Overview
ISO 11357-5:2013 - Plastics - Differential scanning calorimetry (DSC) - Part 5 specifies a standardized DSC method for determining characteristic reaction-curve temperatures and times, enthalpy of reaction, and degree of conversion for monomers, prepolymers and polymers (solid or liquid). The method covers materials that may contain fillers and/or initiators and complements the general principles and apparatus requirements given in ISO 11357‑1. It supports both temperature‑scanning and isothermal DSC test modes.
Key topics and technical requirements
- Test scope: Applies to monomers, prepolymers and polymers; filled materials and those containing initiators are acceptable.
- Methods covered:
- Temperature‑scanning method - perform a scan (ambient to a temperature below decomposition) at 5 K/min to 20 K/min; use same scan rate for comparative tests.
- Isothermal method - either hold at constant measurement temperature or heat rapidly from ambient to the measurement temperature; choose measurement temperature based on a scanning trial.
- Characteristic temperatures and times:
- Temperatures: onset, extrapolated onset, temperature of maximum reaction rate (Tmax), extrapolated end, end of reaction.
- Times (isothermal): time to reach equilibrium, onset time, extrapolated onset time, time of maximum reaction rate, end time.
- Enthalpy of reaction (ΔHr): obtained by integrating the reaction peak area above an interpolated/extrapolated baseline (from start to end of reaction).
- Degree of conversion (α): calculated as percent of partial enthalpy to total enthalpy (from a scan or isothermal run) using α = (ΔHpartial / ΔHtotal) × 100.
- Specimen mass: typical mass 5–20 mg (adjust if thermal effect is too large or small).
- Calibration, test specimen conditioning and apparatus: as specified in ISO 11357‑1.
- Safety and precautions: caution for materials that may exhibit runaway reactions; use gas‑tight crucibles for volatile specimens; ensure final scan temperature is below decomposition onset.
Applications and users
Who uses ISO 11357‑5:2013:
- Polymer R&D and formulation scientists studying curing, crosslinking and polymerization.
- Quality control and materials testing laboratories assessing batch consistency and reaction completeness.
- Process engineers optimizing curing profiles and reaction conditions.
- Standards and compliance teams documenting thermal reaction properties for specifications.
Practical applications:
- Quantifying curing enthalpy and degree of conversion for thermosets and adhesives.
- Comparing reactivity of initiators or formulations.
- Determining characteristic reaction temperatures for safe processing limits.
- Supplying kinetic input (reaction extent vs. time/temperature) for process design and simulation.
Related standards
Keywords: ISO 11357-5:2013, differential scanning calorimetry, DSC, plastics, enthalpy of reaction, degree of conversion, isothermal DSC, temperature-scanning DSC, polymer curing, reaction temperatures.