Near-Model Amphiphilic Polymer Conetworks Based on Four-Arm Stars of Poly(vinylidene fluoride) and Poly(ethylene glycol): Synthesis and Characterization
Near-Model Amphiphilic Polymer Conetworks Based on Four-Arm Stars of Poly(vinylidene fluoride) and Poly(ethylene glycol): Synthesis and Characterization
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DOI：
10.1021/acs.macromol.7b02475
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发表时间：
2018-04-10
期刊：
影响因子：
5.5
通讯作者：
Gohy, Jean-Francois
中科院分区：
文献类型：
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作者：
Apostolides, Demetris E.;Patrickios, Costas S.;Gohy, Jean-Francois
在N，N-二甲基甲酰胺（DMF）中，通过四臂星星型聚偏氟乙烯（PVDF，M-n = 8800 Da）和四臂星星型聚乙二醇（PEG，M-n = 10 kDa）的相互连接，制备了两亲性聚合物网络（APCN）。采用四黄原酸酯链转移剂，通过偏氟乙烯的可逆加成断裂链转移聚合反应制备了聚偏氟乙烯星形聚合物。APCN在各种溶剂中的平衡溶胀取决于APCN组分与溶剂的相容性，溶胀度（DS）从DMF（PEG和PVDF的良好溶剂）中的22变化到水中的8（PEG的良好和选择性溶剂），甚至到乙醚（两种聚合物的非溶剂）中的3。使用小角中子散射（SANS）表征D2 O中的conetworks表明在纳米级下的相分离，如通过（宽）相关峰所证明的，与所形成的基于PVDF的10 nm直径的疏水簇之间的19 nm间距和约10 nm的聚集数一致。50（随着PVDF含量的增加而增大）。这种行为与25至70摄氏度的温度无关，并略微依赖于偏差（+/- ca. 50摩尔%）。使用原子力显微镜（AFM）在本体中的网络表征揭示了14 6 nm的畴间距，与从上述SANS结果（19 nm）计算的11 nm的间距良好一致，但也考虑到D2 O中的DS（5.5）。在200摄氏度（高于PVDF熔点的温度）下退火，并没有改善AFM图像中的形态有序性。最后，在双（三氟甲磺酰基）亚胺锂：双（三氟甲磺酰基）亚胺1-乙基-3-甲基咪唑（1：9）的室温离子液体二元混合物中制备的APCNs具有高达4.3 V的电化学稳定性和0.6 mS cm（-1）的室温离子电导率。
Amphiphilic polymer conetworks (APCN) were prepared in N,N-dimethylformamide (DMF) by the interconnection of four-arm star poly(vinylidene fluoride) (PVDF, M-n = 8800 Da) end-functionalized with benzaldehyde groups and four-arm star poly(ethylene glycol) (PEG, M-n = 10 kDa) end-functionalized with benzaacylhydrazide groups. The PVDF stars were prepared via the reversible addition fragmentation chain transfer polymerization of vinylidene fluoride using a tetraxanthate chain transfer agent. Equilibrium swelling of the APCNs in various solvents was dependent on the compatibility of the APCN components with the solvent, with the degrees of swelling (DS) varying from 22 in DMF (a good solvent for both PEG and PVDF), down to 8 in water (a good and selective solvent for PEG), and even down to 3 in diethyl ether (a nonsolvent for both polymers). Characterization of the conetworks in D2O using small-angle neutron scattering (SANS) indicated phase separation at the nanoscale, as evidenced by a (broad) correlation peak, consistent with a 19 nm spacing between the formed PVDF-based hydrophobic clusters of 10 nm diameter and an aggregation number of ca. 50 (growing in size with PVDF content). This behavior was independent of temperature from 25 to 70 degrees C and slightly dependent on deviations (+/- ca. 50 mol %) from the PVDF: PEG stoichiometry. Conetwork characterization in the bulk using atomic force microscopy (AFM) revealed a domain spacing of 14 6 nm, in good agreement with the spacing of 11 nm calculated from the SANS results above (19 nm) but also taking into account the DS in D2O (5.5). Annealing the conetworks at 200 degrees C, a temperature above the melting point of PVDF, did not improve the morphological order in the AFM images. Finally, APCNs prepared in the room temperature ionic liquid binary mixture lithium bis(trifluoromethanesulfonyl)imide:1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (1:9 molar ratio) exhibited an electro-chemical stability up to 4.3 V and a good room temperature ion conductivity of 0.6 mS cm(-1).