Pyrolysis of poly-methyl methacrylate (PMMA) binder in thermoelectric green tapes made by the tape casting method

The pyrolysis of poly-methyl methacrylate (PMMA) binder in thermoelectric green tapes, are analysed through differential thermal analysis (DTA), thermogravimetric analysis (TGA). These analyses confirmed that the main mechanism of the PMMA binder decomposition is the depolymerization or the unzipping mechanism. The best pyrolysis procedure was found to be in air to a maximum temperature of 410°C with 1.30–2 h hold out time. Some small amount of binder residue was found to remain in tapes after the pyrolysis procedure. This was suspected to be due to an interaction between the thermoelectric powder and the PMMA binder. Despite this small residue, the thermoelectric tape was sintered successfully to almost 95% of its theoretical density, in vacuum at 1200°C after 4 h.