Application of Thermogravimetric Analysis Technology in Rubber Testing

Rubber is a widely used material in various industries, with excellent properties such as high elasticity, viscoelasticity, cushioning and shock absorption, electrical insulation, flexibility, and waterproofing. Mainly used in the automotive industry, construction industry, medical industry, electronics industry, and so on. With the development of technology in the era, the application fields of rubber materials are constantly expanding and innovating. However, in order to explore more applications of rubber, it is necessary to deeply study the thermal characteristics of materials, research the composition and product life of rubber. The commonly used methods for studying the thermal effects of rubber are DSC (differential scanning calorimetry) and TGA (thermogravimetric analysis).

TGA method measurement is a process in which the sample quality continuously changes with the increase of temperature. These changes can provide rich information on material stability and composition, and can detect moisture, ash content, and rubber content in rubber products.

Determine different components in rubber materials using TGA's dynamic isothermal heating method and static isothermal weight loss method. If conducting moisture or volatility testing, static constant temperature weight loss method can be used for quantitative detection, and the specific weight loss situation can be observed by entering the temperature constant temperature at a specified temperature. The dynamic isothermal heating method is a commonly used TGA detection method, which can simultaneously detect other components in rubber, such as resistance or ash content.

　Figure 1-1 Measuring Instruments

　　1、 Rubber research and testing　

TGA can be used to evaluate the weight loss differences of different product batches with different levels of additives. As shown in Figure (2-1), both batches of samples were heated to 350 ° C under the same experimental conditions. Observing the addition of different amounts of additives at a weight loss of 0.5%, it was found that there were significant differences in the temperature points at which the 0.5% weight loss occurred. The difference in the content of different additives is very significant on the TGA curve. TGA detection technology can quickly detect the pass rate of different batches and is a very effective detection method.

　　Figure 2-1 Test spectrum of rubber sample

　2、 Static constant temperature weight loss method for rubber TGA　

If other problems are found with the batch material, static constant temperature weight loss method can be used to detect and observe its condition. For example, when using TGA weight loss technology to determine the content of organic additives in vulcanizing agents, the decomposition temperature of organic additives is relatively close to that of rubber. Through dynamic heating testing, the weight loss peaks will fold each other, making it difficult to analyze the results. But the weight loss state can be clearly observed through static constant temperature weight loss. By controlling the temperature rise through a program to set a temperature range, and then analyzing and processing the TG curve within the temperature range again, a temperature point can be determined at which organic additives will evaporate while rubber will not. By continuously maintaining a constant temperature at this temperature, the TG weight loss curve of additive evaporation can be observed, and the weight loss content of the curve can be analyzed.