ASTM D4273-23 PDF
Name in English:
St ASTM D4273-23
Name in Russian:
Ст ASTM D4273-23
Original standard ASTM D4273-23 in PDF full version. Additional info + preview on request
Full title and description
Standard Test Method for Polyurethane Raw Materials: Determination of Primary Hydroxyl Content of Polyether Polyols — a procedure using carbon-13 nuclear magnetic resonance (13C NMR) to quantify the fraction of primary hydroxyl groups in ethylene oxide (EO) / propylene oxide (PO) polyether polyols used for flexible polyurethane foams.
Abstract
This test method (D4273-23) specifies a high‑resolution 13C NMR procedure for measuring primary hydroxyl content in polyether polyols. The method determines the primary hydroxyl percentage from the ratio of the primary‑hydroxyl carbon signal area to the total hydroxyl carbon area and is intended for polyether polyols with primary hydroxyl contents in the approximate range 10–90%.
General information
- Status: Active / Published.
- Publication date: March 1, 2023 (current edition approved March 1, 2023).
- Publisher: ASTM International.
- ICS / categories: Plastics; polyurethane raw materials — ICS 83.080.20.
- Edition / version: D4273-23 (current edition).
- Number of pages: 7 pages.
Scope
This standard covers the use of 13C NMR spectroscopy to measure primary hydroxyl content of EO/PO polyether polyols intended for flexible polyurethane foam production. It is applicable to polyether polyols having primary hydroxyl contents typically between about 10% and 90% and specifies instrument and sample requirements necessary to obtain reproducible primary/secondary hydroxyl peak areas.
Key topics and requirements
- Measurement technique: high‑resolution carbon‑13 NMR (13C NMR) spectroscopy for quantifying primary hydroxyl content.
- Spectrometer capability: carbon‑13 capability with adequate resonance frequency and signal‑to‑noise (examples in related guidance call for carbon‑13 resonance ≈50 MHz or proton ≈200 MHz or higher for reliable spectra).
- Data treatment: integration of primary‑ and secondary‑hydroxyl carbon resonances and calculation of primary hydroxyl percentage from area ratios.
- Applicable range: optimized for polyether polyols with primary hydroxyl contents roughly 10–90%.
- Reporting: primary hydroxyl content reported as a percentage of total hydroxyl groups; values in SI units.
Typical use and users
Used by polyol manufacturers, polyurethane raw material suppliers, contract testing laboratories, and R&D groups for quality control, raw material characterization, and formulation development where knowledge of primary hydroxyl fraction affects reactivity and foam properties. The method provides information useful for predicting relative polyol reactivity with isocyanates in urethane forming reactions.
Related standards
D4273 is part of the suite of ASTM test methods for polyurethane raw materials; the document references ASTM terminology and practices (for example Terminology D883 and Practice E2977) and is published alongside related test methods such as D4274 (hydroxyl number methods) and other D20 committee standards for polyols and isocyanates. Consult the ASTM plastics/urethane standards collection for the full set of related documents.
Keywords
polyether polyol, primary hydroxyl content, 13C NMR, carbon‑13 nuclear magnetic resonance, polyurethane raw materials, flexible foam, D4273-23, ASTM.
FAQ
Q: What is this standard?
A: ASTM D4273-23 is a Standard Test Method that defines a 13C NMR procedure to determine the primary hydroxyl content of ethylene‑oxide/propylene‑oxide polyether polyols used in flexible polyurethane foams.
Q: What does it cover?
A: It covers instrument capability, spectral acquisition and integration, calculation of primary‑hydroxyl percentage from carbon‑13 resonance areas, and applicable concentration range (approximately 10–90% primary hydroxyl).
Q: Who typically uses it?
A: Polyol manufacturers, quality control and R&D laboratories, formulation chemists, and independent testing labs involved in polyurethane raw material characterization.
Q: Is it current or superseded?
A: Current — the edition D4273-23 was approved/published in March 2023 and is the active ASTM edition at time of publication.
Q: Is it part of a series?
A: Yes — it belongs to the ASTM D20 series of standards for plastics/polyurethane raw materials and sits with other polyol/isocyanate test methods (for example D4274 and other D20 committee outputs).
Q: What are the key keywords?
A: Keywords include primary hydroxyl content, polyether polyol, 13C NMR, polyurethane raw materials, flexible foam, and ASTM D4273-23.