Renewable building blocks for sustainable polyesters: new biotechnological routes for greener plastics

Abstract

The next generation of plastics are expected to contribute to a massive reduction in the carbon footprint by the exploitation, in industrial productive processes, of renewablemonomers such as polyols and dicarboxylic acids obtainable via biotechnological production. More specifically, there is a rising demand for advanced polyesters displaying new functional properties while\ud meeting higher sustainability criteria. Polyesters are part of everyday life with applications in clothing, food packaging, car manufacturing and biomedical devices. This reviewis intended to provide an overviewof the array of renewable building blocks already available for synthetic purposes and exploitable in the production of polyesters. Moreover, newgreener routes formore\ud environmentally friendly polyester production and processing are discussed, pointing out the major technological challenges

Enzymatic Degradation of Poly(ethylene 2,5-furanoate) Powders and Amorphous Films

“…Interestingly, HiC produces similar surfaces with sharp edges at 50 • C in Tris-HCl and at 65 • C in KPO, while fiber-like structures were observed at 65 • C when Tris-HCl was used, or smoother globular-shaped surfaces at 50 • C when KPO was used. These results show the great importance of finding suitable reaction conditions when specific enzymatic surface functionalizations of the polymer are desired [20,34]. Our findings are perfectly aligned with the previous data collected on PET degradation, where taking particle size and crystallinity of the various PET materials into consideration had a tremendous effect on the enzymatic degradation of the polymer [31].…”

Nature Inspired Solutions for Polymers: Will Cutinase Enzymes Make Polyesters and Polyamides Greener?

“…Actually, most of the studies related to enzymatic polymerization make use of lipases, and in particular CaLB which is one of the most widely used enzymes in industry and the 'yardstick' for comparison in academia [3,59].…”

“…In general, the immobilization of the biocatalyst is mandatory in these synthetic processes for several reasons: (1) to avoid the aggregation of the hydrophilic enzyme molecules; (2) to recycle the expensive enzyme; and (3) to prevent the contamination of product by the enzyme protein [2,3]. Considering the data reported in literature, it must be noted that results in terms of molecular weight of polymerization products might be affected by detachment and dispersion of the enzyme when not covalently supported as demonstrated in previous studies [64].…”

“…A closer integration between chemistry and biotechnologies is expected to boost the change of the scenario. Due to their remarkable selectivity and catalytic efficiency under mild conditions, enzymes are an attractive and sustainable alternative to toxic catalysts used in the polycondensation of functional monomers such as itaconic acid, which suffer from isomerization or cross-linking under the harsh conditions required by conventional chemical processes that employ organo-catalysts [3]. The possibility to use enzymes for the polyester synthesis has been known since the 1990s and has also been industrially applied by Baxenden Chemicals (UK) for the production, later dismissed, of highly regular structures of polymers.…”

Combinatorial Engineering of Yarrowia lipolytica as a Promising Cell Biorefinery Platform for the de novo Production of Multi-Purpose Long Chain Dicarboxylic Acids

“…The sustainable production of monomers and polymers is of particular interest for reducing petroleum feedstock dependency and CO 2 emissions. The environmental cost of using petrochemical polymers can be lowered by replacing them with bio-based polymers, produced through fermentation using biomass or byproducts as feedstock [1]. Glycerol is the main byproduct of biodiesel production process, and its efficient valorization would help offset biodiesel production costs.…”