成核剂对聚对苯二甲酸乙二醇酯的结晶行为影响

在HAAKE转矩流变仪中进行了聚对苯二甲酸乙二醇酯(PET)和不同类型成核剂的熔融共混,采用差示扫描量热仪(DSC)研究了不同粘度纯PET、纯PBT及添加小分子成核剂、高分子成核剂、复合成核剂的PET非等温结晶过程。通过红外光谱(FTIR)、热台偏光显微镜(POM)和扫描电镜(SEM)对添加成核剂前后PET的结晶形貌进行对比分析。结果表明低粘度PET的结晶能力较中粘度和高粘度的PET结晶能力强,添加成核剂后PET的结晶峰温移向高温、半结晶时间缩短、结晶速率常数增大。其中高分子成核剂、复合成核剂对PET结晶行为改善效果更好,其成核机理为化学成核,但高分子成核剂不会造成PET分子链的降解。

Influence of Nucleation Agents on the Crystallization Behavior of PET

PET and nucleation agents of various types were blended in a HAAKE rheometer.The non-isothermal crystallization behavior of polyethylene-terethalate(PET) of different intrinsic viscosities,pure polybutylene-terethalate(PBT),PET added with small molecule nucleation agents,high molecular nucleation agents and multiplex nucleation agents were studied by using diffential scanning calorimeter(DSC).The morphology of PET and PET added with nucleation agents were compared by using Fourier transformation infared spectroscopy(FTIR)、polarization microscope HAAKE rheometer(POM) and scan electron microscopy(SEM).The study indicates PET of low intrinsic viscosity has a better crystallization behavior than that of middle intrinsic viscosity and high intrinsic viscosity.Added with nucleation agents,the PET has the following changes: crystalization peak temperature becomes higher;the half crystallization time is shorter;the constant crystalization rate increases.Macromolecule nucleation agents and multiplex necleation agents improve PET crystallization behavior greatly,and their nucleation mechanism is chemical nucleation,but macromolecule necleation agents don′t cause the degradation of PET chains.