1. Properties of Conductive PS Compound

Conductive PS (polystyrene) is a conductive compound with antistatic and electromagnetic interference (EMI) shielding functions.

1.1 Base PS Resin Characteristics

Polystyrene is a milky white polymer that is non-toxic, odorless and very stable in water, and it is classified as an environmentally friendly material. Its density is 0.89–0.91, making it one of the lightest plastic varieties. PS has good mechanical properties: apart from impact resistance, its other mechanical properties are better than those of polyethylene.

1.2 Conductive Performance

Conductive PS compounds have excellent conductivity. According to different application requirements, materials with different conductive properties can be obtained by adjusting the type and amount of conductive filler. Both surface resistivity and volume resistivity can meet a variety of occasions requiring conductive properties, with surface resistivity ranging from 10⁴ to 10⁹ Ω/sq.

1.3 Chemical Resistance

Conductive PS compounds have good chemical resistance and resist most chemicals. They withstand the attack of certain acids, alkalis, salts and other chemicals while maintaining material performance stability. In the chemical and electronics industries they can be used in environments exposed to chemical substances and are especially suitable for semiconductor packaging materials.

1.4 Molding Processability

Conductive PS compounds have good molding processability and can be made into terminal products of various shapes — such as PS sheets, PS plates, PS pipes and injection molded parts — through different processing methods including injection molding, extrusion and blow molding.

2. Disadvantages of Conductive PS Compound

2.1 Relatively Poor Thermal Stability

The glass transition temperature and melting point of conductive PS are relatively low, so its thermal stability is poor, generally around 70 °C–100 °C. When the temperature approaches or exceeds its glass transition temperature, performance changes significantly — for example, reduced hardness and poor dimensional stability. As the temperature continues to rise to the melting point, the material begins to melt.

Conductive PS is therefore limited in high-temperature environments or applications with high heat resistance requirements. In some high-temperature electronic equipment and automotive engine peripheral parts, for example, conductive PS may not be applicable.

2.2 Relatively Large Thermal Expansion Coefficient

The thermal expansion coefficient of conductive PS is relatively large, meaning the dimensions of the material change considerably with temperature. In applications with high dimensional accuracy requirements — such as the packaging of precision electronic components and optical instruments — the thermal expansion characteristics of conductive PS may affect product performance and reliabilit