Novel Biodegradable Copolyesters Containing Blocks of Poly(3‐hydroxyoctanoate) and Poly(ε‐caprolactone): Synthesis and Characterization

Abstract

Novel biodegradable polyester block copolymers have been synthesized by using well-defined poly(3-hydroxyoctanoate) (PHO) oligomers having a hydroxyl end group and an ester end group with M(n) values of 800, 2,500, 5,300, 8,000, or 20,000 as an elastomeric soft segment and poly(epsilon-caprolactone) as a more crystalline segment. These PHO oligomers prepared by methanolysis were subjected to block copolymerization with epsilon-caprolactone. The chemical structure of the copolymers was confirmed by (1)H NMR and (13)C NMR spectroscopy. All the copolyesters are semi-crystalline and two T(g) were observed by differential scanning calorimetry when the molecular weight of the PHO block is about 20,000.

Amphiphilic PHA–mPEG copolymeric nanocontainers for drug delivery: Preparation, characterization and in vitro evaluation

“…Polyhydroxyalkanoates (PHA) are biodegradable thermoplastic polymers produced by microorganisms during unbalanced growth condition as inclusion bodies (Anderson and Dawes, 1990;Lenz and Marchessault, 2005). Different types of PHA homopolymers and copolymers produced by microorganisms have been suggested to be utilizable as tissue engineering materials and controlled release drug vectors (Khang et al, 2001;Köse et al, 2003;Timbart et al, 2004;Yao et al, 2008). Microparticles prepared from either poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) or blends of PHBV and polycaprolactone were used for the sustained release of drugs (Khang et al, 2001;Lionzo et al, 2007).…”

Poly(3-hydroxyalkanoate) sulfonate: From nanoparticles toward water soluble polyesters

“…The molar mass of alkyne-ended PHBHV was calculated by integration of the 1 H NMR spectral signal at 4.68 ppm (c, CH 2 -CCH) against the signal at 5.15-5.30 ppm (3-3', OCHRCH 2 PHA backbone). Well-defined PHONe oligomers were prepared by acid-catalyzed methanolysis [27]. By controlling reaction time, oligomers with molar masses from 3 900 to 10 200 g.mol -1 were obtained.…”

Chemical modifications of bacterial polyesters: from stability to controlled degradation of resulting polymers

“…28,32 Copolymers were prepared through combining in a first step the preparation of poly(3-hydroxyalkanoate)s oligomers, having a hydroxyl end group and in a second step, the controlled coordination-insertion ring opening polymerisation of e-caprolactone initiated by the OH-oligomer end group using a trialkyl metal as catalyst. Oligomers were obtained by methanolysis with different molecular weights according to the time reaction.…”