Polymethacrylimide PMI foam is a cross-linked rigid structure foam material with 100% closed-cell structure. Its uniform cross-linked cell wall structure can give it outstanding structural stability and excellent mechanics. performance. At present, PMI foam has been widely used in aerospace, aviation, military industry, shipbuilding, automobile, railway locomotive manufacturing, radar, antenna and other fields.
The properties of PMI foam: 100% closed-cell structure and isotropic; good heat resistance, heat distortion temperature of 180～240℃; excellent mechanical properties, high specific strength and high specific modulus, in various foams It is the highest; surface contact, with good compression creep performance; can be autoclaved at high temperature (180～230℃, 0.5～0.7MPa), and can be heated under vacuum package (180～230℃, several Pa), It can also be melt-injected to realize the one-time co-curing of the foam interlayer and the prepreg; it does not contain freon and halogen; good fire resistance, non-toxic, low smoke; good compatibility with various resin systems; excellent Dielectric properties: The dielectric constant is 1.05～1.13, and the loss tangent is (1～18)×10-3. In the frequency range of 2～26 GHz, the change of its dielectric constant and dielectric loss is very small, showing good wide-band stability, making it very suitable for the manufacture of radar and radome.
PMI foam does not have the wet heat corrosion of the panel-honeycomb interface of the aluminum honeycomb sandwich structure. Among foams of the same density, the strength and stiffness of PMI foam are the highest among all foams. PMI foam can be used as the core material of the sandwich structure of advanced composite materials in many cases with high requirements for use conditions, such as aerospace, aviation, railway locomotives and ships.
When PMI foam is used as the core material, the Scrim method, filament winding method, pressure casting method and other methods can be used to make composite materials. PMI foam has the advantages of small specific gravity, high temperature resistance, low dielectric constant and loss, high compressive strength, high specific strength, good fatigue and creep resistance, etc. It can be cured with prepreg in one step; at the same time, PMI foam has Excellent secondary processing performance, can be heated to form products with different curved shapes.