ISO 13885-1:2020 PDF

Overview

ISO 13885-1:2020 specifies a standardized procedure for determining the molar-mass distribution and average molar masses Mn (number average) and Mw (weight average) of polymers soluble in tetrahydrofuran (THF) using gel permeation chromatography (GPC), also known as size exclusion chromatography (SEC). The document covers principle, apparatus, reagents, calibration, data acquisition and evaluation, and reporting requirements for THF-based GPC systems used in polymer characterization.

Key topics and technical requirements

• Scope & limitations
  • Applicable to polymers soluble in THF; not applicable to samples with Mw > 1×10^6 g·mol⁻1 or with elution outside the calibration range.
  • Method can fail for polymers that interact with the system (e.g., adsorption); no correction methods for peak broadening are included.
  • For absolute molar-mass values, alternative methods (e.g., membrane osmometry for Mn, light scattering for Mw) are recommended.
• Principle
  • Separation based on molecular coil size: large molecules elute earlier; small molecules penetrate pores and elute later.
• Apparatus & operational parameters
  • Eluent: THF must be degassed (bubble trap, helium purge, or vacuum degassing are acceptable) and protected from atmosphere/light.
  • Pump: smooth, pulse-free flow; recommended 1 mL/min (flow stability ≤ 0.1%).
  • Injection: loops or autosamplers; sample concentration typically