Thermal Gravimetric Analysis (TGA)
Thermal gravimetric testing of plastics involves heating a sample under controlled atmosphere and heating rates. Most instruments are high precision analytical balances that measure to 0.00001 grams or one hundredth of a milligram. The TGA technique measures weight changes in a material as a function of temperature or time.
What information does thermal gravimetric testing provide?
· Quantify the main composition
· Weight percentage of compounds
· Weight loss
· Degradation temperatures
· Thermal stability
· Residual solvents and VOC
· Moisture analysis
· Reaction temperatures
Most plastics contain oil, wax, additives, plastics, pigment, carbon black, inorganic filler and minerals.
Common areas of interest include:
Determine degradation temperatures
Absorbed moisture content of materials
Level of inorganic and organic components
Oil, wax, plasticizer, oligomer and additive
Decomposition points
Organic Fillers and Polymer Blends
Fibers in Polymers, Plastics, and Composites
Oils in Rubbers, PVC, and Elastomers
Plasticizers and Additives in Plastics
Inorganic Fillers in Plastics
Glass Fibers
Metal Oxides, Titanium Oxide
Inorganic Pigments
Talc, Kaolin, Calcium Carbonate, etc
Residual Solvents in Medical Devices and Pharmaceuticals
Oxidative Stability of Plastics
Chemical Foaming Agent Evaluation and Analysis
Characterization and Failure Analysis of Plastics
Composites, Prepreg, Epoxies, Crosslinked Polymers
ASTM methods for TGA testing of plastics:
ASTM E 1131 Compositional Analysis by Thermogravimetry
Testing procedure details using a thermal gravimetric analyzer to determine the amount of volatile organic compounds (VOC’s) combustible material (oligomer and plastic), and ash content of compounds. This test is used in performing compositional analysis of plastics. The temperature range of this test routine is room temperature to 800°C. This test method uses an inert gas environment and air to oxidize samples.