Atom Transfer Radical Polymerization of Methyl Methacrylate Using Telechelic Tribromo Terminated Polyurethane Macroinitiator

作者：Verma Hemant; Kannan Tharanikkarasu^*

来源：Journal of Macromolecular Science, Part A: Pure and Applied Chemistry , 2010, 47(5): 407-415.

DOI：10.1080/10601321003659671

• Atom transfer radical polymerization
• multifunctional macroinitiator
• polyurethane
• beta-scission
• poly(methyl methacrylate)

Novel telechelic tribromo terminated polyurethane (Br(3)-PU-Br(3)) was used as a macroinitiator in atom transfer radical polymerization (ATRP) of methyl methacrylate using CuBr as a catalyst and NN,N',N '',N ''-pentamethyldiethylenetriamine (PMDETA) as a ligand. During the course of polymerization, poly(methyl methacrylate)-b-polyurethane-b-poly(methyl methacrylate) (PMMA-b-PU-b-PMMA) tri-block copolymers were formed. The resulting tri-block copolymers were characterized by gel permeation chromatography (GPC) and (1)H nuclear magnetic resonance (NMR) spectroscopy. Molecular weight of the tri-block copolymers increases with increasing conversion. This result shows Br(3)-PU-Br(3)/CuBr/PMDETA initiating system polymerized methyl methacrylate through ATRP mechanism. NMR spectroscopy results revealed that apart from bromine atom transfer from Br(3)-PU-Br(3) to PMDETA-CuBr complex, bromine atom transfer from the initially formed tri-block copolymer to PMDETA-CuBr complex also takes place, and, as a result, double bond terminated copolymer formed. Mole ratio of polyurethane and poly(methyl methacrylate) present in the PMMA-b-PU-b-PMMA tri-block copolymers was calculated using (1)H-NMR spectroscopy and it was found to be comparable with the mole ratio calculated through GPC results. Differential scanning calorimetric results confirmed the presence of two different phases in the tri-block copolymers.

• 出版日期2010