Sandoz-Rosado Emil, Beaudet Todd D, Andzelm Jan W, Wetzel Eric D
U.S. Army Research Laboratory, Aberdeen Proving Ground, MD, 21005, United States.
Sci Rep. 2018 Feb 27;8(1):3708. doi: 10.1038/s41598-018-22011-7.
The linear polymer poly(p-phenylene terephthalamide), better known by its tradename Kevlar, is an icon of modern materials science due to its remarkable strength, stiffness, and environmental resistance. Here, we propose a new two-dimensional (2D) polymer, "graphamid", that closely resembles Kevlar in chemical structure, but is mechanically advantaged by virtue of its 2D structure. Using atomistic calculations, we show that graphamid comprises covalently-bonded sheets bridged by a high population of strong intermolecular hydrogen bonds. Molecular and micromechanical calculations predict that these strong intermolecular interactions allow stiff, high strength (6-8 GPa), and tough films from ensembles of finite graphamid molecules. In contrast, traditional 2D materials like graphene have weak intermolecular interactions, leading to ensembles of low strength (0.1-0.5 GPa) and brittle fracture behavior. These results suggest that hydrogen-bonded 2D polymers like graphamid would be transformative in enabling scalable, lightweight, high performance polymer films of unprecedented mechanical performance.
线性聚合物聚对苯二甲酰对苯二胺，其商品名凯夫拉尔更为人熟知，因其卓越的强度、刚度和耐环境性而成为现代材料科学的一个标志。在此，我们提出一种新型二维（2D）聚合物“石墨酰胺”，其化学结构与凯夫拉尔极为相似，但因其二维结构而具有机械优势。通过原子计算，我们表明石墨酰胺由大量强分子间氢键桥接的共价键合片层组成。分子和微观力学计算预测，这些强分子间相互作用使得由有限数量的石墨酰胺分子组成的薄膜具有刚性、高强度（6 - 8吉帕）和韧性。相比之下，像石墨烯这样的传统二维材料分子间相互作用较弱，导致其强度较低（0.1 - 0.5吉帕）且具有脆性断裂行为。这些结果表明，像石墨酰胺这样的氢键二维聚合物在实现具有前所未有的机械性能的可扩展、轻质、高性能聚合物薄膜方面将具有变革性。
