L. Z. Rogovina, V. G. Vasil'ev, N. A. Churochkina, and T. A. Pryakhina UDC 532.135:541.64:54-148 A study has been made of the rheological characteristics of the aqueous and water-salt solutions and gels of one class of hydrophobically modified polymers: acrylamide copolymers with a hydrophobic monomer which can be either acrylamide with a hydrophobic "tail" consisting of 9 or 12 carbon atoms or methacrylate with the same "tail." It has been shown that a sharp growth in the viscosity of the solutions and in the limiting stress, the highest Newtonian viscosity, and the elastic modulus of the gels is the greater, the larger the length and the number of hydrophobic groups in the copolymer and the smaller the amount of a surfactant in the process of its synthesis, which leads to a hydrophobicity growth of the copolymer. Consideration has been given to the role of the number of charges introduced into the copolymer apart from the hydrophobic groups and to other factors determining the rheological properties of the gels and their resistance to temperature. A. N. Nesmeyanov Institute of Element-Organic Compounds, Russian Academy of Sciences, Moscow, Russia; email: rogovina@ineos.ac.ru. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 76, No. 3, pp. 48-54, May-June, 2003. Original article submitted December 17, 2002.