• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The Journal of Adhesion >A comparison between lignin modified by ionic liquids and glyoxalated lignin as modifiers of urea-formaldehyde resin
【24h】

A comparison between lignin modified by ionic liquids and glyoxalated lignin as modifiers of urea-formaldehyde resin

机译：离子液体和乙醛酸甘油酸的木质素与脲醛树脂改性剂的比较

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The aim of this research was to compare the influence of modified lignin by ionic liquid (IL) on the physical and mechanical properties of wood-based panels bonded with urea-formaldehyde (UF) resin with the effect of glyoxalated lignin (GL) on UF properties. For this purpose, soda bagasse lignin was respectively modified by 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]) IL and glyoxal and then the various content of modified lignins (10, 15, and 20%) were added at pH=7 during the UF resin synthesis instead of the second urea. The changes in the structure and thermal properties of lignin, after and before modification with glyoxal and IL, were analyzed by Fourier transform infrared spectrometry (FTIR) and differential scanning calorimetry (DSC). The physicochemical properties of the prepared resins as well as the water absorption, shear strength, and formaldehyde emission of the plywood panels made with these adhesives were measured according to standard methods. According to the FTIR spectra, the content of C=O bond increased in GL while in the IL-treated lignin the content of C-N bond markedly increased. DSC analysis indicated that lignin modified by IL had lower glass transition temperature (T-g) value compared to those modified with glyoxal and unmodified lignin, respectively. The UF resins containing IL-treated lignin exhibit a faster gel time compared to those prepared with GL. Equally, the plywood panels prepared with an IL had lower formaldehyde emission and higher mechanical strength compared to those made from UF resin containing GL. There were no significant differences in dimensional stability of the panels bonded with UFs modified with GL and those with IL-modified lignin.
机译：该研究的目的是将修饰的木质素（IL）与离子液体（IL）对脲醛（UF）树脂粘合的木基面板的物理和力学性能进行比较，其具有乙醛酸甘黄素（GL）对UF的影响特性。为此目的，分别由1-乙基-3-甲基咪唑鎓乙酸盐（β）IL和乙二素苷（乙醛）改性的苏打水，然后加入各种含量的改性木质素（10,15和20％）在UF树脂合成期间pH = 7而不是第二尿素。通过傅里叶变换红外光谱法（FTIR）和差示扫描量热法（DSC）分析木质素和IL后木质素的结构和热性质的变化，在用乙二醛和IL进行修饰之后。根据标准方法测量制备的树脂的物理化学性质以及用这些粘合剂制成的胶合板板的吸水，剪切强度和甲醛排放。根据FTIR光谱，C = O键的含量在GL中增加，而在IL治疗的木质素中，C-N键的含量明显增加。 DSC分析表明，与用乙醛和未改性木质素改性的那些，IL改性的木质素具有较低的玻璃化转变温度（T-G）值。与用GL制备的那些相比，含有IL处理的木质素的UF树脂表现出更快的凝胶时间。同样，与由含有UF树脂制成的G1制成的胶合醛排放和较高的机械强度，胶合板具有较低的甲醛发射和更高的机械强度。用GL和IL改性木质素改性的UFS粘合的面板的尺寸稳定性没有显着差异。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号