METHOD FOR PROCESSING CARBON FIBRE WITH FIBRE COMPOSITION COMPATIBLE WITH HIGH TEMPERATURE THERMOPLASTIC BINDERS Russian patent published in 2024 - IPC D06M101/40 D06M10/02 D06M15/59 D06M23/10 

FIELD: carbon fibre.

SUBSTANCE: invention relates to methods for processing carbon fibre with high-temperature sizing compositions and can be used to produce carbon fibre with improved physical and mechanical properties and composite materials based on it, which can be used in various industries to create products and structural elements exposed to elevated temperatures. The use of the present invention provides the following technical result: increasing the strength of the fibre-matrix adhesive connection and improving the technological characteristics of the fibre. A method is proposed for treating carbon fibre with a sizing composition compatible with high-temperature thermoplastic binders, including obtaining a sizing composition by preparing solutions of polyetherimide in chloroform in a mass ratio of 1:(4-6) and polyamide acid in chloroform in a mass ratio of 1:(13-20), combining solution using a mechanical homogenizer for 25-30 minutes, adding to the solution 0.35-0.40 wt.% defoamer and 0.85-1.30 wt.% mixture of anionic and non-ionic surfactants in a mass ratio (8-11):1, adding water in a mass ratio of polyetherimide: water equal to 1:(10-13), transferring to an ultrasonic homogenizer, in which it is kept for 11-15 minutes, varying the high-frequency power in the following sequence: at least 5 minutes at 160 W, cooling to 20°C, a pause of at least 5 minutes, re-processing at 240 W for at least 1 minute, stopping for at least 2 minutes, processing for 1 minute at 320 W and 2 minutes processing at 40 W, then transferring to a round-bottom flask, distilling off the chloroform to vacuum rotary evaporator at a pressure of 500-530 mbar and a temperature of 38-40°C, followed by diluting the resulting suspension with water to the required concentration, and sizing the carbon fibre with the resulting suspension, continuously exposing the sizing agent and the treated fibre to ultrasound, while the polyamide acid solution is prepared by dissolving equimolar amounts of dianhydride not containing aliphatic fragments of aromatic carboxylic acid and aromatic diamine in chloroform and keeping the resulting polyamide acid solution for at least 8 hours.

EFFECT: increasing the strength of the fibre-matrix adhesive connection and improving the technological characteristics of the fibre.

1 cl, 2 dwg, 4 ex