Intercalation of hexylamine into hydrated kaolinite phenylphosphonate

Hydrated kaolinite phenylphosphonate (KPP-hyd) was reacted with hexylamine under ambient conditions. The reaction produced a stable light-yellow compound (KPP-hex) that was isolated and characterized by X-ray diffraction, thermal methods (simultaneous thermogravimetric and differential scanning calorimetric analysis), Fourier transform infrared spectroscopy, and elemental CHN analysis. The increase in the interlayer distance from 15.02 to 16.36 Angstrom on going from KPP-hyd to KPP-hex was attributed to the replacement of water molecules with the longer hexylamine molecules in the phenylphosphonate P-O-H binding sites of the grafted KPP host. Upon heating, the phase KPP-hex release the hexylamine molecules that burn. The resulting KPP-dry is stable up to 498 degrees C, at which temperature the grafted phenylphosphonate begins to burn and the dehydroxilation of kaolinite takes place. (C) 1999 Academic Press.