改性甲基丙烯酸共聚物分散剂对陶瓷复合料浆流变性及坯体强度的影响

Effects of modified poly(methacrylic acid) dispersant concentration on rheological behavior of compound slurry and ceramic strength

烯丙基聚氧乙烯醚与甲基丙烯酸和甲基丙烯酸甲酯可通过自由基共聚获得两亲结构的水溶性高分子MPMA，可作为陶瓷浆料分散剂。研究了MPMA用量对石英／长石／粘土复合浆料流变性及坯体强度的影响，并分析了其原因及分散稳定作用机理。结果表明：MPMA的加入显著优化了料浆的流变性能并提高了成型后陶瓷的强度。在pH值为9～10时，MPMA的最佳用量为0．57wt％（相对绝干浆料），料浆的Zeta电位绝对值由28．5mV升高到65．5mV，零剪切黏度由690．9mPa·s降低到81．6mPa·s，触变面积最小，陶瓷料浆基本呈Newton流动特性，显示了很好的分散性。与添加无机分散剂的陶瓷坯体相比，添加MPMA的陶瓷坯体强度由160MPa升高到268MPa。

Through radical copolymerization, modified waterborne poly methacrylic acid （MPMA） with hydrophilic and hydrophobic groups was prepared by reacting ally poly （ehtenoxy ether）, methacrylic acid and methyl methacry late. Using MPMA as ceramic dispersant, the effects of MPMA concentration on the theological behavior of Dia mond/Feldspar/Clay compound slurry and ceramic breaking strength were studied, and simultaneously the reasons and dispersive mechanism were analyzed. The results show that MPMA can improve the slurry＇s rheological properties and the ceramic strength. The optimum MPMA concentration is 0.57 wt% （based on the absolute dry slurry） with pH ranging from 9 to 10. When adding 0.57 wt% MPMA, the slurry＇s negative Zeta potential increases from 28.5 mV to 65.5 mV, and its zero shear viscosity decreases from 690.9 mPa.s to 81.6 mPa.s. At the same time, its thixotropy area reaches the minimum, and the slurry exhibits Newton flow behavior. Compared with ceramic with inorganic dispersant addition, the ceramic with MPMA addition owns higher breaking strength, which is increased from 160 MPa to 268 MPa.