AbstractA study on aqueous solutions of an alternating copolymer maleic anhydride‐2,4,4,‐trimethylpentene‐1 is reported. The main feature of the hydrolysis product (PTMLA) is the remarkable interaction between nearest neighbor carboxyl groups. The interaction between neighbor dipoles is favored by the presence of hydrophobic side chains, which cause the lowering of the “local” dielectric constant. As a result, the PTMLA behaves like a polydi‐basic acid. From viscosimetric trends and other properties, it is possible to deduce that this copolymer undergoes a transition to a highly coiled form at low pH's and then to an intermolecular aggregation. It maintains an expanded conformation in a wide range of alkaline pH's. It is possible to correlate this behavior with its capacity as dispersant as well as the structural characteristics of the side chain for this and other