Journal of Applied Polymer Science, Vol.128, No.3, 1360-1368, 2013
Alignment and properties of carbon nanotube buckypaper/liquid crystalline polymer composites
Carbon nanotubes (CNTs) have been recognized as a potential superior reinforcement for high-performance, multifunctional composites. However, non-uniform CNT dispersion within the polymer matrix, the lack of adequate adhesion between the constituents of the composites, and lack of nanotube alignment have hindered significant improvements in composite performance. In this study, we present the development of a layer-by-layer assembly method to produce high mechanical performance and electrical conductivity CNT-reinforced liquid crystalline polymer (LCP) composites using CNT sheets or buckypaper (BP) and self-reinforcing polyphenylene resin, Parmax. The Parmax/BP composite morphology, X-ray diffraction, mechanical, thermal, and electrical properties have been investigated. SEM observations and X-ray diffraction demonstrate alignment of the CNTs due to flow-induced orientational ordering of LCP chains. The tensile strength and Young's modulus of the Parmax/BP nanocomposites with 6.23 wt % multi-walled carbon nanotube content were 390 MPa and 33 GPa, respectively, which were substantially improved when compared to the neat LCP. Noticeable improvements in the thermal stability and glass transition temperature with increasing CNT content due to the restriction in chain mobility imposed by the CNTs was demonstrated. Moreover, the electrical conductivity of the composites increased sharply to 100.23 S/cm (from approximately 1013 S/cm) with the addition of CNT BP. These results suggest that the developed approach would be an effective method to fabricate high-performance, multifunctional CNT/LCP nanocomposites. (c) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Keywords:nanocomposites;liquid crystals;nanotubes;graphene and fullerenes;structure-property relations