Triblock bipyridine-centered

Bipyridine-centered triblock copolymers of the type BA-bpy-AB were prepared by a combination of ATRP and ROMP [159]. 4,4 -Bis(hydroxymelhyl)-2,2/-bipyridine was employed for the polymerization of lactic acid, LA or CL in the presence of Sn(Oct)2 in bulk at 130 and 110°C, respectively. The hydroxyl end groups were converted to tertiary or secondary bromo esters by reaction with 2-bromoisobutyryl bromide or 2-bromopropionyl bromide. The reaction yields were very high (> 80%) but not quantitative. These products were used as macroinitiators for the ATRP of MMA or tBuA in the presence of CuBr/HMTETA. 4,4/-bis(Chloromethyl)-2,2 -bipyridine was employed to promote the ATRP of MMA or styrene followed by the addition... 

Johnson RM, Fraser CL. Iron tris(bipyridine)-centered star block copolymers chelation of triblock macroligands generated by ROP and ATRP. Macromolecules 2004 37 2718-2727. 

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