Synthesis and characterization of PBMA-b-PDMS-b-PBMA copolymers by atom transfer radical polymerization



Poly(butyl methylacrylate)–b–poly(dimethylsiloxane)–b–poly(butyl methylacrylate) (PBMA–b–PDMS–b–PBMA) triblock copolymers were synthesized by atom transfer radical polymerization (ATRP). The reaction of α,ω-dichloride PDMS with 2′-hydroxyethyl-2-bromo-2-methylpropanoate gave suitable macroinitiators for the ATRP of BMA. The latter procedure was carried out at 110°C in a phenyl ether solution with CuCl and 4,4′-di (5-nonyl)-2,2′-bipyridine (dNbpy) as the catalyzing system. The polymerization was controllable, with the increase of the monomer conversion, there was a nearly linear increase of molecular weight and a decrease of polydispersity in the process of the polymerization, and the rate of the polymerization was first-order with respect to monomer conversion. The block copolymers were characterized with IR and 1H-NMR and differential scanning calorimetry. The effects of macroinitiator concentration, catalyst concentration, and temperature on the polymerization were also investigated. Thermodynamic data and activation parameters for the ATRP were reported. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 532–538, 2004