ASTM E1131 Compositional Analysis by Thermogravimetry

Get Certified ASTM E1131 Testing for Reliable Compositional Analysis 

Thermogravimetric analysis helps laboratories determine material composition by measuring mass changes during controlled heating. ASTM E1131 provides a standardized approach for determining highly volatile matter, medium volatile matter, combustible material, and ash content using inert and reactive gas environments. For more information about ASTM E1131, consult Matestlab Inc.

The primary purpose of ASTM E1131 is to determine the relative amounts of volatile, combustible, and nonvolatile components in a material. These measurements can support material characterization, quality control, material screening, and material comparison. The scope of ASTM E1131 includes:

• Material type: Solid and liquid materials, including materials such as coal, lubricants, polymers, elastomers, and other materials suitable for thermogravimetric analysis.
• Purpose: Compositional analysis using thermogravimetry.
• Properties measured: Highly volatile matter, medium volatile matter, combustible material, and ash content.
• Method: Controlled thermogravimetric heating under inert and reactive gas environments, with component concentrations determined from measured mass changes.
• Results: Results are reported as the percentage by mass of highly volatile matter, medium volatile matter, combustible material, and ash.
• Applications: Quality control, material screening, compositional analysis, material comparison, and product evaluation. 

What are the Uses of ASTM E1131 Testing?

ASTM E1131 testing helps laboratories determine material composition based on thermogravimetric mass-loss behavior. Thermogravimetric analysis is used in the pharmaceuticals, plastics, and composites industries to determine material composition, thermal stability, and moisture content, providing material reliability under thermal stress. It also ensures that a product is efficacious and nontoxic. The ASTM E1131 standard-

• Supports quality control of materials and products.
• Checks material screening and comparison.
• Evaluates compositional analysis of mixtures and blends.
• Determines volatile, combustible, and ash content.
• Evaluates materials such as coal, coke, lubricants, polymers, elastomers, and calcium oxalate monohydrate.
• Supports material and product problem-solving and performance evaluation.

Which Materials Can Be Tested Under ASTM E1131?

The standard evaluates the parameters of polymers, composites, elastomers, and pharmaceutical compounds. Measurements of weight loss linked to volatile constituents, plasticizers, and additives determine stability and product performance. Composite materials are used in the aerospace and automotive industries to determine filler content, degradation temperatures, and thermal stability. The analyst should consider the material composition and whether its components can be distinguished by their thermogravimetric behavior.

Why is ASTM E1131 Important?

ASTM E1131 is significant as it provides a controlled approach to determine material composition from mass changes during programmed heating. The standard is critical to the quality and reliability of materials used in consumer products and industrial components. Characteristic temperature ranges and mass-loss plateaus determine chemical components. 

ASTM E1131 Testing Process and Data Collection

The analyst selects a representative specimen and determines the compositional components to be evaluated. Technicians record the initial specimen mass and prepare the thermogravimetric apparatus with the specified temperature and gas conditions. The specimen is subsequently heated under an inert atmosphere, with mass changes recorded continuously. After the appropriate mass-loss region, the atmosphere is changed to a reactive gas to determine the combustible material and remaining ash. Finally, analysts assess the thermogravimetric curve, determine the percentage of each component, and report the results.

Common Challenges and Troubleshooting

Problems with the testing are the variability in weight loss due to sample inhomogeneity or humidity. Troubleshooting involves calibration of the thermogravimetric analyzer, sample preparation, test environment control, and proper heating rate.

• The laboratory reports the initial specimen mass and relevant test conditions, including temperature ranges, heating rates, and gas conditions.
• The analyst determines the percentage of highly volatile matter and medium volatile matter from the corresponding mass-loss regions.
• Engineers determine the percentage of combustible material from the mass loss occurring after exposure to the reactive atmosphere. The remaining mass is used to calculate the ash content.
• The report presents the calculated composition values as percentages by mass (wt. %) and may include the thermogravimetric curve used for interpretation.
• A higher value for a particular component indicates a greater proportion of that component under the specified test conditions. 

Link to ASTM E1131