Thermosetting nanocomposites with high carbon nanotube loadings processed by a scalable powder based method

Abstract

A powder based processing route was developed to allow manufacturing of thermosetting nanocomposites with high (20 wt%) carbon nanotube (CNT) loading fractions. Adaptation of high shear mixing methods, as used in thermoplastic processing, ensured that the CNTs were well distributed and dispersed even at the highest loadings. By minimising flow distances, compression moulding of powders ensured that the CNTs did not agglomerate during consolidation, and yielded a percolated CNT network in a nanocomposite with excellent electrical and thermal conductivities of 67 S m−1 and 0.77 W m−1 K−1, respectively. Unusually, the CNTs provided effective mechanical reinforcement at even the highest loadings; embrittlement is minimised by avoiding large scale inhomogeneities and the maximum measured Young's modulus (5.4 GPa) and yield strength (90 MPa) could make the nanocomposite an attractive matrix for continuous fibre composites. The macromechanical measurements were interpolated using micromechanical models that were previously successfully applied at the nanoscale.