Enzymatic Polymerization of Furan-2,5-Dicarboxylic Acid-Based Furanic-Aliphatic Polyamides as Sustainable Alternatives to Polyphthalamides

Abstract

Furan-2,5-dicarboxylic acid (FDCA)-based furanic-aliphatic polyamides can be used as promising sustainable alternatives to polyphthalamides (semiaromatic polyamides) and be applied as high performance materials with great commercial interest. In this study, poly(octamethylene furanamide) (PA8F), an analog to poly(octamethylene terephthalamide) (PA8T), is successfully produced via Novozym 435 (N435)-catalyzed polymerization, using a one-stage method in toluene and a temperature-varied two-stage method in diphenyl ether, respectively. The enzymatic polymerization results in PA8F with high weight-average molecular weight (M̅(w)) up to 54000 g/mol. Studies on the one-stage enzymatic polymerization in toluene indicate that the molecular weights of PA8F increase significantly with the concentration of N435; with an optimal reaction temperature of 90 °C. The temperature-varied, two-stage enzymatic polymerization in diphenyl ether yields PA8F with higher molecular weights, as compared to the one-stage procedure, at higher reaction temperatures. MALDI-ToF MS analysis suggests that eight end groups are present in the obtained PA8F: ester/amine, ester/ester, amine/amine, acid/amine, ester/acid, acid/acid, ester/amide, and no end groups (cyclic). Compared to PA8T, the obtained PA8F possesses a similar Tg and similar crystal structures, a comparable Td, but a lower Tm.

Sustainable Chiral Polyamides with High Melting Temperature via Enhanced Anionic Polymerization of a Menthone-Derived Lactam

“…The TGA profiles of the other entries do not differ remarkably, as expected, due to the similar polymer composition (Figure S17, Supporting Information). Therefore, these polyamides have a similar stability as other previously described sustainable polyamides . Differential scanning calorimetry (DSC) profiles show melting points T m around 300 °C, which are thus remarkably higher than that of Nylon‐6 (220 °C), and crystallization temperatures, T c , between 236 and 265 °C (Figure B; Figure S18 and Table S2, Supporting Information).…”

“…The resulting polyamides (see Figure S23 for photo image in the Supporting Information) contain side groups and stereocenters and have useful and characteristic properties, e.g., high melting temperatures. For instance, though exhibiting lower molecular mass values than the previously described furan‐based polyamides, T m values are remarkably higher. For the future, modifications to come to even higher molar masses and higher yields of these polyamides, detailed kinetics, and further upscaling will be important issues, as well as different methods for processing of the obtained material and measurements of their mechanical properties.…”

The effect of furan molecular units on the glass transition and thermal degradation temperatures of polyamides

“…Enzymatic preparation of furan PAs has been explored showing that FDCA could not be prepared into high‐performance PAs but its dimethyl ester can be effectively polymerized . A glass transition temperature of up to 126 °C was measured for octyl furan PA while an analogous octyl p ‐phenyl polyamide had a glass transition temperature of only 123 °C . This would indicate that furans produce higher glass transitions than benzene units, which is not supported in other findings .…”

“…Others have examined 2,5‐FDCA as a monomer feedstock to make PAs . Enzymatic preparation of furan PAs has been explored showing that FDCA could not be prepared into high‐performance PAs but its dimethyl ester can be effectively polymerized . A glass transition temperature of up to 126 °C was measured for octyl furan PA while an analogous octyl p ‐phenyl polyamide had a glass transition temperature of only 123 °C .…”

Lipase‐Catalyzed Synthesis of Furan‐Based Oligoesters and their Self‐Assembly‐Assisted Polymerization

“…Smallangle X-ray diffraction (SAXD)i sav aluablet echnique in the study of the molecular assembly phenomenont hat involves Hbonding, p-p interactions, and van der Waals interactions. [56][57][58][59] However,t he hydrophobic oligoester 5d,w hich lacks flexible methylene units,d isplayedb road peaks at 2 q = 10 and 228,w hich shows amorphous behavior.A lthough SAXD resultss uggest the aggregation behavior of oligoesters, it is necessaryt oa nalyze selfcuring by using aw ell-established method. (1 00) planes, and similarX RD diffractionp atterns have been reported for furanic polyesters (Figure 2).…”