Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
D1257-22 – Standard Test Method Technical Guide
This standard specification covers high-gravity glycerin with a minimum purity of 98.7 % by weight. It is intended for use in the manufacture of alkyd resins, synthetic resins, and similar industrial applications. The values stated in SI units are regarded as the standard.
⚠️ Historical Context: The primary test method referenced for this specification, Test Methods for High-Gravity Glycerin (D1258), was withdrawn in 2011. Users must consult the latest ASTM guidelines or alternative validated methods for testing compliance.
📐 Scope and Application
D1257-22 defines the quality benchmarks for high-gravity glycerin. It specifically applies to material containing a minimum of 98.7 % glycerol by weight, primarily used as a chemical intermediate in the production of alkyd and other synthetic resins. The standard outlines critical physical and chemical properties to ensure consistent performance in downstream manufacturing processes.
For the purposes of determining conformance, observed or calculated values must be rounded to the nearest unit in the last right-hand digit of the specification limit, in accordance with ASTM Practice E29.
⚙️ Test Methods and Sampling
Sampling of the material and determination of the properties enumerated in this specification must be conducted in accordance with Test Method D1258. This method covers the procedures for verifying the specific gravity, color, sulfate ash content, and acid value of the glycerin sample. While D1258 has been withdrawn, it remains the definitive reference for the historical context and methodology of this specification.
📊 Specified Properties and Limits
The glycerin must conform to the following rigorous requirements to ensure suitability for high-performance industrial applications:
| 🟦 Property | 📏 Specification Limit | 🎯 Requirement Type |
|---|---|---|
| Apparent Specific Gravity (15.6/15.6 °C) | 1.2620 | Minimum |
| Apparent Specific Gravity (25/25 °C) | 1.2587 | Minimum |
| Color (Pt-Co scale) | 20 | Maximum |
| Sulfate Ash | 0.1 % by weight | Maximum |
| Acid Value | 0.3 mg KOH/g | Maximum |
💡 Key Insight: The 20 Pt-Co color limit ensures the glycerin is exceptionally clear and water-white, which is crucial for applications where the color of the final resin is strictly controlled. The tight acid value limit helps prevent unwanted side reactions during polyester or alkyd resin synthesis.
Packaging requirements for high-gravity glycerin are flexible yet compliance-oriented. The package size must be agreed upon between the purchaser and the supplier. Furthermore, packaging must conform to applicable carrier rules and regulations. When specifically mandated by the contract, packaging shall adhere to the requirements outlined in U.S. Federal Standard PPP-C-2020, which governs the packaging of chemicals.
❓ Frequently Asked Questions
🔍 What is the minimum glycerin content required for high-gravity glycerin per D1257-22?
The standard requires a minimum of 98.7 % glycerin by weight. This minimum is functionally ensured by the stringent Specific Gravity (min 1.2620 at 15.6/15.6 °C) and maximum Sulfate Ash (0.1 %) requirements.
💡 How is the color of high-gravity glycerin evaluated under this standard?
Color is measured using the Platinum-Cobalt (Pt-Co) scale, also known as the Hazen or APHA color scale. The standard specifies a maximum value of 20 Pt-Co units, ensuring a water-white appearance.
⚡ Which test method is used to verify the properties in D1257-22?
The material must be sampled and tested in accordance with Test Method D1258 (Test Methods for High-Gravity Glycerin). Although this standard has been withdrawn, it remains the specified method for this standard.
📌 What packaging specifications apply to D1257-22 glycerin?
Packaging must follow carrier rules and regulations or, when specified, conform to Federal Specification PPP-C-2020. The exact package size is subject to agreement between the purchaser and the supplier.