Studies On Preparation And Electrical Properties Of EP/MWNTs/OMMT Composites

The cured epoxy resin (EP) has the excellent insulating properties and thermal behavior, with the rapid development of science and technology, the requirement of excellent epoxy resin has become more and more intense. Modification of epoxy resin has become a new way by adding nano-materials, each type of nano-materials possesses the unique performance, so the modifying effect of epoxy resin is different with various types of nano-materials.In the experiment, bisphenol-A epoxy resin is used as the matrix, the modified multi-walled carbon nanotubes and organic montmorillonite are used as the nano-materials. The curing agent used in the experiment is Methyl hexahydrophthalic anhydride. The matrix and the nano-materials are fully mixed in the condition of mechanical agitation, finishing the preparation on the composites. Morphologies of multi-walled carbon nanotubes and montmorillonite are observed through scanning electron microscopy, the nano-materials are characterized by infrared spectroscopy. The dielectric constant and loss, volume resistivity and strength are respectively tested through various instruments. The content range of MWNTs is0.1～2wt%, and that of OMMT is2～8wt%. In the condition of the frequency conversion, epoxy resin which owns the lowest dielectric constant is chosen to the best the curing process at the room temperature. The dielectric constant of EP/MWNTs/OMMT firstly decreases and finally tends to be a definite value, however, the dielectric loss of EP/MWNTs/OMMT shows a rising tend at the beginning and goes to be flat at last, with the increasing MWNTs content of epoxy resin, dielectric constant of the composites goes up and comes down. The addition of MWNTs damages the insulating properties of epoxy resin when the MWNTs content is especially0.7wt%, volume resistively of the composites rapidly declines to1.2×1013Ω·m by measuring the volume resistively of the composites. In condition of MWNTs content constant, volume resistively of the composites improves obviously and the dielectric loss and constant falls down after adding to the OMMT.