Preparation Of Biurea/Montmorillonte Nanocomposite Via In Situ Synthesis

Biurea/montmorillonte (BU/Mont.) nanocomposite was prepared by in situ synthesis in the layer space of Mont.. Specifically, a certain amount of hydrazine was added into the Urea/montmorillonite (Urea/Mont.) nanocomposite which was prepared from urea and Mont. by solution intercalation, and then they reacted in the layer space to form BU.The BU/Mont. nanocomposite was characterized by means of XRD, solid state NMR, FT-IR and TG-DTA. The results suggested that BU was intercalated into the nano layers of Mont. and hydrogen bonds were formed between the NH2 and C=O of BU and the inner hydroxyls of Mont..The intercalation of BU was confirmed by the increase in basal spacing of Mont. from 1.51 to 1.71 nm, which was larger than that of Urea/Mont. HMI. The 13C chemical shift of the carbonyl of BU/Mont. was shifted from 163.2 ppm in BU to 163.5 ppm after the intercalation, while the 15N chemical shift of the amino of BU/Mont. was shifted from 103.9 ppm,76.8 ppm to 103.4 ppm,76.3 ppm.In the FT-IR spetra, the characteristic carbonyl absorption band of BU was red-shifted from 1688 cm-1 to 1665 cm-1. The strentching vibrations of -NH2were blue-shifted from 3397 cm-1,3305 cm-1 to 3407 cm-1,3334 cm-1, which were due to the hydrogen bonds between-NH2, C=O and the hydroxyl of Mont.. These further confirmed that BU was intercalated into the nano layers of Mont.. After intercalation, due to the increased dispersion of BU, it showed that there were also two endothermic peaks of BU in the layer space of Mont. in TG-DTA curves, however, the decomposition temperature of BU/Mont. lower 10℃than that of pure BU.