共混型PVDF/TPU复合材料的制备与性能研究

Preparation and Properties of Blended PVDF/TPU Composites

为了改善热塑性聚氨酯(TPU)的力学性能及形状记忆性能,采用聚偏氟乙烯(PVDF)为共混改性剂,并经熔融共混法制备了不同PVDF含量的PVDF/TPU复合材料。采用傅里叶红外光谱分析、X射线衍射、扫描电子显微镜、拉伸和形状记忆测试等表征了所得复合材料的微观结构及性能。结果表明,PVDF与TPU间通过氢键形成了强相互作用。PVDF的加入促进了TPU的结晶。与纯TPU相比,PVDF/TPU复合材料的定伸应力升高。加入PVDF后,PVDF/TPU复合材料的形状固定率升高,形状回复率降低。综合拉伸和形状记忆测试结果,当PVDF的质量分数为5%时,PVDF/TPU复合材料的性能最佳。

In order to improve the mechanical and shape memory properties of thermoplastic polyurethane （TPU）, polyvinylidene fluoride （PVDF） was used as the modifier of TPU and PVDF/TPU composites with different PVDF contents were fabricated through melt blending method. The prepared PVDF/TPU composites were systematically characterized by Fourier transform infrared spectroscopy （FTIR）, X-ray diffraction （XRD）, scanning electron microscope （SEM）, tensile tests and shape memory tests. The experimental results show that there is a strong interaction between PVDF and TPU by the formation of hydrogen bond. The addition of PVDF promotes the crystallization behavior of TPU. The stress at definite elongation of PVDF/TPU composites increases compared with pure TPU. After adding PVDF, the shape fixed rate of PVDF/TPU composites is improved, but the shape recovered rate of PVDF/TPU composites decreases. In summary, PVDF/TPU composites show the best performance when 5wt% PVDF is incorporated into TPU matrix.