Green Pathways for the Enzymatic Synthesis of Furan-Based Polyesters and Polyamides

The attention towards the utilization of sustainable feedstocks for polymer synthesis has grown exponentially in recent years. One of the spotlighted monomers derived from renewable resources is 2,5-furandicarboxylic acid (FDCA), one of the most promising bio-based monomers, due to its resemblance to petroleum-based terephthalic acid. Very interesting synthetic routes using this monomer have been reported in the last two decades. Combining the use of bio-based monomers and non-toxic chemicals via enzymatic polymerizations can lead to a robust and favorable approach towards a greener technology of bio-based polymer production. In this chapter, a brief introduction to FDCA-based monomers and enzymatic polymerizations is given, particularly focusing on furan-based polymers and their polymerization. In addition, an outline of the recent developments in the field of enzymatic polymerizations is discussed. </p

Hydrolytic degradation of ROMP thermosetting materials catalysed by bio-derived acids and enzymes: from networks to linear materials

This paper reports the first example of degradable ROMP thermosetting materials catalysed by bio-derived acids and cutinase from Thermobifida cellulosilytica (Thc_Cut1). The ROMP thermosetting materials are based on norbornene dicarboximides containing acetal ester groups only in the crosslinking moiety. The insoluble cross-linked materials were subjected to acid-catalysed hydrolysis using bio-derived acetic and citric acids as well as enzymatic degradation using Thc_Cut1, resulting in the materials becoming completely soluble in dichloromethane. 1H NMR and rheological analysis performed on materials after acid-catalysed hydrolysis showed characteristics indistinguishable to those of the linear polymer analogues. These analyses confirmed the cleavage of the crosslinking moiety upon degradation with the main backbone chains remaining intact. The glass transition temperatures of the polymer materials after acid-catalysed hydrolysis were the same as those observed for the linear polymer analogues. TGA showed that the cross-linked polymers were thermally stable to 150 °C, beyond which they showed weight losses due to the thermal cleavage of the acetal ester linkages

Enzymatic hydrolysis of poly(ethylene furanoate)

The urgency of producing new environmentally-friendly polyesters strongly enhanced the development of bio-based poly(ethylene furanoate) (PEF) as an alternative to plastics like poly(ethylene terephthalate) (PET) for applications that include food packaging, personal and home care containers and thermoforming equipment. In this study, PEF powders of various molecular weights (6, 10 and 40 kDa) were synthetized and their susceptibility to enzymatic hydrolysis was investigated for the first time. According to LC/TOF-MS analysis, cutinase 1 from Thermobifida cellulosilytica liberated both 2,5-furandicarboxylic acid and oligomers of up to DP4. The enzyme preferentially hydrolyzed PEF with higher molecular weights but was active on all tested substrates. Mild enzymatic hydrolysis of PEF has a potential both for surface functionalization and monomers recycling

Enzymatic surface hydrolysis of poly(ethylene furanoate) thin films of various crystallinities

This work reports on the successful production of poly(ethylene furanoate) (PEF) thin films and a comparison of the enzymatic hydrolysis of PEF and poly(ethylene terephthalate) (PET) films with three different crystallinities (0, 10 and 20%). The data suggest that the PEF films are enzymatically hydrolyzed 1.7 times faster than the commonly investigated PET films. QCM-D and SEM/AFM analyses fully confirm the observed reaction trend. The results also show a negative dependence of the hydrolysis rates with the increasing of the film crystallinity