Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) are two techniques commonly used by the CNEP in the study of the thermal properties of polymers.
These techniques provide essential information on the thermal stability, phase transitions, and thermodynamic properties of polymers.
Thermogravimetric Analysis (TGA)
Operation
Thermogravimetric analysis measures the variation in mass of a sample as a function of temperature or time, under a controlled atmosphere. The sample is placed in a thermogravimetric balance and subjected to a gradual increase in temperature. The change in mass is recorded, allowing processes such as decomposition, sublimation, reduction, oxidation, or evaporation of volatile components to be detected.
Applications in the field of polymers
- Thermal stability: TGA helps determine the temperature at which a polymer begins to decompose. This information is crucial for evaluating the thermal stability and processing conditions of polymers.
- Volatile Component Analysis: TGA can be used to measure the content of water or residual solvents in a polymer.
- Study of degradation mechanisms: By analyzing thermogravimetric curves, it is possible to deduce the thermal degradation mechanisms of polymers and identify the decomposition products.
- Quality control: ATG is used to compare batches of polymers and verify their compliance with purity and composition specifications.
Differential Scanning Calorimetry (DSC)
Operation
Differential scanning calorimetry measures the difference in heat flow between a sample and a reference as a function of temperature or time. A sample and an inert reference are subjected to an identically controlled temperature program. Differences in heat flow between the sample and the reference are recorded, allowing thermal transitions such as glass transitions, meltings, crystallizations and exothermic or endothermic reactions to be identified.
Applications in the field of polymers
- Glass transition (Tg): DSC can determine the glass transition temperature of a polymer, a key property that affects the flexibility and mechanical performance of the material at different temperatures.
- Melting and crystallization: DSC measures the melting and crystallization temperatures and enthalpies of semi-crystalline polymers, providing information about their structure and degree of crystallinity.
- Thermal reactions: DSC can detect and quantify exothermic and endothermic reactions, such as curing reactions of thermosetting resins.
- Compatibility and Miscibility: By analyzing the DSC curves of polymer blends, it is possible to study the compatibility and miscibility of the components, which is crucial for the development of new composite materials.
Comparison and complementarity
ATG and DSC are complementary in the analysis of polymers. While ATG focuses on mass changes associated with thermal processes, DSC measures heat fluxes related to thermal transitions. By combining data from both techniques, it is possible to obtain a comprehensive understanding of the thermal behavior and stability of polymers, which is essential for their development, optimization and industrial application.
In conclusion, TGA and DSC are essential tools for the analysis of the thermal properties of polymers, making it possible to characterize their thermal stability, their phase transitions, and their thermodynamic behaviors, and thus to guide their design and their use in various industrial applications.
