Overview
EN ISO 21627-3:2009 (ISO 21627-3:2009) - published by CEN/ISO - specifies a standardized laboratory method for the determination of total chlorine in epoxy resins. The method measures total chlorine (both saponifiable organic chlorine and inorganic/ionic chlorine) present as impurities in epoxy resins produced from epichlorohydrin. The document replaces the 2003 edition and is intended for use in quality control, materials testing and regulatory compliance.
Key topics and technical requirements
- Scope and definition: Total chlorine is defined as the amount of chlorine measurable by this method and includes 1,2- and 1,3-chlorohydrins and chloro‑glycidyl derivatives plus inorganic chloride.
- Principle: Dissolve a test portion in diethylene glycol monobutyl ether, saponify by refluxing with an alcoholic potassium hydroxide solution (KOH in 1,2‑propanediol), then determine chloride by potentiometric titration with standardized silver nitrate.
- Reagents and concentrations: The standard specifies analytical-grade reagents and water (ISO 3696 grade). It gives preparation and standardization procedures for 0.1 mol/L and 0.01 mol/L AgNO3 titrants, and details for KOH solution in 1,2‑propanediol and solvents (diethylene glycol monobutyl ether, acetone, glacial acetic acid).
- Apparatus: Requires potentiometric titration setup (silver electrode and reference), analytical balance (0.1 mg), reflux apparatus and heating (hotplate/oil bath capable >200 °C), magnetic stirring and common volumetric glassware.
- Procedure highlights: Weigh a test portion (selected to give an appropriate chlorine mass), dissolve, add KOH solution, reflux ~10 min, cool, transfer and acid-wash, then titrate with AgNO3. Perform a blank and calculate chlorine content from titrant volume.
- Safety & quality: Users should follow normal laboratory safety and use specified reagent grades and water purity.
Applications and users
- Quality control laboratories in epoxy resin manufacturing to monitor chlorine impurities that can affect cured resin properties.
- Materials testing and certification bodies assessing compliance with product specifications or customer requirements.
- R&D teams analyzing by‑products from epichlorohydrin-based production routes.
- Regulatory and procurement professionals who need standardized test data for material acceptance.
Keywords: epoxy resins, total chlorine, chlorine content determination, potentiometric titration, silver nitrate titration, saponifiable chlorine, inorganic chlorine, ISO 21627-3:2009, CEN.
Related standards
- ISO 21627-1 - Inorganic chlorine (ionic chlorine)
- ISO 21627-2 - Easily saponifiable chlorine
- ISO 4615 - Analytical methods for other impurities in epoxy resins
- ISO 3696 - Water for analytical laboratory use (referenced for reagent water quality)