1. Physical properties

 

The shrinkage of phenolic molding compound depends on many factors, such as resin composition, filler type, moisture content and forming conditions. The linear expansion coefficient of phenolic resin molding plastics has a great relationship with the types of fillers. With the increase of inorganic fillers such as glass fiber, the linear expansion coefficient decreases, while the linear expansion coefficient of plastics containing synthetic fiber is larger.

 

2. Mechanical properties

 

The creep resistance of phenolic molding compounds at room temperature depends on the temperature with different fillers. The creep resistance of phenolic molding compounds with inorganic fillers such as mica and asbestos is better than that with organic fillers. Generally speaking, the tensile strength and bending strength of the molding compound filled with glass fiber are better, and they are less affected by temperature, while some fillers such as wood flour are easy to absorb moisture, which will cause the decrease of bending strength and bending modulus.

 

3. Electrical performance

 

Phenolic resin plastic has good electrical properties. It has high insulation properties at room temperature, such as high volume resistance, surface resistance and breakdown voltage. It can be used as insulation material, but its dielectric constant and dielectric loss tangent are large, so it can only be used as power frequency insulation material.

 

4. Corrosion resistance

 

Phenolic resins without fillers are hardly eroded by inorganic acids, and are insoluble in most hydrocarbons and chlorides, as well as ketones and alcohols. But it is not resistant to concentrated sulfuric acid, nitric acid, high temperature chromic acid and other corrosion.