Atom Transfer Radical Polymerization

Atom transfer radical polymerization ( ATRP) is a special form of 'Living ' / Controlled Free Radical Polymerization ( LFRP ).

It is characterized by the fact that the concentration of free radicals is reduced until by the addition of a transition metal complex and in combination with an atom transfer process with an organic halide that chain termination reactions, such as disproportionation or recombination, are pushed back as far as possible. This is due to the kinetic function of the reaction rates ( both chain growth and termination reactions ) of the concentration of active chain ends. For the growth it follows a rate law first order, for the recombinative termination reactions to a law of 2nd order. Thus, the reaction rate of termination reactions is strongly affected by a decrease in the chain end concentration ( principle of all LFRPs ) than the reaction rate of chain growth.

This polymer can be synthesized, which are characterized by control over the molecular weight and a narrow distribution of molar mass.

The ATRP was first discovered in 1995 almost simultaneously by Mitsuo Sawamoto and Krzysztof Matyjaszewski and described independently.