AGET ATRP of Acrylonitrile Using 1,1,4,7,10,10-Hexamethyltriethylenetetramine as Both Ligand and Reducing Agent

Atom transfer radical polymerization using activators generated by electron transfer (AGET ATRP) of acrylonitrile (AN) initiated by ethyl 2-bromoisobutyrate was approached for the first time using 1,1,4,7,10,10-hexamethyltriethylenetetramine (HMTETA) and 1,1,4,7,7-pentamethyldiethylenetriamine (PMDETA) as both ligand and reducing agent. AGET ATRP of AN with HMTETA as both ligand and reducing agent was better controlled than with PMDETA as both ligand and reducing agent under the same experimental conditions. With an increase content of HMTETA, the polymerization provided an accelerated reaction rate and a broader polymer molecular weight distribution. The rate of polymerization with DMF as solvent was faster than with acetonitrile, cyclohexanone, toluene, and xylene as solvents. The polymerization apparent activation energy was calculated to be 45.7 kJ mol(-1). The end functionality of polyacrylonitrile (PAN) was confirmed by H-1 NMR spectroscopy. The living feature of PAN was verified by chain extensions of PAN with methyl methacrylate and AN. (C) 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 128-133,2010