The determination of catalytic activity of various metallic compounds in the polycondensation of bis(hydroxyethyl)terephthalate using DSC and TG techniques

The catalytic activities of various metal compounds in the polycondensation of bis(hydroxethyl)terephthalate to poly(ethyleneterephthalate) have been investigated by thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). The peak maximum of the reaction peak in the DSC test (Tmax in °C) gave values which corresponded well with the temperature at which the initial mass loss was observed in thermogravimetric analysis experiments (T0 in °C). A comparison of Tmax and T0 at a fixed concentration with conventional methods shows good agreement. The order of catalytic activity obtained using both techniques is: ZnAc > SnO(But)2 > Sb2O3, KTiOx > Gegly. The effect of the concentration of various catalysts on the polycondensation of BHET has also been investigated. These observations agree with data obtained by conventional methods but the techniques used here are judged to be more convenient.