To carry out a TGA test on post-consumer polymers, begin by selecting a minimal yet indicative portion of the material. Use pure, dehydrated reprocessed plastic bits, ideally micronized into powder to ensure uniform heating. Weigh out approximately 3–12 mg of the sample using a high precision analytical balance and place it in a non-reactive vessel made of alumina or gold, depending on the expected temperature range of your analysis.

Place the crucible into the weight-loss measurement system and close the sample compartment to avoid external interference or volatilization. Link the analyzer with a controlled gas environment, typically nitrogen or argon, to establish oxygen-free conditions that prevents oxidation during heating. If you are studying aerobic decomposition, you may introduce ambient air or O₂ at a later stage, but start with an inert gas for reference profile.

Program the analyzer to heat the sample at a linear heating profile, usually between 3–25 °C, from ambient conditions up to 800 degrees Celsius. The temperature ramp speed affects the precision of degradation events, so lower speeds yield finer resolution but increase analysis time. Record mass change of the sample continuously as temperature increases.

As the polymer thermally breaks down, the analyzer will generate a real-time graph of weight percentage versus temperature. The initial plateau represents the dry sample, followed by sharp drops corresponding to the depolymerization events, plasticizers and fillers, or contaminants. Recycled polymers often contain unreacted precursors, softeners, or curing agents that break down across varied thermal thresholds, so several distinct mass-loss events occur.

After the run ends, analyze the data to locate critical thermal transitions, such as the onset temperature, T_max, and final char yield. Benchmark against those of newly manufactured polymer or تولید کننده کامپاند پلیمری industry benchmarks to quantify material deterioration, contamination, or polymer mixing. A increased ash yield may indicate the incorporation of mineral reinforcements, while reduced decomposition temperature suggests prior degradation events or chemical degradation.

Conduct a baseline run with an reference vessel under the matched protocol to correct for instrumental drift. Perform minimum of three replicates to confirm reliability. Note the provenance, recycling history, and preparation procedures, as these factors significantly influence the results. Thermogravimetric analysis provides a validated approach to determine thermal behavior and constituent content of reclaimed plastics, helping to optimize recycling workflows and ensure product consistency in reprocessing.