Effect of Graphene/Spherical Graphite Ratio on the Properties of PLA/TPU Composites

• Published in: Polymers Vol. 14; no. 13; p. 2538
• Main Authors: Yang, Zenghui, Wu, Haihua, Zhang, Renjing, Deng, Kaixin, Li, Yan, Liu, Zhi, Zhong, Qiang, Kang, Yi
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 22.06.2022; MDPI
• Subjects: Carbon; Composite materials; Core-shell structure; Dielectric loss; Dipoles; Epoxy resins; FDM; Frequencies; Fused deposition modeling; Graphene; graphene/spherical graphite ratio; Graphite; High strength; Impedance matching; Mechanical properties; mechanical property; Microwave absorption; microwave absorption performance; Morphology; Particle size; PLA/TPU composites; Polarization; Polylactic acid; Polyurethane resins; Spectrum analysis; Tensile strength; Urethane thermoplastic elastomers; Weight reduction; Wire
• ISSN: 2073-4360; 2073-4360
• DOI: 10.3390/polym14132538

Wave-absorbing materials are developing in the direction of “light weight, wide frequency band, thin layer and high strength”, and it is difficult to achieve the synergy between wave-absorbing performance and mechanical properties when graphene absorbent is compounded with a single resin matrix. In this paper, based on the preparation of a new composite absorbing wire with a graphene (GR)/spherical graphite (SG) double absorbent and polylactic acid (PLA)/thermoplastic polyurethane (TPU) double matrix, we proposed a new method to prepare samples for testing the electromagnetic parameters and tensile strength by fused deposition modeling (FDM). Furthermore, the effect of SG/GR ratio on the microwave absorbing properties and mechanical properties of PLA/TPU composites was specifically studied. It was found that when the ratio of SG/GR was small (0:5, 1:4), the dielectric loss (interfacial polarization loss, dipole polarization loss, conductivity loss) and attenuation ability of the composites were stronger, and the impedance matching was better. When the SG/GR ratio was large (5:0, 4:1), the composites had high strength and toughness. When the ratio of SG/GR was moderate (2:3, 3:2), it could retain the absorbing and mechanical properties of the absorbing materials. On the one hand, the SG and PLA/TPU matrix formed an “island structure”, which improves the dispersion of GR; on the other hand, the GR and PLA/TPU matrix formed a “core-shell structure”, which promotes polarization and multiple scattering.