硬脂酸-钛酸酯偶联剂复合改性天然重晶石研究

采用湿式机械力化学法，以硬脂酸和钛酸酯偶联剂为复合改性剂对贵州产天然重晶石进行改性。考察了球磨时间、球磨转速、球料质量比、复合改性剂用量及改性剂质量配比对重晶石改性效果的影响。通过FTIR、XRD、SEM、TEM、TG对改性前后重晶石的物相结构、形貌特征和包覆情况进行了研究。结果表明，经过单因素试验得到最佳工艺条件为:球磨时间为2 h、球磨转速为800 r/min、球料质量比（介质球/重晶石）为4 GA6FA 1、复合改性剂用量为2%、改性剂质量配比（硬脂酸/钛酸酯偶联剂）为2 GA6FA 1。改性后改性剂成功地化学键合在重晶石表面。与未改性重晶石相比，改性重晶石的平均粒径减小，分散性增强，晶体结构未发生明显的变化。改性后重晶石的接触角从39.07°增大到150.95°，固体表面自由能从18.62 mJ/m2变化到0.72 mJ/m2，改性后重晶石具有较好的超疏水性，可作为制备超疏水涂层材料的原料。 

Study on Composite Modification of Natural Barite of Stearic Acid Titanate Coupling Agent

Using stearic acid and titanate coupling agent as composite modifier, the natural barite powder produced in Guizhou was modified by wet mechanochemical method. The effects of process conditions such as ball milling time, ball milling speed, mass ratio of ball to material, dosage of compound modifier, and mass ratio of modifier on the properties of modified barite were studied. The phase structure, morphological characteristics and coating of barite before and after modification were characterized by FT-IR、XRD、SEM、TEM and TG. The results show that the optimal process conditions are obtained through single factor experiments: the ball milling time is 2 h, the ball milling speed is 800 r/min, the mass ratio of ball to material (ball/barite) is 4 GA6FA 1, the dosage of compound modifier is 2.0% (modifier/barite), and the mass ratio of modifier (stearic acid/titanate coupling agent) is 2 GA6FA 1. After modification, the modifier was successfully chemically bonded to the barite surface. Compared with the unmodified barite, the average particle size of the modified barite is reduced, the dispersibility is enhanced, and the crystal structure does not change significantly. The modified barite's contact angle changes from 39.07° to 150.95°, and the solid surface free energy changes from 18.62 mJ/m2 to 0.72 mJ/m2. The modified barite has better superhydrophobicity and can be used as a raw material for preparing superhydrophobic coating materials.