Atom transfer free-radical polymerisation ATRP

Many publications dealing with the free-radical homo/copolymerisation of saturated fatty acid acrylates and methacrylates appeared between 2001 and 2011, particularly using living systems such as atom transfer radical polymerisation (ATRP) [91-112]. Monomers were prepared, for example, by the reaction of acrylic and methacrylic acid chlorides with fatty alcohols of different chain length, as shown in Scheme 4.23 in the case of methacrylates (which also includes their ATRP conditions). A very... 

In recent years, transition metal mediated free radical processes have gained in importance. In particular the Kharasch addition to olefins such as atom transfer radical addition (ATRA) and atom transfer radical cyclisation (ATRC) and its extension to olefin polymerisation known as atom transfer radical polymerisation (ATRP) have been reported with a wide range of metal catalysts. 

Although free radical polymerisation is most common, other types of polymerisations have been carried out in emulsion polymerisation, including reversible addition-fragmentation transfer (RAFT) (131), atom transfer radical polymerisation (ATRP) (76, 222), and stable free radical polymerisation (SFRP) (77). 

Functionalised PO as block and graft copolymers used as compatibilisers or to increase interactions with other materials are prepared by free radical grafting (the simplest method), metallocene-catalysed copolymerisation of olefins with functional monomers, or anionic polymerisation (silane-containing PO). They are also produced by controlled/living polymerisation techniques such as nitroxide-mediated controlled radical polymerisation, atom transfer radical polymerisation (ATRP), and reversible addition-fragmentation chain transfer (RAFT). 

The general mechanism in atom transfer radical polymerisation is depicted in Scheme 8.11. The main difference to conventional radical polymerisation is in the presence of a metal complex. Free radicals are generated from reaction between the initiator (such as an organic halide) and the metal species which further controls the reaction by reversibly transforming the free radicals into a dormant species.1"6 However, it ought to be pointed out that in ATRP contrary to, for example, Ziegler-Natta-type catalysts, the polymerisation does not take place at the metal centre. 

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