Next Article in Journal
Thiocyanate-Treated Perovskite-Nanocrystal-Based Light-Emitting Diodes with Insight in Efficiency Roll-Off
Previous Article in Journal
Drug Delivery with Polymeric Nanocarriers—Cellular Uptake Mechanisms
Open AccessCommunication

Thermal Upgrade of Enzymatically Synthesized Aliphatic and Aromatic Oligoesters

1
Green Chemistry Centre of Excellence, Department of Chemistry, University of York, Heslington, York YO10 5DD, UK
2
Department of Agrobiotechnology IFA-Tulln, Institute of Environmental Biotechnology, University of Natural Resources and Life Sciences, Konrad Lorenz Strasse 20, 3430 Tulln an der Donau, Austria
3
Division Enzymes & Polymers, Austrian Centre of Industrial Biotechnology, Konrad Lorenz Strasse 20, 3430 Tulln an der Donau, Austria
4
Dipartimento di Scienze Chimiche e Farmaceutiche, Università degli Studi di Trieste, Piazzale Europa 1, 34127 Trieste, Italy
*
Author to whom correspondence should be addressed.
Materials 2020, 13(2), 368; https://doi.org/10.3390/ma13020368
Received: 21 November 2019 / Revised: 29 December 2019 / Accepted: 7 January 2020 / Published: 13 January 2020
(This article belongs to the Special Issue Sustainable Polymers: From Synthesis to Functional Properties)
The enzymatic synthesis of polyesters in solventless systems is an environmentally friendly and sustainable method for synthetizing bio-derived materials. Despite the greenness of the technique, in most cases only short oligoesters are obtained, with limited practical applications or requiring further chemical processing for their elongation. In this work, we present a catalyst-free thermal upgrade of enzymatically synthesized oligoesters. Different aliphatic and aromatic oligoesters were synthesized using immobilized Candida antarctica lipase B (iCaLB) as the catalyst (70 °C, 24 h) yielding poly(1,4-butylene adipate) (PBA, Mw = 2200), poly(1,4-butylene isophthalate) (PBI, Mw = 1000), poly(1,4-butylene 2,5-furandicarboxylate) (PBF, Mw = 600), and poly(1,4-butylene 2,4-pyridinedicarboxylate) (PBP, Mw = 1000). These polyesters were successfully thermally treated to obtain an increase in Mw of 8.5, 2.6, 3.3, and 2.7 folds, respectively. This investigation focused on the most successful upgrade, poly(1,4-butylene adipate), then discussed the possible effect of di-ester monomers as compared to di-acids in the thermally driven polycondensation. The herein-described two-step synthesis method represents a practical and cost-effective way to synthesize higher-molecular-weight polymers without the use of toxic metal catalysts such as titanium(IV) tert-butoxide, tin(II) 2-ethylhexanoate, and in particular, antimony(IV) oxide. At the same time, the method allows for the extension of the number of reuses of the biocatalyst by preventing its exposure to extreme denaturating conditions. View Full-Text
Keywords: bio-based polyesters; enzymatic synthesis; polycondensation; thermal upgrade; metal-free synthesis; biocatalyzed process; solventless reactions bio-based polyesters; enzymatic synthesis; polycondensation; thermal upgrade; metal-free synthesis; biocatalyzed process; solventless reactions
Show Figures

Figure 1

MDPI and ACS Style

Comerford, J.W.; Byrne, F.P.; Weinberger, S.; Farmer, T.J.; Guebitz, G.M.; Gardossi, L.; Pellis, A. Thermal Upgrade of Enzymatically Synthesized Aliphatic and Aromatic Oligoesters. Materials 2020, 13, 368.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop