This paper aims at developing an innovative approach to characterize the char residue of an intumescent coating obtained after a UL1709 furnace test. The intumescent formulation is based on an epoxy resin and contains numerous additives including zinc borate, ammonium polyphosphate and silicate fibers. The purpose is to characterize the numerous reactions that can occur upon burning using crossed methods including Electron Probe Micro-Analysis (EPMA), X-ray diffraction (XRD) and 1D/2D solid state Nuclear Magnetic Resonance (NMR). In particular, it emphasizes the potential of the advanced NMR technique namely two-dimensional Dipolar Heteronuclear Multiple Quantum Correlation (2D D-HMQC) NMR. As a result, EPMA evidenced that B/P and B/Si are located in the same domain suggesting the formation of boron-phosphorus and/or boron-silicone containing compounds on the sample surface. H₃BO₃ was identified by XRD as a main crystalline specie, additional species (e.g. SiO₂, Zn₄O(BO₂)₆) were also identified. The borate, silicate and phosphate chemical species were then characterized using 1D NMR but no definitive assignments could be given. To specify those assignments, 2D D-HMQC NMR was performed and the formation of amorphous borophosphates and borosilicates was evidenced emphasizing the chemical reactivity between the ingredients of the formulation. It was suggested that these species allow reinforcing the char and improving the fire protective properties of the coatings. This work highlights the particular interest of advanced NMR technique, which provides unique information on the characterization of intumescent char.

本文旨在开发一种创新方法，以表征在UL1709炉试验后获得的膨胀型涂料的炭残留物。膨胀型配方基于环氧树脂，并包含许多添加剂，包括硼酸锌，聚磷酸铵和硅酸盐纤维。目的是表征使用交叉方法燃烧时可能发生的多种反应，包括电子探针微分析（EPMA），X射线衍射（XRD）和1D / 2D固态核磁共振（NMR）。特别是，它强调了先进NMR技术的潜力，即二维偶极异核多量子相关（2D D-HMQC）NMR。因此，EPMA证明B / P和B / Si位于同一区域，表明在样品表面上形成了硼磷和/或含硼硅酮的化合物。H₃通过XRD将BO ₃鉴定为主要晶体物种，另外的物种（例如SiO ₂，Zn ₄ O（BO ₂）₆）也被确定。然后使用1D NMR对硼酸盐，硅酸盐和磷酸盐的化学物种进行表征，但无法给出明确的定义。为了指定这些分配，进行了二维D-HMQC NMR，并证明了无定形硼磷酸盐和硼硅酸盐的形成，强调了配方各成分之间的化学反应性。提出这些种类可以增强炭并改善涂层的防火性能。这项工作突出了高级NMR技术的特殊兴趣，该技术提供了有关膨胀型炭的表征的独特信息。