ω-十一烯酸改性纳米碳酸钙工艺研究

Surface modification process of nanometer calcium carbonate using ω-undecylenic acid as modifier

采用正交实验,以ω-十一烯酸作为表面改性剂,无水乙醇为分散介质,在一定的温度下对纳米碳酸钙粉体进行表面改性研究,确定改性纳米碳酸钙的最佳工艺条件为:改性剂用量3.0%,改性温度60℃,改性时间30min。改性后的纳米碳酸钙的吸油量(液体石蜡)降为40mL/100g,活化率提高到99.52%,表明改性后的纳米碳酸钙粒子亲油性得到显著提高。沉降速率和透射电镜(TEM)测试结果表明:改性后的纳米碳酸钙在亲油性溶剂中的分散性得到显著改善,粒度分布更加均匀。

The processes of surface modification of the nanometer calcium carbonate were researched by the orthogonal experimental method using w- undecylenic acid as modifier and using absolute alcohol as dispersing medium at certain temperatures. The optimum conditions of modification were obtained, that is, the dosage of w- undecylenic acid was 3.0 % of the mole-number of nanometer calcium carbonate, the temperature was 60 ℃, the time was 30 min. The oil absorption value, the active ratio and the settling volume of the modified and the un-modified nano-CaCO3 were measured, and their morphology were characterized by TEM. The results showed that the oil absorption va/ue was decreased to 40 mL/100g, and the active ratio was increased to 99.52% after the nano-CaCO3 were modified; the dispersity in oil agents of the modified nano-CaCO3 was increased remarkably; the granularity distribution of the modified nano-CaCO3 was more uniform.