Stiff-Chain Nature of Poly(1-phenyl-1-propyne) in Dilute Solution

Hirao, Takayuki; Teŕamoto, Akio; Sato, Takahiro; Norisuye, Takashi; Masuda, Toshio; Higashimura, Toshinobu

doi:10.1295/polymj.23.925

Cited by 29 publications

(17 citation statements)

References 29 publications

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“…From the intercepts and slopes of the lines, we have determined the weight-average molecular weight M w and the second virial coefficient A 2 for those fractions. Values of A 2 of PCPA in DMSO are comparable to those of a polyacetylene derivative with a similar chemical structure, poly(1-phenyl-1-propyne) (PPP), in toluene (a good solvent) studied by Hirao et al, 13 indicating that DMSO is a good solvent for PCPA.…”

Section: Resultssupporting

confidence: 51%

“…In the previous study, Hirao et al 13 analyzed [η] and also the radius of gyration 〈S 2 〉 1/2 data for PPP in toluene and cyclohexane using the wormlike chain (cylinder) model to estimate the molar mass M L per unit contour length and the persistence length q. They found that to fit both [η] and 〈S 2 〉 1/2 data with the same M L and q, the Flory-Fox constant Φ ∞ must be smaller than the theoretical one ()2.87 × 10 23 ).…”

Section: Resultsmentioning

confidence: 90%

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Helical Structural Change in Poly((4-carboxyphenyl)acetylene) by Acid−Base Complexation with an Optically Active Amine

et al. 2003

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The acid-base complexation of poly((4-carboxyphenyl)acetylene) with an optically active amine [(R)-(+)-1-(1-naphthyl)ethylamine] not only induces strong circular dichroism (CD) but also changes the molecular weight dependence of the intrinsic viscosity in dimethyl sulfoxide. From the intrinsic viscosity data, we have determined the chain stiffness parameter (the persistence length) and have estimated from this parameter the average standard deviation of the internal rotation angle around the single or double bond of the polyacetylene chain to be 21 and 15°before and after the complexation, respectively. The reduction of the torsional fluctuation may arise from the steric hindrance among the amines complexed with the carboxy pendants which makes the internal-rotation energy well steeper for the polyacetylene backbone. The reduction is however not as remarkable as the change in CD due to the complexation. We conclude that the remarkable CD behavior arises from a drastic change in population of the right-and left-handed helices of the polymer, and the helical conformation of the complex is still imperfect.

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Section: Resultssupporting

confidence: 51%

Section: Resultsmentioning

confidence: 90%

Helical Structural Change in Poly((4-carboxyphenyl)acetylene) by Acid−Base Complexation with an Optically Active Amine

et al. 2003

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“…This was also confirmed in a recent investigation on poly(1-phenyl-1-propene) in toluene by Hirao et al, 179 where second virial coefficients were determined by light scattering and by sedimentation equilibrium over a wide range of molar mass. Since the measurement of thermodynamic data by sedimentation equilibrium is not very frequent in the literature this is certainly not a final statement.…”

Section: Ultracentrifugesupporting

confidence: 73%

Methods for the Measurement of Solvent Activity of Polymer Solutions

Wohlfarth

2014

Handbook of Solvents

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“…Plots of log-\ 2 <S 2 ) vs. log,\£ constructed from reported <S 2 ) data for PHIC in hexane (0), 6 CTDC in NMP (e), 13 • 14 Na-HA in 0.5M aqueous NaCl (0), 17 and PPP in toluene (6). 18 Solid line, eq 1; dashed line, empirical fit to the Na-HA data.…”

Section: Model Parameters and Onset Of Volume Effectmentioning

confidence: 99%

Remarks on Excluded-Volume Effects in Semiflexible Polymer Solutions

Norisuye¹,

Tsuboi²,

Teŕamoto³

1996

Polym J

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ABSTRACT:Intramolecular excluded-volume effects in stiff chains are examined by analyzing typical data of (S 2 ) (the mean-square radius of gyration) and ['7] (the intrinsic viscosity) for four different polymers with Kuhn segment lengths A. -l of 7.8-86 nm on the basis of the wormlike chain. The data are shown to be explained almost quantitatively in the YamakawaStockmayer-Shimada scheme for wormlike or helical wormlike chains, leading to the conclusion that the expansion factor versus scaled excluded-volume parameter relations established by Yamakawa, Einaga, and coworkers for (S 2 ) Molecular characterization of semiflexible polymers in dilute solution often requires knowledge of intramolecular excluded-volume effects, but our understanding of those effects in stiff chains still leaves much to be desired. The situation may be explained as follows. More than 10 years ago, Norisuye and Fujita, 1 analyzing available data for the mean-square radius of gyration (S 2 ) on the basis of the Kratky-Porod (KP) wormlike chain, 2 concluded that excluded-volume effects on (S 2 ) of various polymers become experimentally observable when the Kuhn segment number nK exceeds 50 ( ± 30).This nK value was one order of magnitude larger than that predictable from the Yamakawa-Stockmayer perturbation theory 3 for KP bead chains, suggesting that intramolecular volume exclusion in actual stiff polymers is less enhanced than predicted by the theory. Later, Yamakawa and Shimada 4 examined the discrepancy by directly comparing theoretical and experimental (S 2 ) values, and reached the conclusion that the YamakawaStockmayer scheme, now extended to helical wormlike (HW) chains 5 and called the Yamakawa-StockmayerShimada (YSS) scheme, breaks down for poly(hexyl isocyanate) (PHIC), a typical stiff chain, in hexane. 6 Little progress has since been made on the subject, though, as far as flexible polymers are concerned, the validity of the YSS scheme has been substantiated for both dimensional and hydrodynamic properties. 7 -12 Very recently Tsuboi et al.U analyzed data of (S 2 ) and [17] (the intrinsic viscosity) for cellulose tris(3,5-dimethylphenylcarbamate) (CTDC) in 1-methyl-2-pyrrolidone (NMP) to reconcile the YSS theory with Norisuye and Fujita's conclusion mentioned above. The point was that the theory was capable of explaining the observed volume effects that were practically negligible for nK < 40 and appreciable for nK >50. This motivated us to re-examine literature data of (S 2 ) and [17] including those for PHIC with a hope of deepening our understanding of the intramolecular excluded-volume effects in semiflexible polymer solutions. To make our analysis more quantitative than in the earlier work by Norisuye and Fujita, we here confine ourselves to polymers whose (S 2 ) or [17] data show both unperturbed and perturbed behaviors in the molecular weight range studied. They are CTDC in NMP, 13 • 14 sodium salt of hyaluronic acid (Na-HA) in 0.2 and 0.5 M aqueous sodium chloride/ 5 -1 7 and poly(l-phenyl-1-propyne) (PPP) i...

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Stiff-Chain Nature of Poly(1-phenyl-1-propyne) in Dilute Solution

Cited by 29 publications

References 29 publications

Helical Structural Change in Poly((4-carboxyphenyl)acetylene) by Acid−Base Complexation with an Optically Active Amine

Helical Structural Change in Poly((4-carboxyphenyl)acetylene) by Acid−Base Complexation with an Optically Active Amine

Methods for the Measurement of Solvent Activity of Polymer Solutions

Remarks on Excluded-Volume Effects in Semiflexible Polymer Solutions

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