Anionic ring-opening polymerization AROP

Among these reactions, the Cu(l)-catalyzed azide-alkyne cycloaddition (CuAAC) is the most widely used. This reaction has been implemented for the preparation of segmented block copolymers from polymerizable monomers by different mechanisms. For example, Opsteen and van Hest [22] successfully prepared poly(ethylene oxide)-b-poly(methyl methacrylate) (PEO-b-PMMA) and PEO-b-PSt by using azide and alkyne end-functionalized homopolymers as the click reaction components (Scheme 11.2). Here, PEO, PSt, and PMMA homopolymers were obtained via living anionic ring-opening polymerization (AROP), atom transfer radical polymerization (ATRP), and postmodification reactions. Several research groups have demonstrated the combination of different polymerization techniques via CuAAC click chemistry, in the synthesis of poly(e-caprolactone)-b-poly(vinyl alcohol) (PCL-b-PVA)... 

The synthetic strategies for the incorporation of cleavable moieties into the backbone of PEG that have been employed to date (Table 2) mirror the inherent challenges related to this task. The most appreciated approach would be direct synthesis via the anionic ring-opening polymerization (AROP) of ethylene oxide (EO), with an oxirane co-monomer providing the additional functionality (analogous to the synthesis of multifunctional PEGs [38]) since copolymers can be... 

The synthesis of poly(IB-b-pivalolactone (PVE)) diblock copolymers was also recently accomplished by site-transformation ofiiving cationic polymerization of IB to anionic ring-opening polymerization (AROP) of PVE, as shown in Scheme First, PIB with co-carboxylate potassium salt... 

Figure 8 Main mechanistic transformation reactions in living and/or controlled polymerization methods. ATRP, atom transfer radical polymerization RAFT, reversible addition-fragmentation chain transfer NMRP, nitroxide-mediated free radical polymerization CROP, cationic ring-opening polymerization AROP, anionic ring-opening poiymerization.

Fig. 2.14 Scheme illustrating the synthesis of ABC type tri-block polymer with hydrophilic PEO middle block using AROP. 1 Anionic polymerization followed by hydrogenation, 2 Anionic ring-opening polymerization, and 3 Chain end functionalization followed by atom transfer radical polymerization... 

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