Sedimentational-diffusional and viscometric studies on solutions of poly-m-phenylene isophthalamide and the equilibrium rigidity of its molecules

Tsvetkov, V.N.; Lavrenko, P. N.; Bushin, S. V.; Astapenko, E. P.; Boikov, A.A.; Shil'dyayeva, N.A.; Didenko, S. A.; Malichenko, B.F.

doi:10.1016/0032-3950(83)90451-3

Cited by 15 publications

(2 citation statements)

References 11 publications

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“…Alternative analysis of the viscosity and light-scattering 12 data using the semiempirical method proposed by Krigbaum 23 gave similar results for f 0 and q. We note that Tsvetkov and co-workers 25,26 reported values of q as low as 8 Å and as large as 22 Å for the same polymer from hydrodynamic data.…”

Section: Discussionsupporting

confidence: 70%

Tailored Rigid−Flexible Block Copolymers. 3. Fate of the Flexible Block within the Mesophase

et al. 1997

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Diblock copolymers were prepared by condensation of benzoyl-terminated poly(p-benzamide) [PhCO(PBA)] and anilino-terminated poly(m-phenylene isophthalamide) [PhNH(MPD-I)]. The copolymers were freed from unreacted prepolymers and also partially fractionated by selective extraction techniques. The formation of the nematic phase was investigated for three copolymers having a similar length of the rigid PhCO(PBA) block and a fraction β of flexible segment covering a range from 0.5 to 0.7. In the N,N-dimethylacetamide (DMAc) containing 3% LiCl solvent the critical volume fraction v 2 i of the PhCO(PBA) prepolymer was largely unaffected by copolymerization with a similar length of the flexible PhNH(MPD-I) block. At the largest β value only a 25% increase in the critical composition of PhCO(PBA) was observed. The mesophase appears capable of admitting much longer flexible sequences than anticipated. These results are qualitatively in line with a reduced flexibility of the flexible segment due to the self-consistent orientational field of the mesophase. However, comparison of data in aggregating and nonaggregating solvents suggests that mesophase formation should be described in terms of supramolecular assemblies rather than molecularly dispersed units.

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Section: Discussionsupporting

confidence: 70%

Tailored Rigid−Flexible Block Copolymers. 3. Fate of the Flexible Block within the Mesophase

et al. 1997

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“…To estimate the length of the monomer unit of the macroinitiator L 0 , it was assumed that the length of valence bonds is 0.14 nm and the bond angles are tetrahedral; then, in accordance with the APE O structural formula, the sum of its bond lengths along the chain direction is L 0 = 1.6 nm (without deformation of the bond angles) and the macromolecular chain length is L = 60.7 nm. The equilibrium rigidity, which is measured by the Kuhn segment length A, for an APE O can be estimated by comparing its characteristics with the A value for a polymer of close chemical structure, for example, semi-rigid poly(m-phenylene isophthalamide) (PMPhIPhA), studied in [73]. For this polymer, the values A ≈ 4-4.7 nm were obtained, which are increased, compared to flexible-chain polymers, due to aromatic fragments in the meta position.…”

Section: Molecular and Conformational Properties Of Ape O And Ape O -...mentioning

confidence: 99%

Loose Semirigid Aromatic Polyester Bottle Brushes at Poly(2-isopropyl-2-oxazoline) Side Chains of Various Lengths: Behavior in Solutions and Thermoresponsiveness

et al. 2022

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A polycondensation aromatic polyester with an oxygen spacer was synthesized and used as a macroinitiator for the grafting of linear poly(2-isopropyl-2-oxazoline) (PiPrOx) by the cationic polymerization method. The length of the thermosensitive side chains was varied by the initiator:monomer ratio. Using methods of molecular hydrodynamics, light scattering and turbidimetry, the copolymers were studied in organic solvents and in water. The molecular characteristics of the main chain and graft copolymers, the polymerization degree of side chains and their grafting density have been determined. The equilibrium rigidity of the macroinitiator and the conformations of grafted macromolecules were evaluated. In selective solvents, they take on a star-like conformation or aggregate depending on the degree of shielding of the main chain by side chains. The thermoresponsiveness of graft copolymers in aqueous solutions was studied, and their LCST were estimated. The results are compared with data for graft copolymers composed of PiPrOx side chains and flexible or rigid chain backbones of aromatic polyester type.

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Sedimentation Coefficients, Diffusion Coefficients, Partial Specific Volumes, Frictional Ratios, and Second Virial Coefficients of Polymers in Solution

Lechner

Nordmeier

Steinmeier

1999

The Wiley Database of Polymer Properties

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Sedimentational-diffusional and viscometric studies on solutions of poly-m-phenylene isophthalamide and the equilibrium rigidity of its molecules

Cited by 15 publications

References 11 publications

Tailored Rigid−Flexible Block Copolymers. 3. Fate of the Flexible Block within the Mesophase

Tailored Rigid−Flexible Block Copolymers. 3. Fate of the Flexible Block within the Mesophase

Loose Semirigid Aromatic Polyester Bottle Brushes at Poly(2-isopropyl-2-oxazoline) Side Chains of Various Lengths: Behavior in Solutions and Thermoresponsiveness

Sedimentation Coefficients, Diffusion Coefficients, Partial Specific Volumes, Frictional Ratios, and Second Virial Coefficients of Polymers in Solution

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