Phase Morphology, Mechanical and Thermal Properties of Poly (Trimethylene Terephthalate) and Poly (Ethylene Terephthalate) Blends

Abstract

The poly (ethylene terephthalate)/poly (trimethylene terephthalate) (PET/PTT) blends were prepared and their phase morphology, mechanical and thermal properties were investigated by scanning electron microscopy (SEM), polarized optical microscopy (POM), universal material testing machine, differential scanning calorimetry (DSC), wide-angle X-ray (WAXD), respectively. The glass transition and SEM results suggest apparently that the PET and PTT have good miscibility at amorphous state. The blends with more PET content less likely undergo a melting/recrystallization process during DSC heating scan. In the blends, PET component with higher supercooling degree crystallizes first, and then the crystallites of PET will be the nucleating agents for PTT, which greatly improves the crystallization rate of PTT. Because of the interaction between the PET and PTT, there are much smaller spherulites formed in blends with increasing PET component. The blend with more PET contents has larger tensile strength and modulus.