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Organo-catalytic polymerisation

The last type of ring-opening polymerisation of lactones discussed in the present work Involves the use of organic compounds as catalysts. Although alcohols and amines are generally not nucleophilic enough to initiate polymerisation, in some cases, tertiary amines are able to initiate the polymerisation of highly reactive -lactones [30]. [Pg.762]

However, for less reactive monomers, catalysts are generally required. These compounds can activate the monomer, the initiator or both. Hedrick and co-workers were pioneers in this field because of the discovery and thus, the Introduction of a route towards metal-free polyesters [61-65]. Organo-catalytic polymerisations generally involve nucleophiles activating the monomer ring [Pg.762]

The most widely applied catalyst systems in organocatalytic ROP include N-heterocyclic carbenes [62, 64, 67], guanidine and amidine bases [51,65] and phosphorane-based compounds [68,69]. Strong organic acids are excluded from this section as their mechanism follows the one described for cationic ring-opening polymerisations [70, 71]. [Pg.763]

In some cases, the polymerisation is performed in the presence of a thiourea compound as co-catalyst to extend the application of organo-catalysis towards less reactive monomers [63, 65, 69]. These compounds activate the carbonyl group via hydrogen bonding and thus render the carbonyl carbon more electrophilic as shown in Fig. 21.7. [Pg.763]

3 Ring-Opening Polymerisation of Cyclic Ketene Acetals [Pg.764]


See other pages where Organo-catalytic polymerisation is mentioned: [Pg.762]    [Pg.762]    [Pg.365]    [Pg.114]    [Pg.236]    [Pg.193]    [Pg.382]   


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Catalytic polymerisation

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