Synthesis of microsphere aluminum hypophosphite and its application in polyurethane elastomer

ABSTRACT Microsphere aluminum hypophosphite (AHP) is prepared via the hydrothermal method and characterized by Fourier transform infrared spectrometry, X‐ray diffraction, and scanning electron microscopy. Then the hydrothermal AHP and the precipitation AHP are added to the polyurethane elastomer (PUE). The flame retardant properties, thermal stability, and mechanical properties of the PUE with different kinds of AHP added are studied. The results show that the hydrothermal AHP is microsphere with a uniform particle size of around 5 µm. The limited oxygen index of the PUE with the addition of 5% hydrothermal AHP increases to 28.5 vol %. Compared with the PUE including different kinds of AHP, the peak heat release rate of added hydrothermal AHP decreases by about 6%. Hydrothermal AHP could improve the char yield which provides better flame retardancy for PUE. Meanwhile, the hydrothermal AHP‐added PUE has better mechanical properties than that with precipitation AHP added. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42370.