Nitroxide-mediated radical polymerization of 2-(dimethylamino)ethyl acrylate and its sequential block copolymerization with styrene and N-butyl acrylate

摘要

Nitroxide-mediated radical polymerization (NMRP) of 2-(dimethylamino) ethyl acrylate (DMAEA) was carried out at 100-120 degrees C, initiated by MONAMS, an alkoxyamine based on N-tert-butyl-N-(l-diethyl phosphono-2,2-dimethylpropyl)nitroxide, SG1. Controlled polymerization can be achieved by the addition of free SG1 (the initial molar ratio of SG1 to MONAMS ranged from 0.06 to 0.12), giving a linear first-order kinetic plot up to 55-70% conversion depending on the reaction conditions. The molecular weights show a near linear increase with conversion; however, they deviate to some extent with theoretical values. SG1-mediated polymerization of DMAEA at 112 degrees C is also controlled in organic solvents (N,N-dimethylformide, anisole, xylene). Polymerization rate increases with increasing solvent polarity. Chain transfer to polymer produces similar to 1 mol % branches in bulk and 1.2-1.9 mol % in organic solvents, typical of those for acrylates. From poly(styrene) (pS) and poly(n-butyl acrylate) (pBA) macroinitiators, amphiphilic di- and triblock copolymers p(S-b-DMAEA), p(DMAEA-b-S-b-DMAEA), p(BA-b-DMAEA), and p(DMAEA-b-BA-b-DMAEA) were synthesized via NMRP at 110 degrees C. Polymers were characterized by GPC, NMR, surface tension measurements, and DSC. (c) 2005 Wiley Periodicals, Inc.