Synthesis and characterization of calix[4]arene-containing polyimides

Three types of amino-functionalized calixarenes, i.e. the diaminocalix[4]arenes 5,17-diaminomethyl-25,26,27,28-tetrapropoxycalix[4]arene, 25,27-diaminoethoxy-26,28-dihydroxycalix[4]arene and 5,11,17,23-tetra-tert-butyl-25,27-diaminoethoxy26,28-dihydroxycalix[4]arene, were synthesized and incorporated as comonomers into the backbones of aromatic polyimides. As a first step, polyimide precursors (poly(amic acid) s) were prepared by condensation reaction of diamine with dianhydride at the stoichiometric ratio. The diamine component was composed of synthesized diaminocalix[4] arene and commercial 4,4'-oxydianiline combined in various molar ratios. The dianhydride used was 4,4'-oxydiphthalic anhydride. The poly(amic acid) s were characterized using intrinsic viscosity measurements and their chemical composition was determined using (1)H NMR spectroscopy. The precursors were then transformed into the polyimides using a thermal treatment. Thermal and dynamic mechanical behaviour, wide-angle X-ray diffraction and solubility of the resulting polyimide films in selected solvents were evaluated. The structure-property relationship of the novel types of synthesized polyimides is discussed in terms of the calixarene monomer used and the fraction of it incorporated into the polymer backbone. (C) 2010 Society of Chemical Industry