焦磷酸钠对改性膨润土分散性的影响

Influence of Sodium Pyrophosphate on Dispersion of Bentonite

膨润土／改性膨润土分散体系可用于制备水性仿石涂料。通过焦磷酸钠作为分散剂对膨润土水溶液进行改性，研究了焦磷酸钠对膨润土结构的影响，并研究了膨润土浓度（5％-10％）对分散体系结构的影响，采用x射线衍射（XRD）、傅里叶红外光谱（FT-IR），激光粒径分布和Zeta电位对溶液以及烘干后的粉末的结构进行表征。结果表明：焦磷酸钠和膨润土的比例在1：10左右时，晶面间距小，溶液的Zeta电位最低；采用该比例焦磷酸钠分散改性膨润土，改性膨润土浓度对该分散体系结构的影响是，随着改性膨润土浓度的增加，晶面间距先减小后增大，溶液中平均粒径呈现增大的趋势。而焦磷酸钠与膨润土之间存在氢键作用。

The bentonitel or modified bentonite can be used to formulate waterborne stone -like coatings. The sodium pyrophosphate is used as dispersant to modify the bentonite solution. The effect of the concentration （5 % - 10% ） of bentonite on the structure of dispersion obtained thereof is studied. The structures of the dispersion and dried powder are characterized by X -ray diffraction （XRD）, infrared spectroscopy （IR）, laser particle size distribution and Zeta potential respectively. The results indicate that when the ratio of sodium pyrophosphate to bentonite is about 1 ： 10, the Zeta potential is the smallest and lattice spacing is small. When sodium pyrophosphate is used to modify bentonite, with the bentonite concentration increasing, the lattice spacing first decreases and then increases, and the average particle size of the dispersion gradually increases. Infrared analysis confirmes that the hydrogen bonds are formed between sodium pyrophosphate and bentonite.