In vitro degradation of a polyhydroxybutyrate/polyhydroxyvalerate copolymer

  • J. C. Knowles
  • G. W. Hastings


Injection-moulded PHB/7% PHV (molecular mass 580 000) samples were placed in buffered saline at varying pHs for long-termin vitro studies. Anomalies between sample mass loss and Young's modulus were found for the different pHs. The Young's modulus anomaly was explained by examination of the molecular mass distribution (MMD) changes with time. The molecular mass measurements also showed that the MMD moved to a lower molecular mass, and also showed an increase in peak height, irrespective of pH. From theMn data, curves for (Mn(O)/Mn(t) −1) were plotted and the linearity showed that the solution pH was a rate-controlling factor.


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Copyright information

© Chapman & Hall 1992

Authors and Affiliations

  • J. C. Knowles
    • 1
  • G. W. Hastings
    • 2
  1. 1.Biomedical Engineering UnitMedical InstituteStoke-on-TrentUK
  2. 2.Department of MaterialsQueen Mary and Westfield CollegeLondonUK

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