Abstract New poly(sodium carboxylate)s consisting of neutral or ionic allyl glycoside (AGlu) monomers and maleic acid or itaconic acid as comonomers were examined as substitutes for water‐soluble homo‐ and copolymers of acrylic acid, which are used as cobuilders in detergent formulations. Standardized tests allowed us to measure the calcium sequestering capacity, kaolin dispersing capacity, biodegradability, and thermal stability. These parameters were correlated with the different degrees of functionalization and charge densities of the new polycarboxylates. Comparison with some commercial monomolecular and oligomeric polycarboxylates indicate that the new copolymer poly(allyl‐β‐D‐glucofuranosiduronic acid‐co‐maleic acid) (P(AGlu‐MA)) has an interesting cobuilder performance and is a potentially attractive substitute.