Polyurethanes (PUs) are novel and versatile polymers based on the reaction of diisocyanate and polyol groups; its advantage lies in its mechanical properties and the modifications that can be made of those properties through changes in synthesis conditions. On the other hand, graft polymers are produced by the insertion of polymer chains into the main chain of other polymer in order to give specific and novel properties. The main purpose on this work was developing PU cores as precursors of new graft polymers which can be easily polymerized by free radicals. In this context, a vinyl monomer (vinyl benzyl-N-methyl-D-glucamine, VbNMDG) was synthesized from N-methyl-D-glucamine and p-chloromethylstyrene. The synthesized monomer was employed for the formation of PU core using 4,4́-methylene-bis-(phenyl isocyanate) (MDI). The monomer synthesis and the double bond incorporation to the PU matrix were verified by NMR 13C and 1H. Thereafter, 0.1 g of different PU cores was mixed with an equal VbNMDG amount, using a dioxane-water mixture as solvent in the presence of radical initiator (ammonium per sulfate, 2% molar of VbNMDG). The reaction was carried out at 70 °C using nitrogen atmosphere for 24 h. The graft polymers obtained were characterized by FT-IR and elemental analysis. The insertion of poly(VbNMDG) chains into the PU cores gives them the boron retention capacity in aqueous solutions. Our results show the possibility to obtained PU cores which can be polymerized via free radicals to the graft of functional polymer chain in a second polymerization.