Poly(Beta-Hydroxybutyrate) Stereoisomers: A Model Study of the Effects of Stereochemical and Morphological Variables on Polymer Biological Degradability

Abstract

In this study, we have prepared poly(Beta-hydroxybutyrate), PHB, random stereocopolymers from beta-butyrolactone, BL, using a diethylzinc/water (1.0/0.6) catalyst system. (R)-and (S)-BL were synthesized in high enantiomeric purity (>98% ee(enantiomeric excess), and approximately 5% racemization occurred at the methine stereocenters upon polymerization. The PHB stereoisomers produced had R repeat unit compositions of 95, 90, 85, 81, 77, 67, and 50%. In addition, a 50% (R)-PHB stereoisomer with a predominantly syndiotactic repeat unit placement was prepared in our laboratory. The relative degradability of these PHB stereoisomers was studied with a PHB depolymerase enzyme isolated from Penicillium funiculosum. This enzyme has been shown to catalyze the hydrolysis of (R)-PHB, but does not show activity for the enantiomeric substrate (S)-PHB.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1992
Accession Number
ADA271046

Entities

People

  • John E. Kemnitzer
  • Richard A. Gross
  • Stephen P. Mccarthy

Organizations

  • University of Massachusetts Lowell

Tags

Communities of Interest

  • Advanced Electronics
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Chemical Industry
  • Chemical Synthesis
  • Chemistry
  • Engineered Materials
  • Films
  • Fungi
  • Macromolecules
  • Material Degradation Processes
  • Materials
  • Materials Laboratories
  • Materials Science
  • Materials Testing
  • Measurement
  • Polymer Degradation
  • Polymeric Films
  • Polymers
  • Spectra

Fields of Study

  • Chemistry

Readers

  • Allergy and Immunology.
  • Analytical Chemistry
  • Organic Chemistry