Overview
ISO 21627-1:2009 - Plastics - Epoxy resins - Determination of chlorine content - Part 1: Inorganic chlorine specifies a direct potentiometric titration method to measure inorganic chlorine (ionic chlorine, Cl−) in epoxy resins. Results are reported as milligrams of chlorine per kilogram of resin (mg/kg). This part is one of three in the ISO 21627 series covering inorganic, saponifiable and total chlorine in epoxy resins.
Key topics and requirements
- Scope and definition
- Measures inorganic chlorine (chloride ion) in epoxy resins.
- Requires laboratory practices and safety awareness; uses analytical-grade reagents and water per ISO 3696.
- Analytical principle
- Dissolve a representative sample in an appropriate solvent (acetone typical; alternatives: methyl ethyl ketone or THF if needed).
- Titrate directly with a 0.002 mol·L−1 silver nitrate (AgNO3) solution using potentiometric end-point detection with a combined silver/silver‑chloride electrode.
- Determine the end-point from the inflection of potential vs. volume curve.
- Reagents and apparatus
- Analytical reagents (acetone, isopropanol, glacial acetic acid), AgNO3 titrant prepared and calibrated, microburette, potentiometer/titrator, combined Ag/AgCl electrode, analytical balance (0.1 mg), magnetic stirrer.
- Calculation and reporting
- Content calculated from titrant volume, titrant concentration, and sample mass; results rounded to one decimal place (mg/kg).
- Test report must include reference to ISO 21627-1, sample identification, solvent used (if not acetone), test results and date.
- Performance (fidelity)
- Repeatability and reproducibility established by an interlaboratory study (10 labs). Example reproducibility (R) values: 0.13 mg/kg for w(Cl)
Open preview (PDF)Plastics — Epoxy resins — Determination of chlorine content — Part 1: Inorganic chlorine