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天然纤维素的详细溶解步骤 已有1人参与
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越详细越好，谢谢！ 发自小木虫IOS客户端 |
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9楼2018-08-23 22:51:17
2楼2017-08-22 22:48:18
| 7%NaOH/12%尿素水溶液预冷至-10 oC后，将50g纤维素(粘均分子量Mη为11.4×104)分散于1000g该溶剂中，室温下剧烈搅拌5分钟即获得透明的纤维素溶液。 |
» 本帖已获得的红花（最新10朵）
xiaoLifeiD3楼2017-08-23 14:11:25
celan
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从事NMR和有机结构鉴定40余年
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xiaoLifeiD: 金币+50, ★★★很有帮助 2017-09-09 16:05:27
感谢参与，应助指数 +1
xiaoLifeiD: 金币+50, ★★★很有帮助 2017-09-09 16:05:27
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Macromol Biosci. 2005 Jun 24;5(6):539-48. Rapid dissolution of cellulose in LiOH/urea and NaOH/urea aqueous solutions. Cai J1, Zhang L. Author information Abstract Rapid dissolution of cellulose in LiOH/urea and NaOH/urea aqueous solutions was studied systematically. The dissolution behavior and solubility of cellulose were evaluated by using (13)C NMR, optical microscopy, wide-angle X-ray diffraction (WAXD), FT-IR spectroscopy, DSC, and viscometry. The experiment results revealed that cellulose having viscosity-average molecular weight ((overline) M eta) of 11.4 x 104 and 37.2 x 104 could be dissolved, respectively, in 7% NaOH/12% urea and 4.2% LiOH/12% urea aqueous solutions pre-cooled to -10 degrees C within 2 min, whereas all of them could not be dissolved in KOH/urea aqueous solution. The dissolution power of the solvent systems was in the order of LiOH/urea > NaOH/urea >> KOH/urea aqueous solution. The results from DSC and (13)C NMR indicated that LiOH/urea and NaOH/urea aqueous solutions as non-derivatizing solvents broke the intra- and inter-molecular hydrogen bonding of cellulose and prevented the approach toward each other of the cellulose molecules, leading to the good dispersion of cellulose to form an actual solution. PMID: 15954076DOI: 10.1002/mabi.200400222 按这个地址自己可以下载全文 |
4楼2017-08-25 09:34:04