Preparation of KH570-SiO2 and their modification on the MF/PVA composite membrane

Melamine-formaldehyde/polyvinyl alcohol (MF/PVA) composite membranes modified by nano silica (SiO2) and silane coupling agent KH570 modified SiO2 (KH570-SiO2) were prepared. The surface properties and morphology of KH570-SiO2 were characterized using fourier transform infrared spectrometer (FTIR), thermogravimetric analysis (TGA), contact angle measurement instrument and X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and particle size analyzer. The morphology and properties of nanoparticles modified MF/PVA membranes were also studied with scanning electron microscopy (SEM), TGA, dynamic mechanical analysis (DMA) and tensile tester. The results show that KH570 is grafted on the surface of nano SiO2. KH570-SiO2 has better dispersion in MF/PVA resin than that of unmodified SiO2. The thermal stability, mechanical and crystallizing properties of MF/PVA membrane are increased after modified with nano SiO2. KH570-SiO2 makes MF more compatible with PVA resin, and further increases the mechanical properties and thermal stability of MF/PVA membrane.