Zavada Scott R, McHardy Nicholas R, Gordon Keith L, Scott Timothy F
Advanced Materials and Processing Branch, NASA Langley Research Center, Hampton, Virginia 23681, United States.
ACS Macro Lett. 2015 Aug 18;4(8):819-824. doi: 10.1021/acsmacrolett.5b00315. Epub 2015 Jul 27.
Autonomously healing materials that utilize thiol-ene polymerization initiated by an environmentally borne reaction stimulus are demonstrated by puncturing trilayered panels, fabricated by sandwiching thiol-ene-trialkylborane resin formulations between solid polymer panels, with high velocity projectiles; as the reactive liquid layer flows into the entrance hole, contact with atmospheric oxygen initiates polymerization, converting the liquid into a solid plug. Using infrared spectroscopy, we find that formulated resins polymerize rapidly, forming a solid polymer within seconds of atmospheric contact. During high-velocity ballistics experiments, additional evidence for rapid polymerization is provided by high-speed video, demonstrating the immediate viscosity increase when the thiol-ene-trialkylborane resins contact atmospheric oxygen, and thermal imaging, where surface temperature measurements reveal the thiol-ene reaction exotherm, confirming polymerization begins immediately upon oxygen exposure. While other approaches for materials self-repair have utilized similar liquid-to-solid transitions, our approach permits the development of materials capable of sealing a breach within seconds, far faster than previously described methods.
通过用高速射弹刺穿由在固体聚合物面板之间夹入硫醇-烯-三烷基硼烷树脂配方制成的三层面板，展示了利用环境反应刺激引发的硫醇-烯聚合的自主修复材料；当反应性液体层流入入口孔时，与大气中的氧气接触引发聚合反应，将液体转化为固体塞。通过红外光谱，我们发现配制的树脂迅速聚合，在与大气接触的几秒钟内形成固体聚合物。在高速弹道实验中，高速视频提供了快速聚合的额外证据，证明硫醇-烯-三烷基硼烷树脂与大气中的氧气接触时粘度立即增加，热成像显示表面温度测量揭示了硫醇-烯反应放热，证实聚合反应在接触氧气后立即开始。虽然其他材料自修复方法也利用了类似的液-固转变，但我们的方法允许开发能够在几秒钟内密封裂缝的材料，比先前描述的方法快得多。
