Polymer, Vol.138, 113-123, 2018
Morphologies and dielectric properties of epoxy thermosets containing poly(N-vinylcarbazole), fullerene-C-60 and their charge transfer complex nanophases
Both poly(ethylene oxide)-block-poly(N-vinylcarbazole) (PEO-b-PVK) diblock copolymer and fullerenecapped poly(ethylene oxide) (PEO-C-60) were synthesized in this work. The former was obtained via reversible addition-fragmentation chain transfer/macromolecular design via the interchange of xanthate process whereas the latter via click reaction of azido-capped poly(ethylene oxide) with fullerene-C-60. Both of the amphiphiles were incorporated into epoxy to obtain the nanostructured thermosets. It was found that the PVK-C-60 charge transfer complexes were formed in the ternary thermosetting blends of epoxy, PEO-b-PVK and PEO-C-60. The nanostructured epoxy thermosets containing PVK or/and fullerene displayed the enhanced dielectric constants whereas the dielectric loss remained almost unchanged. Nonetheless, the dielectric constants were significantly decreased while both PEO-b-PVK and PEO-C-60 were simultaneously incorporated into the thermosets. The depression in dielectric constant is attributable to the formation of the charge transfer complexes of PVK with fullerene-C-60. It was found that the dielectric constants can be modulated with the contents of the PVK-C-60 charge transfer complexes. (C) 2018 Elsevier Ltd. All rights reserved.