New Eco-Friendly Phosphorus Organic Polymers as Gas Storage Media.

Three phosphate esters ⁻ were successfully synthesized from the reaction of 2-, 3- and 4-hydroxybenzaldehyde with phosphoryl chloride. Reactions of ⁻ with benzidine in the presence of glacial acetic acid gave the corresponding novel phosphorus organic polymers ⁻ 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 ⁻ 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 ⁻ exhibit tunable porosity with Brunauer⁻Emmett⁻Teller surface area (SA = 24.8⁻30 m²·g), pore volume (0.03⁻0.05 cm³·g) and narrow pore size distribution, in which the average pore size was 2.4⁻2.8 nm. Polymers ⁻ were found to have high gas storage capacity and physico-chemical stability, particularly at a high pressure. At 323 K and 50 bars, polymers ⁻ have remarkable carbon dioxide uptake (up to 82.1 cm³·g) and a low hydrogen uptake (up to 7.4 cm³·g). The adsorption capacity of gasses for polymer was found to be higher than those for polymers and .