INTERCALATION OF INSULATING POLYMERS INTO LAYERED ZIRCONIUM-PHOSPHATES

The ability of layered alpha- and gamma-zirconium phosphates to interc alate directly some insulating oligomers (PEG 300 Da, PEG 600 Da) or p olymers (PEO 2 x 10(5) Da, PEO 6 x 10(5) Da, PEI 2 x 10(5) Da) has bee n investigated. The intercalation was obtained by various synthetic st rategies: the zirconium phosphates, pre-swelled with ethanol or butano l, were equilibrated with the oligomers as such or with the polymers d issolved 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 pho sphate 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 ob tained have been characterized by H, C, N elemental analysis, XRD powd er 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 inter layer distance suggests that the polymers are intercalated with the ch ain axis parallel to the layer plane; in only one case does the expans ion indicate the presence in the interlayer region of the polymer in a coiled conformation. The PEG and PEO guests are displaced when the co mposites are washed with water or exposed to NH3 vapor or heated at te mperatures higher than 180-degrees-C.