Polyoxymethylene/Carbon Nanotube Self-Assembly Networks with Improved Electrical Conductivity for Engineering Functional Structural Materials

In order to construct a conductive self-assembly polyoxymethylene (POM)-based composite with low percolation threshold, carbon nanotubes (CNTs) were preferentially compounded with antistatic polyethylene glycol (PEG) as a secondary polymer, and PEG-CNT hybrids were prepared, while POM/PEG-CNT nanocomposites were fabricated via the conventional melt processing method. The oxygen-containing groups on the CNT surface formed stronger hydrogen bonding with PEG than that with POM molecules, and the interfacial tension between PEG-CNT was much lower than that between POM-CNT, leading to stronger interfacial interaction of PEG-CNT. The CNT surface in the composite was fuzzy and rough, and the diameter increased significantly, showing a structure coated by a large number of POM molecules. The percolation threshold of POM/PEG-CNT nanocomposite reached as low as 0.72 wt %, for which the composite exhibited a frequency-independent modulus “plateau”, while CNT particles self-assembled into large-sized aggregates under induction of PEG, and the aggregates were connected to each other to form a perfect three-dimensional conductive network. The composite with excellent mechanical and electrical conductive properties showed prospective application as engineering functional structural materials.