【作者】 闫海妮；

【导师】 张正方；

【作者基本信息】 新疆大学 ， 化学， 2010， 硕士

【摘要】 随着环境保护和火灾安全意识的不断增强,氢氧化镁作为聚合物无卤消烟型阻燃剂正受到越来越多的重视。但由于氢氧化镁的阻燃效率低,在聚合物材料中填充量大,致使材料的力学性能变差,严重影响了其应用。因此,要对氢氧化镁表面进行改性,提高其在聚合物材料中的相容性,从而改善聚合物复合材料的力学性能。本论文的主要研究内容是:(1)采用硬脂酸和硬脂酸钠对氢氧化镁进行表面改性处理,分别分析了改性剂的用量、反应时间、反应温度对改性效果的影响,通过单因素条件改变实验确定最佳改性条件;将改性前后的氢氧化镁分别以4:6和7:3的质量比和聚氯乙烯(PVC SG-5)共混,研究其分散性优劣。实验结果表明:改性剂用量8%(相对干粉质量),反应时间40 min,反应温度70℃时硬脂酸钠比硬脂酸的改性效果好;扫描电子显微镜和红外化学成像的方法分析表明脂酸钠改性的氢氧化镁在PVC中的分散性较硬脂酸改性的氢氧化镁在PVC中的分散性好。(2)采用油酸、油酸/聚乙二醇-600作为表面修饰剂,分别通过化学沉淀法一步制备了表面疏水的氢氧化镁纳米粒子;用此方法,改用硬脂酸盐以及硬脂酸盐/聚乙二醇-600作为表面修饰剂,制备表面疏水的氢氧化镁纳米粒子。实验结果表明:加入聚乙二醇-600,制备的纳米粒子晶粒较小;红外化学成像分析表明硬脂酸盐中改性效果较佳的为硬脂酸钠,在PVC中有较好的分散性。(3)采用原位无皂乳液聚合法制备氢氧化镁/聚苯乙烯纳米复合材料,用红外、热重等方法分析了改性效果,结果表明氢氧化镁表面接枝上了聚苯乙烯,氢氧化镁/聚苯乙烯纳米复合材料具有良好的热稳定性。(4)将10%、20%、30%、40%(质量百分含量)不同含量的Mg (OH )2、SS- Mg (OH )2分别通过熔融共混填充到聚乙烯中,通过比较聚合物复合材料的燃烧性能和机械力学性能,得到复合材料的最佳配比。实验结果表明:20%的改性氢氧化镁作阻燃剂制备聚合物复合材料,较好兼顾了力学性能和阻燃性能。更多还原

【Abstract】 Metal hydroxides as smoking and toxic-free additives have been extensively used in hatogen-free flame-retardant polymeric materials. However, their fatal disadvanta- ges are low flame -retardant efficiency and thus very 1arge usage amount is needed to meet the flame retardant requirement, which lead the mechanical and processing p- roperties of materials to drop down sharply. So, the surface of magnesium hydroxide should be modified in order to improve intermisibility and mechanical processing properties of materials.(1) The surface of magnesium hydroxide is modified with stearic acide and sodium stearate , and this paper analyzes the influence of factors such as quantities of stearic acide and sodium stearate, time, temperature. The influence of the different reaction conditions on the modified magnesium hydroxide samples were investigated by the single factor condition experiment. The dispersity of the polymer blend formed by the modified MH , nonmodified MH and PVC with the proportion of 4:6 and 7:3 respectively had been studied. The experimental result shows that the dosage of modifier is 8% and the modified time is 40 minutes and the modified temperature is 70℃, and using sodium stearate is better than stearic acide in the same condition. Using SEM and CHEMICAL MAPPING indicated that the dispersity of using sodium stearate modified MH in PVC is good.(2) Magnesium hydroxide is prepaired by one step using oleic acid, oleic acid / polyethylene glycol 600 as a surface modification agent. The same method was used by stearate and stearate / polyethylene glycol 600 as a surface modification agent. The experiment result is the particle size adding polyethylene glycol 600 were smaller ; Stearate was better for the modification of sodium stearate , and have good dispersion in PVC.(3) Exfoliated MH / PS nanocomposites were obtained by soap-free emulsion polymerization method without the aid of any surfactant. The MH/PS nanocomposite was analyzed by IR, TGA . The result is MH / PS nanocomposite has good thermal stability.(4) The products which were modified sodium stearate were added into polyethylene , the ratio were 10、20、30、40 percent. The effect of the mount of four flame retardant on the mechanical and flame retardant properties of the composites were discussed. The experimental results is the dosage of 20% is the best giving attention to two or more things on the mechanical and flame retardant properties.更多还原