Overview
ISO 4574:2019 specifies a laboratory method to determine the hot plasticizer absorption of PVC resins intended for general use (designation “G” in ISO 1060‑1). The test quantifies how much plasticizer a PVC polymer absorbs when hot‑mixed with a plasticizer (commonly DOP - di(2‑ethylhexyl) phthalate) in a modified planetary mixer and then separated by centrifuging. Results are reported as the hot plasticizer absorption (HPA) at 75 °C and 30 min and the mean rate of plasticizer absorption (RPA).
Key Topics
- Test principle: Condition plasticizer in a jacketed planetary mixer at 75 ± 0.2 °C, add resin, sample the mixture over time (typically from 1 min up to 30 min), remove unabsorbed plasticizer by centrifuging and calculate absorbed amount in parts per hundred resin (p.h.r.).
- Reagent: Di‑(2‑ethylhexyl) phthalate (DOP) is specified as the test plasticizer.
- Apparatus: Jacketed stainless‑steel planetary mixer with beater and rotating wiper, accurate thermostat, thermometer/thermocouple, centrifuge with horizontal rotor, centrifuge tubes with cotton wool plugs, precision balances, aluminium scoop and timing device.
- Sampling & timing: Samples are taken during mixing (to capture the absorption curve) and final HPA is read at 30 min. The standard describes sample handling (cooling, centrifuging) and timing constraints (centrifuging completed within a set time after sampling).
- Calculations: Formulae are provided to convert mass measurements to absorbed plasticizer (p.h.r.). RPA is derived from the initial slope; HPA is the asymptotic value or the ordinate at 30 min.
- Test report requirements: Includes reference to ISO 4574:2019 and specific test conditions and results.
Applications
- Quality control of PVC resin production - verify compatibility with plasticizers for dry blending.
- Formulation development - compare resins and plasticizers by absorption rate and capacity.
- Supplier and acceptance testing - provide reproducible data for purchasing/specification.
- R&D and failure analysis - understand kinetics of plasticizer uptake affecting processing and end‑product properties.
Typical users: PVC resin manufacturers, compounders and converters, independent materials testing laboratories, and product development teams.
Related Standards
- ISO 1060‑1 (designation of PVC types - “G” for general use)
- ISO 4608 (related procedures for plasticizer absorption testing and referenced in ISO 4574)
Keywords: ISO 4574:2019, PVC resins, hot plasticizer absorption, DOP, planetary mixer, HPA, RPA, PVC testing, plasticizer absorption test, ISO 4608.