Síntese e caracterização de coacervatos de polifosfatos e seus produtos de decomposição térmica

Abstract

In the present work, the relationships between the structure and the decomposition of polyphosphate coacervates were studied. Coacervates are transparent amorphous materials obtained through the process of coacervation of sodium polyphosphate (NaPO3)n solutions using an electrolyte such as calcium chloride (CaCl2). Due to the great scientific and technological importance of polyphosphates and coacervates, there was interest in the attempt to incorporate new materials into coacervates, such as telluric acid [Te(OH)6]. New polyphosphate coacervates of calcium and tellurium were obtained through the coacervation reaction between the polyphophate chains, calcium ions and aqueous telluric acid. The incorporation of telluric acid into coacervate occurred by two different methods. Raman and Infrared Spectroscopy, 31P NMR and X-Ray Diffraction studies were carried out to evaluate the structural properties of the materials and their respective degradation products by the action of time and temperature. This work shows changes in the different connectivity between oxygen and the [PO42-] groups and it was possible to propose structures for the decomposition of coacervates through tetrahedral species (Q0, Q1, Q2 and Q3).