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Evlampieva, N. P.; Михайлова, Н. А.; Корнеева, Е. В.; Ryumtsev, E. I.; Хотимский, В. С.; Литвинова, Е. Г.; Chirkova, M. V.

doi:10.1023/a:1012742721922

Cited by 4 publications

(2 citation statements)

References 9 publications

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“…It is reasonable to assume that the cluster size is associated with the flexibility of the macromolecule, which depends on the configurational composition of the polymer. In [13,22,23], the evaluation of the thermodynamic rigidity was performed for PTMSP based on the double refraction in solutions and hydrodynamic data, and it was shown that a macromolecule enriched with cis-units is characterized by higher flexibility. The increase in the flexibility of macromolecules with the growth in the concentration of cis-units due to the longer cis-fragments provides denser packing of the polymer, which is confirmed by the correlation between the decrease in the size of cluster-like formations and the growth in the concentration of cisunits from 40 to 80%.…”

Section: Resultsmentioning

confidence: 99%

The Supramolecular Organization and Surface Morphology of Films of Poly(1-trimethylsilyl-1-propyne) with Different Configurational Compositions

Матсон

Левин

Ezhov

et al. 2020

Membr. Membr. Technol.

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The structure of the films of poly(1-trimethylsilyl-1-propyne) (PTMSP) with different configurational compositions (the concentration of cis-units of 40 to 80%) is analyzed in this study. The combination of X-ray diffraction analysis and atomic force microscopy makes it possible to reveal the peculiarities of the supramolecular organization and morphology of PTMSP films. The diffraction patterns of PTMSP films indicate an increase in the ordering of the supramolecular organization in the case of an increase in the concentration of cis-units, and the value of the characteristic interchain distance in PTMSP films does not depend on the fraction of cis-units. According to the data of atomic force microscopy, the surface of PTMSP films is characterized by the presence of cluster-like formations the size of which decreases with the increase in the concentration of cis-units (from 18.3 nm for PTMSP with the concentration of the cis-units of 40% to 6.8 nm for PTMSP with the concentration of cis-units of 80%). The decrease in permeability coefficients for O 2 and N 2 with an increase in the concentration of cis-units in PTMSP correlates with the increase in the ordering of the supramolecular organization and decrease in cluster size. The performed study shows that the structural features of the PTMSP films may be due to the effect of both the configurational composition of macrochains and relaxation processes accompanying the formation of a film obtained by evaporation on a substrate.

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Section: Resultsmentioning

confidence: 99%

The Supramolecular Organization and Surface Morphology of Films of Poly(1-trimethylsilyl-1-propyne) with Different Configurational Compositions

Матсон

Левин

Ezhov

et al. 2020

Membr. Membr. Technol.

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“…On the basis of the values of rotation barriers, polymers may be arranged in a sequence that is indirectly related to the rigidity of the backbone chain of polyacetylene: PTMSP 1 > PMP > PTMSP 2 > PTMGP. As was shown in [13][14][15], for PTMSP and PTMGP enriched with trans units, the Kuhn segment length is ~100-80 Å, while in the case of PTMSP pre dominantly composed of cis units, the Kuhn segment length for is much lower: 37-33 Å. Table 3 summarizes the geometrical characteristics of the models for monomer units of polyacetylenes derived from quantum chemical calculations.…”

Section: Potential Barriers To Internal Rotationmentioning

confidence: 85%

Structural features of disubstituted polyacetylenes with bulky substituents at double bonds

2012

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The structural features of polyacetylenes carrying two substituents at double bonds with the gen eral formula [-C(CH 3 )=CR-] n , where R = Si(CH 3 ) 3 , -Ge(CH 3 ) 3 , or CH(CH 3 ) 2 , are studied. It is shown that the experimental IR and Raman spectra of the polymers and the theoretically calculated vibrational spectra for the model polymers consisting of three units coincide well with experimental data. All bands in the IR spectra are interpreted. The potential curves of internal rotation are calculated and constructed; high val ues of rotation barriers indicate a high rigidity of chains for all polymers of interest. The orthogonal arrange ment of neighboring monomer units and, as a result, the absence of electron density conjugation over the polymer chain are revealed. Charges on atoms and electron density on bonds of the monomer unit obtained from theoretical calculations indicate the presence of strong polarization of all bonds, including the -C=C-bond. This effect causes a shift in the frequencies of stretching vibrations due to double bonds in the IR spec tra of polyacetylenes with Si and Ge containing side substituents toward the longwave region. For polyacet ylene with hydrocarbon side substituents -CH(CH 3 ) 2 , such polarization is absent.

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The equilibrium and kinetic rigidity of additive poly(trimethylsilyltricyclononenes) with one and two Si(CH3)3 groups in monomer unit

et al. 2017

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Cited by 4 publications

References 9 publications

The Supramolecular Organization and Surface Morphology of Films of Poly(1-trimethylsilyl-1-propyne) with Different Configurational Compositions

The Supramolecular Organization and Surface Morphology of Films of Poly(1-trimethylsilyl-1-propyne) with Different Configurational Compositions

Structural features of disubstituted polyacetylenes with bulky substituents at double bonds

The equilibrium and kinetic rigidity of additive poly(trimethylsilyltricyclononenes) with one and two Si(CH3)3 groups in monomer unit

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