PET/纳米TiO_2复合材料流变性和力学性能的研究

STUDY ON THE MECHANICAL AND RHEOLOGICAL BEHAVIOR QF PET/NANO-TiO_2 COMPOSITES

通过二步熔融共混法制备了PET/纳米TiO_2复合材料。使用毛细管流变仪、万能材料拉力机、冲击试验仪等研究了复合材料的流变性与力学性能,并借助扫描电子显微镜对其冲击断面形貌进行了观察。发现加入纳米TiO_2粒子明显降低了PET的熔体粘度,并且其流动曲线形状发生了明显改变。在较低和较高剪切速率区,PET/纳米TiO_2体系的粘度随剪切速率的变化趋于平缓;而在中等剪切速率区,其流动行为表现出假塑性流体特性。较低填充量下,纳米TiO_2对基体有一定的增韧增强作用,填充3％时材料的屈服和断裂强度提高了约25％;填充1％时材料的缺口冲击强度提高了约15％。

PET/nano-TiO2 composites were prepared by the surface-modified nano-TiO2 and PET via melt-blending process. The effects of nano-TiO2 on the mechanical and rheological properties were studied with rheometer, tensile tester and impact tester. The fracture morphology of PET and PET/nano-TiO2 composite were observed with SEM. The results showed that under good dispersion condition, incorporation of nano-Tio2 lowered the melt viscosity of the PET and changed the form of flow curves of PET/nano-TiO2 systems obviously. Incorporation of 3% nano-TiO2, the tensile strength of the system was increased by 25% ; Incorporation of 1% nano-TiO2, the Izod impact strengh of the system was increased by 15%.