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Blends of bacterial poly[( R )‐3‐hydroxybutyrate] with oligo[( R , S )‐3‐hydroxybutyrate]‐diol
Author(s) -
Saad G R
Publication year - 2002
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.844
Subject(s) - miscibility , differential scanning calorimetry , glass transition , materials science , amorphous solid , crystallization , melting point depression , polymer , polymer chemistry , melting temperature , polymer blend , chemical engineering , thermodynamics , copolymer , crystallography , organic chemistry , chemistry , composite material , physics , engineering
The miscibility, melting and crystallization behaviour of poly[( R )‐3‐hydroxybutyrate], PHB, and oligo[( R , S )‐3‐hydroxybutyrate]‐diol, oligo‐HB, blends have been investigated by differential scanning calorimetry: thermograms of blends containing up to 60 wt% oligo‐HB showed behaviour characteristic of single‐phase amorphous glasses with a composition dependent glass transition, T g , and a depression in the equilibrium melting temperature of PHB. The negative value of the interaction parameter, determined from the equilibrium melting depression, confirms miscibility between blend components. In parallel studies, glass transition relaxations of different melt‐crystallized polymer blends containing 0–20 wt% oligo‐HB were dielectrically investigated between −70 °C and 120 °C in the 100 Hz to 50 kHz range. The results revealed the existence of a single α‐relaxation process for blends, indicating the miscibility between amorphous fractions of PHB and oligo‐HB. © 2002 Society of Chemical Industry