Thermogravimeteric Analyzer Measures weight loss upon heating, cooling, or when held at a constant temperature. The machine is basically a furnace with a microbalancer that is used to characterize materials with regard to their composition.

Procedure 1.Cut out piece of polymer with hole punch and put in aluminum crucible. 2. Place in platinum microbalancer.

Procedure (Continued) 3. Set the computer for rate of heating (10⁰/min). 4. Set computer for type of gas (air for nylon 6,6 and nitrogen for PETE and PP)

Thermal events and processes that can be determined by TGA Absorption/desorption of gases/moisture. Thermal stability. Identification of decomposition products, solvents, solvates. Pseudopolymorphism. VOCABULARY Solvate- an aggregate that consists of a solute ion or molecule with one or more solvent molecules. Pseudopolymorphism- different crystal types are the result of hydration or solvation.

TGA degradation for two different HDPE bottles due to filler material.

Decomposition kinetics- changes in maximum temperature of decomposition due to changes in heating rate.

DSC - Differential Scanning Calorimeter measures temperatures and heat flows associated with thermal transitions in a material Glass Transition Temperature - T g the temperature at which a solid, such as glass or a polymer, becomes brittle (crystalline) on cooling, or soft (amorphous) on heating

Cooling Heating

Cooling Heating

Anthony Condo Ivan Keresztes Ron Kemp Nevjinder Singhota Kevin Dilley Jane Earle Cornell Center for Materials Research National Science Foundation