Surface organic modified magnesium titanate particles with three coupling agents: Characterizations, properties and potential application areas

Magnesium titanate (MT), as one of the important dielectric materials, is widely used as dielectric resonators for the low dielectric loss and good temperature stability. However, the agglomerate behavior of MT particles limit the application areas in organic materials, especially for polymer materials. In this work, the surface of MT particles was modified by three coupling agents, i.e. bis-(γ-triethoxysilylpropyl) tetrasulphide (Si69), γ-(methacryloyloxy) propyltrimethoxysilane (KH570) and stearic acid (SA). Modification effects were characterized via Fourier transform infrared (FTIR) and contact angle analysis. These characterizations showed an excellent surface modification effect, especially for samples modified by Si69 and SA. The contact angle test presents that the surface of modified MT particles was transformed from hydrophilic (35°) to hydrophobic (135°). The content of coupling agent on particle's surface was investigated by thermal gravimetric analysis (TGA). X-ray diffractometer (XRD) results indicate that surface modification has no effect on the type of MT particle's crystals. Surprisingly, Ultraviolet–Visible-Near infrared (UV–Vis-NIR) measurement shows that MT particles present a better solar reflectance effect than titanium dioxide. The micro-morphology of particles is analyzed by Scanning electron microscope (SEM). Herein, the potential application areas of surface organic modified MT particles can be used in polymer-ceramic composites and solar reflectance materials.