Macrocyclic poly(methyl acrylate) and macrocyclic poly(methyl acrylate-block-styrene) synthesized by radical trap-assisted atom transfer radical coupling

摘要: Abstract Dibrominated poly(methyl acrylate) (BrPMABr) was prepared by atom transfer radical polymerization (ATRP), and this unpurified reaction mixture used directly in a trap-assisted coupling (RTA-ATRC) to achieve cyclic PMA intramolecular chain-end coupling. When the polymerization-to-cyclization crossover performed as one pot-two step sequence simply addition of trap 2-methyl-2-nitrosopropane (MNP) increased amounts ligand-catalyst complex, could be formed yields up 65% adjusting total volume reactant ratios during RTA-ATRC, based on gel permeation chromatography (GPC) analysis. In analogous ATRC trials lacking trap, cyclization not successful instead chain extension continuation ATRP observed. containing BrPMABr precursor added drop-wise into redox active solution MNP, polymer were 85%. The effect ligand studied, with highest product obtained RTA-ATRC reactions using tris[2-(dimethylamino)ethyl]amine (Me 6 TREN) ligand. Cyclic diblock copolymers also method, telechelic acrylate- block -styrene- -methyl (PMA-b-PS-b-PMA) linear precursors sequential reactions.