Enhancing multifunctional properties of thermotropic liquid crystalline polyarylate nanocomposites: Synergistic effects of multi-walled carbon nanotubes on morphology, thermal stability, and EMI shielding

Abstract

This study presents a comprehensive investigation into the morphological, thermal, mechanical, rheological, and electromagnetic interference (EMI) shielding properties of thermotropic liquid crystalline polyarylate (TLCP) nanocomposites reinforced with 1–10 wt% multi-walled carbon nanotubes (MWNTs). Scanning electron microscopy reveals that MWNTs are uniformly coated with TLCP chains, signifying strong interfacial adhesion. Spectroscopic and structural analyses (FT-IR and XRD) indicate molecular-level interactions, evidenced by characteristic band shifts and reduced crystallinity with increasing MWNT content. Thermal analysis demonstrates that MWNT incorporation enhances the melt-crystallization temperature, glass transition temperature, thermal stability, and residual char at 800 °C. Dynamic mechanical analysis shows a substantial increase in the elastic storage modulus (E′), with E′ at 30 °C reaching 6.2 GPa, which is approximately 140 % higher than that of pristine TLCP. Rheological measurements further confirm improved viscoelastic behavior, marked by increases in both complex viscosity and shear storage modulus. Electrical conductivity rises markedly beyond a percolation threshold of ∼2.96 wt%, forming continuous conductive pathways, with a scaling exponent of t = 3.862. Notably, the TLCP nanocomposite with 10 wt% MWNT achieves a high EMI shielding effectiveness of ∼45 dB/mm. These results underscore the promise of TLCP/MWNT nanocomposites as multifunctional materials for next-generation applications demanding superior thermal, mechanical, and EMI shielding performance.