It is still a challenge to fabricate polymer composites with superior gas barrier properties, which is highly demanded in aircraft tire lining with a high gas pressure (1.5 MPa). Herein, a versatile method to fabricate polymer composites with a dense dual network structure via ball-milling was developed. In such a structure, the graphite was in-situ exfoliated to edge-selectively carboxylated graphene (ECG) nanosheets, which were first embedded into ternary copolymerized polyamide (PA) particles to construct an inner well-dispersed network. Subsequently, ECG nanosheets were selectively distributed at the interfaces between resultant particles of PA composites to form an external interconnected network. It was found that the dense dual network of ECG prolongs the pathways for diffusing gas molecules, compared with the pristine PA, up to a 20-fold decrease in nitrogen permeability of ultimate PA composites (from 0.233 × 10⁻¹⁷ to 0.0113 × 10⁻¹⁷ m² S⁻¹ Pa⁻¹) were obtained with only 2 wt% ECG nanosheets. The excellent gas barrier properties were ascribed to the synergistic effect of the dual network. This work provides an efficient, scalable, low-cost and eco-friendly route to fabricate high-barrier polymer composites.

制造具有优异气体阻隔性能的聚合物复合材料仍然是一个挑战，这在具有高气压（1.5 MPa）的飞机轮胎衬里中非常需要。在此，开发了一种通过球磨制造具有致密双网络结构的聚合物复合材料的通用方法。在这种结构中，石墨被原位剥离成边缘选择性羧化石墨烯（ECG）纳米片，首先将其嵌入三元共聚聚酰胺（PA）颗粒中以构建内部良好分散的网络。随后，心电图纳米片选择性地分布在 PA 复合材料的所得颗粒之间的界面上，以形成外部互连网络。结果发现，与原始 PA 相比，ECG 的密集双网络延长了气体分子扩散的途径，^-17到 0.0113 × 10 ^-17  m ²  S ^-1  Pa ^-1 ) 仅用 2 wt% 的 ECG 纳米片获得。优异的气体阻隔性能归因于双网络的协同作用。这项工作为制造高阻隔聚合物复合材料提供了一种高效、可扩展、低成本和环保的途径。