Summary:Polymethacrylimide (PMI) foam is a cross-linked rigid struct...
Polymethacrylimide (PMI) foam is a cross-linked rigid structural foam material with 100% closed-cell structure, and its uniformly cross-linked cell wall structure can give it outstanding structural stability and excellent mechanical properties. At present, PMI foam has been widely used in aerospace, aviation, military, shipbuilding, automobile, railway locomotive manufacturing, radar, antenna and other fields.
Properties: closed cell structure, and isotropic. Good heat resistance, heat distortion temperature is 180 ~ 240 ℃. Excellent mechanical properties, high specific strength and high specific modulus, which are relatively high among various foams, and have good compressive creep properties. It can be formed by high temperature autoclave (180～230℃, 0.5～0.7MPa), can be heated by vacuum bag (180～230℃, several Pa), and can also be melted and injected to realize the one-time use of foam interlayer and prepreg co-cured.
Free of freon and halogen; good fire resistance, low smoke; good compatibility with various resin systems; excellent dielectric properties, dielectric constant 1.05 ~ 1.13, loss tangent in (1 ~ 18) × 10 -3. In the frequency range of 2 to 26 GHz, its dielectric constant and dielectric loss change very little, showing good broadband stability, making it very suitable for the manufacture of radar and radomes.
Damp heat corrosion of the panel-honeycomb interface without an aluminum honeycomb sandwich structure. Among the foams of the same density, the strength and stiffness of PMI foams are higher among all foams. PMI foam can be used as the core material of composite sandwich structures in many situations where the use conditions are high, such as aerospace, aviation, railway locomotives and ships.
When PMI foam is used as a sandwich material, composite materials can be manufactured by Scrimp method, filament winding method, pressure casting method, etc. 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 resistance and creep performance, etc., and can achieve a one-step curing process with prepreg; Secondary processing performance, products with different curved shapes can be formed by heating.
CASCELL® FR rigid PMI foam is self-extinguishing and particularly suitable for applications in rail vehicle and watercraft construction, as well as in the aeronautic industry. It can be processed using prepregs and all common vacuum infusion methods, RTM, and VARTM.