Microbial Synthesis and Properties of Poly(3-hydroxybutyrate-co-4-hydroxybutyrate)

✍ Scribed by Saito, Yuji; Nakamura, Shigeo; Hiramitsu, Masaya; Doi, Yoshiharu

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 433 KB
• Volume: 39
• Category: Article
• ISSN: 0959-8103
• DOI: 10.1002/(sici)1097-0126(199603)39:3<169::aid-pi453>3.0.co;2-z

✦ Synopsis

Microbial synthesis of copolymers of CR1-3-hydroxybutyrate (3HB) and 4-hydroxybutyrate (4HB), P(3HB-co-4HB), by Alcaligenes eutrophus, Alcaligenes latus, and Comamonas acidovorans from various carbon sources has been studied. The copolyester compositions varied from 0 to 100mol% 4HB, depending on the microorganism and the combination of carbon substrates supplied. The thermal and physical properties of compositions with 0-100mol% 4HB were investigated. The copolyesters represented a wide variety of polymeric materials, from hard crystalline plastic to very elastic rubbers, depending on composition. The copolyester films with high 4HB fractions (64-100 mol% 4HB) exhibited the characteristics of a thermoplastic elastomer, and the tensile strength increased from 17 to 104MPa as the 4HB fraction increased. The enzymatic degradation of P(3HB-co-4HB) films was studied in an aqueous solution of extracellular polyhydroxybutyrate (PHB) depolymerase from Alcaligenes faecalis or lipase from Rhizopus delemer. The erosion rate of P(3HB-co-4HB) films was strongly dependent on the copolymer composition. In addition, environmental degradation of P(3HB-co-4HB) films in sea water was investigated.