本文選題：阻燃劑 + 氫氧化鎂��； 參考：《山東大學(xué)》2015年碩士論文

【摘要】：氫氧化鎂作為一種無機(jī)阻燃劑,具有無毒、抑煙、分解溫度高等優(yōu)點,且由于其自身的堿性可以與燃燒過程中產(chǎn)生的酸性有害氣體中和,降低環(huán)境污染而備受市場青睞。氫氧化鎂分解產(chǎn)生氧化鎂和水,分解過程吸收大量的熱量降低燃燒材料周圍的溫度,并且釋放的大量的水分可以稀釋材料周圍氧氣,分解產(chǎn)物氧化鎂也是一種阻燃劑,可以覆蓋在高分子聚合物的表面進(jìn)一步起到阻燃的作用。我國有著世界首屈一指的鎂礦資源,為氫氧化鎂的發(fā)展提供足夠的保障。本論文主要是采用氨法制備阻燃級別的氫氧化鎂,從形貌、粒徑、分散性等方面進(jìn)行工藝研究,并對自然沉降速率及過濾速率進(jìn)行測試。由于氨水法制備氫氧化鎂的濾液中含有未反應(yīng)的氯化鎂、氨水和生成的氯化銨,所以對氨水法制備氫氧化鎂后的一次沉鎂母液進(jìn)行分析處理。濾液中各成分的濃度相對較稀,如果直接蒸發(fā)結(jié)晶或者鹽析結(jié)晶制備氯化銨晶體,會消耗大量的能量,所以本文采用氫氧化鈣法處理濾液。1.氨法制備阻燃級氫氧化鎂實驗以3 mol/1六水氯化鎂為鎂源,氨水為沉淀劑,常溫下制備氫氧化鎂料漿,然后轉(zhuǎn)移至高壓反應(yīng)釜中進(jìn)行水熱。實驗研究了氨水的濃度、滴加速率、攪拌速率、水熱時間及分散劑的使用對氫氧化鎂形貌、粒徑的影響,并對所得的產(chǎn)品進(jìn)行比表面積、自然沉降速率及過濾速率測試,得出結(jié)論：當(dāng)氨水濃度為4 mol/1,滴加速率為2ml/min,攪拌速率為200 rpm,聚乙二醇-2000和油酸鈉為復(fù)合改性劑,180℃水熱4 h制備出粒徑范圍700-900 nm,比表面積為19.7 m2/g,分散性良好的氫氧化鎂納米六方片。2.氫氧化鈣法濾液處理以氫氧化鈣法對氨水沉鎂之后的一次濾液進(jìn)行二次處理,實驗考察了氫氧化鈣的用量、實驗溫度、反應(yīng)時間對鎂離子的沉淀率、氫氧化鎂的純度及蒸氨效率的影響,得出結(jié)論：當(dāng)氫氧化鈣的用量與理論用量的比為1：1,程序升溫90℃反應(yīng)15 min后再在100℃條件下反應(yīng)15 min,鎂離子的沉淀率和蒸氨效率都達(dá)到96%以上,氫氧化鎂的純度為83%。
[Abstract]:As an inorganic flame retardant, magnesium hydroxide has the advantages of non-toxic, smoke suppression, high decomposition temperature and so on. It is favored by the market for its alkalinity and neutralization of acidic harmful gases produced in the combustion process to reduce environmental pollution. Magnesium hydroxide decomposes to produce magnesium oxide and water, the decomposition process absorbs a lot of heat to reduce the temperature around the combustion material, and releases a large amount of water to dilute the oxygen around the material, and the decomposition product, magnesium oxide, is also a flame retardant. It can cover the surface of polymer and further play a role of flame retardancy. China has the world's leading magnesium ore resources, which provides sufficient protection for the development of magnesium hydroxide. In this paper, flame retardant magnesium hydroxide was prepared by ammonia method. The morphology, particle size and dispersion of magnesium hydroxide were studied, and the natural sedimentation rate and filtration rate were tested. Because the filtrate of magnesium hydroxide prepared by ammonia water method contains unreacted magnesium chloride, ammonia water and the generated ammonium chloride, the primary magnesium precipitation mother liquor after the preparation of magnesium hydroxide by ammonia water method is analyzed and treated. The concentration of each component in the filtrate is relatively thin. If the ammonium chloride crystal is prepared by evaporation or salting-out crystallization, a great deal of energy will be consumed, so calcium hydroxide method is used to treat the filtrate. Magnesium hydroxide slurry was prepared by ammonia method with 3 mol/1 magnesium chloride hexahydrate as magnesium source and ammonia water as precipitant, and then transferred to autoclave for hydrothermal treatment. The effects of ammonia concentration, dropping rate, stirring rate, hydrothermal time and dispersant on the morphology and particle size of magnesium hydroxide were studied. The specific surface area, natural sedimentation rate and filtration rate were measured. It is concluded that when ammonia concentration is 4 mol / 1, dropping rate is 2 ml / min, stirring rate is 200 rpm, polyethylene glycol 2000 and sodium oleate are used as composite modifiers for 4 h hydrothermal treatment at 180 鈩，

本文編號：1822241