
Effect of Polymer Stereochemistry and Crystallinity on it’s Enzymatic Degradability
Research carried out on poly(lactic acid) and poly(hydroxybutyrate) biodegradability was used to show that a sensitive balance can be achieved between material crystalline order and polymer stereochemistry to regulate polymer biodegradability. The idea that stimulated this work was that by altering stereocopolymer configuration, crystalline order could be disrupted or even eliminated. By elimination of crystalline order, the biodegradability of the stereocopolymer might be accelerated. However, a stereocopolymer that differs from the stereochemical configuration preferred by a degrading enzyme might retard degradation. Thus, by determining how crystalline order and stereochemical configuration individually contributes to the biodegradation rate, this information can be used to 'fine tune' polymer biodegradability. This work also shattered previous misconceptions that poly(lactic) acid was not readily degraded by common proteases.
References
- Renée T. Macdonald, Stephen P. McCarthy and Richard A. Gross, “Enzymatic Degradability of Poly(lactide): Effects of Chain Stereochemistry and Material Crystallinity”, Macromolecules, Vol. 29, 7356-7361 (1996).(PDF)
- Michael S. Reeve, Stephen P. McCarthy, Milton J. Downey and Richard A. Gross, "Polylactide Stereochemistry: Effect on Enzymatic Degradability, Macromolecules, Vol. 27, 825-831 (1994).(PDF)
- John E. Kemnitzer, Stephen P. McCarthy, and Richard A. Gross, "Poly(ω-hydroxybutyrate) Stereoisomers: A Model Study Of The Effects Of Stereochemical and Morphological Variables On Polymer Biological Degradability", Macromolecules, 25, 5927-5934 (1992).

