刘 瑞,付时雨.H型和Na型羧基纤维素表面改性接枝己内酯的比较研究[J].中国造纸学报,2017,32(1):32-39 |
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H型和Na型羧基纤维素表面改性接枝己内酯的比较研究 |
The Comparison of Grafting Polycaprolactone on Carboxylate Celluloses in H or Na Form |
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DOI:10.11981/j.issn.1000-6842.2017.01.32 |
中文关键词: 羧基纤维素 聚己内酯 接枝改性 疏水性 热稳定性 |
Key Words:carboxylate celluloses polycaprolactone grafting hydrophobic thermal stabilization |
基金项目:国家自然科学基金(31570569);广东省自然科学基金(2014A030311030)。 |
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中文摘要: |
利用TEMPO/NaBr/NaClO反应体系将纤维素表面的C6-伯羟基氧化成羧基,获得羧基纤维素;以羧基纤维素为原料、己内酯为接枝共聚改性剂,通过开环聚合,合成了表面接枝聚己内酯的纤维素产物。讨论了H型和Na型羧基纤维素接枝己内酯的情况;红外光谱、核磁共振、X射线衍射、表面光电子能谱、表面接触角、热重等分析表明,H型羧基纤维素接枝己内酯的接枝率高于Na型羧基纤维素,且其接枝产物的疏水性更好、热稳定性更高。 |
Abstract: |
The main objective of this work is the comparison of the grafting polycaprolactone (PCL) on the surface of carboxylate celluloses in H or Na form via ring-opening polymerization (ROP) in order to enhance the compatibility between the cellulose and the hydrophobic polymer matrix. In this work, cellulose was oxidized with catalysts of 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO), sodium hypochlorite and sodium bromide in water. The primary hydroxyl groups were selectively oxidized into carboxyl groups. TEMPO-oxidized cellulose with sodium carboxylate groups(TOC-COONa) was completely converted to individual TEMPO-oxidized cellulose with free carboxyl groups (TOC-COOH) and dispersed in water. The two carboxylate celluloses (TOC-COONa and TOC-COOH) were dewatered and grafted with PCL by ROP. The PCL-grafted cellulosic materials were characterized by Fourier transform infrared (FT-IR), X-ray diffraction, elemental analysis, X-ray photoelectron spectroscopy (XPS), contact angle measurement, Carbon-13 nuclear magnetic resonance spectroscopy (13C-NMR) spectroscopic techniques and thermogravimetric (TG) analyses, respectively. The results indicated that TEMPO-oxidized cellulose with free carboxyl groups (TOC-COOH) was more likely to be modified by PCL, and its corresponding PCL-grafted cellulosic materials was more hydrophobic and thermal stable than that of TEMPO-oxidized cellulose with sodium carboxylate groups (TOC-COONa). |
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