Miscibility and crystallization behaviors of poly(3-hydroxybutyrate-co-11%-4-hydroxybutyrate)/Poly(3-hydroxybutyrate-co-33%-4-hydroxybutyrate) blends

Autor: Jianyun He, Jueyu Pan, Xiaojuan Wang, Lan Zhiyuan, Kaitian Xu
Rok vydání: 2010
Předmět:
Zdroj: Journal of Applied Polymer Science. 119:3467-3475
ISSN: 0021-8995
DOI: 10.1002/app.32999
Popis: Biopolyesters poly(3-hydroxybutyrate-co-4- hydroxybutyrate) with an 11 mol % 4HB content (P(3HB- co-11%-4HB)) and a 33 mol % 4HB content (P(3HB-co-33%- 4HB)) were blended by a solvent-casting method. The ther- mal properties were investigated with differential scanning calorimetry. The single glass-transition temperature of the blends revealed that the two components were miscible when the content of P(3HB-co-33%-4HB) was less than 30% or more than 70 wt %. The blends, however, were immisci- ble when the P(3HB-co-33%-4HB) content was between 30 and 70%. The miscibility of the blends was also confirmed by scanning electron microscopy morphology observation. In the crystallite structure study, X-ray diffraction patterns demonstrated that the crystallites of the blends were mainly from poly(3-hydroxybutyrate) units. With the addition of P(3HB-co-33%-4HB), larger crystallites with lower crystalli- zation degrees were induced. Isothermal crystallization was used to analyze the melting crystallization kinetics. The Avrami exponent was kept around 2; this indicated that the crystallization mode was not affected by the blending. The equilibrium melting temperature decreased from 144 to 140 � C for the 80/20 and 70/30 blends P(3HB-co-11%-4HB)/ P(3HB-co-33%-4HB). This hinted that the crystallization tendency decreased with a higher P(3HB-co-33%-4HB) content. V C 2010 Wiley Periodicals, Inc. J Appl Polym Sci 119: 3467-3475, 2011
Databáze: OpenAIRE
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