Application of Thermogravimetric Analysis in Testing Carbon Black Content and Ash Content

Thermogravimetric analysis is a technique for analyzing the composition and thermal stability of a sample by measuring the mass changes during heating in a controlled atmosphere. This article provides a detailed introduction to the method of using thermogravimetric analysis to test carbon black content and ash content, including experimental principles, operating steps, influencing factors, and result analysis.

　1. Introduction　

As an important additive in rubber and plastic products, the content and properties of carbon black directly affect the quality and performance of the products. Ash content, as an inorganic impurity in carbon black, also needs to be strictly controlled. Traditional testing methods have problems such as cumbersome steps and long time consumption, while thermogravimetric analysis has gradually become an important means of testing carbon black content and ash content due to its advantages of easy operation and accurate results.

　2. Experimental principle　

Thermogravimetric analysis is based on the change in mass of the sample during heating. Carbon black loses its volatile components during heating, while ash remains at high temperatures. By analyzing the thermogravimetric curve, the thermal stability and content of carbon black, as well as the ash content of the sample, can be determined.

　　3. Operation steps　

3.1 Sample Preparation

Accurately weigh a certain amount of carbon black sample and lay it flat in the crucible of the thermogravimetric analyzer.

3.2 Measuring Instruments

DZ-TGA101Thermogravimetric Analyzer

3.3 Equipment parameter setting

Under a nitrogen atmosphere, raise the temperature from room temperature to 600 degrees Celsius at a rate of 20 ℃/min and maintain the constant temperature for 15 minutes to fully pyrolyze the sample; After maintaining a constant temperature of 600 degrees Celsius, switch to an oxygen atmosphere and raise the temperature at a rate of 20 ℃/min to 900 ℃ to fully oxidize the carbon black.

3.4 Testing Process

Start the thermogravimetric analyzer and record the quality changes of the sample.

　　4. Result analysis

　　Figure 1

4.1 Carbon black content (%)

Calculate the thermal weight loss rate of carbon black based on the missing points in the thermogravimetric curve in Figure 1, and calculate the carbon black content according to the thermal weight loss rate.

After being kept at a constant temperature of 600 ℃, the sample lost 17.17mg, and after being heated to 800 ℃, it lost 6.18mg. The total mass of the sample was 23.6 mg. According to the formula, the carbon black content was calculated to be 26.1% (carbon black content calculation formula: (m2-me3)/m1 x 100%)

4.2 Ash content (%)

At high temperatures, after complete oxidation of carbon black, the remaining mass is the ash content.

Calculate the ash content based on the quality of ash content. The ash content is 1.05%. (Ash content calculation formula: (m2-me0) × 100/(m1-m0))

　　5. Conclusion　

Thermogravimetric analysis is a rapid and accurate method for testing carbon black content and ash content. By optimizing testing conditions and analysis methods, reliable test results can be obtained, providing important basis for quality control and product development of carbon black.

　　6. Test reference standards

GB/T 13021-1991 Determination of carbon black content in polyethylene pipes and fittings (thermogravimetric method)

DB35/T 1558-2016 Thermogravimetric Analysis (TGA) Determination of Carbon Black Content in Polyolefin Products