氧化石墨烯在水性膨胀防火涂料中的阻燃抑烟改性研究

Waterborne intumescent fire retardant coatings have attracted great attention because of the environmental friendliness and flame retardant effectiveness. However, they usually have some shortcomings such as high solid loading and weak charring layer, which restrain the flame retardant effects and the application of synergistic flame retardants. It is therefore, synergistic flame retardants with higher efficiency to reduce the FR loading are required..Recently it has been found that some functional nanoparticles are highly efficient on flame retardant properties. Correspondingly some new mechanisms have been proposed, however, many have not been unified..In this application, some kinds of water-based polymer emulsion are planned to be applied as the matrix material, classic intumescent flame retardant systems (IFR) containing ammonium polyphosphate (APP), melamine (MEL), pentaerythritol (PER) as basic flame retardants, water as dispersed phase, and graphene oxide (GO) nanoparticles as synergistic flame retardants/smoke suppressants to prepare intumescent fire retardant coatings by means of in-situ hybridization. .The modifying effects and the mechanisms of GO are planned to be investigated in combination with the results of burning tests and systemic discussions of the combustion process in four respects: melt fluidity, pore morphology, char strength and degradation products. .On the basis of thorough understanding of the abovementioned effects and mechanisms, some functional treatments such as grafting functional groups and loading transition metal compounds are planned to be tried on GO in order to enhance the flame retarding/ smoke suppressing efficiency. The synergy effects of GO and other kinds of flame retardants are also planned to be investigated.

水性膨胀防火涂料具有环境友好和阻燃效果优异的优点,但通常固含量较高、炭层强度较差，这些问题限制了其阻燃效果和传统阻燃改性剂的使用空间。近年来研究发现，一些功能性纳米碳材料对聚合物的阻燃效率较高，受到了业界的青睐，但阻燃机理尚无定论。本申请拟采用水性聚合物乳液为成膜物质，以典型的聚磷酸铵、三聚氰胺、季戊四醇膨胀阻燃体系为基础配方，通过水相原位混合法加入氧化石墨烯作为协效阻燃/抑烟改性剂制备膨胀防火涂料并研究改性效果。结合其燃烧过程中生成的泡沫状胶体混合物，着重从熔体流动性、泡孔形态、炭层强度、降解产物分析四个方面系统讨论氧化石墨烯的作用机理。在此基础上采取阻燃基团接枝、过渡金属化合物负载等方式对氧化石墨烯做功能化处理，优化出实用、高效、阻燃抑烟性能平衡的协效阻燃/抑烟改性剂，并研究氧化石墨烯与其他阻燃改性剂的协同效应。

本申请采用水性聚合物乳液为成膜物质，以典型的聚磷酸铵、三聚氰胺、季戊四醇膨胀阻燃体系为基础配方，通过水相原位混合法加入氧化石墨烯作为协效阻燃/抑烟改性剂制备膨胀防火涂料并研究改性效果。结合其燃烧过程中生成的泡沫状胶体混合物，着重从熔体流动性、泡孔形态、炭层强度、降解产物分析四个方面系统讨论氧化石墨烯的作用机理。在此基础上采取阻燃基团接枝、过渡金属化合物负载等方式对氧化石墨烯做功能化处理，优化出实用、高效、阻燃抑烟性能平衡的协效阻燃/抑烟改性剂，并研究氧化石墨烯与其他阻燃改性剂的协同效应。将国家大板燃烧法中介绍的方法和仪器进行改良、重新加工，用于对防火涂料的碳层质量的研究。通过测量、记录碳层形成过程，对碳层的表面硬度和内部结构进行分析，形成对防火涂料碳层的整体认识，分析其影响因素并探究怎样的适宜条件能有效提高防火能力。结果发现，加入极少量氧化石墨烯（<0.01%，）可提高涂料的阻燃性，当氧化石墨烯含量在0.005%时，涂料的耐燃时间可达432s，炭层膨胀高度较未加氧化石墨烯涂料增加了11.5%。结合红外光谱（FT-IR）、X射线衍射（XRD）和扫描电子显微镜（SEM）等表征手段对炭层形貌进行分析可知，加入氧化石墨烯后炭层在300~500℃范围的热稳定性提高，燃烧炭层完整密实，隔热性能提高，导致耐燃时间提高。氧化石墨烯能有效提高一些含氢键聚合物基体的强度、韧性以及炭层强度，但同时会限制膨胀阻燃剂中氨气的释放，因此在膨胀涂料中适宜用量非常小，而更适用于膨胀倍率较小的阻燃体系。