ISO 18177-2025 PDF

Full title and description

ISO 18177:2025 — Plastics — Test method for estimation of the short chain branching distribution of semicrystalline ethylene 1‑olefin copolymers — Differential scanning calorimetry (DSC). This international standard defines a DSC-based procedure, using successive self‑nucleation and annealing (SSA), to estimate the short‑chain branching (SCB) distribution and related thermal properties of semicrystalline ethylene/1‑olefin copolymers and their products.

Abstract

This document specifies a test method for estimation of the short chain branching distribution of semicrystalline ethylene 1‑olefin copolymers by successive self‑nucleation and annealing (SSA) using conventional, high‑performance and fast differential scanning calorimetry (DSC). It is applicable to raw materials and finished products and includes procedures for obtaining semi‑quantitative and quantitative information on SCB content, degree of crystallinity and a branching distribution profile for ethylene/1‑butene, ethylene/1‑hexene and ethylene/1‑octene copolymers.

General information

• Status: Published
• Publication date: May 2025
• Publisher: International Organization for Standardization (ISO)
• ICS / categories: 83.080.20 (Thermoplastic materials — Polyolefins and related polymeric materials)
• Edition / version: Edition 1 (2025)
• Number of pages: 20

Scope

ISO 18177:2025 applies to the estimation of the short chain branching distribution of semicrystalline ethylene‑1‑olefin copolymers and their products by DSC using an SSA thermal‑fractionation approach. The method covers conventional, high‑performance and fast DSC instruments and defines procedures for sample conditioning, SSA cycle design, thermal programs, data processing and reporting. Quantitative calculations described in the standard are directed at ethylene/1‑butene, ethylene/1‑hexene and ethylene/1‑octene copolymers; the standard notes limitations and best‑practice precautions (for example avoidance of thermal degradation and correct selection of SSA parameters) when applying SSA to complex or degraded materials.

Key topics and requirements

• Principle: application of successive self‑nucleation and annealing (SSA) thermal fractionation to resolve populations with different short‑chain branching content.
• Instrumentation: suitability and operational requirements for conventional DSC, high‑performance DSC (HP‑DSC) and fast scanning calorimetry (FSC).
• Sample preparation and conditioning: mass, pan type, pre‑treatment (erasure), and precautions to avoid oxidative or thermal degradation.
• SSA protocol design: determination of ideal self‑nucleation temperature (Ts,ideal), holding times, heating/cooling rates and fractionation windows (ΔTs) to ensure reproducible fractionation profiles.
• Data treatment: procedures for baseline treatment, peak deconvolution, calculation of SCB content, degree of crystallinity and construction of SCB distribution histograms or fractionation fingerprints.
• Reporting requirements: mandatory test conditions, instrument settings, calibration records, sample identification, results expressed with uncertainty/precision statements and interpretation guidance.
• Applicability and limitations: recommended materials (ethylene/1‑butene, /1‑hexene, /1‑octene copolymers), caveats for multiphase or heavily filled systems and guidance where SSA provides comparative rather than absolute quantification.
• Quality and reproducibility: guidance on repeatability, use of reference materials or controls, and inter‑laboratory considerations for method transfer.

Typical use and users

Laboratories and organizations that commonly use ISO 18177:2025 include polymer R&D groups, quality assurance and quality control laboratories in polyolefin production, independent testing houses, recyclers assessing feedstock heterogeneity, and academic research groups studying polymer structure–property relationships. Typical uses are grade specification, incoming raw‑material checks, process monitoring, product troubleshooting and research into comonomer distribution effects on crystallization and mechanical performance.

Related standards

Standards commonly used alongside or referenced for complementary methods include the ISO 11357 series (Differential scanning calorimetry — general principles and specific DSC methods), ISO 1133 (MFR/MVR — melt flow determination), ISO 4504 (co‑monomer content determination by solution 13C‑NMR for polyethylene), and established DSC test methods such as ASTM D3418 (transition temperatures and enthalpies by DSC). Users will often combine ISO 18177 results with spectroscopic, chromatographic or rheological characterization standards for a fuller compositional and structural picture.

Keywords

short‑chain branching; SSA; successive self‑nucleation and annealing; DSC; differential scanning calorimetry; ethylene‑1‑olefin copolymers; polyethylene copolymers; ethylene/1‑butene; ethylene/1‑hexene; ethylene/1‑octene; thermal fractionation; crystallinity; polymer characterization.

FAQ

Q: What is this standard?

A: ISO 18177:2025 is an international test method that specifies how to use successive self‑nucleation and annealing (SSA) combined with differential scanning calorimetry (DSC) to estimate the short‑chain branching distribution and related thermal properties of semicrystalline ethylene/1‑olefin copolymers.

Q: What does it cover?

A: It covers instrument suitability (conventional, high‑performance, fast DSC), sample conditioning, SSA protocol design, data processing and reporting for estimation of SCB content, degree of crystallinity and a branching distribution profile—primarily for ethylene/1‑butene, ethylene/1‑hexene and ethylene/1‑octene copolymers.

Q: Who typically uses it?

A: Polymer producers, QA/QC and R&D laboratories, independent testing labs, recyclers and academic researchers who need to characterize comonomer distribution, crystallinity and heterogeneity in polyolefin materials.

Q: Is it current or superseded?

A: ISO 18177:2025 is a current international standard (published May 2025). Users should confirm they hold Edition 1 (2025) and check for any future amendments or corrigenda from their national standards body.

Q: Is it part of a series?

A: The method is complementary to other polymer characterization standards rather than a multi‑part series itself. It is commonly used alongside the ISO 11357 DSC series and other polyolefin standards (for example, melt flow and NMR methods) to provide a broader characterization workflow.

Q: What are the key keywords?

A: Short‑chain branching, SSA, DSC, ethylene 1‑olefin copolymers, thermal fractionation, crystallinity, polymer characterization.