Study On The Preparation And Uranium Adsorption Performance Of Polyphosphazene Materials

In this paper,new inorganic-organic hybrid polyphosphazene materials were prepared by cross-linking hexachlorocyclotriphosphazene with multifunctional compounds containing amine groups and hydroxyl groups.Furthermore,functional or composite polyphosphazene adsorbents were obtained via post-functionalization or composition.Researches are as follows:（1）Multi-amino polyphosphazene microspheres（PCCP）were obtained by precipitation polymerization of hexachlorocyclotriphosphazene（HCCP）and high molecular weight polyethyleneimine（PEI）.Besides,amidoximated polyphosphazene microspheres（PCCP-AO）were prepared by cyanoethylation and then amidoximation of PCCP.U（Ⅵ）adsorption experiments show that PCCP-AO has a faster adsorption rate and a higher adsorption capacity than PCCP.Under the condition of p H 5,an initial uranium（Ⅵ）concentration of 56mg/L and a contact time of about 4h,the U（Ⅵ）adsorption capacity of PCCP-AO is up to319.1 mg/g.Meanwhile,PCCP-AO has a better selectivity than PCCP,which could selectively remove uranyl ions in the presence of K⁺,Mn²⁺,Cu²⁺,Zn²⁺,and Sr²⁺.Mechanism studies indicate that PCCP-AO can capture uranyl ions quickly and efficiently through the amidoxime groups.Besides,PCCP-AO has a good reusability.（2）A composite polyphosphazene material（n-HAP/PCPP）was obtained by introducing nano-hydroxyapatite（n-HAP）into the polymerization system of hexachlorocyclotriphosphazene（HCCP）and phloroglucinol.After coposition,the stability and uranium adsorption performance of n-HAP/PCPP were further improved.Under the conditions of an initial U（Ⅵ）concentration of 54 mg/L and a p H of 5,n-HAP/PCPP can reach adsorption equilibrium in about 90 minutes,and its equilibrium adsorption capacity（q_e）is adout 160.4 mg/g.Data show that n-HAP/PCPP can capture uranyl ions in aqueous solutions via ion exchange and coordination of functional groups.