Journal of Thermal Analysis and Calorimetry

, Volume 112, Issue 3, pp 1439–1446 | Cite as

Evolution of crystal and amorphous fractions of poly[(R)-3-hydroxybutyrate] upon storage

  • Maria Laura Di LorenzoEmail author
  • Maria Cristina Righetti


Quantitative thermal analysis of the evolution of crystal and amorphous fractions of poly[(R)-3-hydroxybutyrate] (PHB) upon storage at room temperature is detailed in this contribution. Conventional and temperature-modulated calorimetry were used to quantify the crystallinity, as well as the mobile and rigid amorphous fractions, of an initially partially crystallized PHB, subsequently maintained at 25 °C for various times. PHB undergoes progressive crystallization during storage, with an increase in crystal fraction (w C) from the initial w C = 0.35 up to w C = 0.71 attained after 1 year of storage. Crystallization is accompanied by vitrification of rigid amorphous segments, which leads to a noteworthy increase of the overall fraction of the material that is solid at room temperature, leaving only a mobile amorphous fraction w A = 0.04 after 1 year at 25 °C. The quantitative thermal analysis allowed to clarify the kinetics of evolution of both the ordered and unordered fractions of PHB upon storage, which leads to a severe deterioration of material’s properties.


Poly[(R)-3-hydroxybutyrate] DSC TMDSC Three-phase structure Rigid amorphous fraction Heat capacity 


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Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2012

Authors and Affiliations

  • Maria Laura Di Lorenzo
    • 1
    Email author
  • Maria Cristina Righetti
    • 2
  1. 1.Istituto di Chimica e Tecnologia dei PolimeriConsiglio Nazionale delle RicerchePozzuoliItaly
  2. 2.Istituto per i Processi Chimico-FisiciConsiglio Nazionale delle RicerchePisaItaly

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