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Direct fluorination of acetyl and ethyl celluloses in perfluorinated liquid medium
Journal of Polymer Research ( IF 2.6 ) Pub Date : 2020-08-29 , DOI: 10.1007/s10965-020-02261-8
Nikolay A. Belov , Ilia A. Blinov , Alexander Yu. Alentiev , Vasilii M. Belokhvostov , Dmitrii A. Mukhortov , Sergey V. Chirkov , Anton S. Mazur , Yulia V. Kostina , Olesia N. Vozniuk , Ekaterina S. Kurapova , Yurii P. Yampolskii

Direct fluorination of acetyl- and ethylcelluloses was performed in a bubble reactor with liquid perfluorinated medium (perfluorodecalin). Concentrated fluorination mixtures (F2 + N2) and long reaction times (up to 3 h) were used for better control of the degree of fluorination than it was made previously in direct gaseous fluorination of polymers. The fluorine consumption in the runs with both polymers only slightly increased with increasing temperature and fluorine concentration in the gas mixture. Fluorine content in the fluorinated polymers did not depend strongly on the fluorination conditions. X-ray analysis, differential scanning calorimetry of the fluorinated samples showed no significant changes in respect of the initial polymers. However, emergence of novel and splitting of initial absorption bands, the change of polarization of C–O bonds in IR spectra for the fluorinated samples were observed. It can directly and indirectly justify the appearance of the C–F bonds in the side groups and glycopyranosyl ring of the fluorinated substituted celluloses.19F, 13C solid NMR spectroscopy of the fluorinated samples confirm hydrogen-substituted fluorination of methyl groups.



中文翻译:

在全氟化液体介质中对乙酰基和乙基纤维素进行直接氟化

乙酰纤维素和乙基纤维素的直接氟化是在鼓泡反应器中使用液体全氟化介质(全氟萘烷)进行的。浓氟化物混合物(F 2  + N 2)和较长的反应时间(长达3小时)用于更好地控制氟化程度,这一点要比以前在聚合物的直接气态氟化中所进行的控制更好。两种聚合物在运行中的氟消耗仅随着温度的升高和气体混合物中氟的浓度而略有增加。氟化聚合物中的氟含量在很大程度上不取决于氟化条件。X-射线分析,氟化样品的差示扫描量热法显示初始聚合物没有明显变化。但是,出现了新颖的光谱和初始吸收带的分裂,观察到了氟化样品的IR光谱中C–O键的极化变化。氟化样品的19 F,13 C固体NMR光谱证实了甲基的氢取代氟化。

更新日期:2020-08-29
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