Table . Physico-chemical characteristics of PDF-DLF copolyester. Furthermore, to verify changes in the molecular weight, SEC measurements were conducted on materials both before and after 35 days of degradation. The observed molar mass changes (Table ) along with the increased dispersity index suggest that the material has undergone enzymatic degradation. The degradation of polyesters with semi-aromatic structures is typically known to be relatively inefficient, however, in this case, it appears that the enzyme is targeting the amorphous regions, specifically the DLF soft segments. The visible alterations in molecular weight serve as a clear indicator of ester bond cleavage. This phenomenon is significant as it highlights the susceptibility of specific regions to enzymatic attack, contributing to the molecular rearrangement and changes observed. Interestingly enough, SEM analysis displayed noticeable surface changes, including breaks and holes after degradation. Figure illustrates these alterations on the material surface, indicating a localized impact. The results suggest that enzymatic degradation likely occurs through a surface erosion mechanism rather than extensive bulk breakdown. Finally, the detected mass loss of slightly more than 2% over 35 days indicated relatively slow progress of enzymatic degradation (Fig. ). This behavior is typical of the first phase of enzyme-assisted chemical hydrolysis, and only after this is usually followed by metabolization of the fragments and rapid loss of polymer mass. All these factors collectively suggest that PDF-DLF is susceptible to enzymeassisted chemical hydrolysis, despite not significant mass loss. However, further indepth investigation and research in this matter are necessary, potentially involving the use of different enzymes. For example, enzymatic degradation was also studied utilizing recombinant Thermobifida cellulosilytica cutinase 1 (Thc_Cut1), cutinase from Humicola insolens (HiC), and lipase from Porcine pancreas (LPP) on poly(ethylene furanoate) (PBF), revealing promising results and correlations . Thc_Cut1 exhibited higher activity on higher molecular weight PEF powders, releasing 13 mM of FDCA after 72 hours . Crystallinity significantly impacted degradation rates, accelerating hydrolysis in cases of lower crystallinity. On the other hand, HiC demonstrated greater activity than Thc_Cut1 on highly crystalline forms of PEF, thereby slowing enzymatic hydrolysis .