METHOD FOR PRODUCING POLYIMIDE COMPOSITE MATERIAL REINFORCED WITH NANOSTRUCTURED BORON CARBIDE (VARIANTS)

摘要

FIELD: chemistry.;SUBSTANCE: invention concerns technology of obtaining nanocomposites based on nanostructured boron carbide with a polyimide matrix. Method for producing a polyimide composite material reinforced with nanostructured boron carbide is proposed. the method is carried out by condensation reaction of aromatic polycarboxylic acids and aromatic diamines in presence of nanostructured boron carbide, which is in form of suspension in dry organic solvent containing 2–60 % by weight of boron carbide, based on the weight of resulting composite, is mixed under the influence of ultrasound in current of inert gas with an organic diamine, cooled to 10–25 °C, after that, resulting reaction mass is added to aromatic polycarboxylic acid dianhydride, introduced in equimolar amount with respect to organic diamine, and benzoic acid, added in amount corresponding to molar ratio of benzoic acid with respect to aromatic polycarboxylic acid dianhydride equal to 1:(0.1–2), after which formed reaction mass is exposed to ultrasound influence at 30–40 °C for 10–30 minutes, then mixed at 60–85 °C for 3–8 hours and then at 170–200 °C for 12–22 hours with simultaneous distillation of formed water, after which resulting dispersion is poured into ethyl alcohol or a solution of ethyl alcohol in water, filtered and dried by heating from 70 to 90 °C for 3–8 hours in vacuum, followed by vacuum cooling or cooling in current of inert gas. Variant of method for producing polyimide composite material reinforced with nanostructured boron carbide is also described.;EFFECT: method for producing composite material of polyimide and nanostructured boron carbide with high mechanical and thermal stability is proposed.;10 cl, 1 tbl, 5 ex