Oligomers, acrylamide terminated

Table 1. Physical and Chemical Properties of the Acrylamide-terminated Oligomers... 

In summary, the reaction of alkenyl azlactones with amine-terminated oligomers has been found to be an excellent method for preparing the corresponding (meth)acrylamide-terminated oligomers. The reaction is characterized by a very simple synthetic sequence in which equivalent quantities of reactants are mixed at room temperature with no catalyst reactions are complete to the almost exclusion of side reactions within 16-18 hours. Furthermore, the reaction is a nucleophilic addition. This is the same manner in which nucleophiles react with isocyanates and epoxides. Indeed, this nucleophilic addition mode of reaction which involves no by-products likely accounts for the widespread use of these latter functional groups by industry. In comparison with isocyanate and epoxide, amine nucleophiles react with azlactones at controlled and predictable rates, intermediate between the very reactive isocyanate and the slow reacting epoxide. 

In the same way, Oishi et al. [256] used IEM to functionalize oligomers carrying an acid function obtained by polymerization of chiral acrylamides. Chiral polyacrylamide macromonomers were synthesized from 2-methacryloyloxyethyl isocyanate and prepolymers, i.e., poly[(S)-methyl-benzyl acrylamide] or poly(L-phenylalanine ethylester acrylamide) with a terminal carboxylic acid or hydroxyl group. Radical homopolymerizations of polyacrylamide macromonomers were carried out under different conditions to obtain the corresponding optically active polymers, as shown in Scheme 52. 

Soluble polystyrene supports differ from the terminally functionalized PEGs and polyethylene oligomers discussed above in that the catalyst moieties are attached to polystyrene via pendant groups, the loading of which can affect both the catalyst activity and separability. One example of a simple polystyrene-supported catalyst is the polystyrene copolymer-supported quaternary ammonium salts 66 and 67 [ 103]. These copolymers can be prepared with varying ratios of the styrene unit in the copolymer - the most active catalysts had 20-40 mol% of the vinylbenzylammonium groups in the copolymers. The utility of these catalysts was studied in a variety of solvents in the addition reaction of glycidyl methacrylate and carbon dioxide (Eq. 23). Polar solvents were most useful. The necessary polymer supports for preparation of catalysts 66 and 67 were prepared from chloromethylstyrene-styrene or chloromethyl-styrene-iV,JV-dimethylacrylamide copolymers that were in turn prepared by radical polymerization of the styrene or acrylamide monomers. The catalysts were recycled up to four times with small (ca. 6%) decreases in activity - de-... 

FUNCTIONAL, TELECHELIC POLYMERS DERIVED FROM REACTIONS OF NUCLEOPHILIC OLIGOMERS AND ALKEYNL AZLACTONES, PART I TELECHELIC ACRYLAMIDES DERIVED FROM REACTIONS OF ALKEYNL AZLACTONES AND AMINE-TERMINATED OLIGOIERS ... 

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