Crystal structure of poly(trimethylene 2,5-furandicarboxylate) redux - a new model supported by computational spectroscopy

abstract

Poly(trimethylene 2,5-furandicarboxylate) (PTF) is an emergent biobased polymer potentially able to outperform the fossil-based poly(ethylene terephthalate) counterpart. In this work, computational chemistry and vibrational spectroscopy tools are combined to elucidate the conformational preferences of PTF in both crystalline and amorphous regions. This approach departs from previous studies and leads to a new proposal for the crystal structure of this significant biobased polymer. In crystalline domains, PTF chains take on a helical conformation due to the gauche-gauche kinks present in 1,3-propanediol (PDO) segments, while 2,5-furandicarboxylate (FDCA) moieties adopt the syn-syn motif. Similarly to its counterparts, poly(ethylene 2,5-furandicarboxylate) (PEF) and poly(butylene 2,5-furandicarboxylate) (PBF), syn-syn FDCA units allow the formation of a vast array of C-H & ctdot;O contacts between furanic hydrogens and adjacent carbonyl moieties. The proposed crystal structure of PTF consists of two-dimensional sheets of chains connected by C-H & ctdot;O bonds, which are stacked upon one another forming pi-pi interactions among furanic rings. A thorough vibrational analysis of PTF's infrared and inelastic neutron scattering intensity profiles, with identification of vibrational modes sensitive to conformation and degree of crystallinity, sets a blueprint for future studies employing vibrational spectroscopy techniques. The crystal structure of biobased poly(trimethylene 2,5-furandicarboxylate) is revisited following new evidence from vibrational spectroscopy and computational chemistry tools.

keywords

VIBRATIONAL SPECTROSCOPY; MECHANICAL-PROPERTIES; POLY(ETHYLENE 2,5-FURANDICARBOXYLATE); BARRIER PROPERTIES; TEREPHTHALATE); COPOLYESTERS; TRANSPORT; DYNAMICS; SORPTION; SPECTRA

subject category

Polymer Science

authors

Araújo, CF; Pandeirada, SV; Oliveira, IM; Rosa, GB; Agostinho, B; Silvestre, AJD; Sousa, AF; Rudic, S; Vaz, PD; Nolasco, MM; Ribeiro-Claro, P

Groups

G4 - Renewable Materials and Circular Economy
G6 - Virtual Materials and Artificial Intelligence

Projects

European network of FURan based chemicals and materials FOR a Sustainable development (FUR4Sustain)

CICECO - Aveiro Institute of Materials (UIDB/50011/2020)

CICECO - Aveiro Institute of Materials (UIDP/50011/2020)

Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)

Collaboratory for Emerging Technologies, CoLab (EMERGING TECHNOLOGIES)

acknowledgements

This publication was supported by COST Action FUR4Sustain-European network of FURan based chemicals and materials FOR a Sustainable development, CA18220, supported by COST (European Cooperation in Science and Technology). This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 (DOI: https://doi.org/10.54499/UIDB/50011/2020), UIDP/50011/2020 (DOI: https://doi.org/10.54499/UIDP/50011/2020) & LA/P/0006/2020 (DOI: https://doi.org/10.54499/LA/P/0006/2020), financed by national funds through the FCT/MCTES (PIDDAC). This work was also supported by FEDER through the program COMPETE - Programa Operacional Factores de Competitividade - and by national funds through FCT under the project UID/EMS/00285/2020 and ARISE funding (LA/P/ 0112/2020). FCT is also acknowledged for the research contract under Scientific Employment Stimulus to AFS (CEECIND/02322/2020) and for the Ph.D. grants to CFA (SFRH/BD/129040/2017), SVP (2023.01628.BD) and BA (2020.04495.BD). The STFC Rutherford Appleton Laboratory is thanked for access to neutron beam facilities (TOSCA/RB2000214, DOI: https://doi.org/10.5286/ISIS.E.RB2000214, and Xpress RB2291064). CASTEP calculations were made possible due to the computing resources provided by STFC Scientific Computing Department's SCARF cluster.