氢氧化镁表面改性及在高密度聚乙烯中的应用

摘要

采用硬脂酸钠/聚乙二醇(NaSt/PEG)为复合改性剂,对氢氧化镁(MH)阻燃剂进行表面改性研究.采用活化指数、接触角、样品在液体石蜡中悬浮液体积、红外光谱、热失重等对改性前后的MH进行表征分析.并将改性前后的MH应用于高密度聚乙烯(PE-HD),测试其阻燃性能和力学性能.结果表明,NaSt/PEG的质量比为3∶1,改性温度为80℃,改性时间为1 h时,MH的表面改性效果最佳,活化指数达到97.7%,接触角高达135°.当改性MH添加量为30%,PE-HD/MH复合材料的极限氧指数提高到24.6%,拉伸强度为12.3 MPa,验证了复合改性后的MH与PE-HD有较好的相容性.%Magnesium hydroxide (MH) flame retardant was complex modified by sodium stearate/polyethylene glycol (NaSt/PEG). The MH before and after modified was characterized by activation index,contact angle,volume of suspensions in liquid paraffin,infrared spectroscopy and thermo gravimetric analysis. Then the flame retardancy and mechanical properties of the high density polyethylene (PE-HD) after addition of MH were tested. The results showed that when the mass ratio of NaSt and PEG was 3:1,the reaction temperature was 80℃and the reaction time was 1 h,the modification effect was the best,the activation index reached 97.7% and the contact angle was up to 135°. When the addition amount of the modified MH was 30%,the limit oxygen index of the complex material increased to 24.6% and the tensile strength was 12.3 MPa,illustrating the compatibility between the modified MH and PE-HD was good.