Automotive Application Tech Brief
Material Characterization of Rubber in the Automotive Industry Using Pyrolysis
The following tech brief describes how the Frontier Multi-Shot Pyrolyzer can be used for material characterization of rubber, in order to identify impurities during the manufacturing process.
The automobile manufacturing industry is one of the largest users of rubber products. Tires, dashboards, and floor mats are just a few examples of products and applications that are based on rubber material. Rubber compounding can be a mixture of different types of polymers and additives. There is always a high possibility of impurities contained in the composition of a rubber from and during the compounding and the manufacturing process. As the result, material characterization of compounding rubbers (qualitatively and quantitively) is one of the analytical challenges in many rubber manufacturing and polymer makers laboratories.
In response to these analytical challenges, the Frontier Multi-Shot Pyrolyzer’s “method map” was developed (more information on the “method map” can be found here). The first step when developing the method map using the Frontier Multi-Shot Pyrolyzer is to perform an Evolved Gas Analysis (EGA). This technique provides a clear picture of the sample’s composition by identifying its thermal zones. The EGA thermogram is then used to determine the next step in the evolution of the analytical method map using the Multi-Shot Pyrolyzer which may include thermal desorption, pyrolysis, reactive pyrolysis, or heart cutting.
How can a compounded rubber be analyzed using Pyrolysis GCMS technique, and what information can be obtained?
A compounded rubber was analyzed by the Frontier Multi-Shot Pyrolyzer operating in Evolved Gas Analysis (EGA) mode, 100 to 700 °C at 20 °C/min.
Fig. 1 shows the EGA thermogram of the compounded rubber. Weak peaks are observed in 100 to 300 ºC zone due to the thermal desorption of additives. In the 300 to 500 ºC zone, a broad peak due to thermal decomposition of the rubber is observed. From this result, thermal desorption was performed from 100 to 300 ºC (20ºC/min), and then pyrolysis was done at 550 ºC.
Fig. 2 shows results of the analysis for thermal desorption and pyrolysis. In the chromatogram of the thermal desorption shown in Fig. 2a, cyclic siloxanes (D3 to D6) originated from the silicon coupling agent, benzothiazole (a vulcanization accelerator). A higher molecular weight aliphatic acid (vulcanizing agent), and waxes (antioxidants) were also observed. Because isoprene and limonene were mainly observed in the pyrogram shown in Fig. 2b, the major component of this sample is natural rubber. In fact, using Frontier F-search engine (includes 4 unique libraries for additives, polymers, pyrolyzates, and EGS-MS), the fragments of natural rubber were identified in the pyrolysis chromatogram.
A growing number of laboratories in the automotive industry are integrating pyrolysis into their mainstream analytical protocols due to the advantages and immediate quality improvements this technique provides. The Frontier Multi-Shot Pyrolyzer is one of the most viable and efficient techniques in identifying automobile parts’ composition because it provides the users with a clear picture of the sample’s composition by identifying its thermal zones and the compounds in each zone.
Using the obtained EGA thermogram, one can simply program the Multi-Shot Pyrolyzer with the appropriate temperature and method, such as a single, double, or multiple shots. In fact, the Frontier Multi-Shot Pyrolyzer allows multiple analysis on a single sample. There is no need for solvent and sample preparation as the sample is simply introduced into the GCMS by the Frontier Pyrolyzer.
Want more? Check out other automotive applications using pyrolysis:
Learn more about Frontier Pyrolyzers
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The Rx3050TR Tandem micro-Reactor is a unique system designed for research and development labs that work with catalysts.
Simple but effective pyrolysis for any type of isothermal sample introduction to GC or GC/MS from 40-800ᵒC.
Elegantly designed for qualitative and quantitative analysis with excellent accuracy and precision—guaranteed!