再生PET非等温结晶动力学研究

he nonisothermal crystallization behaviors of conventional PET, recycled PET from polyester industrial waste yarn (rPET1) and recycled PET from waste polyester melt (rPET2) were investigated by Differential Scanning Calorimetry. The experimental results showed that the Avrami exponents of PET ranged from 2.0 to 2.6, and the ones of rPET1 and rPET2 ranged from 2.4 to 3.03, indicating that the nonisothermal crystallization mechanism for three polymers was the combination of homogeneous and heterogeneous nucleation. However, the influence of heterogeneous nucleation on recycled PET was greater due to more impurities. The crystallization peaks of rPET1 and rPET2 were still obvious at high cooling rate, which suggested the recycled polyester can crystallize at high cooling rate. Compared with conventional PET, half-crystallization time (t1/2) of recycled PET was smaller at the same cooling rate, revealing that their crystallization rates were faster than that of PET.