高浓度水热法制备改性纳米氢氧化铝及流变性能

Preparation of modified aluminuma trihydroxide at high concentration by thermal hydrolysis and rheology study of ATH suspension

从流变学角度对高浓度水热法制备改性纳米氢氧化铝(MATH)进行了研究。流变研究结果表明:纳米氢氧化铝(ATH)悬浮液是黏度极高的时变性非牛顿流体,其黏度随质量分数增加而显著增加。在酸性条件下,采用流变的方法筛选出对纳米ATH悬浮液有明显降黏作用的改性聚合物分散剂。将改性聚合物分散剂添加在高浓度ATH水热改性反应中,纳米ATH悬浮液的最大固含量从78g/L提高到293g/L,成功制备出了超薄菱形、热失重温度超过350℃、热失重率约为50%的改性纳米氢氧化铝。

Preparation of modified aluminum thrihydroxide at a high concentration by thermal hydrolysis was studied by examining the rheology of ATH suspension. The ATH suspension was a very sticky time-dependent non-Newtonian fluid and its viscosity increased rapidly with the content of ATH. Rheology study was used to select dispersants for the ATH suspension in acid. A polyelectrolyte surfactant was found to decrease the viscosity of the ATH suspension apparently. The maximum content of ATH with added polyelectrolyte surfactant increased to 293 g/L from 78 g/L. Nano modified ATH could thus be prepared by thermal hydrolysis precipitation. The resulting modified ATH had ultra thin rhombic morphology with the beginning of thermal decomposition higher than 350 ℃ and weight loss of 50% approximately.