Abstract
Three phosphate esters 1-3 were successfully synthesized from the reaction of 2-, 3-and 4-hydroxybenzaldehyde with phosphoryl chloride. Reactions of 1-3 with benzidine in the presence of glacial acetic acid gave the corresponding novel phosphorus organic polymers 4-6 containing the azomethane linkage. The structures of the synthesized compounds were confirmed by Fourier transform infrared spectroscopy, nuclear magnetic resonance and elemental analysis. Interesting physiochemical properties for the polymeric materials 4-6 were observed using a combination of several techniques such as gel permeation chromatography, scanning electron microscopy, Brunauer-Emmett-Teller and nitrogen adsorption-desorption isotherm, Barrett-Joyner-Halenda and H-sorb 2600 analyzer. The mesoporous polymers 4-6 exhibit tunable porosity with Brunauer-Emmett-Teller surface area (SA(BET) = 24.8-30 m(2) . g(-1)), pore volume (0.03-0.05 cm(3).g(-1)) and narrow pore size distribution, in which the average pore size was 2.4-2.8 nm. Polymers 4-6 were found to have high gas storage capacity and physico-chemical stability, particularly at a high pressure. At 323 K and 50 bars, polymers 4-6 have remarkable carbon dioxide uptake (up to 82.1 cm(3).g(-1)) and a low hydrogen uptake (up to 7.4 cm(3).g(-1)). The adsorption capacity of gasses for polymer 5 was found to be higher than those for polymers 4 and 6.