Compared with pure plastics, PMI foam has low density, light weight and high specific strength. Its strength increases with density, has the ability to absorb impact loads, and has excellent cushioning and shock absorption performance, sound insulation and sound absorption performance, and thermal conductivity. Good thermal insulation performance, excellent electrical insulation performance, corrosion resistance, mold resistance. Soft foam has excellent properties such as elasticity.
PMI foam is available in three types: rigid, flexible, and semi-rigid (semi-soft).
1. Rigid foam is a crystalline or amorphous form of foam at normal temperature, and its glass transition temperature is higher than normal temperature. Therefore, the texture of the foam is hard at normal temperature.
2. Soft foam that is, the melting point of the polymer constituting the foam is lower than normal temperature or the glass transition temperature of the amorphous polymer is lower than normal temperature, and the material is soft at room temperature.
3. Semi-rigid (or semi-soft) foam is a foam between the above two types.
Foam can also be divided into low foam and high foam. Generally, the expansion ratio (the multiple of the volume increase after expansion compared with that before foaming) is called low foam if it is less than 5, and it is called high foam if it is greater than 5.
There are many micropores inside the PMI. Light weight, heat insulation, sound absorption, shockproof, corrosion resistance. There are soft and hard points. Widely used as insulation, sound insulation, packaging materials and automobile casings.
