The thermal conductivity of ordinary plastic products is mostly in the range of 0.15~0.22W/(m, K), while the thermal conductivity of PMI foam plastic is generally in the range of 0.01~0.04W/(m.K), which is higher than that of ordinary plastics. The product is as much as 15 to 50 times lower, and has excellent thermal insulation performance. The resins commonly used for thermal insulation foam products include rigid PU, PF, urea-formaldehyde and PS. When used at high temperatures, attention should be paid to the heat-resistant temperature of different varieties.
PS and PVC should be used at low temperature, and PU and PF should be used at high temperature. Urea-formaldehyde foam has good thermal insulation, and has the advantages of flame retardant, low price and wide source. However, due to its high brittleness and serious water absorption, it affects its wide application. It can now be widely used for building insulation, reducing house heat loss by 70%.
PMI foam has high specific strength and high specific modulus, and its tensile, compression, bending, shearing and other strengths and modulus are far superior to other foam or balsa core materials such as pvc, pu, pet, etc., and Isotropic, can improve strength, improve rigidity, reduce weight; high heat resistance: has a unique cross-linked structure, imide ring structure, high temperature stability and pressure resistance, heat distortion temperature 200 ℃, suitable for high temperature molding Or vacuum autoclave co-curing molding process to shorten process time, improve production efficiency, and improve structural performance.
The closed cell rate is 95%~98%. It is used in the composite sandwich structure, which can avoid the moisture absorption and degumming problems that may occur in the honeycomb core material, improve the safety performance and prolong the service life. Due to its high closed porosity and water pressure resistance, it can be used as an underwater buoyancy material. High closed cell ratio and fine and uniform cells also make the material have good sound insulation, heat insulation and moisture barrier properties. Easy to bond: adapt to various resin systems such as epoxy, unsaturated polyester, etc., with high bonding strength.
Fatigue resistance: The unique molecular structure endows it with good fatigue resistance, especially suitable for composite sandwich structures subjected to dynamic loads. Dielectric properties and aluminum equivalent: Low dielectric constant, low dielectric loss in a wide frequency range, good electrical insulation, suitable for radar equipment. Low aluminum equivalent, suitable for medical device industry. It is easy to machine and can be bent into various curved surfaces under heating, which improves the degree of freedom of design.
