油酸钠改性锌镁铝水滑石的制备及对聚丙烯的增强作用

Preparation of Modified Zn Mg Al-LDHs with Sodium Oleate and Its Reinforcing Effect in Polypropylene

为改善水滑石（LDHs）的颗粒分散性和表面活性,提高LDHs 填料与聚合物的界面相容性,采用快速成核/晶化法合成了锌镁铝水滑石（ZnMgAl-LDHs）,并以油酸钠为表面改性剂,对ZnMgAl-LDHs 进行了表面改性,通过粒度分析、X 射线衍射（XRD）、傅里叶变换红外光谱（FT-IR）、热重分析（TG）及扫描电镜（SEM）/透射电镜（TEM）对改性前后的ZnMgAl-LDHs 进行了表征.将改性前后的ZnMgAl-LDHs 分别添加到聚丙烯（PP）中,制得ZnMgAl-LDHs/PP 复合材料,通过拉伸强度和弯曲强度测试考察改性前后ZnMgAl-LDHs的添加量对复合材料力学性能的影响.结果表明：所制备的ZnMgAl-LDHs 的平均粒径为838.9 nm,当油酸钠的质量浓度为0.6 g/L 时,平均粒径减小至647.2 nm.当ZnMgAl-LDHs 添加量的质量分数为2%-8%时,改性前后的ZnMgAl-LDHs 均对PP 的力学性能有增强作用.改性ZnMgAl-LDHs 具有更好的颗粒分散性,改性ZnMgAl-LDHs 与PP 相容性更好,对PP 力学性能的增强作用优于未改性的ZnMgAl-LDHs.

For improving the particle dispersity and surface activity of layered double hydroxides (LDHs) and enhancing the interfacial compatibility between LDHs filler and polymer, ZnMgAl-LDHs were synthesized via a rapid nucleation/crystallization method and the surface of the ZnMgAl-LDHs was modified with sodium oleate. Particle analysis, X-ray diffraction, Fourier transform infrared spectroscopy, thermal gravimetric, scanning electron microscope and transmission electron microscope were used to characterize the microstructure, thermal stability and morphologies of the ZnMgAl-LDHs before and after the modification. The ZnMgAl-LDHs or modified-ZnMgAl-LDHs were mixed with polypropylene (PP) to prepare ZnMgAl-LDHs/PP composites. The influence of the addition of ZnMgAl-LDHs or modified-ZnMgAl-LDHs on mechanical properties was evaluated by the test of tensile and bending. The as-prepared average particle size of ZnMgAl-LDHs was 838.9 nm; when the mass concentration of sodium oleate was 0.6 g/L, the average particle size of modified-ZnMgAl-LDHs was 647.2 nm. The mechanical properties of ZnMgAl-LDHs/PP composites were enhanced by adding 2%-8%(w) ZnMgAl-LDHs or modified-ZnMgAl-LDHs. The modified-ZnMgAl-LDHs exhibited preferred particle dispersion and better compatibility with PP, and the reinforcing effect was more remarkable than pristine ZnMgAl-LDHs.