PP/POE表面微结构的热压印成型及润湿稳定性

表面微结构赋予高分子材料超疏水性能,但是在实际应用中,微结构易受刮擦破坏,为增强其润湿稳定性,微结构的耐久性亟待提高。采用热压印成型聚丙烯/乙烯-辛烯共聚物(PP/POE)表面微结构,其水接触角(CA)为150. 8°(测试水滴体积为10μL),且随POE含量增加而增加。对PP/POE样品进行浸没测试和摩擦测试,结果表明,PP/POE表面在液面以下150 mm处仍未被浸润,其具有良好的润湿稳定性。由于弹性体POE提高了PP/POE的延展性,因此,当微柱顶面受到砂纸磨粒的剪切作用后被拉长,且不断形成新的微纤维和微沟壑,不仅减少了微柱间隙磨屑的产生,还增加了PP/POE表面的粗糙度,有利于提高润湿性能的稳定性。

Wetting Stability of Microstructured PP/POE Surfaces Molded by Micro-Hot Embossing

Microstructure on surfaces endowed polymer materials with superhydrophobicity.However,the microstructure was destroyed by scratching in practical applications.Therefore,the durability of microstructured surfaces needed to be improved urgently to enhance wetting stability of superhydrophobic materials.Polypropylene/ethylene-octene copolymer(PP/POE)samples with microtopology structure on the surface were prepared by micro-hot embossing technology.The water contact angle(CA)of PP/POE surfaces was 150.8°(the measured droplet volume was 10μL),and the CAs increased with the POE content.Immersion test and abrasion test for PP/POE samples were carried out.The results showed that the microstructured PP/POE surface was still not wetted 150 mm beneath the liquid level and could maintain significant wetting stability.Since the ductility of the PP/POE was improved by the addition of the elastomer POE,the top surface of the microcolumn was sheared and elongated by the abrasive grains on the sandpaper,and new microfibers and microgrooves continuously formed.These not only reduced the generation of wear debris between every two microcolumns,but also increased the roughness of the PP/POE surface,resulted in the improvement of the wetting stability.