ISO 15064:2017 PDF

Overview

ISO 15064:2017 specifies laboratory methods for determining the isomer ratio in toluenediisocyanate (TDI) mixtures used to produce polyurethanes. The standard describes two infrared-based analytical procedures (Method A and Method B) that quantify the proportions of 2,4‑TDI and 2,6‑TDI by measuring characteristic aromatic C–H deformation absorption bands. ISO 15064:2017 is essential for accurate TDI isomer ratio measurement in quality control, regulatory compliance and materials R&D.

Key topics and technical requirements

• Analytical principle: Quantitative infrared spectroscopy (single/double-beam or FTIR) of absorption bands at 810 cm−1 (2,4‑TDI) and 782 cm−1 (2,6‑TDI) corresponding to out-of-plane C–H deformation vibrations (12.3 μm and 13.8 μm).
• Two methods to cover the full composition range:
  • Method A: For samples containing 5 % to 95 % 2,6‑TDI. Uses diluted solutions (cyclohexane) and the 810/782 absorbance ratio referenced to calibration curves.
  • Method B: For low 2,6‑TDI content (0 % to 5 %). Measures the 782 cm−1 band in undiluted samples against a dedicated calibration curve.
• Sample preparation and calibration:
  • Use reagent‑grade cyclohexane and pure 2,4‑TDI / 2,6‑TDI standards to prepare calibration mixtures.
  • Method A: sealed NaCl liquid cell with 0.2 mm path length; Method B: 0.1 mm path length. Path lengths must be known to ±0.002 mm.
  • Construct calibration curves (absorbance ratio vs. mass ratio or % mass) for accurate conversion.
• Laboratory conditions & safety:
  • Isocyanates react with moisture - maintain low humidity (preferably