【作者】 王琳琳；

【导师】 化全县； 李永振；

【作者基本信息】 郑州大学 ， 化学工程（专业学位）， 2013， 硕士

【摘要】 磷化工产业是主要由磷复肥及精细磷化工组成的磷资源加工产业,其中精细化是其未来的主要发展方向之一。羟基磷酸钙(HAP)是近年来新兴发展起来的一种精细磷化工产品,在悬浮聚合分散剂以及荧光材料、生物材料、陶瓷等方面都有应用。在石化行业的悬浮聚合中,作为当今用量最大的一种新型无机悬浮分散剂,HAP能使聚合工艺稳定,反应压力、温度平稳,清釜周期延长,从而得到粒度分布集中、透明度和外观质量均改善的聚合树脂,产品档次明显提高。目前我国高质量的HAP主要依靠进口,国产的HAP在用于悬浮聚合时,树脂产品在外观、粒度分布等方面存在一定缺陷。研究发现HAP悬浮分散剂的活性与其比表面积成正比,将其超细纳米化,增大其比表面积,可以提高其分散活性。但HAP纳米化后微粒之间容易发生二次团聚,影响树脂产品在悬浮聚合时的注塑成型；而减少微粒间的团聚增大粒径使比表面积减小,又会降低其活性影响分散性能。因此,为了解决HAP纳米化和分散性能之间的矛盾,须选择一种有效的合成方法和表面处理使制得的HAP粒径达到纳米级、比表面积大、分散活性高。本课题采用酸碱中和法,以H3P04和CaO为原料制备HAP悬浮聚合分散剂。该工艺原理简单,易操作,原料易得,通过严格控制反应条件就可以得到具有特定性能的粒子。课题系统研究了原料Ca/P、反应体系pH、反应温度、陈化时间及十二烷基苯磺酸钠(SDBS)加入量等工艺条件对产品的结构、化学组成、粒度大小及其粒径分布的影响,并采用正交设计法优化工艺条件。通过激光粒度分析仪、X-射线衍射、全化学分析法等手段对产物进行了表征。为改善HAP粉体粒度,降低其团聚现象,采用不同的改性剂对HAP粉体进行表面改性以制备出纳米尺寸的羟基磷酸钙粉体,并分别研究了改性剂种类、改性剂加入时间、改性剂用量等因素对HAP粉体改性的影响。主要研究成果如下：(1)所制备的HAP悬浮分散剂具有羟基磷酸钙(Caio(P04)6(OH)2)的晶体结构。(2)当以产物Ca/P值为控制指标时,优惠工艺条件应为反应物Ca/P为1.77,SDBS加入量为1.5mL,反应温度45℃,体系pH为11。当以产物粒度及其粒径分布为控制指标时,优惠工艺条件应为反应物Ca/P为1.57,SDBS加入量为1.5mL,反应温度45℃,体系pH为9。当以产率为控制指标时,优惠工艺条件应为反应物Ca/P为1.67,SDBS加入量为1.0mL,反应温度55℃,体系pH为9。优惠工艺条件的验证实验证明设计方案的正确性和可行性。(3)优惠条件下合成的HAP微粒的各项指标均符合部颁标准HG/T3583-2009,而且其平均粒径这项指标明显高于标准HG/T3583-2009。(4)单一改性剂以柠檬酸效果最佳,扫描电镜(SEM)结果显示柠檬酸的加入使得粉体粒度明显变小,激光粒度仪测定结果表明HAP粉体尺寸约为70nm；复合改性剂以柠檬酸和SDBS复合时改性效果最佳,优于单一改性剂的作用效果；改性剂在中和反应前加入效果较好；改性剂最佳用量为4%,最优改性产品的活化指数为94%,沉降体积为2.2mL/g。更多还原

【Abstract】 Phoschemical industry, which is composed of phosphate and compound fertilizer as well as fine phosphorous chemicals, mainly aims at phosphorus resources for processing. And the refine technology is further developed in the future of this field. The Hydroxyapatite (HAP) is emerging as a kind of fine phosphorus chemical products in recent years, which has been used in many ways, such as the suspension polymerization dispersant, fluorescent material, biological material as well as ceramic. As a new kind of inorganic suspension polymerization dispersant, HAP is the most widely used in the suspension polymerization of petrochemical industry. It can make the polymerization process stable, the pressure and temperature more smooth, and can prolong the period of cleaning kettle. In brief, HAP can improve the appearance quality and transparency of the product, and enhance the grade of the product.At present, the HAP with high quality is mainly from imports. The HAP at home makes from suspension polymerization, and it has some drawbacks in the appearance, particle size distribution of resin products. Recent studies show that the activity of HAP dispersant for suspension polymerization is proportional to its specific surface area. Nanoparticle of HAP could improve the dispersion cativity because of its large specific surface area. When HAP particle size reaches to nanometer level, the HAP particles are liable to agglomerate, which can affect resin products injection molding. Increasing the size of the particles for reducing their agglomeration, however, can lower surface activity and influence its dispersion activity. In order to resolve the contradiction between the nanocrystallization of HAP dispersant and its dispersing property, a kind of effective synthetic method and surface treatment must be choosed, as a result, this method can be used to prepare nano-sized HAP particles with large specific surface area and high surface activity.An acid-base neutralization was adopted using phosphoric acid and calcium oxide as starting materials to prepare HAP dispersants for suspension polymerization. The principle of this synthesis technique that is easy to handle is simple, raw materials are cheap and easily-accessible, and the controllable preparation on some properties of particles can be achieved by means of strictly controlling reaction conditions. In this paper, the effects of the process conditions, including the Ca/P of raw materials, the pH value of the reaction system, temperature of reaction, aging time, as well as SDBS addition amount on the structure, chemical composition, grain size and partical size distribution of the HAP products were researched in detail, and the process conditions were optimized by using orthogonal design method. The samples were characterized by laser particle size analyzer, X-ray diffraction instrument, chemical analysis and so on. In order to improve the grain size and the aggregation of Hydroxyapatite powders, different modifiers are used to perform the surface modification of HAP powders to obtain nano-sized particles. The influences of modifiers types, modification time as well as surfactant dosages are investigated. The results were listed as follows:(1) The crystal structure of the prepared HAP is same to Ca10(PO4)6(OH)2.(2) When the control indicators are Ca/P of the HAP products, the optimum process conditions are Ca/P of raw materials1.77, SDBS addition amount1.5mL, temperature of reaction45℃and the pH value of the reaction system11.When the control indicators are grain size and partical size distribution of the HAP products, the optimum process conditions are Ca/P of raw materials1.57, SDBS addition amount1.5mL, temperature of reaction45℃and the pH value of the reaction system9.When the control indicators are the yield of the HAP products, the optimum process conditions are Ca/P of raw materials1.67, SDBS addition amount1.0mL, temperature of reaction55℃and the pH value of the reaction system9. Under the optimum process conditions the experiment for verification is done. It validates the correctness and feasibility of the design method further.(3) All the indicators of the prepared HAP under the optimum process conditions are in line with the ministerial standard HG/T3583-2009, of which the average particle diameter is significantly higher than the standard HG/T3583-2009.(4) As a single modifier, C6H8O7is the best, and scanning electron microscope (SEM) analysis reveals that the size of HAP powders with C6H8O7decreases significantly. Further study under laser particle size analyzer demonstrates that the average size of HAP powders is70nm or so. When C6H8O7and SDBS as the compound modifier are used, it turns out a better consequence. If the modifier is added before acid-base neutralization reaction, the effect of modification is noteworthy and the optimum content of modified agents is4%. The activation index and sedimentation volume of optimal modified products is94%and2.4mL/g, respectively.更多还原