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

FIELD: polymer materials.

SUBSTANCE: method for obtaining sized carbon fibers, and polymer composite materials intended as structural polymer materials in additive processes, including PEI and CF, sized 1. 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 79-80°C, characterized in that the sizing agent is applied from a solution with a mass concentration of 0.41% in an organic solvent of chloroform and a stepwise rise in temperature and distillation of the solvent are carried out according to the following mode: 20° C - 7 min; 33° C - 22 min; 43° C - 17 min; 53° C - 17 min; 63° C - 20 min, and the quantitative ratio of the components corresponds in wt.%: carbon fiber 96; 1,4-diaminobenzene 3.5÷0.5; oligomeric ethersulfone based on 4,4' -dioxyphthalophenone and 4,4' -dichlorodiphenylsulfone with degree of polycondensation n= 5÷ 7 0.5÷ 3.5.

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 rheological properties of the created composite materials due to the introduction of a sizing composition - 1,4-diaminobenzene and oligomeric ethersulfone with a degree of polycondensation n= 5÷7 which increases the wettability of the carbon fiber and increases the interface interactions between the filler and the polyesterimide matrix.

2 cl, 1 tbl, 6 ex