Polymers, biodegradable, aliphatic polyesters

What Is a biodegradable polymer Give an example of a biodegradable aliphatic polyester. 

Coulembier O, Degee Ph, Hedrick JL, Dubois Ph (2006) From controlled ring-opening polymerization to biodegradable aliphatic polyester especially poly(P-malic acid) derivatives. Prog Polym Sci 31 723-747... 

Yoshikawa Y, Ofuji N, Imaizumi M, Moteki Y, Fujimaki T (1996) Molecular weight distribution and branched structure of biodegradable aliphatic polyesters determined by s.e.c-MALLS. Polymer 37 1281... 

Poly(butylene succinate) (PBS) is an important member of biodegradable aliphatic polyester family. PBS and related copolymers have shown considerable promise for uses as environmentally biodegradable thermoplastics, as well as bioabsorbable/biocompatible medical materials (/). In both cases, practical applications require that the polymer possess a high molecular weight (M >20,000) so that it can have useful mechanical properties. 

Drug delivery systems based on biodegradable aliphatic polyesters have advanced remarkably over the past few decades. Commonly used polymers such as poly(e-caprolactone) (PCL), poly (lactide acid) (PLA), and poly (lactic-co-glycolic acid) (PLGA) are FDA approved and well known for their biodegradability, biocompatibility, and non-toxic properties, which make them suitable as matrices for controlled release drug delivery systems. 

Tserki, V, Matzinos, R, PavUdou, E. et al. (2006) Biodegradable aliphatic polyesters. Part 1. Properties and biodegradation of poly (butylene succinate-co-butylene adipate). Polymer Degradation and Stability,... 

Taniguchi I, Nakano S, Nakamura T, El-Salmawy A, Miyamoto M, Kimura Y (2002) Mechanism of enzymatic hydrolysis of poly(butylene succinate) and poly(butylene succinate-co-L-lactate) with a lipase from Pseudomonas cepacia. Macromol Biosci 2 447-455 Tomita K, Kuroki Y, Hayashi N, Komukai Y (2000) Isolation of a thermophile degrading poly(butylene succinate-co-butylene adipate). J Biosci Bioeng 90 350-352 Tserki V, Matzinos P, PavUdou E, Panayiotou C (2(X)6a) Biodegradable aliphatic polyesters. Part II. Synthesis and characterization of chain extended poly(butylene succinate-co-butylene adipate). Polym Degrad Stab 91 377-384... 

Poly(L-lactide) (PLLA) is a biodegradable aliphatic polyester produced by ring-opening polymerization of lactide (i.e., with cyclic dimer of lactic acid) or by polycondensation of lactic acid. Although PLLA is a synthetic polymer, it is considered a renewable and bio-based plastic because its raw material lactic acid is synthesized from biomass or renewable resources such as sugars and starch. PLLA has some properties that are similar to some petroleum-based plastics, thereby making it suitable for a variety of applications in the medical, textile, and packaging industries. 

Chrissafis K., Paraskevopoulos K.M., Bikaris D.N. Thermal degradation kinetics of the biodegradable aliphatic polyester, poly(propylene succinate), Polym. Deg. Stab. 91 (2006) 60. 

Surface alkali hydrolysis treatment is also a convenient mediod to modify PLA poljmier siuTace [42 - 47]. In general, biodegradable aliphatic polyesters, such as PGA and PLA, contain ester bonds. The polymer film or scaffolds are immersed into aqueous NaOH solution. The ester bonds at the surface can be hydrolyzed and results in the generation of carboxylic acid and hydroxyl groups at the polymer surface. 

Because these polymers in general have poor water resistance, and poorer mechanical properties than conventional polymers, they have been introduced into the market either as blends (with biodegradable aliphatic polyesters, such as Ecoflex from BASF, or BionoUe from Showa Polymers) or as grafts with others synthetic monomers such as vinylalcohol, caprolactone, or acrylonitrile [25,26]. 

As far as biodegradable aliphatic polyesters are concerned, a main classification divides them into two groups. In the first group, the repetitive unit of the polymer is constituted by a hydroxyacid unit, while in the second one it is constituted by a diol... 

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