SOLUTION-FREE METHOD OF PRODUCING PHTHALONITRILE PREPREG AND POLYMER COMPOSITE MATERIAL BASED THEREON Russian patent published in 2021 - IPC C08L79/08 C08J5/24 C08J5/04 B32B27/28 

FIELD: chemistry.

SUBSTANCE: invention relates to polymer chemistry and the technology of producing polymer composite materials (PCM), specifically to a method of producing a prepreg with a phthalonitrile matrix in a nonsoluble technology, as well as to a method of producing polymer composite material for use in aircraft and space industries. Method of producing a prepreg with a phthalonitrile matrix involves forming, first, a film of a low-melting phthalonitrile binder with thickness of 20–400 mcm between two polymer films with an anti-adhesion coating. Formation of film is carried out in thermo press at pressure from 2 to 10 bar and temperature from 80 °C to 140 °C for 20–600 seconds. Then film of low-melting phthalonitrile binder is applied by direct method using roller on reinforcing filler at 35 ± 5 wt. % binder per weight of reinforcing filler. Method of producing polymer composite material consists in assembling vacuum package around layer-by-layer layers of said prepreg with phthalonitrile matrix, evacuating air to vacuum values <1 mm Hg and cured. Curing is carried out according to the following mode: heating to 120–150 °C at speed 2 ± 0.5 °C/min and contact pressure, followed by heating to 180 ± 2 °C at speed 2 ± 0.5 °C/min and pressure 2–8 bar, subsequent pressure increase up to 10 ± 0.5 bar, holding at this temperature for 8 ± 0.1 hour. Further, composite is removed from mold, post-hardened at temperature of 330 ± 5 °C for 8 ± 0.1 h and cooled to room temperature with cooling rate of not more than 5 °C/min.

EFFECT: invention enables to obtain prepregs with phthalonitrile matrices without using organic solvents and obtain a polymer composite material with high strength properties and high heat resistance.

8 cl, 5 tbl, 35 ex, 5 dwg