Using the Toms effect for rheokinetic study of the initial stage of polymerization

Traditionally, the Toms effect was widely used in its direct application fo r drag reduction in channel flow or for the movement of solids through a li quid medium. In this paper, however, we have considered a possibility for u sing this effect as a method allowing one to monitor the very beginning of the polymerization process. Our approach was based on the high sensitivity of the Toms effect to minor changes in polymer concentration in a low-molec ular-weight solvent. We have centered our discussion on chemical reactions that occurred in very dilute solutions. As a typical example, we have exami ned ionic polymerization of hexene. Application of the Toms effect gave us a unique chance to investigate chemical processes happening when the polyme r concentration is on the order of tens of ppm. This concentration range wa s much lower that the ranges studied by traditional chemical or physical me thods. (C) 2000 The Society of Rheology. [S0148-6055(00)01102-0].