PTT／纳米CaCO3复合材料流变行为及结晶性能研究

以毛细管流变仪研究了聚对苯二甲酸丙二酯(PTT)/纳米CaCO3复合材料的流变行为,讨论了复合材料的组成、剪切应力和剪切速率及温度对熔体流变行为、熔体黏度的影响,测定了不同配比的复合材料熔体的非牛顿指数 n。结果表明,PTT/纳米CaCO3复合材料熔体为假塑性流体,表观黏度随着剪切速率增加而降低。纳米CaCO3的加入量较少(1％)时,熔体黏度较纯PTT迅速下降;随着纳米CaCO3含量增加(2％-20％),熔体黏度随之上升,但都小于纯PTT的;直到含量为30％时,熔体黏度才超过纯PTT的。差示扫描量热仪测定复合材料的结晶和熔融性能发现,复合材料的熔体结晶温度Tpc和熔融温度Tm较纯PTT、都有所升高,说明纳米CaCO3的加入对PTT的结晶起到了异相成核作用。

Study on Rheological Behavior and Crystallization of FIT/Nano-CaCO3 Composites

The rheology, crystallization and melting behavior of the PTT/nano-CaCO3 composites were investigated using capillary rheometre and differential scanning calorimeter (DSC). The melt of the composites showed a pseudoplastic behavior, with the non-Newtonian index n increasing gradually with increasing content of nano-CaCO3 particles. The viscosity of the melt with 1 wt% loading of nano-CaCO3 decreased promptly compared to that of neat PTT. As the contents of nano-CaCO3 increased from 2 wt% to 20 wt% , the melt viscosity increased gradually, but lower than that of neat PTT. Both the crystallization and melting temperatures Tpc and Tm were higher than that of neat PTT, indicating that nano-CaCO3 acted as a nucleation agent in the composites.