Photochemical
Transformation of Poly(butylene adipate-<i>co</i>-terephthalate)
and Its Effects on Enzymatic Hydrolyzability
Guilhem
X. De Hoe
Michael T. Zumstein
Gordon J. Getzinger
Isabelle Rüegsegger
Hans-Peter E. Kohler
Melissa A. Maurer-Jones
Michael Sander
Marc A. Hillmyer
Kristopher McNeill
10.1021/acs.est.8b06458.s001
https://acs.figshare.com/articles/journal_contribution/Photochemical_Transformation_of_Poly_butylene_adipate-_i_co_i_-terephthalate_and_Its_Effects_on_Enzymatic_Hydrolyzability/7726505
Biodegradable polyesters are being
increasingly used to replace
conventional, nondegradable polymers in agricultural applications
such as plastic film for mulching. For many of these applications,
poly(butylene adipate-<i>co</i>-terephthalate) (PBAT) is
a promising biodegradable material. However, PBAT is also susceptible
to photochemical transformations. To better understand how photochemistry
affects the biodegradability of PBAT, we irradiated blown, nonstabilized,
transparent PBAT films and studied their enzymatic hydrolysis, which
is considered the rate-limiting step in polyester biodegradation.
In parallel, we characterized the irradiated PBAT films by dynamic
mechanical thermal analysis. The rate of enzymatic PBAT hydrolysis
decreased when the density of light-induced cross-links within PBAT
exceeded a certain threshold. Mass-spectrometric analysis of the enzymatic
hydrolysis products of irradiated PBAT films provided evidence for
radical-based cross-linking of two terephthalate units that resulted
in the formation of benzophenone-like molecules. In a proof-of-principle
experiment, we demonstrated that the addition of photostabilizers
to PBAT films mitigated the negative effect of UV irradiation on the
enzymatic hydrolyzability of PBAT. This work advances the understanding
of light-induced changes on the enzyme-mediated hydrolysis of aliphatic-aromatic
polyesters and will therefore have important implications for the
development of biodegradable plastics.
2019-02-06 00:00:00
PBAT films
UV
hydrolysis
PBAT films mitigated