Atom transfer radical polymerization through N-chlorosulfonamides

Controlled polymerizations of vinyl monomers such as methyl methacrylate an d styrene are achieved using N-chloro,N-propyl-p-toluenesulfonamide (NCPT) together with a cuprous bromide/hexahexyl triethylenetetramine (CuBr/H-TETA ) complex. Although N-halosulfonamides are known to decompose radically to give free chlorine, NCPT alone (without a cuprous complex) does not initiat e any polymerization even in prolonged reaction times. Instead these add to the double bonds to give 2-chloroethylsulfonamides. In the present polymer ization system a good chlorine donator (NCPT) is combined with an organic s oluble complex (CuBr/H-TETA) to perform atom transfer radical polymerizatio ns (ATRPs) in homogenous conditions. The linear proportionality of the mole cular weights to the conversions and straight lines observed in ln(M-o/M) ( where M-o and M are the monomer contents at the beginning and at any time, respectively) versus time plots indicate typical controlled polymerization characteristics. The use of freshly prepared NCPT is advisable due to its s low and spontaneous decomposition when standing at room temperatures. Becau se of their easy preparation, N-chlorosulfonamides can be used and are pref erred instead of special halogen compounds commonly used in copper mediated ATRP. (C) 2001 John Wiley & Sons, Inc.