1. Thermal conductivity

For thermal insulation materials, the size of thermal conductivity is a very important index. Paper plastic has low thermal conductivity, good heat preservation effect and low energy loss. The thermal conductivity is closely related to the structure of foam. At present, the thermal conductivity of phenolic aluminum foil composite sandwich board is 0.028W/MK (at 50 C).

Thermal conductivity of foam (W/MK)

Normal Temperature Foaming Heated Foaming Modified Foaming

0.033 0.028 0.035

2. Combustibility

According to GB2406-2408-80, the sample was burned for 5 minutes in a 25-30_high blue flame (about 1000 C), and the self-extinguishing material was extinguished 2 seconds after leaving the flame. For paper and plastic, we will burn the phenolic foam on the prescribed flame for 5 seconds, do not burn, extend the time to continue burning, and still do not burn. It can be seen that it belongs to self-extinguishing materials.

3. Critical oxygen index

The critical oxygen index (COI) of the material is a characterization of its flammability. The larger the critical oxygen index is, the less easy it is to burn. On the contrary, the smaller the critical oxygen index is, the easier it is to burn.  Flammability is poor. Because phenolic resin molecule contains a large number of benzene rings, the proportion of carbon atoms is high, it is easy to carbonize at high temperature, so its critical exponent value is large.

In order to enhance the flame retardancy of phenolic foam plastics, we choose A1 (OH) chlorinated phosphorus phenethyl ester TCEP101505 and other flame retardants as experimental materials.