Electrophysical properties of composites based on the epoxy resin and expanded graphite
DOI:
https://doi.org/10.15407/hftp09.04.442Keywords:
conductive composites, percolation threshold, expanded graphite, microwave rangeAbstract
The composites of epoxy resin-expanded graphite(EG)-vermiculite and epoxy resin-expanded graphite-perlite were obtained and their electrophysical properties were analysed at low frequencies and in the microwave range.
High values (> 30) of real and imaginary components of the complex permittivity for both systems were achieved with a content of EG of less than 2 wt. %. The values of the percolation threshold and critical index of systems were defined: for a system with vermiculite the percolation transition (?c = 0.0018); and for a system with perlite (?c =0.0039). The method of impedance spectroscopy (10-2–106 Hz) shows that for all investigated composites there is no dependence of electrical conductivity to frequency, but up to a value of 103 Hz, indicating a low level of ionic conductivity.
It was found that the difference in electrophysical characteristics of two systems with the same content of the expanded graphite arises due to the nature of the surface of the dielectric components. The best indicators, namely, the lower percolation threshold and the achievement of maximum electrical conductivity values at lower EG, are in the system with vermiculite. It is due to the hydrophobic properties of the surface the filler particles, as well as the effect of the flow of a dielectric particle of vermiculite by a suspension of an epoxy resin-EG, while the particles perlite is impregnated with it.
Changing the content of such dielectric ingredients allows us to expand the functionality of composites when used for shielding from electromagnetic fields.
References
1. Gantayat S., Prusty G., Rout D.R., Swain S.K. Expanded graphite as a filler for epoxy matrix composites to improve their thermal, mechanical and electrical properties. New Carbon Mater. 2015. 30(5): 432. https://doi.org/10.1016/S1872-5805(15)60200-1
2. Stelmakh O.I., Vovchenko L.L., Matzui V.I. Electrical Resistivity of Composite Materials Based on Thermoexfoliated Graphite. Physics and chemistry of solid state. 2007. 8(2): 408. [in Ukrainian].
3. Melnyk L. Research of electrical properties of epoxy composite with carbon fillers. Materials science. Technology audit and prodaction reserves. 2017. 3/1(35): 28.
4. Saifutdinova M.V., Lyga R.I., Mikhal'chuk V.M. Amine-cured composite materials based on epoxy resin and expanded graphitr. Journal Advances in Chemistry and Chemical Technology. 2017. 31(11): 102. [in Ukrainian].
5. Hanyuk L.M., Ihnatkov V.D., Makhno S.M., Soroka P.M. Study of the dielectric properties of the fibrous material. Ukr. fiz. zhurn. 1995. 40(6): 627. [in Ukrainian].
6. Makhno S.N. Electrophysical properties of polychlorotrifluoroethylene–copper oxide system. Him. Fiz. Tehnol. Poverhni. 2014. 5(1): 23. [in Ukrainian].
7. Lisova O.M., Makhno S.M., Gunya G.M., Sementsov Yu.I., Kartel M.T. Electrophysical properties of polyamide – graphene nanoplates composites. Nanosistemi, Nanomateriali, Nanotehnologii. 2017. 8(2):107. [in Ukrainian].
Downloads
How to Cite
Issue
Section
License
- Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work.
