Abstract:The synthesis of segmented poly(tetramethylene oxide) (PTMO) zwitterionomers and their homologous ionenes was achieved through a multistep strategy involving (i) polyaddition of living bifunctional monodisperse PTMO chains (THFACFsSChhO/^O °C, M% ~(2-7) x 103) over diamines (CHahNXCH^kNXCHsk (x = 2, 3, 6) or , -dimethylamino-PTMO to yield segmented PTMO ionenes with fairly high degrees of chain extension (ATW ~20-170), (ii) quantitative exchange of the triflate anion on the ionene by propanesulfonate (CHaCCH^k… Show more
“…DiMethylAminoPropylMethAcrylamide DMAPMA was vacuum distilled over CaH 2 immediately before use. Dicyanoketene ethylene acetal DCKEA was prepared according to the literature 27…”
“…DiMethylAminoPropylMethAcrylamide DMAPMA was vacuum distilled over CaH 2 immediately before use. Dicyanoketene ethylene acetal DCKEA was prepared according to the literature 27…”
“…These complex heterogeneous structures may be readily analyzed within the “multiplet−cluster” concepts recently revisited by Eisenberg et al or within the elegant framework of phase separation in multiblock copolymers considered in the so-called “superstrong segregation regime” (very high Flory χ(A−B) interaction parameter, which is precisely the case of ionomers and zwitterionomers) and extrapolated to the limiting case of only one polar B unit per polar block . On the other hand, we described in the first paper of this series the synthesis and the molecular characterization of a series of homologous segmented zwitterionomers and ionenes based on poly(tetramethylene oxide) (PTMO) corresponding to the general formula: …”
Phase separation has been quantitatively analyzed through DSC and solid state 1 H-NMR spectroscopy (line shape and T1F analysis) on a series of segmented PTMO zwitterionomers carrying dipolar functions of the ammoniopropanesulfonate or ethoxydicyanoethenolate type and of their analogous ionenes. All the amorphous copolymers (M n 0 (PTMO segment) < 3 × 10 3 ) display a typical biphasic structure characterized by a strongly predominant soft matrix of pure PTMO (T g S ) -77 °C) and polar hard domains (T g H ) -5 to 40 °C) where all the polar junctions are concentrated and where every polar unit locks and rigidifies about the two or three vicinal PTMO monomeric units. The thermal stability of the polar aggregates which persist at temperatures much higher than the glass transition T g H depends on their chemical structure: for promoting high cohesion, zwitterions are much more efficient than ion pairs (zwitterionomers versus ionenes) and the ammoniopropanesulfonate function is more efficient than the ethoxydicyanoethenolate one in spite of similar dipole moments (∼25 D). Semicrystalline copolymers (M n 0 (PTMO segment) > 3 × 10 3 ) still show phase separation in their amorphous state in the higher temperature range above their melting points (Tm ∼ 10-25 °C). The typical biphasic morphologies of all these copolymers may be readily interpreted within the multiplet-cluster concept revisited by Eisenberg, and the rigidification of the PTMO units immediately surrounding the polar multiplets is unambiguously evidenced in solid state NMR spectroscopy. The specific segmented chain topology results, however, in an earlier (lower polar unit contents) and far better phase separation than in similar statistical copolymers.
“…Conducting polymers have been studied intensely over the past several decades by many different procedures. [1][2][3][4][5][6][7][8][9] These types of polymers have electrical properties and conductivities which are very similar to those of metals. Examples of the many types of conducting polymers include ionene, polyaniline, polypyrrole, polyferrometallocenes and polythiols.…”
The analysis of synthetic 6-2, 6-3 and 6-4 ionene polymers by electrospray ionization Fourier transform mass spectrometry (ESI-FTMS) is reported here. This is the first in a series of papers on the analysis of conducting polymers utilizing soft ionization techniques, thus allowing for the analysis of intact molecular ions. The syntheses of these individual polymers result in a variety of compounds with different molecular structures which are related to the normal linear ionene polymer. While the mechanisms by which the 6-2 and the 6-3 ionene polymers are synthesized are very similar, the synthesis of 6-4 ionene proceeds differently. In addition, the presence of a gas-phase bromide ion salt-bridged to the backbone of the polymer chain is observed in the resulting mass spectra, as well as the possibility of intramolecular cyclization. The latter has been proposed previously. This cyclization process becomes more possible as the number of methylene groups in the linking chain increases. Finally, we observed that the presence of a bromide ion in the sample helped the interpretation of sustained off-resonance irradiation collisionally-activated dissociation (SORI-CAD). Based on the isotopic pattern provided by the halogens, a "built-in" label which can be traced from the fragment ions back to the parent ion peak is found to be useful in structural assignments.
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