Overview
ISO 3673-2:2012 specifies methods for the preparation of test specimens and determination of properties of crosslinked epoxy resins. The standard is focused on cast, unfilled epoxy plates used to obtain the intrinsic properties of thermoset epoxy polymers. It does not cover non‑crosslinked (liquid) epoxy resins (see ISO 18280). Test selection and result presentation draw on the general test methods in ISO 10350‑1:2007 to ensure reproducible and comparable data.
Key topics and requirements
- Scope: Applies only to crosslinked (cured) epoxy resins; excludes non‑crosslinked resins.
- Specimen preparation: Cut test specimens from cast plates (recommended thicknesses: 2 mm, 3 mm or 4 mm) produced by a casting process using unfilled resin to measure intrinsic properties.
- Apparatus and materials: Two glass or polished stainless steel plates (~300 × 350 mm, 6 mm thick), spacers (2/3/4 mm), silicone/latex seal, clamps, vacuum dessicator or centrifuge for degassing, mixing tools, laboratory oven.
- Typical curing guidance (example): when using methyl tetrahydrophthalic anhydride and amine accelerators, a post‑cure such as 2 h at 100 °C followed by 15 h at 150 °C is shown as an illustrative cure schedule (manufacturer recommendations may differ).
- Degassing and handling: Remove entrapped air by centrifugation or vacuum; maintain assemblies vertical during cure.
- Conditioning: Unless otherwise specified, condition specimens ≥16 h at 23 °C ± 2 °C and 50 % ± 5 % RH before testing.
- Testing environment and presentation: Most tests performed at 23 °C ± 2 °C and 50 % ± 5 % RH; presentation of intrinsic data follows ISO 10350‑1.
Technical properties covered
ISO 3673-2 cross‑references specific test methods for a broad set of properties, including:
- Rheological / molding shrinkage (ISO 2577)
- Mechanical: tensile (ISO 527‑2), flexural and flexural modulus (ISO 178), Charpy impact (ISO 179)
- Thermal: glass transition (DSC, ISO 11357‑2), heat deflection temperature (ISO 75‑2), coefficient of linear thermal expansion (ISO 11359‑2)
- Flammability: IEC/IEC‑type flame tests (IEC 60695 series), limiting oxygen index (ISO 4589‑2)
- Electrical: permittivity, dissipation factor (IEC 60250), resistivity (IEC 60093), dielectric strength (IEC 60243‑1), comparative tracking index (IEC 60112)
- Water absorption (ISO 62)
Applications and users
- Material characterization for R&D, formulation development and comparison of epoxy chemistries
- Quality control and QA/QC laboratories validating cured epoxy batches
- Specification writers, procurement and compliance engineers requiring intrinsic property data for selection and material datasheets
- Test laboratories performing standardized mechanical, thermal, electrical and flammability testing of cured epoxy systems
Related standards
Keywords: ISO 3673‑2, epoxy resins, crosslinked epoxy, test specimens, specimen preparation, material properties, epoxy testing, ISO standards.