Synthesis and Adsorption Characteristics of Polystyrene Based Chelating Resins
Choi KS, Chung TS, Park KD, Han SU
폴리스티렌 유도체계 킬레이트수지의 합성 및 그 흡착특성에 관한연구
최규석, 정택상, 박기동, 한승욱
Abstract
Aminated polystyrene-based chelating resins were prepared by chloromethylation of styrenedivinybenzene copolymer(DVB 3%), followed by the reaction with amines such as diethylenetriamine(A23), triethylenetetramine(A34), and tetraethylene-pentamine(A45), respectively, Graft poly(styrene-g-ethyleneimine) chelating resin(MH resin) was synthesized by the reaction of chloromethyated copolymer with 2-methyl-2-oxazoline, followed by alkali hydrolysis, The carboxymethylated chelatin resins were also prepared by carboxymethylation of the aminated resins with monochloroacetic acid, and adsorptivities of the heavy metal ions such as Hg++, Pb++, Cd++ and Cr+6 ions to these chelating resins were investigated. In the case of Hg++ ions, all the aminated resins showed high adsorptivity (>95%) and adsorptivities of the metal ions at pH range 4.5∼7.0 to A23, A34, and A45 resins were in the following order: Hg++>Cr++>Cd++>Pb++. However, to MH resin, the order was altered as follows: Hg++>Pb++>Cd++>Cr+6. Comparing the adsorptivity of the carboxymethylated resins with the aminated resins, it was concluded that the adsorptivity of Cr+6 ion was improved remarkably by introducing carboxymethyl group, but to Hg++ and Cd++ ions adsorptivity were not improved, and it was also observed that the adsorption of Hg++ ion to the aminated resins was not affected by the presence of Na+ and Ca++. It was noteworthy that the carboxymethylated chelating resins containing the ligand of the similar structure to EDTA in the side chain showed the following adsorptivity order in agreement with the order of the stability constants of these metal ions to the low molecular weight EDTA i.e.: Hg++>Pb++>Cd++.
스티렌-디비닐벤젠 공중합체(DVB 3%)를 합성하여 클로로메틸화 반응으로 -CH2Cl기를 도입시킨후 디에틸렌트리아민(A23), 트리에틸렌테트라민(A34), 테트라에틸렌펜타민(A45)등의 아민류와 반응시켜 아미노화폴리스티렌계 킬레이트수지를 합성하였으며, 또한 2-메틸-2-옥사졸린과 반응시켜 그라프트공중합체인 폴리(스티렌-g-에틸렌아민) 킬레이트수지(MH수지)를 합성하였다. 이 수지들을 다시 카르복시메틸화시켜 카르복시메텔유도체계 킬레이트수지를 합성하였고, 이 수지들의 중금속이온들(Hg++, Pb++, Cd++ 및 Cr+6)에 대한 흡착성능을 검사하였다. 아미노화 킬레이트수지의 경우 Hg++이온에 대한 흡착능은 한결같이 95%이상으로 좋았으며 A25, A34, A45 수지들에 대한 흡착능의 순서는 pH 4.5이상에서 Hg++>Cr+6>Pb++이지만 MH수지의 경우는 Hg++>Pb++>Cd++>Cr+6의 순서였다. 아미노화 및 카르복시메틸화 수지의 흡착능을 비교해보면 Cr+6이온의 경우는 카르복세메틸화로 크게 향상되었으나 Hg++ 및 Cd++이온에 대해서는 개선되지 않았다. 또한 Hg++이온이 Na+와 Ca++이온과 혼합용액을 이룰때의 흡착능은 단독용액인 경우와 거의 같았다. EDTA와 유사구조의 리간드를 곁사슬에 가진 카르복시메틸화수지의 흡착능이 저분자인 EDTA에 대한 안정도상수의 순서인 Hg++>Pb++>Cd++와 일치하는 흥미있는 사실이 관측되었다.
Polymer(Korea) 폴리머
Frequency : Bimonthly(odd) ISSN 0379-153X(Print) ISSN 2234-8077(Online) Abbr. Polym. Korea