Hydrophobically-modified polyacrylamides prepared by micellar polymerization

The characteristic features of hydrophobically-modified polyacrylamides (HMPAM) prepared by a micellar polymerization technique are reviewed. This method of synthesis leads to copolymers in which the hydrophobic units are randomly distributed as small blocks in the acrylamide backbone. Special emphasis is put on the improvement of the technique so that well characterized and homogeneous samples are synthesized. The effect of the various parameters controlling the rheological behavior of HMPAM is thoroughly analyzed. In particular, it is shown that a determining factor for a good thickening ability is the copolymer microstructure, i.e. the hydrophobe distribution. Some recent advances are presented towards a better understanding of the association structure, thus allowing the design of tailored materials with good controllable rheological properties. (C) 1999 Elsevier Science B.V. All rights reserved.