Crystallization Behavior And Crystallization Kinetics In PTT And PTT/PBT Blends

Poly (trimethylene terephthalateis) a new kind of polyester, which will be widely used in textile, engineering plastics, films etc. for its special structure and excellent physical-chemical property. PTT is expensive. PBT exhibits fast crystallization rate and good chemical stability. If PTT is blended with PBT, it will certainly affect phase morphology and the thermal behavior. The crystallization behavior and crystallization kinetics of these polyesters was studied by POM, XRD and DSC. It will reduce the costs and improve performance. It is of interest to study this for academic studies and practical applications.Spherulite radius of PTT increased with crystallization temperature crystallization and half-time of PTT reduced with cooling rate when PTT crystallized at temperature range of145-170℃. The crystallization process is dominated by nucleation and higher temperature will help to obtain a more perfect crystal. PTT-rich blends (WPBT≤40%) isothermally crystallize to form ring-banded spherulite. The spacing of ring-bands decreases with increasing crystallization temperature.There will be great difference in crystalline growth velocity among crystallized polyers for their structure of molecule and crystallizing conditions. We took the further study on crystallization property of PTT and PBT by kinetics method. The non-isothermal crystallization date of PTT and PBT was investigated by Jeziomy method, Ozawa method and Mo method. The non-isothermal rate crystallization kinetics behavior of PTT agrees with the Jeziorny equation. The Jeziorny value of PTT is4and PBT is2.62. The nucleation of PTT and PBT is different. PTT is homogeneous and PBT is heterogeneous.