Unveiling the uncommon crystallization features of 3,4-PEF, a thermal and DFT study

resumo

The development of furandicarboxylic acid (FDCA) based polymers and materials is a rapidly growing research field in both academia and industry, driven by the need to replace fossil-based polymers with more sustainable alternatives. Despite the unequivocal potential of poly(ethylene 2,5-furandicarboxylate) (2,5-PEF), many other furanic polyesters, such as poly(ethylene 3,4-furandicarboxylate) (3,4-PEF), synthetized from the 3,4-FDCA isomer, remain underexplored. This study is the first to explore the conformational preferences of 3,4-PEF polyester using vibrational spectroscopy and density functional theory calculations. Additionally, a comprehensive thermal characterization of 3,4-PEF addresses current gaps in the literature. The results suggest that, in crystalline domains, 3,4-PEF chains adopt a conformation where the 3,4-FDCA segment exhibits a syn-syn motif and the ethylene glycol (EG) segment is in the trans conformation (ss-t). In amorphous regions, however, multiple conformations coexist, with syn-syn-gauche (ss-g) and anti-syn-gauche (asg) segments accounting for the bulk of the population distribution. As previously observed for 2,5-PEF, the formation of C-H & ctdot;O interactions in the crystalline domain is the main driver for the crystallization preferences of 3,4-PEF. The energetic gain from interchain C-H & ctdot;O bond formation compensates for the energy penalty associated with the ss-g/as-g to ss-t conformational transition. Differential scanning calorimetry (DSC) analysis revealed that 3,4-PEF has a glass transition temperature (Tg) of 39 degrees C and a melting temperature (Tm) of 155 degrees C. Kinetic studies showed that the fastest crystallization rate for 3,4-PEF occurs at 110 degrees C, with a half crystallization time of 12 min. Interestingly, 3,4-PEF crystallizes faster than 2,5-PEF at its optimal crystallization temperature (170 degrees C), though still more slowly than poly(ethylene terephthalate). These findings suggest that 3,4-PEF holds promise as a renewable polymer with fast crystallization behaviour.

palavras-chave

BIOBASED POLY(ETHYLENE 2,5-FURANDICARBOXYLATE); MELTING BEHAVIOR; ISOTHERMAL CRYSTALLIZATION; POLYMER CRYSTALLIZATION; PET; POLY(ETHYLENE-TEREPHTHALATE); KINETICS; MOBILITY

categoria

Polymer Science

autores

Pandeirada, SV; Araujo, CF; Nolasco, MM; Vaz, PD; Rudic, S; Silvestre, AJD; Guigo, N; Ribeiro-Claro, P; Sousa, AF

Grupos

G4 - Materiais Renováveis e Economia Circular
G6 - Materiais Virtuais e Inteligência Artificial

Projectos

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)

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

agradecimentos

This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 (DOI 10.54499/UIDB/50011/2020) , UIDP/50011/2020 (DOI 10.54499/UIDP/50011/2020) & LA/P/0006/2020 (DOI 10.54499/LA/P/0006/2020) , financed by national funds through the FCT/MCTES (PIDDAC) . The FCT is also acknowledged for the research contract under Scientific Employment Stimulus to AFS (CEECIND/02322/2020) (DOI 10.54499/2020.02322.CEECIND/CP1589/CT0008) and for the Ph.D grants to CFA (SFRH/BD/129040/2017) and SVP (2023.01628.BD) . This publication is based upon work from COST Action FUR4Sustain, CA18220, supported by COST (European Cooperation in Science and Technology) .