ABSTRACT

Polypropylene/wood flour composites having different nano-ZnO content were fabricated using melt compounding and subsequent injection moulding. The long-term water absorption and thickness swelling of the composites were studied for a range of water immersion times. It was found that the moisture absorption and dimensional stability of the specimens progressively decreased with an increasing nano-ZnO loading. The lowest water diffusion coefficient and swelling rate parameter were observed in the specimens produced with 4 phc nano-ZnO. The mechanism of water transport processes the specimens was proved to follow the kinetics of Fickian diffusion theory. Morphological findings revealed that the void content in the composite decreased by adding nano-ZnO. The hydrophobicity of the specimens reinforced with nano-ZnO improved by creating a tortuous path as a result of its characteristic barrier property. In comparison with the contact angle of untreated samples (71°), adding 4 phc of nano-ZnO increased the contact angle by 34% (95°).

摘要

具有不同纳米 ZnO 含量的聚丙烯/木粉复合材料是使用熔融复合和随后的注塑成型制造的。研究了复合材料在一系列水浸时间下的长期吸水率和厚度膨胀。结果表明，随着纳米 ZnO 负载量的增加，样品的吸湿性和尺寸稳定性逐渐降低。在用 4 phc 纳米 ZnO 制备的样品中观察到最低的水扩散系数和溶胀速率参数。证明了试样的水分输送过程的机理遵循 Fickian 扩散理论的动力学。形态学发现表明，通过添加纳米 ZnO，复合材料中的空隙含量降低。纳米 ZnO 增强的样品的疏水性由于其特有的阻隔性而产生曲折路径而得到改善。与未处理样品的接触角 (71°) 相比，添加 4 phc 的纳米 ZnO 使接触角增加了 34% (95°)。