Overview
ISO 23075:2021 specifies a validated laboratory procedure for the determination of antidegradants in vulcanized rubbers using high-performance liquid chromatography (HPLC). The standard covers five groups of common antidegradants: aminoketone, naphthylamine, diphenylamine, p‑phenylenediamine and monophenol. It defines sample extraction, chromatographic conditions, calibration and calculation methods, and includes examples of chromatograms, UV spectra and precision data.
Keywords: ISO 23075:2021, antidegradants, vulcanized rubbers, HPLC, 6PPD, TMQ, ODPA, IPPD, extraction.
Key Topics
- Scope and limits: Targets specific antidegradant groups (see Table A.1 for chemical names and CAS numbers). Notes that extender oils can interfere and that polymeric antidegradants (e.g., poly‑2,2,4‑trimethyl‑1,2‑dihydroquinoline) are estimated only approximately.
- Sample preparation:
- Cut rubber to small pieces and weigh test portion (~200 mg).
- Extract with an organic solvent mixture (examples provided) using an ultrasonic bath for 3 h at ≤30 °C.
- Filter extracts through 0.45 µm PTFE before analysis.
- Chromatography:
- Reverse‑phase HPLC (C18) with gradient elution (eluent A: methanol/0.01 mol·L⁻¹ ammonium acetate, eluent B: methanol).
- Typical operating parameters provided: flow 1.0 mL/min, column 40 °C, injection 10 µL.
- Detection wavelengths: 235 nm for aminoketone group, 290 nm for other antidegradants.
- Calibration and quantification:
- Use external calibration curves (examples and preparation steps in Annex B).
- Ensure linearity (coefficient r > 0.99) and duplicate injections; report averaged values.
- Concentration calculated from measured peak area and calibration (formula provided in the standard).
- Quality and reporting: Duplicate test portions, precision data in Annex D, and mandatory elements for the test report (product description, method reference, results, etc.).
Applications
ISO 23075:2021 is intended for:
- Quality control in rubber and tyre manufacturing to verify antidegradant levels.
- Materials testing laboratories performing routine compositional analyses of vulcanized rubbers.
- R&D and failure analysis where identification and quantification of antioxidants/antidegradants inform formulation or degradation studies.
- Compliance and supplier verification when contractual or regulatory specifications cite antidegradant content.
Laboratories applying this method benefit from reproducible HPLC conditions, defined extraction procedures, and examples that assist method implementation and troubleshooting.
Related Standards (if applicable)
- Table A.1 in ISO 23075 references antidegradant identifiers (chemical names and CAS numbers) and links to related ISO listings. Users commonly apply ISO 23075 alongside other ISO test methods for rubber materials and internal laboratory HPLC validation protocols.
For practitioners implementing the method, follow all safety and waste disposal guidance in the standard and validate the method for specific rubber formulations (noting potential oil interferences and polymeric antidegradant limitations).
Open preview (PDF)Vulcanized rubbers — Determination of antidegradants by high-performance liquid chromatography
