摘要：为了解决氧化铁黄颜料的热稳定性较差,受热易脱水变色,从而影响在塑料加工等领域应用的问题,采用沉淀法在氧化铁黄颜料表面包覆羟基氧化铝,来提升氧化铁黄颜料的耐热性,探索反应温度、包覆量和晶化时间等因素对颜料耐热性能的影响,并采用X射线衍射、红外光谱、热重-差热分析等手段对颜料结构进行表征。结果表明:优化包覆条件是温度为80℃,包覆层质量分数为15%,晶化时间大于4 h,在此条件下包覆氧化铁黄颜料的耐热性可以达到240℃;氧化铁黄的包覆层物相为羟基氧化铝,包覆后氧化铁黄受热分解分为2步,245℃处的吸热峰由表面羟基氧化铝受热脱水所致,295℃处的吸热峰由内部的氧化铁黄结构水分解所致。

关键词：氧化铁黄；羟基氧化铝；包覆；耐热性能

Abstract：To solve the problem of iron oxide yellow pigment being easy to be discolored because of its poor thermal stability,thus affecting its application in plastics processing and other fields,the iron oxide yellow pigment coated with hydroxyl alumina was prepared by the method of precipitation to improve the heat resistance property of iron oxide yellow pigment. The effect of reaction temperature,coating amount and crystallization time on the heat resistance property of pigment was discussed. The structure characterization of the pigment is tested using the technologies of XRD,IR and TG-DTA. The results show that the optimized coating conditions are that the reaction temperature is 80 ℃,coating mass fraction is 15%,and crystallization time is more than 4 h.Under this condition,the heat resistance of the coated iron oxide yellow pigment can reach 240 ℃. The coating phase of iron oxide yellow is hydroxyl alumina. The thermal decomposition of iron oxide yellow pigment coated with hydroxyl alumina is divided into two steps. The endot hermic peak at 245 ℃ is contributed by the heating dehydration of surface hydroxyl alumina,and the endothermic peak at 295 ℃ is contributed by the decomposition of structure water of internal iron oxide yellow.

Keywords: iron oxide yellow；hydroxyl alumina；coating；heat resistance property