AbstractThe study is primarily focused on the possibility to utilize organic asymmetric flow field‐flow fractionation (A4F) coupled to a multi‐angle light scattering (MALS) detector for the characterization of copolymers of methyl methacrylate with various acrylates prepared by emulsion polymerization. The effects of acrylate monomer type and content on the molar mass distribution and degree of branching of acrylic copolymers have been studied by A4F‐MALS using tetrahydrofuran as a carrier solvent. It has been found that the growing amount of acrylate results in the increase of molar mass, polydispersity, and branching degree as a result of chain transfer to polymer. Highly branched compact macromolecules with ultra‐high molar mass were identified in all copolymers containing a high level of acrylate. In contrast to size traditionally used exclusion chromatography, organic A4F‐MALS has been proved as a very efficient technique for the characterization of high molar mass acrylic emulsion copolymers. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40995.