【作者】 庞慧慧；

【导师】 罗立文；

【作者基本信息】 中国石油大学 ， 化学， 2011， 硕士

【摘要】 目前，社会对环境保护极其重视，伴随着人们环保意识的增强，Mg(OH)2作为一种新开发的添加型环保无机阻燃剂，已经受到各界重视。其较传统阻燃剂具有稳定性好、不挥发、环保、分解温度高等优点。由于国内Mg(OH)2的生产工艺路线长，纯度和产率不高，表面极性强，不宜添加到聚丙烯等高分子材料中，本课题旨在研究高纯度、高产率、表面极性弱的Mg(OH)2一步法合成工艺。此工艺反应条件温和，工艺流程短，设备投资小，产品成本低。因此，本课题的研究对Mg(OH)2阻燃剂工业化生产具有一定的指导意义。本论文以超声波为前提，以纯度和产率为指标，通过单因素考察Mg(OH)2生产工艺条件，再经过正交实验优化工艺条件。对Mg(OH)2阻燃剂进行改性效果的研究，对比两种复配表面处理剂的改性效果，初步探讨了表面处理剂复配的影响因素及表面处理剂的改性机理。通过对改性Mg(OH)2的各种性能测试分析，对其在聚丙烯中的应用进行了预测。通过实验研究得到：实验在反应初期采用超声波处理，可以明显改善Mg(OH)2的过滤问题，在一定程度上缓解Mg(OH)2的抽滤洗涤这一难题。合成Mg(OH)2的较佳工艺条件为：Mg2+的初始浓度2.5 mol·L-1，NH3·H2O与Mg2+的物料比4.5:1，表面处理剂A 5 mL，超声波处理2 min(脉冲4 s)，反应温度55℃，恒温反应时间2 h。产品质量远优于工业标准。通过各种改性效果研究，表面处理剂A的最佳用量为5 mL，表面处理剂B的最佳用量为8 mL，且表面处理剂A改性效果优于B。初步探讨阴离子与非离子表面活性剂复配时，具有降低表面张力的增效作用，而相等或相近碳链长的两种表面活性剂具有较强的相互作用，使其活性增强。表面活性剂的复配，使Mg(OH)2改性处理多样化，不仅仅局限于单一表面活性剂改性。改性后的Mg(OH)2热稳定性增强，粒径小，粒度分度均匀，极性减弱，亲油性增强，预测其能在聚丙烯中分散均匀，不易团聚，与聚合物相容性增强，可改善聚丙烯复合材料的力学性能和加工性能，能够达到较好的阻燃效果。更多还原

【Abstract】 At present, the society has paid much attention to environmental protection, and theenvironmental requirement has increasingly improved. Magnesium hydroxide, one of theinorganic additive flame retardants, as a newly developed flame retardant, has attracted muchattention because of its good stability, non-volatile, environmental protection and higherdecomposition temperature. Since the domestic production of magnesium hydroxide has along synthesis route, low purity and yield, strong surface polarity and is unsuitable to add tosuch polymer materials as polypropylene. The research is aimed at the one-step synthesistechnology of magnesium hydroxide. Improving the purity and the yield , and bringing downthe surface polarity, this process has mild reaction condition, short process flow, smallequipment investment and low production cost. Therefore, this research has certain directivesignificance for magnesium hydroxide flame retardants industrial production.The thesis takes ultrasonic as the premise and takes the purity and yield as the index,using single factor experiment to test magnesium hydroxide production conditions, in theabstract, the optimal reaction condition was confirmed by orthogonal experiment. Using twocompound surface treatment agents as modification agent, modification effects wereinvestigated and contrasted. This study elementarily examined factors into compound of surfacetreatment and the modification mechanism of the surface treatment. Through test ing variousperformances of modificated magnesium hydroxide, the application in the polypropylene isforcasted.The experiment shows that the filtration problem of magnesium hydroxide obviouslyimproved by using ultrasonic processing in the initial stage of experiment. the best conditionsof synthesis were the initial concentration of Mg2+was 2.5 mol·L-1, the molar ration of NH3·H2O and Mg2+was 4.5 : 1, surface treating agent A was 5 mL, ultrasonication 2 min(impulse 4s), The reaction temperature was 55℃, and reaction time under constanttemperature was 2 h, The product quality is far superior to the industry standard. Throughvarious modification effect researches, the optimum dosage of surface treating agent A was 5mL, B was 8 mL, and the modification effect of A was better than that of B. This paperinvestigates when the anionic and nonionic surfactant mixed, the surface tension lowered. Thetwo surfactants with equal or similar carbon chain length have so strong interaction that theiractivity increased. Due to Compound of surfactant, magnesium hydroxide modificationdiversified, not limited to a single surfactant modification. The results indicated that thethermal stability of modified magnesium hydroxide was improved, the particle size becomesmaller, The size distribution was uniform, the polarity abated and made oil wettabilitystronger. This paper also predicts that magnesium hydroxide in the polypropylene has a gooddispersion and is not agglomerate in the the particles and the polymer compatibility isenhanced. Meanwhile the mechanical properties and processing properties of thepolypropylene compound material is ameliorated. From the above, the modified magnesiumhydroxide can achieve a good flame retardant effect.更多还原