Plastics - Phenolic resins - Determination of electrical conductivity of resin extracts
1 Scope
This standard specifies a method for the determination of the electrical conductivity of phenolic resin extracts at 23℃±2℃.
The method is important for applications in which such resins are used as impregnating materials.
2 Principle
An acetone/water mixture is added to a solution of the resin. The precipitate thus produced is allowed to settle, and the conductance of the suspension remaining above the resin is measured. The conductivity is then calculated from the measured conductance.
3 Reagents
3.1 Acetone: reagent grade.
3.2 Water: deionized, conductivity less than or equal to 2.0μS/cm.
3.3 Acetone/deionized-water mixture: containing 8 volumes of acetone (3.1) and 4 volumes of deionized water (3.2).
4 Apparatus
4.1 Conductivity cell: with known cell constant K.
4.2 Conductance-measuring instrument: capable of measuring conductance to a minimum reading of 1μS with a precision of 5%, at a frequency range of 50Hz.
4.3 Beaker: nominal capacity 250mL.
4.4 Magnetic stirrer.
4.5 Balance: scale interval 1mg.
Foreword II
ISO Foreword III
1 Scope
2 Principle
3 Reagents
4 Apparatus
5 Procedure
6 Expression of results
7 Test report
