Starch/carbon nanofibers bionanocomposites via melt mixing: Effect of dispersion and compatibility on conductivity and mechanical properties

• Published in: International journal of biological macromolecules 2024-01, Vol.256 (Pt 2), p.128519-128519, Article 128519
• Main Authors: Fonseca-Florido, Heidi Andrea, Yañez-Macías, Roberto, Ávila-Orta, Carlos Alberto, Cruz-Delgado, Víctor Javier, Covarrubias-Gordillo, Carlos Andrés
• Format: Article
• Language: English
• Subjects: Bionanocomposites; Carbon nanofibers; Conductivity properties; Mechanical properties; Starch films
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2023.128519

Biodegradable polymers with conductivity and mechanical properties are required in several applications where it is necessary to substitute conductive synthetic plastics due to the high waste produced. In this study, bionanocomposites (BNCs) have been compounded by thermoplastification of rice starch via melt mixing with carbon nanofibers (NPs) and modified NPs (NPs [M]) using plasma of acrylic acid. Spectroscopy analysis, X-ray diffraction, and morphology were studied to elucidate the effect of dispersion and compatibility on the conductivity and mechanical properties. The incorporation of NPs promoted esterification reactions with starch during the melt mixing process, giving rise to changes in its crystal structure. NPs [M] showed better dispersion and compatibility because the plasma prevents reagglomeration and generates a stronger affinity. BNCs showed significative flexibility with remarked % elongation at break from 5.64 % to 248.60 %, and thermal conductivity increased from 0.10 to 0.58 W/m K, with NPs [M] at 5 %. In contrast, the electrical conductivity remained in the same magnitude order (10−4 S/cm). The better compatibility between starch-NPs [M] hinders electronic transport but increases the propagation of phonons to promote thermal conductivity. BNCs fabricated in this study by a dry and scalable process could be of interest in some application areas (intelligent food packing, electronics, textiles, etc.). •A dried scalable process was used to prepare starch/NPs bionanocomposites.•Melt mixing promotes esterification reactions between starch and NPs.•A better compatibility and dispersion was promoted by plasma modification of NPs.•Interface adhesion generates a greater phonons path to favor thermal conductivity.•The compatibility does not play an essential role in the electrical conductivity.