Synthesis and hydrolysis kinetics of a six-membered heterocyclic borate ester

摘要

Borate ester become an important interfaces modifying agent which can reinforce the mechanical and processing property of energetic composites. Thus, we synthesized a borate ester with a six-membered ring by borate acid, 1,3-propylene glycol and 1,2,4-butanetriol through two steps reaction. Chemical structures of the compound were characterized by Fourier transform infrared (FT-IR) spectroscopy. Then the structure of the borate ester was further confirmed by boron nuclear magnetic resonance (~(11)B NMR) and proton nuclear magnetic resonance (~1H NMR) spectroscopy. The hydrolysis kinetics of the synthesize borate ester in water and in air was investigated by online infrared spectroscopy. The hydrolysis kinetic model was established. The results show that the hydrolysis reaction of the synthesized six-membered ring borate ester followed a pseudo-first-order kinetics on above two conditions. The reaction rate constant of the borate ester in water and in air is 2.06×10~(-6) s~(-1) and l.01×10~(-3) d~(-1), respectively. The half life in water and in air is 93.5 hour and 686 day, respectively. The hydrolysis kinetics results provide the theoretical foundation for revealing the hydrolysis mechanism of borate ester.