2014 It is shown that the dynamical properties of long polymers made of N links, in solutions, converge much more slowly to the asymptotic limit (N ~ oo) than the static properties. This effect, which has a simple origin, explains why dynamical measurements of critical indices lead to results which seem to disagree with static measurements and recent theories. LE JOURNAL DE PHYSIQUE TOME 40, JANVIER 1979, 1 Classification Physics Abstracts 61.40K 05.40 47.90

Dynamics of polymers in dilute solutions : an explanation of anomalous indices by cross-over effects

Statistical Physics of Polymer Solutions: Conformation‐Space Renormalization‐Group Approach

Viscosity – Molecular Weight Relationships and Unperturbed Dimensions of Linear Chain Molecules

In order to test the two‐parameter theory of dilute polymer solutions, light‐scattering and intrinsic‐viscosity measurements were carried out on fractions of poly‐p‐methylstyrene in toluene, dichloroethane, cyclohexane, and methyl ethyl ketone at 30°C, and in diethyl succinate at temperatures ranging from 16 to 60°C. The theta temperature for this polymer in diethyl succinate was found to be 16.4°C. With the data for the statistical‐radius expansion factor αS and the interpenetration function Ψ appearing in the second virial coefficient, validity of a theory of these quantities was examined using the two criteria introduced previously: (1) consistency in the values of the excluded‐volume parameter z determined from αS and Ψ, and (2) linearity between z and the square root of the molecular weight. It was found that the Yamakawa–Tanaka theory of αS and the Kurata–Yamakawa theory of Ψ were a self‐consistent pair of intramolecular and intermolecular theories of interaction which satisfied both of the two crit...

Experimental Test of the Two‐Parameter Theory of Dilute Polymer Solutions: Poly‐p‐methylstyrene

Further comments on the analysis of dilute solution data are provided. Light-scattering and intrinsic-viscosity data used for this purpose are those obtained for monodisperse polystyrenes, prepared anionically in tetrahydrofuran, in benzene, toluene, and dichloroethane at 30°C and in cyclohexane at temperatures ranging from 32.2 to 60.1°C. The value of [η]θ/M1/2 is somewhat greater than the corresponding value for Berry’s polystyrenes prepared anionically in benzene, where [η]θ is the intrinsic viscosity at the theta temperature and M is the polymer molecular weight. This suggests that the two types of samples differ in microstructure, though the precise difference is unknown. However, it is shown that the two-parameter relationships established experimentally in the previous papers are well reproduced in the present data. The relationships are different from those determined by Kato, et al., for monodisperse poly(α-methylstyrene) prepared anionically. Since there is shown to be no essential difference between our and their methods of determining mean-square radii, it seems unlikely that the difference is related to measurements and subsequent treatments. It is suggested rather that the problem is related to Kato’s samples.

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More on the Analysis of Dilute Solution Data: Polystyrenes Prepared Anionically in Tetrahydrofuran

Data of the statistical radius 〈 S2 〉1 / 2 and the second virial coefficient A2 were obtained for sharp fractions of polychloroprene (PCP) in methyl ethyl ketone (MEK), n‐butyl acetate, and carbon tetrachloride at 25°C and in trans‐decalin at temperatures ranging from 1° to 50°C. MEK at 25°C and trans‐decalin at 2°C were found to be theta solvents for PCP. From these data two dimensionless quantities defined by αs2 = 〈 S2 〉 / 〈 S2〉0and Ψ = A2M1/2[4π3/2NA( 〈 S2 〉 / M3 / 2]−1 were calculated for all combinations of molecular weight M, solvent species, and temperature, where 〈 S2 〉0 is the value of 〈 S2 〉 under θ conditions and NA is Avogadro's number. These two quantities should be functions of a single parameter z, usually known as the interaction parameter, which is proportional to M1/2. With the data for these quantities from the present experiments on PCP as well as from Berry's experiments on polystyrene, comparative tests of typical theories for the excluded‐volume effects on dilute polymer solutions ...

K. Kawahara

Papers

Excluded-Volume Effects in Dilute Polymer Solutions. I. Equilibrium Properties