Polyol Structure Influences Enzymatic Hydrolysis of Bio-Based 2,5-Furandicarboxylic Acid (FDCA) Polyesters

Area of Science:

• Polymer Chemistry
• Biotechnology
• Materials Science

Background:

• Polyesters derived from 2,5-furandicarboxylic acid (FDCA) are emerging as sustainable, bio-based alternatives to petroleum-derived polyesters.
• Understanding the biodegradation pathways, particularly enzymatic hydrolysis, of FDCA-based polyesters is crucial for their environmental application.
• Limited data exists on how structural variations in FDCA polyesters influence their susceptibility to enzymatic degradation.

Purpose of the Study:

• To investigate the impact of different polyols on the enzymatic hydrolysis of FDCA-based polyesters.
• To evaluate the efficacy of cutinase 1 from Thermobifida cellulosilytica (Thc_Cut1) in degrading these bio-based polyesters.
• To correlate polyester structure (diol type, chain length, branching) with hydrolysis rates.

Main Methods:

• Synthesis of a series of FDCA-based polyesters incorporating various diols.
• Characterization of polyester properties including molecular weight (GPC), glass transition temperature (DSC), and crystallinity.
• Enzymatic hydrolysis assays using Thc_Cut1 to quantify the released FDCA.
• Analysis of structure-degradation relationships.

Main Results:

• FDCA-based polyesters exhibited molecular weights ranging from 9360-35,800 g/mol.
• Glass transition temperatures decreased with increasing diol chain length.
• Crystallinity was low (<1%) except for polyesters with 1,6-hexanediol, 1,8-octanediol, and 1,12-dodecanediol (27-37%).
• Thc_Cut1 showed highest hydrolysis activity towards polyesters with 1,5-pentanediol (57.7%) and 1,9-nonanediol (52.8%).
• Enzyme activity was enhanced by using branched diols (1,2-propanediol) or incorporating ethoxy units.

Conclusions:

• The choice of polyol significantly influences the enzymatic hydrolysis rate of FDCA-based polyesters.
• Polyesters with specific diol structures, such as 1,5-pentanediol and 1,9-nonanediol, are more susceptible to Thc_Cut1 degradation.
• Structural modifications like branching or ether linkages can improve the biodegradability of these bio-based polymers.
• This research provides valuable insights for designing and developing more readily biodegradable FDCA-based polyesters.