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.

Abstract

Calcium containing organic phosphorous compounds were synthesized through reactions of calcium acetate monohydrate with phenylphosphonic acid or phosphoric acid mono-n-butyl ester in 50vol% ethanol/water solution, and they were abbreviated as Phenyl Ca-P and Butoxy Ca-P, respectively. The effects of 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 calcium containing organic phosphorous compounds changed from 0.5 to 1. Calcium 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 Phenyl Ca-P particle was an aggregate of tubular particles. The specific surface area of Phenyl Ca-P (30m2/g) was larger than that of Butoxy Ca-P (5-6m2/g). The thermal decomposition temperature of Phenyl Ca-P (300°C) was higher than that of Butoxy Ca-P (250°C). The crystal structure of calcium phosphate transformed from amorphous calcium phosphate to u-Ca2P2O7 by the thermal decomposition of calcium containing organic phosphorous compounds. It was possible to prepare a porous material with a hydrophobic group by using phenylphosphonic acid as a starting material.