METHOD FOR INCREASING THE TENSILE STRENGTH OF FIBROUS COMPOSITES BY STRENGTHENING THE MATRIX-FILLER INTERFACE OF CARBON FIBERS WITH FUNCTIONALIZED CARBON NANOTUBES Russian patent published in 2021 - IPC C09D201/00 B05D5/10 B82B3/00 B82Y30/00 C01B32/174 D01F9/12 D01F11/10 

FIELD: chemistry.

SUBSTANCE: invention can be used in the manufacture of composites for aircraft parts. Prepared is a dispersion of functionalized carbon nanotubes (CNTs) containing from not less than 1 to not more than 10% functional groups in n-methylpyrrolidone with a concentration of 20-250 μg / ml. When preparing this dispersion, a solvent with a boiling point of 120-180 °C is additionally added from the group consisting of cyclohexanone, cyclohexanol, cyclopentanone, dimethylacetamide or their mixture taken in a volume ratio from not less than 1:1 to not more than 1:5 to the specified dispersion. The prepared dispersion is applied to the surface of carbon fiber with simultaneous heating of its surface to 60-120 °C by aerosol spraying in the form of separate microdroplets forming a discontinuous uniformly distributed CNT layer. Dispersion consumption does not exceed 0.1 ml / min. Then, with simultaneous heating of the carbon fiber surface to 60-80 °C by aerosol spraying, a hardener containing amino groups is applied, selected from polyethylene polyamine, triethylenetetramine, diethylenetriamine, tetraethylenepentamine, m-xylylenediamine, m-phenylenediamine or a mixture thereof, with a concentration of propanol in or butanol 60-800 μg/ml. Consumption of the hardener solution does not exceed 0.3 ml/min. Before aerosol spraying of these solutions, the carbon fiber surface can be treated with ultraviolet light with a wavelength of 200-400 nm in water vapor for at least 1 min to no more than 15 minutes at ultraviolet radiation intensity of 0.5-100 W/cm².

EFFECT: invention provides increase in the tensile strength of a composite based on carbon fibers with an epoxy matrix by strengthening the interface by forming on their surface a network consisting of functionalized CNTs surrounded by molecules of a hardener chemically interacting with binder molecules.

2 cl, 2 ex, 3 dwg