Electrical Conductivity of Aqueous Resin Extracts

Where epoxy resins are used as insulation for electronic devices, ionic impurities such as chloride, sodium and catalyst residues present in the epoxy resin can cause failure of the device. Instead of determining these impurities separately, a test method may be used to evaluate their contents as a whole by measuring the electrical conductivity of a resin extract obtained by extraction of the resin with water at an elevated temperature. Because of its practical usage and simplicity, this method is becoming widely used in the quality control of epoxy resins for electronic insulation applications.

The EC500T and EC510T conductivity meter could test electrical conductivity of a resin extract obtained by extraction of the resin with water at an elevated temperature.

Standard Reference

ISO 21318:2007 Plastics — Epoxy resins — Determination of electrical conductivity of aqueous resin extracts

The Principle

ISO 21318:2007 specifies a method for the determination of the electrical conductivity of an aqueous extract obtained by extraction of an epoxy resin with water at 95 °C. The method is applicable only to epoxy resins that are in the molten state at the extraction temperature (95 °C).

The method is important for epoxy resins which are used as insulation materials for electronic devices. The electrical conductivity of the extract is used as a measure of the concentration of the ionic species in the resin.

The Measurement

The EC500T and EC510T conductivity meter could test electrical conductivity of a resin extract obtained by extraction of the resin with water at an elevated temperature.

Γ=γ_s-γ_B

γ_B，Blank Conductivity: It needs to measure the electrical conductivity of distilled water or pure water. The distilled water or pure water of electrical conductivity needs to be lower than 2.0 μS/cm.

Γ_s, electrical conductivity of the resin extract sample .

Γ, electrical conductivity of a resin extract.

Recommended Configuration

EC500T and EC510T Conductivity Meter

EC500T 

50. Conductivity Range: 0.000 μS/cm～2000mS/cm
50. Conductivity Resolution: 0.001 μS/cm, automatic switching according to the range
50. Conductivity Accuracy: ±0.5% (FS)

EC510T 

50. Conductivity Range: 0.000 μS/cm～3000mS/cm
50. Conductivity Resolution: 0.001 μS/cm, automatic switching according to the range
50. Conductivity Accuracy: ±0.5% (FS)

Electrodes

    DJS-0.01VT Conductivity Electrode, apply to test the conductivity of blank.

DJS-0.1VTG Conductivity Electrode, apply to test the condcutivity of sample.