Łątka Łukasz, Goc Kamil, Kapusta Czesław, Zapotoczny Szczepan
Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Krakow, Poland.
Research and Development Center, Azoty Group S.A., Kwiatkowskiego 8, 33-101 Tarnow, Poland.
Materials (Basel). 2021 Feb 5;14(4):751. doi: 10.3390/ma14040751.
Polyamide-based nanocomposites containing graphene platelets decorated with poly(acrylamide) brushes were prepared and characterized. The brushes were grafted from the surface of graphene oxide (GO), a thermally conductive additive, using atom transfer radical polymerization, which led to the formation of the platelets coated with covalently tethered polymer layers (GO_PAAM), accounting for ca. 31% of the total mass. Polyamide-6 (PA6) nanocomposites containing 1% of GO_PAAM were formed by extrusion followed by injection molding. The thermal conductivity of the nanocomposite was 54% higher than that of PA6 even for such a low content of GO. The result was assigned to strong interfacial interactions between the brushes and PA6 matrix related to hydrogen bonding. Control nanocomposites containing similarly prepared GO decorated with other polymer brushes that are not able to form hydrogen bonds with PA6 revealed no enhancement of the conductivity. Importantly, the nanocomposite containing GO_PAAM also demonstrated larger tensile strength without deteriorating the elongation at break value, which was significantly decreased for the other coated platelets. The proposed approach enhances the interfacial interactions thanks to the covalent tethering of dense polymer brushes on 2D fillers and may be used to improve thermal properties of other polymer-based nanocomposites with simultaneous enhancement of their mechanical properties.
制备并表征了含有用聚（丙烯酰胺）刷修饰的石墨烯片的聚酰胺基纳米复合材料。使用原子转移自由基聚合从导热添加剂氧化石墨烯（GO）的表面接枝这些刷，这导致形成涂覆有共价连接的聚合物层（GO_PAAM）的片材，其占总质量的约31％。通过挤出然后注塑成型形成含有1％GO_PAAM的聚酰胺-6（PA6）纳米复合材料。即使对于如此低含量的GO，纳米复合材料的热导率也比PA6高54％。该结果归因于刷与PA6基体之间与氢键相关的强界面相互作用。含有类似制备的用不能与PA6形成氢键的其他聚合物刷修饰的GO的对照纳米复合材料没有显示出导电性的增强。重要的是，含有GO_PAAM的纳米复合材料还表现出更大的拉伸强度，而不会降低断裂伸长率值，而其他涂覆的片材的断裂伸长率值则显著降低。所提出的方法由于在二维填料上共价连接致密的聚合物刷而增强了界面相互作用，并且可用于改善其他聚合物基纳米复合材料的热性能，同时增强其机械性能。
