ISO 16014-5:2019

Overview

ISO 16014-5:2019 specifies a general, absolute method for determining the average molecular weight and molecular weight distribution of polymers using size‑exclusion chromatography coupled with light‑scattering detection (SEC‑LS). The standard describes how to combine a light‑scattering detector with a concentration‑sensitive detector to obtain molecular weight and weight‑concentration data continuously as a function of elution time. SEC‑LS under this standard is applicable to a wide range of polymer architectures and molecular weights (from monomer up to 3 000 000), with stated limitations for samples containing high fractions of very low molecular‑weight components.

Key topics and technical requirements

• Principle: SEC coupled with light‑scattering detection measures scattered light intensity proportional to molecular weight × concentration; combining with a concentration detector allows absolute molecular weight determination.
• Applicability and limits: Suitable for linear homopolymers and nonlinear homopolymers (branched, star‑shaped, comb‑like, stereo‑regular/irregular). Applicable to heterophasic copolymers only when molecular composition is constant. Not applicable to block, graft or composition‑varying heterophasic copolymers. Not intended for samples with >30% components <1 000 Da.
• Measurement range: From monomer molecular weight up to 3 000 000.
• Calibration and setup: Procedures for calibration of the light‑scattering and concentration detectors (multiple calibration methods), determination of delay volume, sensitivity normalization and refractive index increment (dn/dc).
• Operation & data processing: Requirements for sample preparation, column performance checks, operating parameters (flow rate, injection mass, column temperature), baseline determination, selection of calculation range, signal integration, and molecular weight calculation.
• Additional analyses: Guidance on calculation of second virial coefficient (A2), differential and cumulative molecular weight distribution curves, expression of results and precision assessment.
• Documentation: Test report content and mandatory calibration and instrument parameter records.

Applications and users

• Applications: Polymer characterization for R&D, quality control, process monitoring, formulation development and materials verification where absolute molecular weight and molecular weight distribution data are required.
• Who uses it: Analytical chemists, polymer scientists, QC laboratories, instrument manufacturers and testing facilities implementing SEC‑LS for plastics and polymer analysis.

Keywords (for SEO)

ISO 16014-5:2019, SEC‑LS, size‑exclusion chromatography, light‑scattering method, molecular weight distribution, polymer characterization, refractive index increment, absolute molecular weight.

Related standards

• ISO 16014-1: General principles
• ISO 16014-2: Universal calibration method
• ISO 16014-3: Low‑temperature method
• ISO 16014-4: High‑temperature method
• ISO 472: Plastics - Vocabulary

This summary helps laboratories and engineers understand the scope, technical requirements and practical use cases of ISO 16014-5:2019 for SEC‑LS polymer analysis.