L. Z. Rogovina1, V. G. Vasil’ev, N. A. Churochkina,
T. A. Pryakhina, and A. R. Khokhlov
Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences,
ul. Vavilova 28, Moscow, 119991 Russia
Received June 9, 2003;
Revised Manuscript Received November 26, 2003
Abstract—Using the method of micellar copolymerization, hydrophobically modified copolymers of various
types and compositions are synthesized. They are binary and ternary copolymers of acrylamide containing
small amounts (0.2–3 mol %) of acrylamide or methacrylate derivatives with apolar side groups (9 or 12 CH2
groups) and, in the case of ternary copolymers, also containing monomers capable of ionization (mostly sodium
acrylate). The properties of the amide and ester copolymers are found to differ. The relationship between the
composition, structure, and formation conditions of the hydrophobically modified copolymers, on the one hand,
and the formation and rheological properties of their physical gels, on the other hand, is studied. The zero New-
tonian viscosity and the elastic modulus of the gels are shown to be determined by the hydrophobicity of the
copolymer. The latter property depends both on the length or amount of hydrophobic groups in the macromol-
ecules and on the arrangement of these groups along the chain. The properties of the gels show an extreme
dependence on the amount of charged groups in the copolymer due to the mutual influence of charges and
hydrophobic groups. As the number of charges in the chain increases, it becomes possible to introduce a larger
amount of hydrophobic groups into the copolymer without phase separation of its gel. This and other factors
make it possible to vary the rheological properties of gels of hydrophobically modified copolymers and their
stability with respect to elevated temperatures within wide limits.
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