稀土复合偶联剂对氢氧化镁的表面改性研究  

Surface modification of magnesium hydroxide by rare earth complex coupling agent

作　　者：周卫平[1] 李林茂[1] 

机构地区：[1]惠州学院化学工程系,广东惠州516015

出　　处：《无机盐工业》2009年第5期24-27,45,共5页Inorganic Chemicals Industry

基　　金：广东省惠州市科技项目(2006P43)

摘　　要：对超细无机阻燃粉体氢氧化镁进行表面改性可大大改善其与有机高聚物的相容性和加工流动性。选择稀土偶联剂/螯合磷酸酯钛偶联剂作为氢氧化镁的复合改性剂,采用湿法改性处理氢氧化镁。通过表面分析技术测定改性氢氧化镁粉体表面性质;利用差热分析技术(DTA)测定其热起始分解温度;利用傅里叶变换红外光谱仪(FT-IS)证实了氢氧化镁表面改性层的存在。通过实验,得到稀土偶联剂/螯合磷酸酯钛偶联剂复合改性剂表面处理氢氧化镁的最佳工艺条件:浆料质量分数为30%,改性剂稀土偶联剂与螯合磷酸酯钛偶联剂质量比为1.9:1,改性剂用量为2.5%,改性温度为80℃,搅拌速率为760r/min,改性时间为30min。在此条件下,改性氢氧化镁的吸油值从0.4997g/g降至0.3365g/g,活化指数从0上升到99.86%,热起始分解温度从341.1℃升至366.5℃。Compatibility and processing flow ability of magnesium hydroxide superfine powder with organic high polymers materials would be significantly improved after being surface modified. Rare earth coupling agent and Wt -200S were chosen as compound modifier for magnesium hydroxide by wet - modification method. Surface properties of magnesium hydroxide were measured by surface analysis technique. Initial thermal decomposition onset temperature of modified magnesium hydroxide was measured by DTA and the existence of magnesium hydroxide＇s surface modification layer was verified by fourier transform infrared spectroscopy （ FT - IS）. Meantime, optimum processing condition of surface modification was also studied. The optimal conditions for rare earth coupling agent and Wt - 200S as the compound modifiers for magnesium hydroxide as following：mass concentration fraction of sizing agent was 30% ,mass ratio of rare earth coupling agent to Wt - 200S was 1.9：1 ,dosage of modifiers was 2.5% ,modification temperature was 80 ℃ ,stirring speed was 760 r/min,and for modification was 30 min. Under such conditions for modified magnesium hydroxide, oil absorbability was lowered from 0. 499 7 g/g to 0.336 5 g/g, activate index was increased from 0 to 99.86% , and initial thermal decomposition temperature was increased from 344.1 ℃ to 366.5 ℃.

关 键 词：氢氧化镁 稀土偶联剂 螯合磷酸酯钛偶联剂 

分 类 号：TQ132.2[化学工程—无机化工]