,随着处理程度加深,明度值L*持续降低。热改性程度较浅时色饱和度C*略有增加,木材颜色趋于鲜艳,而随着处理程度加深色饱和度C*大幅降低,颜色趋于黯淡。木材颜色变化的总色差ΔE*可反映热改性的程度,改性处理越剧烈,总色差ΔE*越大,处理温度比处理时间对木材颜色变化的影响更为显著。UV-Vis光谱显示,热改性材在350~550nm波段的吸收显著增强,说明有大量发色基团和助色基团生成。结合FTIR光谱,可以推测热改性过程木质素的相对含量升高,紫丁香基团上的甲氧基脱落,木素上苯环氧键的含量稳步降低,从侧面印证可能发生了生成醌的反应。同时,FTIR光谱中有迹象显示可能在155℃处理2 h时半纤维素的乙酰基就开始大量脱落。

关 键 词:橡胶木  热改性  颜色  红外光谱  紫外-可见光谱
收稿时间:2018-07-10

The Characterization of Effects of Thermal Modification on Rubber Wood Color Change Based on FTIR and UV-Vis Analysis
LI Xiaowen,LI Tongtong,LI Guanjun,LI Min,QIN Shaoshan,LU Quanji.The Characterization of Effects of Thermal Modification on Rubber Wood Color Change Based on FTIR and UV-Vis Analysis[J].Chinese Journal of Tropical Crops,2019,40(4):746-752.
Authors:LI Xiaowen  LI Tongtong  LI Guanjun  LI Min  QIN Shaoshan  LU Quanji
Institution:Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences / State Engineering and Technology Research Center for Key Tropical Crops, Danzhou, Hainan 571737, China
Abstract:The color changes of thermally modified rubber wood, which was treated at 155 ℃ and 185 ℃ for 2 and 6 h, and 215 ℃ for 2 h respectively, were analyzed using the CIE L *a *b * color space. Changes in chemical structure of the wood samples were analyzed by UV-visible spectrophotometer (UV-Vis) and Fourier transforms infrared spectroscopy (FTIR). The results showed that the color of rubber wood became orange and then approached dark brown, and the light value L * decreased steadily. The parameter C * increased at the beginning of thermally modified treatment and then went down rapidly. The parameter ΔE * showed a positive correlation with the modification degree, and treatment temperature played a more important role in the change of wood color compared with treatment time. A significant increase emerged in the 350-550 nm in UV-Vis spectra of heat-treated rubber wood above 185 ℃, indicating the generation of chromophoric groups. According to FTIR spectra, the content of lignin increased as hemicellulose and cellulose degraded at high temperature; and the loss of syringyl units or breaking of aliphatic side-chains could be inferred from a shift of maximum absorption from 1507 cm -1 to approximately 1511 cm -1 due to decrease of methoxyl groups. The cleavage of acetyl groups was considered to be detected in FTIR spectra in the samples treated at 155 ℃ for 2 h.
Keywords:rubber wood  thermal modification  color  FTIR  UV-Vis  
本文献已被 CNKI 维普 等数据库收录!
点击此处可从《热带作物学报》浏览原始摘要信息
点击此处可从《热带作物学报》下载免费的PDF全文
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号