Overview
EN ISO 11357-4:2021 - "Plastics - Differential scanning calorimetry (DSC) - Part 4: Determination of specific heat capacity" specifies standardized DSC methods to determine the specific heat capacity (cp) of plastics. Approved by CEN in 2021, this third edition supersedes the 2014 version and updates the measurement procedure and reference data for calibration material (commonly α‑alumina). The standard defines test runs, apparatus requirements and calculation principles to obtain reliable cp values for thermal characterization, modelling and quality control.
Key topics and technical requirements
- Scope and principle
- Methods for measuring cp of polymer materials by DSC, avoiding regions of first‑order phase transitions.
- Measurements use three DSC runs at the same scanning rate: blank, calibration and specimen.
- Measurement approaches
- Continuous‑scanning method - single scan baseline adjustment and direct heat‑flow comparison.
- Stepwise‑scanning method - temperature range divided into intervals; integrate heat flow ΔQ over ΔT for each step.
- Calibration
- Calibration material of known cp is required; α‑alumina (≥99.9% purity) is typically used.
- Apparatus and consumables
- DSC instrument per ISO 11357‑1; matching crucibles for sample and calibration material.
- Crucible mass difference shall not exceed 0.1 mg.
- Data processing
- Baseline adjustment, subtraction of blank run, and formulae to calculate cp from heat flow, heating rate and sample mass.
- Guidance on numerical rounding, precision, bias and reporting.
- Specimen preparation & conditions
- Requirements for specimen mass, conditioning and test temperatures are provided to ensure reproducibility.
Applications and users
EN ISO 11357-4:2021 is used where accurate cp data for plastics are needed:
- R&D and materials science - thermal property databases, polymer formulation and phase behaviour studies.
- Product and process engineering - thermal modelling, heat‑transfer calculations, injection‑moulding and extrusion process design.
- Quality control & certification - batch verification, specification compliance and acceptance testing.
- Instrument manufacturers & calibration labs - method validation and calibration services.
Keywords: EN ISO 11357-4:2021, differential scanning calorimetry, specific heat capacity, DSC, plastics cp measurement.
Related standards
- ISO 11357‑1 - DSC general principles (referenced for apparatus and terminology).
- ISO 472 - Plastics vocabulary.
- ISO 80000‑1 - Quantities and units.
- Other parts of the ISO 11357 series address melting, crystallization and thermal transitions relevant to DSC testing.