Carbon black acts as a reinforcing agent, enhancing properties of rubber products such as tensile strength, tear strength, and abrasion resistance. The loading level, particle size, and structure (shape) of the carbon black incorporated into the compound all influence the physical properties of the final product.

Using a thermobalance (thermal balance), only a few milligrams of sample are required, and the carbon black content can be determined in approximately 20 minutes.

The rubber is heated in a nitrogen atmosphere to around 600°C, at which point organic components other than carbon black decompose. After the decomposition of organics, oxygen is introduced to burn off the carbon black. The carbon black content is then determined based on the weight loss recorded in the TG curve.

This method can also be applied to determine the carbon black content in other polymeric materials. The error for parallel tests using this method is typically around 2%.

In this project at Qingdao University of Technology, a TGA-1150 thermogravimetric analyzer was used for on-site sample testing. The data is shown in the figure below:

As shown in the figure, the instrument demonstrates excellent repeatability! The three curves from the measurements almost perfectly overlap!