Supramolecular polymers are dynamic materials; consequently, their molar mass is
concentration dependent. However, the present experimental results show that an efficient chain stopper
(i.e., a monofunctional monomer) can be used to block the concentration dependence of the molar mass
of a hydrogen-bonded supramolecular polymer, over a realistic concentration range. This fact was used
to derive the molecular weight and radius of gyration of the stopped supramolecular chains (by light
scattering) as well as the intrinsic viscosity. In a second step, the molecular weight of the bis-urea-based
supramolecular polymer (EHUT) was determined in the absence of a chain stopper