三维石墨烯/聚氨酯复合材料的制备与特性

Preparation and properties of three-dimensional graphene/polyurethane composites

摘要:

以氧化石墨烯(GO)为网络骨架的前驱体，通过水热还原、冷冻干燥制备了石墨烯气凝胶(GA)；再以聚氨酯(PU)为复合材料的填充体，调节PU软硬度与流动性并真空浸渍气凝胶GA，两步法制备出互咬型三维石墨烯/聚氨酯(3DGP)复合材料。利用SEM、Raman、FTIR对GO、GA、3DGP的结构与形貌进行了表征，并采用TGA-DSC和自制压阻测试平台分析热稳定性和压阻特性。结果表明：6 g/L GO水溶液在还原剂乙二胺（EDA）作用下，GO片层间相互连接形成规整蜂窝状三维网络结构，其孔径约0.8 mm，3DGP中PU与GA能很好地咬合；三维网络骨架的连续性为热运输载体声子提供了良好通道，使得3DGP热稳定性能显著提升，失重率5%时温度较PU提升了45 ℃；具有低迟滞性(8.7%)并且在压阻测量区间表现出两种压阻效应。

Abstract:

The preparation of three dimensional graphene/polyurethane (3DGP) composites in cross-bite can be achieved through two steps. To begin with, Graphene aerogel (GA) is prepared by hydrothermal reduction and freeze-drying with graphene oxide (GO) as the precursor of network framework. Secondly, it is necessary to employ polyurethane (PU) as a filler of composite material with adjusted hardness and fluidity to impregnate GA in a vacuum state. The structure and morphology of GO、GA and 3DGP were characterized and analyzed with the help of SEM, Raman and FTIR, as the thermal stability and piezoresistive characteristics are tested by means of TGA-DSC and self-made piezoresistive test platform. The results demonstrate that: the 6 g/L aqueous solution of GO is interconnected with GO layers impacted by the action of EDA reducing agent, which can also form a regular honeycomb three-dimensional network with the pore size about 0.8 mm, as PU and GA can be well occluded in 3DGP. Besides, the continuity of the three-dimensional network skeleton provides a good channel for the phonon of the heat transport carrier, which remarkably enhances the thermal stability of 3DGP and increases by 45 degrees centigrade than that of the PU at the weight loss rate of 5%. Additionally, it has low hysteresis (8.7%) and shows two piezoresistive effects in piezoresistive measurement range.