Isothermal crystallization kinetics of tricomponent blends of polycarbonate, poly(trimethylene terephthalate) and polybutylene terephthalate

The isothermal crystallization kinetics of two different types of linear aromatic polyesters, namely poly(trimethylene terephthalate) (PTT), poly(butylene terephthalate) (PBT) and their blend with polycarbonate (PC) has been investigated using differential scanning calorimetry (DSC). The blend composed of PTT25/PBT25/PC50 (wt/wt.%) was synthesized using a twin screw extruder. Isothermal studies for PTT were conducted between 129 and 159 °C. The temperature ranged between 168-177 °C for PBT and between 170 and 183 °C for the blend. Avrami, Tobin and Malkin models were used to estimate the crystallization kinetic parameters, such as crystallization rate order (n), crystallization rate constant (k) and half time of crystallization (t 0.5). The values of average sum of square of errors (ASE) of all models were comparable. This detailed study indicates that the models investigated are suitable for describing the crystallization kinetics of the blend and the neat polymers. © Smithers Rapra Technology, 2010.