The application brief presents the use of the new PerkinElmer Pyris TGA 9 thermogravimetric analyzer in determining the composition of an unknown polymer sample. Thermogravimetric analysis (TGA) tracks the mass change of the sample under controlled heating, identifying the weight loss due to bound water, polymer degradation, decarboxylation of calcium carbonate, and combustion of carbon. The analysis provided detailed insights, including the percentage of water, polymer, calcium carbonate, and carbon in the sample, enabling a comprehensive understanding of its composition. The study underscores the TGA 9's utility in analyzing complex materials, facilitated by PerkinElmer's Pyris software for precise calculations of mass losses, enhancing materials research efficiency.