Polylactone

Thermodynamics of fusion of poly-p-propiolactone and poly-e-caprolactone. Comparative analysis of the melting of aliphatic polylactone and polyester chains, Eur. Polym. J.. 8, 449-463, 1972. 

Anionic block copolymerizations of MM A with lactones proceeded smoothly to give copolymers with Mw/Mn = 1.11-1.23 when the monomers were added in this order. However, when the order of addition was reversed, no copolymerization took place [3c], i.e., no addition of MMA to the polylactone active end group occurred (Scheme 12). 

Dubois P, Jerome R, Teyssie P (1989) Macromolecular engineering of polylactones and polylactides. I. End-functionalization of poly-e-caprolactone. Polym Bull 22 475 82... 

Kricheldorf HR, Strieker A, LangankeD (2001) Polylactones, 50. The reactivity of cyclic and noncyclic dibutyltin bisaUcoxides as initiators in the polymerization of lactones. Macromol Chem Phys 202 2525-2534... 

Kricheldorf HR, Jonte JM, Dunsing R (1986) Polylactones. 7. The mechanism of cationic polymerization of (3-propionolactone and E-caprolactone. Makromol Chem 187 771-785... 

Kricheldorf HR, Sumbel MV (1988) Polylactones, 15. Reactions of 5-valerolactone and E-caprolactone with acidic metal bromides. Makromol Chem 185 317-331... 

Kricheldorf HR, Fechner B (2002) Polylactones. 59. Biodegradable networks via ring-expansion polymerization of lactones and lactides. Biomacromolecules 3 691-695... 

Kricheldorf FIR, Lee SR (1996) Polylactones. 40. Nanopretzels by macrocyclic polymerization of lactones via a spirocyclic tin initiator derived from pentaerythritol. Macromolecules 29 8669-8695... 

Kricheldorf HR, Lee SR (1995) Polylactones. 35. Macrocyclic and stereoselective polymerization of P-D,L-butyrolactone with cyclic dibutyltin initiators. Macromolecules... 

Kricheldorf HR, Eechner B (2001) Polylactones. 51. Resorbable networks by combined ring-expansion polymerization and ring-opening polycondensation of -caprolactone or DL-lactide. Macromolecules 34 3517-3521... 

Macrocyclic polycarbonyls are cyclic ligands containing carbonyl functionalities. Several categories come under this heading the macrocyclic oligoketones (7), the polylactones (8) and the polylactams (9). 

Polylactones (for an example, see Fig. 14.4) are synthetic analogues of naturally occurring ionophores such as enniatin (species that transport ions across biological membranes). Molecular mechanics calculations have been used to predict the stability and selectivity with respect to Li+, Na+, and K+ of a series of new polylactones12661. Metal-ligand interactions were again modeled using a combination of van der Waals and electrostatic terms. 

Star-shaped polylactones with functional end groups via ring-expansion polymerization of f-caprolactone or y-o,i-butyrolactonc with a spiroinitia-tor was synthesized as shown in Fig. 44 [146]. The spirocyclic polylactones formed were reacted with various carboxylic acid chlorides and yielded fourarmed stars with the elimination of Bu2SnCl2. Star arms with chloroacetate, 4-bromobenzoate, 4-nitrobenzoate, cinnamate, stearate, or methacrylate end groups were obtained by varying the acid chlorides. 

Polylactones and polylactides of high molecular weight are exclusively produced by the ROP of the corresponding cyclic monomers. A polyester is formed when cyclic esters are reacted with a catalyst or initiator. Scheme 1 presents the reaction pathway for the ROP of a cyclic ester. 

Not all monomers are anionically polymerizable. Nevertheless, one can take advantage of the activity of the living ends to introduce reactive end groups at the extremity of homopolymers and then use such end groups to initiate the polymerization of anionically non polymerizable monomers. This method has been applied to the synthesis of copolymers with polyvinyl and polylactone blocks19 and of copolymers with polyvinyl and polypeptide blocks20-2S). One can at last use both anionic and cationic polymerization to prepare block copolymers of tetrahydrofuran with styrene or methylstyrene2. ... 

Polyoxa macrocycles, known more commonly as the crown ethers, comprise an extensive area of research, with a repertoire of types and variations. Some of these macrocycles have been utilized predominantly for purposes other than metal ion complexation, and these will not be discussed in depth in this review. Included in this latter category are the polycarbonyls, polylactones,polylactams and carcerands. " ... 

The results of Figure 7 demonstrate that CO2 evolution from polyester films can also be measured and offers a convenient way of monitoring the photodegradation of polymers such as polylactones which are of increasing interest because of their biodegradability. However, unlike polyalkenes. 

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