Isocyanatoethyl methacrylate telomerization and cotelomerization

This article describes the use of isocyanatoethyl methacrylate (IEM) as a monomer in telomerization and cotelomerization reactions. First, the selectivity of benzenethiol addition to the unsaturation of IEM is proven. Even with an equimolar amount of reactants, benzenethiol reacts almost selectively with the ethylenic double bonds. The radical telomerization of IEM and its cotelomerization with MMA, in the presence of benzenethiol, has been achieved and shows that control of molecular weight is possible. Finally, the addition of a phosphonated alcohol to these telomers, followed by ester cleavage reactions, leads selectively to families of mono or diphosphonate products. The study of the thermal properties of the cotelomers shows that the degradation starts at 180 degrees C on the isocyanate group of IEM, and then on the ester group of MMA, and the decomposition is complete at 450 degrees C. The introduction of the phosphonated ester group decreases the glass transition temperature of the cotelomers, but after hydrolysis these values increase.