TY - JOUR
T1 - Photochemical Transformation of Poly(butylene adipate- co-terephthalate) and Its Effects on Enzymatic Hydrolyzability
AU - De Hoe, Guilhem X.
AU - Zumstein, Michael T.
AU - Getzinger, Gordon J.
AU - Rüegsegger, Isabelle
AU - Kohler, Hans Peter E.
AU - Maurer-Jones, Melissa A.
AU - Sander, Michael
AU - Hillmyer, Marc A.
AU - McNeill, Kristopher
N1 - Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/3/5
Y1 - 2019/3/5
N2 - 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-co-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.
AB - 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-co-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.
UR - http://www.scopus.com/inward/record.url?scp=85062057791&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85062057791&partnerID=8YFLogxK
U2 - 10.1021/acs.est.8b06458
DO - 10.1021/acs.est.8b06458
M3 - Article
C2 - 30726677
AN - SCOPUS:85062057791
SN - 0013-936X
VL - 53
SP - 2472
EP - 2481
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 5
ER -