Anionic Polymerization of Methyl Methacrylate as Promoted by a N-Butyl Lithium-Pyridazine-Polyether Alkoxide Based Complex Initiator System

Authors : Z. Tim HAMAUDI, Nihan Nugay And Turgut NUGAY

Pages : 387-394

View : 13 | Download : 5

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :Polymerization of methyl methacrylate was conducted using a n-butyl lithium/pyridazine system as initiator in tetrahydrofuran insert ignore into journalissuearticles values(THF); and toluene. Special attention was focused on using some lithium polyether alkoxides as polymerization is promoted at ambient temperatures. The positive effects of these m /s -type ligands such as lithium 2-insert ignore into journalissuearticles values(2-methoxyethoxy);ethoxide and lithium 2-insert ignore into journalissuearticles values(methoxy);ethoxide on controlling the living character, molecular weight, stereoregularity and yield of the produced polymers were all demonstrated. It was found that initiator/lithium-2-insert ignore into journalissuearticles values(methoxy);ethoxide in a 1/10 ratio gives the most controlled polymerization. All products were then characterized by size exclusion chromatography insert ignore into journalissuearticles values(SEC);, proton nuclear magnetic resonance insert ignore into journalissuearticles values(1H NMR); and differential scanning calorimeter insert ignore into journalissuearticles values(DSC);. The molecular weight distributions obtained were as narrow as 1.28 and the glass transition temperatures were comparable with that of a syndiotactic PMMA and approximately 100% conversions achieved. Moreover, the effect of the polarity of the solvents on the association equilibrium has been discussed. It was found that the molecular weight of the produced polymethylmethacrylate could be better controlled in THF than in toluene.
Keywords : Pyridazine complex initiator, Polyether alkoxide, PMMA