Radicals radical scavenger, polymer synthesis

Even if several studies demonstrate that PBT is less stable than PET, less attention has been paid to the improvement of the stability of poly(bntylene terephthalate). [7,8] The nsnal strategy to increase PBT stability is the addition, dnring the synthesis or the mannfactnring, of anti-oxidizers, like Ultranox and Irganox the typical phenol-type radical scavengers. [20] However, dnring the last years, a good nnmber of new catalytic systems are claimed to catalyse efficiently PBT synthesis, but in these studies very few information are available about possible relationships between catalyst composition and polymer stability. [21-23]... 

Frechet and coworkers have reported the development of a functionalized polymer monolith for use in parallel solution phase synthesis in continuous flow applications [10]. In this report, the authors outline the preparation of an azalac-tone-functionalized monolith for scavenging nucleophiles. This method involves the preparation of a macroporous polyfchloromethylstyrene co-divinylbenzene) monolith via the polymerization of the relevant mixture of monomer, initiator and porogen. These are allowed to react with a free radical initiator (4-cyanovaleric acid), followed by reaction with the monomer of choice, to synthesize the functionalized monolith. The authors have thus prepared monoliths functionalized with VAZ to provide an azalactone-functionalized monolith. These monoliths were then demonstrated to completely remove amines after flowing a solution of amine in THF through the monolith for 30 min. They have also reported the reaction of these monoliths with alcohols as well. A small demonstration library of ureas was prepared and after 8 min of residence time up to 76% of the alkyl amines were found to be scavenged (Scheme 8.6). 

Fournier D, Pascual S, Montembault V, Haddleton DM, Fontaine L (2006) Well-defined azlactone-functionalized (Co)polymers on a solid support synthesis via supported living radical polymaization and application as nucleophile scavengers. J Comb Chem 8 522-530... 

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