Influence Of Solvent On Reaction Of N-butyl Methacrylate By ATRP

The influence of solvent and temperature on reaction of atom transfer radical polymerization of n-butyl methacrylate is studied in this paper. Polymerizations of n-BMA have been carried out under homogeneous conditions using Cu(I)Br/2,2'-bpy catalyst with ethyl-2-bromoisobutyrate used as the initiator and IPA, IPA/H2O, acetone, acetone/H2O acetone/methanol used as solvent. It is shown that: 1.The polymerizations are controlled using whether IPA or IPA/H2O as solventleading to a result of PDI<1.2. 2.A small amount of water in IPA enhances the rate of polymerization, at the sametime, making the living characters more apparent. 3.In the system of acetone, small quantity of water or methanol also leads to the resultof fast polymerization speed and keeps it good living features. By contrast, theinfluence of water is more greater. 4.When other conditions are the same, the influence of water or methanol on thereaction is more obvious at lower temperature. The influence becomes weaker withthe temperature increasing. 5.We consider that water or methanol reduces Ea of the system leading to the result offast polymerization.We also find out that the conversion keep constant after reach a max when the temperature reach some extent. This phenomenon appears in IPA/H2O, acetone, acetone/H2O, acetone/methanol used as solvent. The result of chain extension suggests that PBMA has died forever and cannot initiate monomer; GC-MS indicates that there is C4H9Br in the product; 13C-NMR shows that there are also some C-Br bonds in the end of the polymers. MALDI-TOF-MS proves that there are other three products in the system besides polymers terminated with C-Br bond — polymers terminated with vinylidene, polymes have a lactone end group and chain transfer product.