Preparation of Polymer Microspheres Using Silane Coupling Agent Modified Nano-SiO2 as Single Stabilizer

摘要

This paper demonstrates that silica nanoparticles were modified by the four silane coupling agents (KH151, KH-550, KH-560, KH-570) firstly, then polystyrene/silica (PS/SiO2) composite microsphere with PS core and silica nanoparticles shell were prepared by Pickering emulsion polymerization.The characterization of optical microscope (OM), scanning electron microscope (SEM), and thermogravimetic analysis (TGA) illustrates that these microsphere are composed of PS and silica nanoparticles.Silica nanoparticles modified by the different silane coupling agents could form the stable PS/SiO2 microsphere over 70 °C, while the unmodified silica nanoparticles are difficult to form stable PS/SiO2 microspheres at the same temperature.The PS/KH-151-SiO2 microsphere exhibits the least average particle size, while the PS/KH-570-SiO2 microsphere produces the largest.Both SEM and TGA confirm that microsphere surface exists solid nanoparticles.