Studies On The Synthesis Of Polythioether-polyurethane Foam And Application Of Treating Heavy Metal Inwater

Polythioether–polyurethane foam was synthesized by polythioether modifingpolyurethane which is a new type of adsorption materials for heavy metal ions–newsulfide ether polyurethane foam.Study on the synthetic technology and adsorptionperformance of polythioether–polyurethane foam.Polythioether （PTE） was synthesized by sodium sulfide and1,2–dichloroethane.Under the action of the additives sodium silicate and catalyst of lithium chloride, withthe molar ratio of raw materials （sodium sulfide:1,2–dichloroethane） being1:1.1,stirring8h under（85±1）℃,finding white polythioether with productivity by81.42%.The main topic of the researeh is to determine the optimal conditions polythioether,makes its charaeter by elemental analysis, DSC and IR. Then mix PTE into thesynthetic raw material of polyurethane foam, modify traditional polyurethane foam,figure out the best molar ratio of every synthetic raw material is polythioether of2.5grams, polyther of10grams, tween–80of0.3mL, dibutyltin dilaurate of0.4mL,dimethyl silicone of0.5mL，glycerin of0.2mL，water of1.5mL and5mL ofTDI.The product of polythioether–polyurethane foam whose density is0.148g/mL,the rate of foam0.98,appearance and characters are relatively stable.After the token of the product, selected five heavy metal ions (Pb²⁺、Cu²⁺、Cd²⁺、Hg²⁺、Ni²⁺), made the static and dynamic adsorption tests for the product, andconsider the impactions of time, temperature, pH, velocity. Determine the bestadsorption conditions of static and dynamic adsorption. The adsorption balance timeof this foam on the five types of heavy metal ions is4h; the best adsorption pH ofPb²⁺,Cd²⁺is5.5; Cu²⁺is5.0; Hg²⁺is3.0, and it isn’t changed with pH to theadsorption rate of Ni²⁺. With the rise of temperature the adsorption capacity decreases,and with the increase of the initial concentration increases. Polythioether–polyurethane foam selected five heavy metal ions(Pb²⁺、Cu²⁺、Cd²⁺、Hg²⁺、Ni²⁺),theirsaturation adsorption capacity were7.13mg/g,6.45mg/g,6.07mg/g,7.34mg/g,3.57 mg/g with the optimal conditions. The optimum flow is l.0mL/min in the dynamicadsorption. Then find that the adsorption function has decreased by about8%after theelution function regeneration with the mixed solution of the concentration of2%thiourea and5%HCl20mL.