Preparation of Aluminum Phosphate Low in Acidity and its Application on Fiber Protection
With excellent physical and chemical properties, aluminum phosphate is a great potential high temperature protective coating of fiber. In this paper, a kind of aluminum phosphate low in acidity was prepared from aluminum isopropoxide (AIP) and diammonium phosphate ((NH4)2HPO4) by hydrothermal and liquid-phase reaction methods respectively. The performance of aluminum phosphate prepared by the two methods was comparatively evaluated using FTIR, XRD, TG techniques. As a protective coating, aluminum phosphate was applied to the pre-treatment of high silica reinforced fiber cloth. After added 1% MgO, The SEM images indicated that aluminum phosphate prepared by hydrothermal method could cover the surface of the fiber more uniformly. The mechanical testing results showed that tensile strength of the obtained coated material was improved at high temperature.