Activators Regenerated by Electron Transfer Atom Transfer Radical Polymerization in Miniemulsion with 50 ppm of...

The design and synthesis of a powerful ligand is reported for use in activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP) in miniemulsion. The structure of N',N″-dioctadecyl-N',N″-bis[2-(4-methoxy-3,5-dimethyl)pyridylmethyl]ethane-1,2-diamine (DOD-BPED*) was formulated to produce a tetradentate ligand which was both hydrophobic and highly active. Studies in homogeneous ARGET ATRP with CuBr₂/DOD-BPED* demonstrated a high degree of control, similar to those ligands traditionally used. CuBr₂/DOD-BPED* also proved itself to be extremely useful in ARGET ATRP miniemulsion systems, at concentrations of catalyst as low as 50 ppm while maintaining control over the polymerization of butyl methacrylate (BMA). Additionally, the catalyst was tested over a range of degrees of polymerization, DP = 2000-10 000, all of which resulted in successful polymerizations. Most notably, high molecular weight polymers with M_n,exp > 700 000 and M_w/M_n < 1.4 were prepared with only 50 ppm of CuBr₂/DOD-BPED* catalyst under miniemulsion conditions.