| Nitroxide-mediated radical polymerization (NMRP) is one of several new controlled/living radical polymerization techniques that can afford polymers with well-defined architectures such as controlled molecular weight, narrow molecular weight distribution and the capability of forming block copolymers. While NMRP is well studied and successful for the polymerization of styrenics, its applicability to functional monomers still needs to be extended.; The NMRP of two functional water-soluble monomers 2-hydroxyethyl acrylate (HEA) and 2-(dimethylamino)ethyl acrylate (DMAEA)) was thoroughly studied in this work. The controlled polymerization was achieved by initiation with MONAMS, an alkoxyamine based on N-tert-butyl-N-(1-diethylphosphono-2, 2-dimethylpropyl)nitroxide (tradename SG1) in the presence of additional, excess SG1. The kinetics of polymerization in bulk, in organic solvents, and even in aqueous medium at temperatures ranging 100-120°C were investigated and kpK values were estimated. Chain transfer to polymer was also studied by 13C NMR techniques. By a sequential block copolymerization, a series of di-/tri-block copolymers based on these two monomers were synthesized, using poly(butyl acrylate) and/or polystyrene macroinitiators.; Surface-initiated polymerization is one of the most important methods to modify and improve the surface properties of polymer materials. Using the NMRP method, homo- and block polymers were grafted from the surface of microspheres. We first began with 2,2,6,6-tetramethyl-1-piperidinyloxy nitroxide (TEMPO)-immobilized Merrifield resins to graft polystyrene, poly(acetoxystyrene) and related copolymers. All the microspheres show a significant increase in particle size, which was interpreted that not only was a brush structure formed on the surface, but also some new polymers filled in the microspheres. A functional monomer (DMAEA) was then grafted from colloidal particles that were prepared by emulsion polymerization and afterwards surface functionalized with SG1. The polymerization in solution exhibited good control, and particle size increased with the molecular weight of untethered poly(DMAEA). Characterization of these microspheres grafted with DMAEA-based homo- and block copolymers using IR, TEM and thermal analysis strongly supports the formation of brush-like functional microspheres. |
