A study on the effectiveness of hexamethyltriethylenetetraamine ligand in the copper mediated atom transfer radical polymerization of acrylamide

Polymer Science Unit, Indian Association for the Cultivation of Science, Jadavpur, Kolkata-700 032, India Manuscript received 5 April 2005, accepted 6 July 2005 Atom transfer radical polymerization (ATRP) of acrylamide was carried out in a glycerol-water (1 : 1 v/v) medium with 2-halopropionamide initiators, CuX (X = Cl, Br)/N,N,N',N'N'N"-hexamethyltriethylenetetraamine (HMTETA) catalyst, CuX2/HMTETA (20 mol% of CuX/HMTETA) and excess alkali halide (ca. 0.2-1 M) additives. The first-order kinetic plots for the disappearance of monomer were linear when either LiC1 (0.2 or 1 M) (or both LiCI (1 M) and CuCl2/ HMTETA (20 mol% of CuCI/HMTETA) were added into the system, to start with. However, in all the cases molecular weights do not increase with conversion. This signifies the uncontrolled nature of polymerization. These results suggest that CuX2/HMTETA is a poor deactivator as far as the ATRP of acrylamide is concerned