水性无机膨胀型防火涂料的制备及性能研究 第二部分——膨胀阻燃过程的研究  

Preparation of waterborne inorganic intumescent fire-retardant paint and study on its properties:PartⅡ-Study on the process of intumescent flame retardation

作　　者：孙娜娜 黎春阳[2] 李国军[1] SUN Nana;LI Chunyang;LI Guojun(School of Materials Science and Engineering,Dalian Jiaotong University,Dalian 116028,China)

机构地区：[1]大连交通大学材料科学与工程学院,辽宁大连116028 [2]大连交通大学环境与化学工程学院,辽宁大连116028

出　　处：《电镀与涂饰》2020年第20期1434-1437,共4页Electroplating & Finishing

摘　　要：采用扫描电镜(SEM)、X射线衍射(XRD)和热重−差式扫描量热(TG–DSC)分析了主要由碱性硅溶胶和甲基硅酸钾为基料,钛白粉、滑石粉、白云石、绢云母、可膨胀石墨为颜填料所制备的水性无机膨胀型防火涂料的膨胀阻燃过程。结果表明:在灼烧前期,甲基硅酸钾和可膨胀石墨协同阻燃。甲基硅酸钾受热分解生成的CO2和水蒸气可稀释可燃气体,水蒸气还具有一定的冷却、抑烟作用;可膨胀石墨受热膨胀形成的蠕虫状多孔炭层能够有效延缓热量及氧气的传递。在灼烧中期,主要是白云石发挥阻燃作用。在520~720°C,白云石剧烈分解成CO2,其主要产物──MgO和CaO起到阻燃作用。在灼烧后期,体系在800~1000°C发生了相变化,由固态变为液态并吸收热量后形成玻璃相。The intumescent flame retardation process of a waterborne inorganic intumescent fire-retardant paint prepared with alkaline silica sol and potassium methylsiliconate as binders and titania,talc,dolomite,sericite,and expandable graphite as pigments and fillers was analyzed by scanning electron microscopy(SEM),X-ray diffractometry(XRD),and thermogravimetry–differential scanning calorimetry(TG-DSC).The results showed that in the early stage of ignition,there exists a synergic flame retardation of potassium methylsiliconate and expandable graphite.The combustible gases are diluted by CO2 and water vapor produced by the decomposition of potassium methylsiliconate when being heated.Besides,the water vapor has not only a cooling effect,but also a smoke suppression effect.The porous carbon layer formed from expandable graphite effectively prevents the heat and oxygen transfer.At the middle stage of ignition,dolomite plays a key role in flame retardation.In the temperature range from 520°C to 720°C,dolomite is decomposed violently to produce CO2,and its main decomposition products namely MgO and CaO act as flame retardants.At the last stage of ignition,the system is changed from solid to liquid,which absorbs heat and forms glass phase between 800°C and 1000°C.

关 键 词：水性无机膨胀型防火涂料 甲基硅酸钾 可膨胀石墨 白云石 阻燃 机理 

分 类 号：TQ637.8[化学工程—精细化工]