No abstract

The optimization of the synthesis of homopolymers from n-butyl acrylate (BA), styrene (Sty), and methyl methacrylate (MMA), using copper-based atom transfer radical polymerization (ATRP) with tris(2-dimethylaminoethyl)amine (Me6-TREN) as a ligand is reported. Catalyst concentration (copper bromide complexed with 1 equiv of Me6-TREN) as low as 1% relative to initiator (50 ppm in the reaction mixture) was sufficient to successfully prepare well-defined poly(n-butyl acrylate) in bulk. With 50% catalyst to initiator, styrene was polymerized in bulk. The deactivator species had poor solubility in nonpolar solvents. Finally, the polymerization of methyl methacrylate with CuBr/Me6-TREN required the use of a high concentration of catalyst and the addition of Cu(II)Cl2 at the beginning of the reaction; the resulting polymers were of higher molecular weight than predicted by theory and had relatively broad molecular weight distributions.

No abstract

No abstract

Atom transfer radical polymerization (ATRP) has been used to directly prepare linear pHEMA of controlled molecular weight and low polydispersity. Reaction conditions were adjusted to successfully polymerize the functional, polar methacrylate monomer. These adjustments included the use of a mixed solvent system consisting of methyl ethyl ketone and 1-propanol, lowering the temperature to 50 °C or less and using an alkyl bromide initiator with a copper chloride catalyst. The Cu/2,2′-bipyridyl (bpy) complex, normally a heterogeneous mixture in nonpolar, organic solvents, was completely soluble in the above solvent system. A block copolymer was prepared with a poly(methyl methacrylate) macroinitiator. The monomer can also be protected and polymerized under conditions very similar to those used for the ATRP of methyl methacrylate.