Reactivity of 2-Phosphonobutane-1,2,4-tricarboxylic Acid Esterification

摘要

In this study. 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA), a phosphorus-containing monomer, was used as raw materials to synthesize phosphate polyester polyol by esterification reaction. The esterification of PBTCA was investigated with different small primary alcohols by the change of acid value (A,) and the products were characterized with Fourier transform infrared spectra and phosphorus nuclear magnetic resonance (~(31)P NMR). The results indicated that there were three types of phosphorus-containing esters formed in the esterification reaction system of PBTCA. Firstly, one of hydroxyl groups in the phosphonic group reacted with small molecules of primary alcohols and then the carboxylic acid groups at 1,4 sites reacted with primary alcohols to form esters. The effects of initial reactant molar ratio and water content of PBTCA on corresponding ester composition were examined.