Selective localization of multi‐walled carbon nanotubes in epoxy/polyetherimide system and properties of the conductive composites

ABSTRACT Multi‐walled carbon nanotubes (MWCNTs) were introduced into the diglycidyl ether of a bisphenol A/polyetherimide (DGEBA/PEI) system. A co‐continuous phase structure could be formed by the reaction‐induced phase separation (RIPS). The MWCNTs localized selectively in PEI‐rich phase which was predicted by theoretical calculations of the wetting coefficient (ωa) and then confirmed both by optical microscopy and scanning electron microscopy. The thermomechanical properties of DGEBA/PEI/MWCNTs were studied by dynamic mechanical analysis. As the MWCNTs content increased from 0.5 to 1.0 wt %, storage modulus had a tendency of increasing monotonically from 2491 to 2948 MPa and the values of Tg for epoxy‐rich phase were almost unchanged at about 130 °C. Subsequently, the result of electrical and thermal properties measurement for composites indicated that their volume resistivity decreased from 3.29 × 1015 to 3.86 × 106 at 2.0 wt % MWCNTs and thermal conductivity were improved by 36.1% at the same time. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47911.