Using diphenylmethane diisocyanate (MDI) and trimethylol propane (TMP) as raw materials

polyurethane midbodys were synthesized under mild conditions. The surface end group —NCO and chelating agent containing —NH

2

—SH active group were added to extend the chain reaction to prepare the chelating polyurethane adsorbent (PU-MEAM). The types and dosages of chelating agents were optimized with adsorption capacity and adsorption rateas the index

the structure was characterized by IR

XRD and SEM

the adsorption performance was investigated of the amino modified polyurethane adsorbent of Hg (Ⅱ) ions in water. The results showed that the adsorption capacity reached 48.34mg·g

-1

of PU-MEAM was better when the chelating agent melamine was 1 mmol

at normal temperature

pH value 4

time was 60min and initial concentration was 100mg·L

-1

Adsorption kinetics conforms to the quasi-second-order kinetics model and belongs to chemical adsorption

Adsorption thermodynamics conforms to the Langmuir model of monolayer adsorption

In Hg(Ⅱ) and Ca(Ⅱ)

Mg(Ⅱ) in the mixed system of Hg (Ⅱ) with high selectivity

respectively

selectivity coefficients were 14.82 and 7.75.