Overview
EN ISO 11357-7:2022 - Plastics - Differential scanning calorimetry (DSC) - Part 7: Determination of crystallization kinetics - specifies laboratory methods for studying the crystallization behaviour of partially crystalline plastics using differential scanning calorimetry (DSC). The standard covers two complementary approaches: isothermal and non‑isothermal crystallization measurements. It applies only to molten polymers and is not suitable where the polymer’s molecular structure changes during the test.
Key topics and technical requirements
- Two measurement modes:
- Isothermal crystallization procedures for kinetics at fixed temperature.
- Non‑isothermal crystallization procedures for cooling/rate‑dependent kinetics.
- Apparatus and materials: DSC instrument, crucibles and balance specified as per ISO 11357‑1; verify crucible material does not alter crystallization kinetics.
- Specimen preparation and mass control: Test specimens and conditioning follow ISO 11357‑1; for comparative work maintain specimen mass within ±0.5 mg to avoid self‑heating artifacts.
- Calibration and temperature control: Calibration in heating mode (per ISO 11357‑1) and checks for symmetry of the temperature scale between heating and cooling using suitable low‑undercooling substances.
- Data treatment and results: Relative crystallinity is determined from partial enthalpy vs total enthalpy (ΔH) measured by DSC; the document defines methods for deriving crystallization rate parameters and includes formulae (Annex A) for kinetic analysis.
- Procedure and reporting: Detailed steps for loading crucibles, melting protocol, measurement sequences, precision statements and required test report elements are provided.
Applications and who should use it
- Polymer R&D and material characterization: Determine crystallization rates, nucleation and growth behaviour during formulation and processing development.
- Process optimization and scale‑up: Inform cooling profiles and cycle times in extrusion, injection molding and film casting.
- Quality control and comparative testing: Batch-to-batch monitoring of crystallization behaviour for semi‑crystalline polymers.
- Thermal analysis laboratories and instrument manufacturers: Standardized test methods for DSC method validation, calibration and software algorithm development.
- Regulatory and standards bodies: Reference method within the ISO/CEN framework for thermal property characterization.
Related standards
- ISO 11357‑1 - DSC general principles (calibration, apparatus, specimen handling)
- ISO 11357‑3 - Determination of melting/crystallization temperatures and enthalpies
- ISO 472 - Plastics vocabulary
Keywords: EN ISO 11357‑7:2022, DSC, differential scanning calorimetry, crystallization kinetics, isothermal crystallization, non‑isothermal crystallization, plastics testing, polymer thermal analysis.
