3D-Printed Co-continuous Segregated CNT/TPU Composites with Superb Electromagnetic Interference Shielding and Excellent Mechanical Properties

Abstract

Segregated conductive polymer composites (CPCs) have important application prospects in the field of electromagnetic interference (EMI) shielding but suffer from weak mechanical properties that significantly limit their practical applications. In this work, three-dimensional (3D) printing is employed to construct continuous thermoplastic polyurethane (TPU) scaffolds with different interlayer angles of π/5, π/4, π/3, 2π/5, and π/2. Subsequent carbon nanotube (CNT) dip-coating and hot-pressing lead to the successful fabrication of co-continuous segregated CNT/TPU (CNT/TPU-CCS) composites. It is found that the composites not only achieve high EMI shielding properties but also obtain excellent mechanical properties. With only 4.0 wt % of CNT, the CNT/TPU-CCS composites with the interlayer angle of π/3 (CNT/TPU-CCS-π/3) exhibit a high electrical conductivity of 42.2 S/m and a remarkable EMI shielding effectiveness (EMI SE) of 43.1 dB, which are 75% and 72%, respectively, higher than that of the CNT/TPU composites with conventional segregated structure. The CNT/TPU-CCS-π/3 composites also have superior mechanical properties, showing a tensile strength and elongation at break of 17.8 MPa and 377.3%, respectively, which are 196.8% and 1540.6% higher than those of the conventional segregated CNT/TPU composite. This work provides a new facile, economic, and efficient strategy to construct segregated CPCs with both high EMI shielding performance and mechanical properties, and could promote the practical application of segregated CPCs in the next-generation electronic devices.

Performance and 4D Printing of Thermoplastic Polyurethane/Cellulose Nanocrystal-Poly(vinyl acetate) Nanocomposites

“…(e, f) Tensile stress–strain curves and the tensile modulus of TCP nanocomposites. (g) Ashby charts of the mechanical performance of TCP nanocomposites versus other TPU-based nanocomposites in the previous reports. − …”

3D Printing Interconnected Segregated Composites To Simultaneously Enhance Thermal Conductivity and Mechanical Properties

“…Utilizing 3D-printed continuous scaffolds, composites featuring 3D-printed segregated structures are expected to maintain robust mechanical properties. , Figure a illustrates part of typical stress–strain curves of 3D-fillers/PLA with a 30 wt % filler loading, showing a substantial improvement in mechanical performance when compared to the randomly blending samples and the neat PLA matrix (the remaining stress–strain curves are shown in Figure S2. As described in Figure a,b, the tensile strength (19.3 MPa) and the elastic modulus (36.4 MPa) of 3D-L-BN/PLA exhibit a remarkable increase of 99 and 158%, respectively, compared to RM-L-BN/PLA.…”

Development of CNT-Based Nanocomposites with Ohmic Heating Capability towards Self-Healing Applications in Extrusion-Based 3D Printing Technologies

“…Several researchers have shown that it is possible to fabricate 3D-printed sensors using functionalized nanocomposites based on CNTs and TPU [42][43][44]. Niu, Yang et al [45] showed that 3D-printed CNT/TPU composites could offer both EMI-shielding performance and mechanical properties in next generation electronic devices. Wu, Zou et al [46] proves the possibility of 3D printing self-healable strain gauges and humidity sensors using CS/CNT nanocomposites because of their high stretchability and conductivity.…”