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Electrically Insulated Epoxy Nanocomposites Reinforced with Synergistic Core–Shell SiO 2 @MWCNTs and Montmorillonite Bifillers
Author(s) -
Wu Zijian,
Gao Sheng,
Chen Lei,
Jiang Dawei,
Shao Qian,
Zhang Bing,
Zhai Zhaohui,
Wang Chen,
Zhao Min,
Ma Yingyi,
Zhang Xiaohong,
Weng Ling,
Zhang Mingyan,
Guo Zhanhu
Publication year - 2017
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.201700357
Subject(s) - materials science , composite material , nanocomposite , epoxy , carbon nanotube , montmorillonite , heat deflection temperature , curing (chemistry) , dielectric , flexural strength , izod impact strength test , ultimate tensile strength , optoelectronics
With unique physicochemical properties, multiwalled carbon nanotubes (MWCNTs) have enabled major achievement in polymer composites as reinforcing fillers. Nevertheless, high conductivity of raw MWCNTs (R‐MWCNTs) limits their wider applications in certain fields, which require outstanding thermal conductivity, mechanical, and insulation properties simultaneously. In this article, silica (SiO 2 ) coated MWCNTs core–shell hybrids (SiO 2 @MWCNTs) and organically modified montmorillonite (O‐MMT) are employed to modify epoxy (EP) simultaneously. The epoxy‐clay system is cured by using anhydride curing agent. The impact strength and flexural strength of final nanocomposites are greatly improved. Meanwhile, the final composites remain in high electrical insulation. Compared to mixed acid treated MWCNTs (C‐MWCNTs) (0.5 wt%)/EP nanocomposites, the volume resistivity of the O‐MMT(4 wt%)/SiO 2 @MWCNTs(0.5 wt%)/EP nanocomposites increases more than six orders of magnitude. Synergistic toughening effect occurs when using core–shell SiO 2 @MWCNTs and MMT bifillers. The electrical insulation is attributed to the suppressed electron transport effect by SiO 2 layer on the CNTs surface, and the blocked conductive CNTs network by the buried 2D structural O‐MMT. The SiO 2 @MWCNTs core–shell hybrids also benefit to decrease the dielectric constant and dielectric loss of CNTs/EP composites. This work provides guidance to using CNTs as reinforcement fillers to toughen the polymers for electric insulating applications.