A novel hydrophobically associating copolymer composed of acrylamide(AM) and a low amount of 2-phenoxylethyl acrylate (POEA) (＜1.0 mol％) was prepared by a micellar copolymerization technique．These polymers exhibited a strong hydrophobic effect

and showed a large viscosity enhancement at concentrations above c*

owning to occurrence of the interchain hydrophobic association．The different synthesis conditions for copolymers

such as the total monomer concentration

feed composition and ratio of the surfactant to the hydrophobic monomer (SMR) significantly influenced the composition and properties of the polymer．The experimental results showed that the viscosity property and association behavior were pronouncedly dependent on the molecular weight and the hydrophobe content of the polymer

as well as the block length and the distribution of hydrophobes in the polymer chain．