【作者】 李小芳；

【导师】 王训遒；

【作者基本信息】 郑州大学 ， 化学工艺， 2010， 硕士

【摘要】 纳米CaCO3作为一种重要的功能材料,已在纸张、塑料、油墨、橡胶、涂料等行业得到了较广泛的应用。但由于纳米CaCO3具有较大的比表面积和较高的表面能,颗粒极易发生团聚,严重制约了纳米CaCO3产业的发展。故寻找合适的分散剂来较好地分散纳米CaCO3,使其粒径稳定在纳米级,是纳米CaCO3获得广泛应用所要解决的最关键的技术问题。论文采用十二烷基苯磺酸钠SDBS、聚丙烯酸钠PAANa,山东泰和TH-904和美国罗门哈斯B-02等四种分散剂分别对52%(wt)纳米CaCO3浆体进行分散,通过重力沉降、细度和粘度的表征,考察了分散剂用量、分散方法及pH值的影响,分别得到较佳的分散工艺条件。通过对比发现分散剂TH-904对纳米CaCO3浆液的分散稳定性最优,利用该分散剂所制得的纳米CaCO3浆液粘度低至28mPa·S。论文根据纳米CaCO3的表面性质和超分散剂的作用机理等因素,选用丙烯酸、马来酸酐和甲基丙磺酸钠为单体,通过水溶液聚合制得了一种超分散剂。通过正交实验和单因素实验优化得到制备该分散剂的较佳配比工艺：单体质量配比为AA:MAn:SMAS=10:2.5:4,去离子水占三种单体总质量的120%,引发剂占三种单体总质量的10%。经测定,所制得超分散剂的分子量为3091。利用该分散剂所获得的52%(wt)纳米CaCO3浆液沉降分布均匀,粘度低至13.1mPa·s,静置一个月无明显变化。通过IR和SEM对添加分散剂前后的纳米CaCO3进行表征,发现自制分散剂已较好的吸附于纳米CaCO3,而且分散后的纳米CaCO3颗粒边界清晰硬团聚少。结果表明自制超分散剂对纳米CaCO3具有良好的分散效果,可应用于高固含量纳米CaCO3浆液的制备。更多还原

【Abstract】 As an important functional material, nano-CaCO3 have been more widely used in paper, plastic, printing ink, rubber, paint and other industries. However, its aggregation problem has severely restricted the development of the industry, because of its larger surface area and high surface energy. So that, a suitable dispersing agent is needed to disperse nano-CaCO3 satisfactorily, and stabilize particle size in the nanometer level, which is the key of the widespread application of nano-CaCO3 in many aspects.Determination of gravity sedimentation, fineness and viscosity were employed to characterize 52%(wt) nano-CaCO3 slurry, which were respectively dispersed by four kinds of dispersant SDBS, PAANa, TH-904 and B-02. Then the influences of those parameters such as dispersant dosage, dispersion method and the pH value’of suspension were discussed, with the purpose of getting better dispersion conditions. By comparison, TH-904 is the optimal dispersing agent to disperse nano-CaCO3, and the viscosity of nano-CaCO3 slurry is as low as 28 mPa-s.According to the surface properties of nano-CaCO3, and the mechanism of hyperdispersant, a kind of hyper-dispersant was polymerized in aqueous solution, by using acrylic acid (AA), methyl propylene sulfonate (SMAS) and maleic anhydride (MAn) as the monomers. The orthogonal and single factor experiments for optimizing raw material proportion show when the monomer mass ratio is AA:MAn:SMAS= 10:3:3, the total water is 120% of total monomers mass, the initiator is 8%, the hyper-dispersant is better to disperse 52%(wt) nano-CaCO3 slurry. The dispersion is well-distributed and no significant changes in standing for one months, moreover, the dispersion viscosity is as low as 13.1mPa-s.The molecular weight of self-made dispersant is 3091. After being dispersed by this dispersant, the nano-CaCO3 were characterized by SEM and IR, the result show that the dispersant has a good adsorption ability for nano-CaCO3, moreover, nano-CaCO3 particles have clear outline, little reunion. So the hyper-dispersant has a greatly effect on the dispersion of nano-CaCO3, and it is good for preparing nano-CaCO3 solution of high solid content.更多还原