Gegenhuber Thomas, Krekhova Marina, Schöbel Judith, Gröschel André H, Schmalz Holger
Makromolekulare Chemie II, Universität Bayreuth, 95440 Bayreuth, Germany.
Department of Applied Physics, Aalto University School of Science, 00076 Aalto, Finland.
ACS Macro Lett. 2016 Mar 15;5(3):306-310. doi: 10.1021/acsmacrolett.6b00033. Epub 2016 Feb 11.
Surface-modified carbon nanotubes (CNTs) have become well-established filler materials for polymer nanocomposites. However, in immiscible polymer blends, the CNT-coating is selective toward the more compatible phase, which suppresses their homogeneous distribution and limits harnessing the full potential of the filler. In this study, we show that multiwalled CNTs with a patchy polystyrene/poly(methyl methacrylate) (PS/PMMA) corona disperse equally well in both phases of an incompatible PS/PMMA polymer blend. Unlike polymer-grafted CNTs with a uniform corona, the patchy CNTs are able to adjust their corona structure to the blend phases by selective swelling/collapse of respective miscible/immiscible surface patches. Importantly, the high interfacial activity of patchy CNTs further causes a significant decrease in PMMA droplet size with increasing filler content. The combined effect of compatibilization and homogeneous distribution makes patchy CNTs interesting materials for polymer blend nanocomposites, where next to the compatibilization, a homogeneous filler distribution is important to gain the desired materials property (e.g., reinforcement).
表面改性的碳纳米管（CNTs）已成为聚合物纳米复合材料中成熟的填充材料。然而，在不相容的聚合物共混物中，碳纳米管涂层对相容性更好的相具有选择性，这会抑制它们的均匀分布，并限制了填料全部潜力的发挥。在本研究中，我们表明，具有聚苯乙烯/聚甲基丙烯酸甲酯（PS/PMMA）斑块状电晕的多壁碳纳米管在不相容的PS/PMMA聚合物共混物的两相中分散得同样良好。与具有均匀电晕的聚合物接枝碳纳米管不同，斑块状碳纳米管能够通过各自可混溶/不可混溶表面斑块的选择性溶胀/塌陷来调整其电晕结构以适应共混相。重要的是，斑块状碳纳米管的高界面活性随着填料含量的增加还会导致PMMA液滴尺寸显著减小。增容和均匀分布的综合作用使斑块状碳纳米管成为聚合物共混纳米复合材料的有趣材料，其中除了增容之外，均匀的填料分布对于获得所需的材料性能（例如增强）也很重要。
