Alkyl methacrylates, controlled/living anionic polymerization

Controlled/Living Anionic Polymerization of Alkyl Methacrylates Using Flow Microreactor Systems... 

Similarly, MF synthesis offers crucial benefits for living anionic polymerization [39b,46]. For example, for polymerization of alkyl methacrylates conducted in a flow microreactor system, control over molecular weight distribution was achieved under easily accessible conditions at temperatures of —28 °C (methyl methacrylate, Mw/Mn = 1.16), 0°C (butyl methacrylate, M /M = 1.24), and 24°C (t-butyl methacrylate, M /M = 1.12) [39b]. The molecular weight of the polymer increased with increasing monomer to initiator ratio. Furthermore, a subsequent reaction of a reactive polymer chain with alkyl methacrylate yielded a block copolymer with a narrow molecular weight distribution. 

Polar Vinyl Monomers The anionic polymerization of polar vinyl monomers is often complicated by side reactions of the monomer with both anionic initiators and growing carbanionic chain ends, as well as chain termination and chain transfer reactions. However, synthesis of polymers with well-defined structures can be effected under carefully controlled conditions. The anionic polymerizations of alkyl methacrylates and 2-vinylpyridine exhibit the characteristics of living polymerizations under carefully controlled reaction conditions and low polymerization temperatures to minimize or eliminate chain termination and transfer reactions [118, 119]. Proper choice of initiator for anionic polymerization of polar vinyl monomers is of critical importance to obtain polymers with predictable, well-defined structures. As an example of an initiator that is too reactive, the reaction of methyl methacrylate (MMA)... 

Although organometallic catalysts have attracted the most attention lately with regard to the anionic polymerization of alkyl methacrylates, it is important to recognize that alkali metal alkoxides in a variety of media can initiate the polymerization of both alkyl methacrylates and alkyl acrylates. Especially in view of the recent discovery and reporting of controlled, living acrylate and methacrylate polymerizations via group transfer... 

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