Lou Feipeng, Wu Kai, Wang Quan, Qian Zhongyu, Li Shijuan, Guo Weihong
Polymer Processing Laboratory, Key Laboratory for Preparation and Application of Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China.
Polymers (Basel). 2019 Jan 12;11(1):125. doi: 10.3390/polym11010125.
Ceramifiable flame-retardant ethylene-vinyl acetate (EVA) copolymer composites for wire and cable sheathing materials were prepared through melt compounding with ammonium polyphosphate (APP), aluminum hydroxide (ATH) and fluorophlogopite mica as the addition agents. The effects of ammonium polyphosphate, alumina trihydrate, and APP/ATH hybrid on the flame retardant, as well as on the thermal and ceramifiable properties of EVA composites, were investigated. The results demonstrated that the composites with the ratio of APP:ATH = 1:1 displayed the best flame retardancy and the greatest char residues among the various EVA composites. The tensile strength of the composites was 6.8 MPa, and the residue strength sintered at 1000 °C reached 5.2 MPa. The effect of sintering temperature on the ceramifiable properties, microstructures, and crystalline phases of the sintered specimen was subsequently investigated through X-ray diffraction, Fourier transform infrared, and scanning electron microscopy. The XRD and FTIR results demonstrated that the crystal structure of mica was disintegrated, while magnesium orthophosphate (Mg₃(PO₄)₂) was simultaneously produced at an elevated temperature, indicating that the ceramization of EVA composites had occurred. The SEM results demonstrated that a more continuous and compact microstructure was produced with the rise in the sintering temperature. This contributed to the flexural strength improvement of the ceramics.
通过将聚磷酸铵（APP）、氢氧化铝（ATH）和氟金云母作为添加剂进行熔融共混，制备了用于电线电缆护套材料的可陶瓷化阻燃乙烯-醋酸乙烯酯（EVA）共聚物复合材料。研究了聚磷酸铵、三水合氧化铝以及APP/ATH混合物对EVA复合材料的阻燃性能、热性能和可陶瓷化性能的影响。结果表明，在各种EVA复合材料中，APP与ATH比例为1:1的复合材料表现出最佳的阻燃性能和最大的残炭率。该复合材料的拉伸强度为6.8MPa，在1000℃烧结后的残炭强度达到5.2MPa。随后通过X射线衍射、傅里叶变换红外光谱和扫描电子显微镜研究了烧结温度对烧结试样的可陶瓷化性能、微观结构和晶相的影响。XRD和FTIR结果表明，云母的晶体结构被破坏，同时在高温下生成了磷酸镁（Mg₃(PO₄)₂），这表明EVA复合材料发生了陶瓷化。SEM结果表明，随着烧结温度的升高，产生了更连续、致密的微观结构。这有助于提高陶瓷的抗弯强度。
