Polyester ring-opening copolymerizations

Biodegradable polyesters were synthesized via ring-opening copolymerizations of various oxiranes (glycidyl phenyl ether, benzyl glycidate, glycidyl methyl ether, styrene oxide) and various dicarboxylic anhydrides (succinic anhydride, phthalic... 

Matsumura, S., Okamoto, T., Tsukada, K., and Toshima, K. (1998) Novel lipase-catalyzed ring-opening copolymerization of oxiranes and succinic anhydride forming polyesters bearing functional groups. Macromol. Rapid Commun., 19 (6), 295-298. 

The living R-ROP of cyclic ketene acetals was achieved with nitroxy-mediated polymerization (NMP) (29), ATRP (30), and RAFT (31) methods to afford the polyesters with low polydispersities. Recently, it has been reported that the block and random copolymers with vinyl monomers showing low polydispersities could also be obtained by living radical ring-opening copolymerizations (32, 33). 

The ring-opening copolymerization of propylene oxide and carbon monoxide forms the polyester poly(p-hydroxybutyrate) (PHA, Equation 17.52). The physical and mechanical properties of some PHAs are similar to those of isotactic polypropylene. This polymerization was first reported by Furukawa and co-workers in 1965, and more recent studies have been reported by Osakada, Rieger, and Alper. These polymerizations have been conducted with Co2(CO)j and additives. The combination of Co2(CO)j, a 1,10-phenan-throline derivative, and benzyl bromide afforded polyester with an value of 19.4 kg/ mol and M /M of 1.41. In addition to propylene oxide, 1,2-epoxybutane was successfully copolymerized with CO to yield the corresponding poly(3-hydrox5 entanoate) with an value of 16.7 kg/mol and a M /M of 1.28. The role of benzyl bromide is unclear. Related copolymerizations of aziridines and CO to form polyamides have also been reported. Polymer values as high as 27.5 kg/mol have been reported, and tjqjical M /M values varied from 1.11 to 1.64. 

Uyama H, Takeya K, Kobayashi S (1993) Synthesis of polyesters by enzymatic ring-opening copolymerization using lipase catalyst. Proc Jpn Acad B 69 203—207... 

Ring-opening polymerizations and copolymerizations also offer novel routes to polyesters and polyketones. These polymers are not otherwise available by radical polymerization. Finally, ring-opening copolymerization can be used to give end-functional polymers. For example, copolymerization of ketene acetals with, for example, S, and basic hydrolysis of the ester linkages in the resultant copolymer offers a route to a,co-difunctional polymers. 

Nishimura, X, Kameyama, A., Sakurai, X, and Nishikubo, X, Synthesis of polyesters carrying norbomadiene (NBD) moieties by the ring-opening copolymerization of glycidic esters containing NBD moieties with carboxyKc anhydrides and their photochemical reactions. Macromolecules, 29, 3818-3825, 1996. 

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