硬脂酸对W型六角晶系铁氧体粉体的表面改性

Suface Modification of W Type Hexagonal Ferrite Powders with Stearic Acid

采用硬脂酸对W型六角晶系铁氧体粉体进行表面改性,研究改性剂用量、改性时间和改性温度等因素对铁氧体粉体表面改性的影响,采用红外光谱、差热分析及润湿性实验对改性前后的铁氧体粉体进行表征。结果表明,在硬脂酸质量分数为1.5%,改性时间为30 min,改性温度为80℃的条件下,制备的产品性能优良,活化指数达95.2%;铁氧体粉体经硬脂酸改性后,硬脂酸在铁氧体粉体表面发生化学吸附;改性后的铁氧体粉体表面性质由亲水变为疏水,复合体系黏度降低,从而改善加工流动性以及提高铁氧体-环氧树脂复合材料的力学及热稳定性能。

The surface modification of W type hexagonal ferrite powders by stearic acid was investigated. The impact of modifier dosage, modification time and modification temperature on the surface modification of ferrite powders were studied. The unmodified and modified ferrite powders were tested with FTIR, TG-DSC and the experiments of wettability. The results show that the modified ferrite powders with excellent modification effect as well as 95.2% activation exponential are prepared in the conditions of 80 ~C, with 1.5% stearic acid added （mass fraction） and stirring for 30 min. The stearic acid molecules occur chemical sorption on the surface of ferrite particles. The surface property of ferrite powders modified with stearic acid is changed from hydrophilicity to hydrophobicity. Viscosity is reduced, and the flow properties of the composite system are improved. The mechanical and thermal properties of ferrite-epoxy resin composites are enhanced after modification.