一种PP用高性能膨胀型阻燃涂层的制备及应用

Preparation and Application of a High Performance Intumescent Flame Retardant Coating for Polypropylene

将甲基丙酸乙二醇酯膦酸环己二醇酯-铝(EMPCP-Al)、聚乙烯醇缩甲醛(PVFO)和三聚氰胺氰尿酸盐(MCA)按特定比例在聚丙烯(PP)表面制备得到不同厚度的阻燃涂层。当涂层厚度达到104μm时可使PP的极限氧指数(LOI)由18.2%提高至30.2%,垂直燃烧测试达到UL94 V-0级别。微形量热测试结果表明阻燃涂层对PP的热释放速率抑制作用明显。热重-红外光谱联用(TG-FTIR)分析证实阻燃涂层能显著的降低PP热分解过程中可燃性气体的释放。扫描电镜-X射线能谱(SEM-EDX)及拉曼光谱分析证实阻燃复合材料燃烧后出现明显的发泡膨胀,且炭层的石墨化程度有较大提升,阻燃涂层中磷、氮两种元素在气相和凝聚相中实现了良好的协同阻燃。此外,相比于普通添加型阻燃剂,阻燃涂层对PP的力学性能影响较小。

The flame retardant coatings with different thicknesses were prepared on the surface of polypropylene(PP)by aluminum-ethylene glycol methyl propionate cyclohexanediol phosphonate(EMPCP-Al),polyvinyl formal(PVFO)and melamine cyanurate(MCA)with specific ratio.When the thickness of coating is 104 μm, the limit oxygen index(LOI)of PP increases from 18.2% to 30.2%,and the vertical burning test could pass UL94 V-0 rating.Microscale combustion calorimeter result indicates that the flame retardant coating exhibited superior performance in the inhibition of heat release rate for PP.Thermogravimetry-Fourier transform infrared spectroscopy(TG-FTIR)combination analysis confirms that the flame retardant coating could effectively reduce the release of flammable gases during the thermal decomposition process of PP.In addition, scanning electron microscopy-energy dispersive X-ray(SEM-EDX)and Raman spectroscopy analysis confirms that the flame retardant composites show obvious foam expansion after combustion, and the graphitization degree of the carbon layer is greatly improved, moreover, the two elements of phosphorus and nitrogen in flame retardant coating could achieve benign synergistic flame retardancy in the gas phase and condensed phase.Furthermore, comparing with common additive flame retardants, the flame retardant coating displays less impact on the mechanical properties of PP.