Near-Model Amphiphilic Polymer Conetworks Based on Four-Arm Stars of Poly(vinylidene fluoride) and Poly(ethylene glycol): Synthesis and Characterization

• DOI: 10.1021/acs.macromol.7b02475
• Publication Date: 2018-03-19T19:37:04Z
• Authors: Demetris E. Apost...; Costas S. Patrickios; Takamasa Sakai; Marc Guerre; Gérald Lopez; Bruno Améduri; Vincent Ladmiral; Miriam Simon; Michael Gradzielski; Daniel Clemens; Christian Krumm; Joerg C. Tiller; Bruno Ernould; Jean-François Gohy
• Keywords: Chain transfer

Amphiphilic polymer conetworks (APCN) were prepared in N,N-dimethylformamide (DMF) by the interconnection of four-arm star poly(vinylidene fluoride) (PVDF, Mn = 8800 Da) end-functionalized with benzaldehyde groups and poly(ethylene glycol) (PEG, 10 kDa) benzaacylhydrazide groups. The PVDF stars via reversible addition–fragmentation chain transfer polymerization vinylidene fluoride using a tetraxanthate agent. Equilibrium swelling APCNs various solvents was dependent on compatibility APCN components solvent, degrees (DS) varying from 22 DMF (a good solvent for both PEG PVDF), down to 8 water selective PEG), even 3 diethyl ether nonsolvent polymers). Characterization D2O small-angle neutron scattering (SANS) indicated phase separation at nanoscale, as evidenced (broad) correlation peak, consistent 19 nm spacing between formed PVDF-based hydrophobic clusters ∼10 diameter an aggregation number ca. 50 (growing size content). This behavior independent temperature 25 70 °C slightly deviations (±ca. mol %) PVDF: stoichiometry. Conetwork characterization bulk atomic force microscopy (AFM) revealed domain 14 ± 6 nm, agreement 11 calculated SANS results above (19 nm) but also taking into account DS (5.5). Annealing 200 °C, melting point PVDF, did not improve morphological order AFM images. Finally, room ionic liquid binary mixture lithium bis(trifluoromethanesulfonyl)imide:1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (1:9 molar ratio) exhibited electrochemical stability up 4.3 V ion conductivity 0.6 mS cm–1.