| Abstrakt: |
Four different approaches to introduce a specific functional group at the ω terminus of poly(methacrylate)s (PMMAs) prepared via copper(I)bromide/pyridinalimine-mediated atom transfer polymerization, under polymerization conditions, are reported. Method 1 involves the homolysis of the ω-C&bond;Br bond with a subsequent reaction, via coupling or disproportionation, with an external radical species. The reaction with 2,2,6,6-tetramethylpiperidin-N-oxyl shows a high conversion (>78%) of the ω-bromo PMMA chains into their corresponding macromonomer analogues. Method 2 utilizes monomers that are able to undergo radical addition followed by subsequent fragmentation. Reactions with trimethyl[1-(trimethylsiloxy)phenylethenyloxy]silane and allyl bromide show quantitative and 57% transformation, respectively. Method 3 is the reaction of a monomer that yields a relatively more stable secondary, or primary, carbonhalogen bond. Reactions with divinylbenzene, n-butylacrylate, and ethylene showed quantitative, 62%, and quantitative additions, respectively. Method 4 is the addition of nonhomopropagating monomers, that is, maleic anhydride. This reaction proceeds quantitatively. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 26782686, 2000 |
Plný text