How to Conduct Thermogravimetric Analysis on Recycled Polymers

To conduct a thermogravimetric analysis on post-consumer polymers, begin by preparing a small, representative sample of the material. Use clean, dry recycled polymer fragments, ideally micronized into powder to ensure uniform heating. Measure approximately 5 to 10 milligrams of the sample using a high precision analytical balance and load into a non-reactive vessel made of ceramic or platinum, اکسیر پلیمر depending on the maximum operating temperature of your analysis.

Load the vessel into the TGA instrument and secure the lid to eliminate environmental exposure. Link the analyzer with a controlled gas environment, typically ultra-pure inert gas, to establish oxygen-free conditions that minimizes unwanted chemical reactions. If you are studying aerobic decomposition, you may transition to oxidizing gas at a post-inert phase, but start with an inert gas for control measurements.

Configure the system for heat the sample at a linear heating profile, usually between min, from room temperature up to 850°C. The thermal gradient affects the precision of degradation events, so slower rates provide more detailed information but take longer. Record mass change of the sample continuously as temperature increases.

As the polymer undergoes pyrolysis, the analyzer will produce a dynamic curve of relative mass vs. kelvin. The pre-decomposition phase represents the moisture-free material, followed by sudden declines corresponding to the chain scission processes, plasticizers and fillers, or impurities. Recycled polymers often contain unreacted precursors, softeners, or curing agents that degrade at different temperatures, so multiple weight loss steps are common.

After the run finishes, analyze the data to identify key decomposition temperatures, such as the onset temperature, peak decomposition temperature, and final char yield. Compare these values with those of virgin polymer or industry benchmarks to quantify material deterioration, foreign substance presence, or blending with other polymers. A elevated char content may indicate the addition of calcium carbonate, glass fibers, or talc, while reduced decomposition temperature suggests prior heating cycles or chemical degradation.

Always run a blank analysis with an null sample under the identical parameters to correct for instrumental drift. Repeat the test with at least three samples to validate consistency. Record the origin, processing background, and preparation procedures, as these factors profoundly affect outcomes. This method delivers a validated approach to evaluate the thermal stability and composition of reclaimed plastics, helping to inform downstream processing and ensure product consistency in reprocessing.