ISO 17257:2020

Overview

ISO 17257:2020 specifies a qualitative pyrolytic gas‑chromatographic method with mass‑spectrometric detection (pyrolysis‑GC/MS) for the identification of rubber polymers. The method is applicable to raw rubbers, unvulcanized and vulcanized compounds, and to compounds based on single rubbers or blends. Results are obtained by solvent extraction, controlled pyrolysis of the polymer, separation by gas chromatography and interpretation of mass spectra of characteristic pyrolysis products.

Keywords: ISO 17257:2020, pyrolytic gas chromatographic method, GC‑MS, rubber identification, pyrolysis.

Key topics and requirements

• Scope and purpose: A qualitative identification technique for polymer type determination; NOT a quantitative assay.
• Sample types: Raw rubber, unvulcanized and vulcanized compounds, and blends (note: detection and identification of a polymer present at <10% in a blend can be difficult).
• Procedure overview:
  • Solvent extraction (referencing ISO 1407) when required.
  • Pyrolysis to generate volatile degradation products.
  • Separation by gas chromatography and detection by mass spectrometry (electron impact mode).
  • Interpretation of chromatograms and mass spectra to identify polymer-specific pyrolysates.
• Equipment: Pyrolysis system, gas chromatograph with suitable columns, and MS detector. Common pyrolyser types include platinum‑filament, Curie‑point, and micro‑furnace devices.
• Reagents and conditions: Analytical‑grade solvents and inert carrier gas; pyrolysis parameters (temperature/time) must be established for reproducible results. Annexes provide example operating conditions and chromatogram examples.
• Polymer coverage and limitations: Non‑restrictive list of rubbers (Groups M, O, Q, R). The standard notes where the method cannot distinguish between certain polymers (e.g., EPM vs EPDM, NR vs IR, MQ vs VMQ) or can distinguish specific cases (e.g., HNBR from NBR/XNBR).

Applications and users

ISO 17257:2020 is used for:

• Quality control and incoming material verification by rubber manufacturers.
• Failure analysis and root‑cause investigations in engineering and automotive sectors.
• Material identification for recycling, sorting and reuse of elastomers.
• Forensic and regulatory laboratories requiring polymer identification.
• R&D and product development for polymer formulation checks.

Typical users: testing laboratories, OEMs, compounders, recyclers, certification bodies and forensic analysts.

Related standards

• ISO 1407 - Rubber - Determination of solvent extract (referenced for extraction).
• ISO 1629 - Rubber and latices - Nomenclature (used for polymer naming and grouping).

ISO 17257:2020 provides a standardized, reproducible approach for identifying rubber polymers by their pyrolysates using GC‑MS, supporting material traceability, compliance and technical investigations.