INTERCALATION OF INSULATING POLYMERS INTO LAYERED ZIRCONIUM-PHOSPHATES

The ability of layered alpha- and gamma-zirconium phosphates to intercalate directly some insulating oligomers (PEG 300 Da, PEG 600 Da) or polymers (PEO 2 x 10(5) Da, PEO 6 x 10(5) Da, PEI 2 x 10(5) Da) has been investigated. The intercalation was obtained by various synthetic strategies: the zirconium phosphates, pre-swelled with ethanol or butanol, were equilibrated with the oligomers as such or with the polymers dissolved in organic solvents at different temperatures; PEO of various molecular weights was intercalated by bringing the hosts into contact with the polymers held at a temperature a little higher than that of their glass transition. Intercalation compounds of alpha-zirconium phosphate with PEG 300 and PEG 600 have also been obtained by leaving the host to form in the presence of the oligomers. The composites thus obtained have been characterized by H, C, N elemental analysis, XRD powder patterns at room and high temperature and TG-DTA coupled analysis. The composition of the intercalates, expressed as moles of monomer per mole of Zr, ranges from 1 to 2.2. The observed expansion of the interlayer distance suggests that the polymers are intercalated with the chain axis parallel to the layer plane; in only one case does the expansion indicate the presence in the interlayer region of the polymer in a coiled conformation. The PEG and PEO guests are displaced when the composites are washed with water or exposed to NH3 vapor or heated at temperatures higher than 180-degrees-C.