Overview
EN ISO 8985:2022 (ISO 8985:2022, corrected version 2022-08) defines standardized methods for the determination of vinyl acetate (VAC) content in ethylene/vinyl acetate (EVAC) thermoplastics. Published by CEN/ISO, this standard divides analytical approaches into reference methods and test methods. Reference methods are used to calibrate other (test) methods; calibrated test methods may be used for routine analysis provided they meet specified repeatability criteria. The standard supports material designation per ISO 21301-1 and supersedes earlier editions.
Key Topics
- Scope and purpose: Procedures to quantify vinyl acetate content (VAC) in EVAC copolymers for classification and quality control.
- Two method categories:
- Reference methods (Clause 4): used to produce calibration data. Examples listed include:
- Hydrolysis and back titration
- Saponification and potentiometric titration
- Measurement of oxygen (method for oxygen-related determination)
- Test methods (Clause 5 and examples): alternative analytical techniques that must be calibrated against a reference method and demonstrate permissible repeatability. Examples include:
- Infrared (IR) spectrometry
- Acidimetric and iodometric titration methods
- Thermogravimetric analysis (TGA)
- Calibration and repeatability: Test methods require calibration with a reference method (see Clause 4) and validation against repeatability limits before use for official designation or QC.
- Reporting requirements: The standard specifies how results and method details should be reported (test report content).
Applications
- Quality control in EVAC production: monitor VAC content for consistency in polymer properties (flexibility, adhesion, thermal behavior).
- Incoming material inspection: verify supplier specifications of vinyl acetate content for raw EVAC resins and compounds.
- Product certification and material designation: determine VAC for classification according to ISO 21301-1 and for regulatory or customer specifications.
- R&D and formulation: support formulation development, property tuning and troubleshooting where VAC content affects performance.
- Third‑party testing laboratories: implement standardized procedures for traceable VAC quantification in laboratory test reports.
Who should use this standard
- Polymer manufacturers and compounders working with EVAC
- QC chemists and analytical laboratories
- Materials engineers and product designers requiring composition data
- Certification bodies and standards committees
Related standards
- ISO 21301-1 - Material designation and classification of EVAC copolymers (referenced for designation based on VAC content).
Keywords: EN ISO 8985, ISO 8985:2022, EVAC, ethylene vinyl acetate, vinyl acetate content, vinyl acetate (VAC) determination, reference methods, test methods, IR spectrometry, thermogravimetry.
