Abstract: In this thesis, quaternary ammonium salts with asymmetry groups are successfully synthesized. Single substituted quaternary ammonium salt (salt 1) is synthesized according to quaterization between Benzyl bromide and tropane, and double substituted quaternary ammonium salt (salt 2) is synthesized according to quaterization between α,α′-dibromo-o-xylene and tropane. Solution polymerization of acrylonitrile carries out in DMF under moderate condition, using tricyclohexyl phosphine (PCy3) as an initiator. Both conversion and polymerization velocity increase in systems of adding quaternary ammonium salts selected. Polymerization velocity decreases in the order of system with salt 1, salt 2, tetrabutyl ammonium bromide and none. All the systems have a high conversion at the beginning, approximately linear relationship between Ln([M]0/[M]) and reaction time. Atactic PAN which contains a few branches can be synthesized with number average molecular weight Mn upon 2×105g/mol, Mw/Mn about 2.0 in each system, and the number of branches decreases appreciably when adding different quaternary ammonium salts. Molecular weight increases with an increase in reaction time, which can be adjusted better in system with salt 2, such as Mw/Mn.
Keywords: Quaternary ammonium salt, Anionic polymerization,, Polyacrylonitrile, Structure
