Synthesis of biodegradable polyhydroxyalcanoate copolymer from a renewable source by alternate feeding
Contribuinte(s) |
UNIVERSIDADE DE SÃO PAULO |
---|---|
Data(s) |
20/10/2012
20/10/2012
2008
|
Resumo |
Polyhydroxyalcanoates copolymers with 3-hydroxybutirate (3HB) and 3-hydroxyvalerate (3HV) co-monomers, P3(HB-co-x%HV), were produced in fed-batch culture by Ralstonia eutropha DSM428 using fructose as a single carbon source in the first step and adding propionic acid in the second step by alternating feeding. Polymer yield was 0.18 g/L with a content of 24 mol% of the 3HV fraction determined by H-1 NMR. NMR measurements indicated that the polymer obtained is isotactic. The copolymer attained 35% of crystallinity according to X-ray diffraction measurements, and two (020) planes were observed. Thermal behavior presented melting temperature at 154 degrees C and the crystallization temperature was 65 degrees C. A glass transition temperature was observed at -10 degrees C. Average molecular weight measured by GPC was 4.9 x 10(5) Dalton. Isothermal radial growth rates of spherulites of P3(HB-co-24%HV) were studied. All experimental facts and the analysis of the sequence distribution of diads and triads of 3HB and 3HV units led to the conclusion that it is not a completely statistical random copolymer once it contains different types of segments. POLYM. |
Identificador |
POLYMER ENGINEERING AND SCIENCE, v.48, n.10, p.2051-2059, 2008 0032-3888 http://producao.usp.br/handle/BDPI/28350 10.1002/pen.21178 |
Idioma(s) |
eng |
Publicador |
JOHN WILEY & SONS INC |
Relação |
Polymer Engineering and Science |
Direitos |
restrictedAccess Copyright JOHN WILEY & SONS INC |
Palavras-Chave | #BACTERIAL POLY(BETA-HYDROXYBUTYRATE-CO-BETA-HYDROXYVALERATE) #POLY(3-HYDROXYBUTYRATE-CO-3-HYDROXYVALERATE) #POLY(3-HYDROXYBUTYRATE) #COPOLYESTERS #Engineering, Chemical #Polymer Science |
Tipo |
article proceedings paper publishedVersion |