Polyether esters of zirconium phosphate

Abstract

The reaction of ethylene oxide with (alpha)-zirconium phosphate, (alpha)-Zr(HPO(,4))(,2)(.)2H(,2)O was investigated. (gamma)-Zirconium phosphate, Zr(HPO(,4))(,2)(.)2H(,2)O, with a 12.2(ANGSTROM) interlayer spacing is known to react with ethylene oxide solutions to esterify the monohydrogen phosphate groups. It has been shown that (alpha)-zirconium phosphate with a smaller interlayer distance, 7.6(ANGSTROM), also behaves similarly. With highly crystalline samples of (alpha)-zirconium phosphate, reaction takes place only at the surface. However, if the interlayer distance is first increased (by means of amine, alcohol, or glycol intercalates, or by use the more hydrated (theta)-phase, with a 10.4(ANGSTROM) of interlayer spacing) so that ethylene oxide can diffuse into the interior, complete reaction occurs. Less crystalline samples were found to react directly with ethylene oxide, either gaseous or as a solution. Attempts to form long chains by direct reaction with ethylene oxide were unsuccessful. Use of intercalates and stronger reaction conditions, as compared to those used for (gamma)-zirconium phosphate, gave positive results in the exchange of orthophosphate groups when small phosphate esters were tried. The compounds obtained have the general formula (alpha)-Zr(ROPO(,3))(,2), where R = CH(,2)-CH(,3) and CH(,2)-(CH(,2))(,2)-CH(,3). A series of polyether phosphates R(-OCH(,2)-CH(,2)-)(,n)OPO(,3)H(,2) (R = H, -CH(,3), -CH(,2)-CH(,3); and n = 1, 2, 3, 4, 9, 12, 13, 22.) were prepared and reacted with Zr(IV). Polyether analogues of (alpha)-zirconium phosphate were obtained. These derivatives become more hydrophilic as the chain length of the polyether increases, as shown by the greater degree of swelling on contact with water and culminating in the colloidal dispersion of the complex when n = 9. Polyether diphosphates were also prepared and reacted with Zr(IV). The resultant derivatives are pillared compounds with a cage-like structure in which the sides of the cages are polyether chains. Phosphonate derivatives were obtained from the corresponding phosphonic acid and Zr(IV). These compounds exhibit higher thermal stability and resistance towards hydrolysis. The ion exchange and complexing properties of this new family of compounds were examined. Cu(II), Pd(II), and Ru(bpy)(,3) ('2+) were used in this study. It was found that the chain length has no influence on the amount of cation exchanged. . . . (Author's abstract exceeds stipulated maximum length. Discontinued here with permission of author.) UMI