Overview
ISO 11089:2010 specifies a validated analytical procedure for determining antidegradants in raw synthetic rubber by high-performance liquid chromatography (HPLC). The standard targets N‑alkyl‑N'‑phenyl‑p‑phenylenediamines, N‑aryl‑N'‑aryl‑p‑phenylenediamines and poly‑2,2,4‑trimethyl‑1,2‑dihydroquinoline, and can be adapted to other amine antidegradants. It covers sample preparation, extraction, chromatographic conditions, calculation of results and precision data, and warns that extender oils can interfere with measurements.
Key topics and requirements
- Scope: Quantitative determination of specified antidegradants in raw synthetic rubbers; method adaptable for other amine antidegradants.
- Sample preparation: Thin-sheet milling to 0.25–0.5 mm; duplicate ~200 mg test portions; extraction in an ultrasonic bath for 3 h (temperature kept below 30 °C).
- Extraction solvent: 2:1 (v/v) isopropanol : dichloromethane.
- Chromatography:
- Eluent A: methanol : 0.01 M aqueous ammonium acetate (1:1 v/v); Eluent B: methanol.
- Gradient elution program defined in the standard (start 100% A → 100% B → return to 100% A).
- Reverse‑phase HPLC column (examples: HYPERSIL ODS, SPHERI‑5 ODS); flow rate 0.25 mL/min; column temperature 40 °C; injection 10 µL.
- Detector wavelengths: 233 nm for poly‑2,2,4‑trimethyl‑1,2‑dihydroquinoline and 295 nm for other antidegradants; 550 nm reference.
- Quantification: Compare peak areas of sample extracts with those from a reference antidegradant solution of known mass; calculation uses the ratio of peak areas and masses to report percent antidegradant.
- Precision: Interlaboratory data show repeatability r = 0.24 percentage points and reproducibility R = 0.36 percentage points (type 1 precision study).
Applications and users
- Intended for quality control laboratories, rubber compounders, raw synthetic rubber manufacturers, independent testing laboratories and material researchers who need reliable quantification of stabilizers/antidegradants.
- Useful for product compliance, formulation development, batch release testing and troubleshooting ageing/stability problems where antidegradant levels affect performance.
- Note: users should account for potential interference from extender oils and confirm reference antidegradant composition matches the sample.
Related standards
- ISO/TR 9272:2005 - referenced for precision determination procedures used in the interlaboratory test program.
- ISO 11089:2010 replaces ISO 11089:1997 (second edition includes updated precision data).
Keywords: ISO 11089:2010, antidegradants, raw synthetic rubber, HPLC, high-performance liquid chromatography, 6PPD, DTPD, analytical method, precision, repeatability, reproducibility.
