Analysis of the temperature quotient of the intrinsic viscosity of stiff-chain polymers

Reddy, G. Venkata Ramana; Bohdanecký, M.

doi:10.1021/ma00172a037

Cited by 5 publications

(1 citation statement)

References 11 publications

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“…While  −1 for CTPC in tetrahydrofuran (THF), acetone, dioxane, and pyridine at the temperatures T of 20 or 25 C was reported to be in a rather narrow range from 19 to 27 nm, the parameter in benzophenone, cycohexanol, and anisol was much smaller, that is, 7 -10 nm at relatively high temperatures (73 -94 C). Even though we consider the known temperature dependence of CTPC in four different solvents, that is, d ln −1 / dT ~ −6.5  10 −3 K −1 [13,22], the chain stiffness in the latter three solvents was found to be smaller than those in the former solvents. The solvent dependent conformation suggests that the intramolecular hydrogen bonding interactions and/or polymer-solvent interactions play an important role to determine the conformation of CTPC in dilute solution as pointed out by Sutter et al [9].…”

Section: Introductionmentioning

confidence: 92%

Chain stiffness of cellulose tris(phenylcarbamate) in tricresyl phosphate (TCP)

2017

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Small-angle X-ray scattering (SAXS) measurements were carried out for two cellulose tris(phenylcarbamate) (CTPC) samples in tricresyl phosphate (TCP) at 25 C to determine the particle scattering function P(q) and the z-average mean-square radius of gyration S 2  z. The obtained data were analyzed in terms of the wormlike chain model to estimate the Kuhn segment length  −1 (the stiffness parameter, equivalent to twice the persistence length) and the helix pitch (or helix rise) per residue h. The resultant  −1 and h were 11.5  0.5 nm and 0.51 nm, respectively. While the latter value (h) is consistent with the previously reported values both for cellulose and cellulose derivatives, appreciably higher chain flexibility was found for CTPC in TCP than that in tetrahydrofuran at 25 C (19-24 nm). The value is fairly close to that in anisol, cyclohexanol, and benzophenone assuming an appropriate temperature coefficient. We may thus conclude that CTPC behaves as a semiflexible chain in TCP.

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Section: Introductionmentioning

confidence: 92%

Chain stiffness of cellulose tris(phenylcarbamate) in tricresyl phosphate (TCP)

2017

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Dilute solution properties, chain stiffness, and liquid crystalline properties of cellulose propionate

Casay

George

Hadjichristidis

et al. 1995

J Polym Sci B Polym Phys

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The solution properties of cellulose derivatives are of interest from both technological and purely scientific aspects. At high concentrations these solutions form liquid crystalline structures. In dilute solution cellulosic chains can be described as semiflexible or wormlike with properties intermediate between random coils and rigid rods. A series of fractions of cellulose propionate have been examined by dilute solution viscometry, static and dynamic light scattering, and polarizing microscopy. Power law exponents are considerably larger than those observed for flexible chains and analysis of the intrinsic viscosity and hydrodynamic radii has yielded chain diameters and Kuhn statistical segment lengths. Corresponding aspect ratios from the hydrodynamic measurements are in good agreement with those obtained from polarizing microscopy, as analyzed in light of Flory's theory. Some aggregation and specific solvent effects have been observed, however separation of these effects has proven to be difficult. Results of these studies are compared to previous work for other cellulose derivatives. ©1995 John Wiley & Sons, Inc.

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