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Frictional behavior of the correlated chain

1972; Wiley; Volume: 154; Issue: 1 Linguagem: Inglês

10.1002/macp.1972.021540105

0025-116X

Arturo Horta,

Polymer crystallization and properties

Abstract The friction coefficient of linear macromolecules is calculated for the correlated chain model using K IRKWOOD 's approximation. This model (proposed by S ANCHEZ and F RANKENBERG ) incorporates a certain long‐range correlation between the segments of a random chain, and contains two parameters: C F , which depends on this correlation (C F = 1 for a random coil and C F = 0 for a fully extended chain), and the radius of gyration R G . In the limit of long chains, the friction coefficient B is a function of these two parameters and the ratio B/6 πη0 R G (η 0 = solvent viscosity) decreases with C F . This means that the correlation between segments has a greater influence on R G than on the equivalent S TOKES radius of the macromolecule. These results are used to interpret the influence of excluded volume on B. The validity of the model is ascertained by comparing the theory with the light scattering envelopes and friction coefficients recently reported by M IJNLIEFF et al. for poly(α‐methylstyrene) in good and poor solvents.