Preparation and thermal properties of calcium containing organic phosphorous compounds synthesized through reactions of calcium acetate monohydrate with phenylphosphonic acid or phosphoric acid mono-n-butyl ester

Calcium containing organic phosphorous compounds were synthesized through r eactions of calcium acetate monohydrate with phenylphosphonic acid or phosp horic acid mono-n-butyl ester in 50 vol% ethanol/water solution, and they w ere abbreviated as Phenyl Ca-P and Butoxy Ca-P, respectively. The effects o f the phenyl and butoxy groups on the specific surface area, particle shape and thermal properties of calcium containing organic phosphorous compounds were investigated. As the amounts of added calcium acetate monohydrate (Ca /P) increased from 0.5 to 2 in the reaction solutions, the Ca/P ratios in c alcium containing organic phosphorous compounds changed from 0.5 to 1. Calc ium containing organic phosphorous compounds are self-assembled and have a layered structure. The interlayer distance of Phenyl Ca-P was shorter than that of Butoxy Ca-P. The Butoxy Ca-P particle was flake shaped, and the Phe nyl Ca-P particle was an aggregate of tubular particles. The specific surfa ce area of Phenyl Ca-P (30 m(2)/g) was larger than that of Butoxy Ca-P (5-6 m(2)/g). The thermal decomposition temperature of Phenyl Ca-P (300 degrees C) was higher than that of Butoxy Ca-P (250 degreesC). The crystal structur e of calcium phosphate transformed from amorphous calcium phosphate to alph a -Ca2P2O7 by the thermal decomposition of calcium containing organic phosp horous compounds. It was possible to prepare a porous material with a hydro phobic group by using phenylphosphonic acid as a starting material.