Effect of Block Architecture on the Self-Assembly of Copolymers of Ethylene Oxide and Propylene Oxide in Aqueous Solution

Five block copolymers with three linear architectures were prepared by sequential anionic copolymerization, i.e., E102P37, E103P34, E52P34E52, E57P46E57, and P19E113P19 (where E denotes oxyethylene and P denotes oxypropylene), and the properties of their aqueous solutions were studied across a wide range of concentration. The techniques used to study micellization and micellar properties in dilute solution were static and dynamic light scattering, surface tension, and elution gel-permeation chromatography. The results showed, for example, that critical micelle temperatures for solutions of given composition fell in the order E m P n < E m P n E m < P n E m P n , in agreement with the prediction of theory. The gelation of concentrated solutions was also investigated.