New approach for the measurement of glass transition temperature of polymer

Global thermally stimulated discharge current (TSDC) and partial thermally stimulated discharge current (PTSDC) spectra were recorded to investigate the molecular motions at glass transition temperature (T g ) level in both sided vacuum aluminized 30 μm thick poly (methyl methacrylate) samples. The calculated values of charge released, relaxation time and activation energy correspond to a and β relaxation processes. The TSDC peak occurred at a temperature, which is close to T g of the polymer. This temperature is in agreement with the T g determined using DSC technique.