Ge Chengbiao, Zhai Wentao, Park Chul B
School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China.
Ningbo Key Lab of Polymer Materials, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China.
Polymers (Basel). 2019 May 10;11(5):847. doi: 10.3390/polym11050847.
The way in which a perforated structure is formed has attracted much interest in the porous membrane research community. This novel structure gives materials an excellent antifouling property as well as a low operating pressure and other benefits. Unfortunately, the current membrane fabrication methods usually involve multi-step processes and the use of organic solvents or additives. Our study is the first to offer a way to prepare perforated membrane by using a physical foaming technique with CO as the blowing agent. We selected thermoplastic polyurethane (TPU) as the base material because it is a biocompatible elastomer with excellent tensility, high abrasion resistance, and good elastic resilience. Various processing parameters, which included the saturation pressure, the foaming temperature, and the membrane thickness, were applied to adjust the TPU membrane's perforated morphology. We proposed a possible formation mechanism of the perforated membrane. The as-prepared TPU membrane had good mechanical properties with a tensile strength of about 5 MPa and an elongation at break above 100%. Such mechanical properties make this novel membrane usable as a self-standing filter device. In addition, its straight-through channel structure can separate particles and meet different separation requirements.
多孔结构的形成方式在多孔膜研究领域引起了广泛关注。这种新颖的结构赋予材料优异的抗污染性能以及低操作压力等优点。不幸的是，目前的膜制备方法通常涉及多步工艺以及有机溶剂或添加剂的使用。我们的研究首次提供了一种以CO作为发泡剂，采用物理发泡技术制备多孔膜的方法。我们选择热塑性聚氨酯（TPU）作为基础材料，因为它是一种具有优异拉伸性、高耐磨性和良好弹性回复性的生物相容性弹性体。通过应用包括饱和压力、发泡温度和膜厚度在内的各种加工参数来调整TPU膜的多孔形态。我们提出了一种多孔膜可能的形成机制。所制备的TPU膜具有良好的力学性能，拉伸强度约为5MPa，断裂伸长率超过100%。这样的力学性能使得这种新型膜可用作自立式过滤装置。此外，其直通通道结构能够分离颗粒并满足不同的分离要求。
