Study of the critical concentration c** in dynamic and static state

The critical concentration c** which separates the regime of extremely dilu te solutions from that of dilute solutions of polymers was studied in the s tatic state and in flowing solution. This concentration is lower when deter mined by UV measurements in the static state compared to the critical conce ntration determined in the dynamic state using viscosimetry. The influence of the molecular mass of the polymer and of the temperature on the critical concentration was studied. Further arguments are presented which can be ma de in favor of the assumption that in the critical concentration c** entang lements emerge between the macromolecular chains.