METHOD FOR OBTAINING SIZED CARBON FIBERS AND POLYESTERIMIDE COMPOSITES Russian patent published in 2023 - IPC C08K7/02 C08J5/06 C08L79/08 

FIELD: polymer materials.

SUBSTANCE: method for obtaining sized carbon fibers, and polyesterimide composite materials intended as structural polymer materials in additive processes, including PEI and CF, sized 1,4- A method for obtaining finished carbon fibers intended for structural polymeric materials based on the sizing of carbon fiber by applying a sizing component from a solution, followed by drying in an oven under vacuum at 81-82°C, characterized in that the sizing agent is applied from a solution with a mass concentration of 0.5% in an organic solvent of chloroform and a stepwise rise in temperature and simultaneous distillation of the solvent and exposure to ultrasound with an operating frequency of 46 kHz are carried out according to the following mode: 20°C - 2.5 min; 40°С - 3 min; 50°C - 3 min; 70°C - 2 min; and the quantitative ratio of the components corresponds in wt.%: carbon fiber 96.0; 1,4-diaminobenzene 0.5÷1.0; oligomeric polyethersulfone based on 4,4 -dioxyphthalophenone and 4,4 -dichlorodiphenylsulfone with degree of polycondensation n = 57: 3.5÷3.0.

A polyesterimide composite material is used in the manufacture of products in additive techniques, containing a polymer matrix based on polyesterimide and finished carbon fiber, characterized in that carbon fiber is used, obtained by the method according to cl. 1, and the quantitative ratio of components in the composite material corresponds to wt .%: polyetherimide 80, finished carbon fiber 20.

EFFECT: improvement of the melt flow rate and impact strength of the created polyesterimide carbon fiber composition due to the introduction of a sizing composition, which increases the wettability of the filler and increases intermolecular interactions between the carbon fiber and the polyesterimide matrix.

2 cl, 1 tbl, 6 ex