Anionic copolymerization of methacrylates

Abstract An investigation was carried out of the anionic copolymerization of methyl methacrylate ( M 1 ), 2‐methoxyethyl methacrylate ( M 2 ), and 2‐(N, N‐dimethylamino) ethyl methacrylate ( M 3 ) in benzene solution at 20°C initiated with lithium tert‐butoxide. The monomer reactivity ratios ( M 1 – M 2 ) r 1 = 1.51 ± 0.05, r 2 = 2.10 ± 0.10, ( M 1 – M 3 ) r 1 = 1.20 ± 0.10, r 3 = 0.40 ± 0.05, ( M 2 – M 3 ) r 2 = 1.40 ± 0.15, r 3 = 0.60 ± 0.15 show that the reactivities of the individual monomers M 1 , M 2 , and M 3 do not differ too much from each other. A study of the microstructure of copolymers M 1 – M 2 by the NMR method revealed that at low conversions the tacticity of the copolymers depends on the concentration of 2‐methoxyethyl methacrylate in the starting monomer mixture; in the initial stage of copolymerization it is strongly dependent on conversion. Already a low content of M 2 in the starting monomer mixture (below 1%) strongly affects the tacticity of the forming copolymer by depressing the content of the isotactic component.