New fluorinated surfactants based on vinylidene fluoride telomers
New fluorinated surfactants based on vinylidene fluoride telomers
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DOI：
10.1016/j.jfluchem.2011.06.019
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发表时间：
2012-02-01
影响因子：
1.9
通讯作者：
Ameduri, B.
中科院分区：
文献类型：
--
作者：
Boutevin, G.;Tiffes, D.;Ameduri, B.
介绍了CnF_（2n +1）（VDF）（x）-（CH_2）（p）-（n = 2，4; x = 2，3，4; p = 0，1，2）和VDF（VDF）的合成，VDF和VDF分别代表偏氟乙烯（VDF）和I，OH或CO_2 H。首先，在各种实验条件下研究了VDF与C-nF 2n +1-1的自由基调聚以直接低分子量调聚物：引发剂，温度和溶剂，以有利于形成C（n）F2（n+1）（VDF）（x）1。无论实验条件如何，都观察到中心点CnF 2n +1自由基区域选择性地加成到VDF的亚甲基位点上。然后，这些VDF调聚物的乙烯化，实现了在过氧引发剂的存在下与含VDF的碘化物反应物的定量转化。R-F（VDF）（x）C_2H_4I转化为R-F（VDF）C_2H_4OH的化学反应分两步进行：（i）在DMF/水混合溶剂中（DMF/水的比例为6/1时反应条件最佳）;（ii）在碱性介质中皂化R-F（VDF）（x）CH_2CH_2OCOH甲酸酯，得到相应的含VDF的醇。发现合适的条件以避免VDF调聚链的任何脱氢。这些含氟醇在H2SO 4/CrO 3混合物存在下氧化生成相应的CnF 2n +1（VDF）（x）CH 2CO 2 H羧酸。这些含VDF的羧酸的表面张力达到19.8 mN m（-1）的值为5 g L-1的表面活性剂浓度显示类似的值作为商业上可获得的全氟辛酸（PFOA），而临界胶束浓度值C2F 5CH 2CF 2CH 2CF 2CH 2CO 2 H在室温下为1.4 g L-1。(C)2011 Elsevier B. V.保留所有权利。
The synthesis of CnF2n+1(VDF)(x)-(CH2)(p)- where n = 2, 4; x = 2, 3, 4; p = 0, 1, 2 and VDF and stand for vinylidene fluoride (VDF) and I, OH, or CO2H, respectively, are presented. First, the radical telomerization of VDF with C-n F2n+1-1 to direct low molecular weight-telomers was investigated in various experimental conditions: initiators, temperatures and solvents to favour the formation of C(n)F2(n+1)(VDF)(x)1. Whatever the experimental conditions, it was observed the regioselective radical addition of center dot CnF2n+1 radical onto the methylene site of VDF. Then, ethylenation of these VDF telomers was achieved in the presence of peroxy initiator with a quantitative conversion of the VDF-containing iodide reactants. Chemical change of R-F(VDF)(x)C2H4I into R-F(VDF)C2H4OH occurred in two steps: (i) front a mixture of DMF/water (for which a 6/1 content led to the best conditions); (ii) followed by a basic medium to saponify R-F(VDF)(x)CH2CH2OCOH formiate into the corresponding VDF-containing alcohols. Suitable conditions were found to avoid any dehydrofluorination of the VDF telomeric chain. Oxidation of these fluorinated alcohols in the presence of H2SO4/CrO3 mixture led to the corresponding CnF2n+1(VDF)(x)CH2CO2H carboxylic acids. Surface tensions of these VDF-containing carboxylic acids were achieved reaching a value of 19.8 mN m(-1) for a surfactant concentration of 5 g L-1 showing similar values as that of commercially available perfluorooctanoic acid (PFOA) while critical micellar concentration value of C2F5CH2CF2CH2CF2CH2CO2H was 1.4 g L-1 at room temperature. (C) 2011 Elsevier B.V. All rights reserved.