Characterization of the Epoxy Resin and Carbon Fiber Reinforced Plastic Stress-Strain State by Modified Carbon Nanotubes

Abstract

The epoxy resin in the form of Etal Inject-T compound, Sigratex KDK carbon fabric, Taunit-M carbon nanotubes conditionally named as CNT-1, as well as functionalized (modified) variety of them by grafting to the surface of new chemical groups: carboxylated ‒ CNT-2, carboxyl-hydroxylated ‒ CNT-3, amidated ‒ CNT-4 were used in the work. The experiments were performed on the compression strength and bending strength of the samples. The injection of CNT-1 into epoxy resin or carbon fiber reinforced plastic did not produce the hardening. The injection of 0.05% of CNT-2 into the epoxy resin had the following effect: there is no influence in the area of quasielastic strains, the hardening was up to 25% in the areas of plastic and elastic-plastic strain. The injection of 0.15% of functionalized carbon nanotubes into the carbon fiber reinforced plastic produced the hardening for compression with CNT-2 ‒ 6%, CNT-3 ‒ 12%, CNT-4 – 17%, for bending – CNT-2 – 44%, CNT-3 – 59%, CNT-4 – 132%. It is established that with an increase in the strain rate of epoxy resin from 1 to 5 mm/min the areas of plastic and elastic-plastic strain gradually are reduced, there is only quasielastic strain with brittle fracture at 20 mm/ min, this value can be accepted as its strength characteristic. With an increase in the strain rate of carbon fiber reinforced plastic from 1 to 20 mm/min the compression strength gradually increases from 398 MPa to 425 MPa, and then stabilizes.

Study of Radio Transparency and Dielectric Permittivityof Glass-and Aramid Epoxy Composites

“…One such material is polymer composites reinforced with aramid fiber that is the aramide epoxy-filled composite (AEC). They have low dielectric permittivity, low dielectric absorption losses, and outstanding mechanical characteristics, this is why they are widely used for manufacturing of fairings, stabilizers and vertical fins in the modern airplane industry [6][7][8]. The dielectric properties of AEC are important parameters since they directly affect the speed and loss of the wireless power during signal transmission.…”