A NEW APPROACH TO THE DETERMINATION OF THE STATISTICAL SEGMENT LENGTH OF WORMLIKE POLYMERS

The Stockmayer-Fixman-Burchard (SFB) and the Dondos-Benoit (DB) equations have been applied to determine the unperturbed dimensions parameter K-- of wormlike polymers. An empirical relation between the Flory's constant Phi and the Mark-Houwink-Sakurada (MHS) exponent a has been proposed. The Phi values found by this equation are lower than the value 2.5 x 10(23) used in the case of flexible polymers and this deviation is attributed to the influence of the draining effect. From the K-- value and the so calculated value of Phi, we calculate the Kuhn statistical segment length of wormlike polymers. The obtained - for a great number of wormlike polymers - statistical segment lengths are almost the same as these calculated by the Yarnakawa-Fujii and the Bohdanecky methods. The molecular mass regions in which the SFB, the DB, and the MHS equations are valid are explored. A criterion for the distinction between flexible and wormlike polymers is proposed based on the way of approach to the power law.