Poly(ethylene oxide) grafted onto polystyrene-divinylbenzene macroporous resins. Covalent binding of mercuric chloride
✍ Scribed by M. Lauth; Y. Frère; B. Meurer; Ph. Gramain; M. Prévost
- Publisher
- Elsevier Science
- Year
- 1990
- Weight
- 781 KB
- Volume
- 12
- Category
- Article
- ISSN
- 0923-1137
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✦ Synopsis
Chelating resins selective for mercuric chloride have been prepared by the reaction between chloromethylated macroporous styrene-divinylbenzene copolymers (PS-DVB) and monomethoxy-polyoxyethylenes of three different molecular weights (M w = 164, 350 and 750). It has been shown that the degree of grafting on the PS-DVB matrix is limited by the steric hindrance of the initially grafted polymeric coils. These resins bind mercuric chloride by forming polycomplexes with one mercury atom for each four ethylene oxide units. This stoichiometry is independent of the chain length, in contrast to the case observed with poly(ethylene oxide) (PEO) in water or ethanolic solution. Infrared spectroscopy and anion effects confirm that the complexed species is covalent mercury and not any ionic form. 1H NMR experiments, using the free induction decay technique on a wet resin containing the longer PEO chain at the maximum ratio of grafting, indicate that 77% of the PEO hydrogens are mobile at room temperature and become rigid in the complex.