袁英杰,李如燕,孙可伟,李根.柠檬酸交联纤维素气凝胶的制备及其网络结构的表征[J].材料导报,2016,30(14):72-75, 103 |
柠檬酸交联纤维素气凝胶的制备及其网络结构的表征 |
Preparation of Citric Acid Crosslinked Cellulose Aerogel and Characterization of the Aerogel′s Network Structure |
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DOI:10.11896/j.issn.1005-023X.2016.14.016 |
中文关键词: 纤维素气凝胶 柠檬酸 交联剂 网络结构 |
英文关键词: cellulose aerogel, citric acid, crosslinking agent, network structure |
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摘要点击次数: 2470 |
全文下载次数: 2007 |
中文摘要: |
以柠檬酸作为交联剂,在氯化锂/N,N-二甲基乙酰胺(LiCl/DMAc)的纤维素溶解体系中,通过溶剂置换、酯化交联反应和超临界干燥工艺制备了纤维素气凝胶。通过电子显微镜、傅里叶红外光谱分析仪、差示扫描量热仪以及密度、吸水率和力学性能测试对纤维素气凝胶的结构和性能进行了表征。结果表明:柠檬酸的改性或纤维素初始浓度的增大均能使纤维素气凝胶的网络结构变得更加紧密,改性获得的气凝胶网络结构能够获得更加稳定的化学交联点且具有更小的孔隙和更好的形变恢复能力;柠檬酸与纤维素结构单元的物质的量比为1∶1时纤维素气凝胶具有更好的热、力稳定性能;在25~120 ℃温度范围内反应温度越高交联反应程度越大。讨论了使用柠檬酸作为交联剂以及改变交联反应条件对纤维素气凝胶网络结构的影响。 |
英文摘要: |
Cellulose aerogels were prepared by solvent replacement, esterification crosslinking reaction and supercritical drying process in the lithium chloride/N,N-dimethyl-acetamide(LiCl/DMAc) solvent system, using citric acid as the crosslinking agent. The structure and properties of prepared cellulose aerogels were characterized by SEM, FT-IR and DSC. The density, bibulous rates and mechanical property were measured as well. Results showed that the network structure of cellulose aerogels would be closer when citric acid was used as the crosslinking agent and the initial concentration of the cellulose was increased. Cellulose aerogels achieved more stable chemical crosslinking points after crosslinking which had smaller pores and better shape recovery property. Cellulose aerogels showed better thermal and mechanical stability when the molar ratio of citric acid and cellulose structural units was 1∶1. When the temperature lay in the range of 25 ℃ to 120 ℃, the degree of crosslinking reaction increased with the increase of temperature. The effect of using citric acid as the crosslinking agent and changing the crosslinking reaction conditions on the network structure of cellulose aerogel were discussed. |
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