Materials Research and Technology Department, Luxembourg Institute of Science and Technology , 41, rue du Brill, L-4422 Belvaux, Luxembourg.
Université de Toulouse , UPS, INP, LAPLACE (Laboratoire Plasma et Conversion d'Energie), 118 route de Narbonne, F-31062 Toulouse, France.
ACS Appl Mater Interfaces. 2016 May 18;8(19):12422-33. doi: 10.1021/acsami.6b01819. Epub 2016 May 9.
An innovative approach to produce high-performance and halogen-free flame-retardant thin films at atmospheric pressure is reported. PDMS-based coatings with embedded dopant-rich polyphosphates are elaborated thanks to a straightforward approach, using an atmospheric pressure dielectric barrier discharge (AP-DBD). Deposition conditions have been tailored to elaborate various thin films that can match the fire performance requirements. Morphology, chemical composition, and structure are investigated, and results show that the coatings performances are increased by taking advantage of the synergistic effect of P and Si flame retardant compounds. More specifically, this study relates the possibility to obtain flame retardant properties on PolyCarbonate and PolyAmide-6 thanks to their covering by a 5 μm thick coating, i.e. very thin films for this field of application, yet quite substantial for plasma processes. Hence, this approach enables deposition of flame retardant coatings onto different polymer substrates, providing a versatile fireproofing solution for different natures of polymer substrates. The presence of an expanded charred layer at the surface acts as a protective barrier limiting heat and mass transfer. This latter retains and consumes a part of the PC or PA-6 degradation byproducts and then minimizes the released flammable gases. It may also insulate the substrate from the flame and limit mass transfers of remaining volatile gases. Moreover, reactions in the condensed phase have also been highlighted despite the relatively thin thickness of the deposited layers. As a result of these phenomena, excellent performances are obtained, illustrated by a decrease of the peak of the heat release rate (pHRR) and an increase of the time to ignition (TTI).
本文报道了一种在常压下制备高性能、无卤阻燃薄膜的创新方法。通过一种简单的方法，利用常压介质阻挡放电（AP-DBD），制备了具有嵌入式富掺杂多磷酸盐掺杂剂的 PDMS 基涂层。沉积条件经过精心调整，以制备各种能够满足防火性能要求的薄膜。对形貌、化学成分和结构进行了研究，结果表明，利用 P 和 Si 阻燃化合物的协同效应可以提高涂层性能。具体来说，本研究证明了通过在聚碳酸酯和聚酰胺-6 上覆盖 5μm 厚的涂层来获得阻燃性能的可能性，即对于该应用领域来说非常薄的薄膜，但对于等离子体工艺来说相当厚。因此，这种方法能够在不同的聚合物基底上沉积阻燃涂层，为不同性质的聚合物基底提供了一种通用的防火解决方案。表面膨胀的炭化层作为一种保护屏障，限制了热量和质量的传递。后者保留并消耗了一部分 PC 或 PA-6 降解副产物，并最大限度地减少了释放的可燃气体。它还可以使基底与火焰隔离，并限制剩余挥发性气体的质量传递。此外，尽管沉积层的厚度相对较薄，但在凝聚相中也发生了反应。由于这些现象的存在，获得了优异的性能，表现为放热率峰值（pHRR）的降低和点火时间（TTI）的增加。
