Influence of cooling rate on the thermal behavior and solid‐state morphologies of polyhydroxyalkanoates |
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| Authors: | Yuping Xie Isao Noda Yvonne A Akpalu |
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| Affiliation: | 1. Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180;2. The Procter & Gamble Company, Beckett Ridge Technical Center, West Chester, Ohio 45069;3. Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, New York 12180 |
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| Abstract: | The influence of cooling rates on the thermal behavior and solid‐state morphologies of polyhydroxyalkanoates have been investigated. The thermal behavior was studied by differential scanning calorimetry (DSC). The crystal structures (～ Å), lamellar (tens of nanometers), fibrillar (several hundred nanometers), and spherulitic (～ μm) morphologies of poly (3‐hydroxybutyrate) (PHB) and the copolymers of poly (3‐hydroxybutyric acid‐co‐3‐hydroxyvaleric acid) (PHBV) and poly (3‐hydroxybutyric acid‐co‐3‐hydroxyhexanoic acid) (PHBHx) crystallized under different cooling rates were studied using simultaneous small angle X‐ray scattering (SAXS) and wide angle X‐ray scattering, simultaneous ultra small angle X‐ray scattering (USAXS) and SAXS, and polarized optical microscopy, respectively. The experimental results showed that the lamellar and spherulitic morphologies depended strongly on cooling rates. However, there was little influence of cooling rates on the crystal structures. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 |
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| Keywords: | X‐ray thermal properties morphology processing |
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