AbstractThe structural and rheological properties of poly(acrylamide‐co‐sodium acrylate) latexes prepared in inverse nonionic microemulsions have been investigated. The formation of stable and optically transparent microlatexes is strongly related to the acrylate content in the feed due to a salting‐out effect of the ethoxylated surfactant. This salting‐out effect determines the optimum HLB value of the blend. The dimensions of the particles are rather low (d<100nm) with a narrow distribution. The inverse microlatexes which consist of water‐swollen copolymer particles dispersed in an isoparaffinic oil show a newtonian behavior up to high volume fractions (⋍ 50%) and a shear‐thinning behavior for volume fractions above 50%. The presence of charges in the copolymer leads to an apparent close‐packing volume fraction lower than that of 64% predicted for a random packing