J. Kahovec

Chemical modification of macroreticular 2-hydroxyethyl methacrylate-ethylene dimethacrylate copolymers

SummarySeveral chemical modifications of commercial macroreticular 2-hydroxyethyl methacrylate-ethylene dimethacrylate copolymers are described. The derivatives containing pendant imidazole, primary amino groups and complexon (EDTA and DTPA) groupings as well as oligo(N-acetyliminoethylene) and oligo(iminoethylene) grafts were prepared.

Polymer-supported dimethyl sulfoxide as phase-transfer catalyst

SummaryCrosslinked polystyrenes with pendant -CH2SOCH3 grouping are efficient phase-transfer catalysts in liquid-liquid reactions of 1-bromooctane with several inorganic nucleophiles. Direct introduction of -CH2SOCH3 grouping into polystyrene by the reaction of a halogenated polystyrene with methylsulfinyl-methylsodium is described.

EDTA ester of bead cellulose a fast-kinetics chelating sorbent

SummaryCrosslinked EDTA ester of cellulose (with 1–1.3 mmole bonded EDTA/g) was synthesized by the treatment of bead cellulose with EDTA bis-anhydride. Compared with the iminodiacetic acid resin, the cellulose EDTA ester exhibits a higher stability of Cu(II) chelates at low pH and a very high sorption rate of Cu(II). The sorbent is stable in neutral and acid medium, but is hydrolyzed by alkalies.

Polymer-supported oligo(N-acetyliminoethylenes) new phase transfer catalysts

SummaryOligo(N-acetyliminoethylenes), both free and grafted on polystyrene, polymethacrylate and cellulose were prepared by the ring-opening polymerization of 2-methyloxazoline. Their phase transfer catalytic activity in nucleophilic substitution reactions was examined.

Aldehyde functionalization of styrene polymers

SummaryTwo methods of the introduction of aldehyde group into polystyrene skeleton are described.

Immobilized complexon amides-cation exchangers of high chelating activity

SummarySeveral complexon cation exchangers with EDTA or DTPA complexon groupings attached through the amide bond to the polymer matrix of bead cellulose or of the methacrylate type were prepared. The cation exchangers are comparatively stable to alkaline hydrolysis. Chelating ability of the sorbents was examined by measuring the distribution coefficients in Cu(II) and Ni(II) sorption from EDTA solutions. In spite of the low total capacity cation exchangers with immobilized DTPA have distribution coefficients higher by an order of magnitude than a commercial iminodiacetic resin.

Simple synthesis of polymeric primary aromatic amines

SummaryA new simple and versatile method of obtaining polymers bearing aromatic primary amino groups was developed. The method consists in the reaction of an alkylating polymer with sodium 4-acetylaminobenzenesulfinate and subsequent deacetylation of the intermediate polymer by acid hydrolysis. Alkylating polymers such as chloromethylated polystyrene resin, tosylated macroporous poly (2-hydroxyethyl methacrylate), macroporous poly(glycidyl methacrylate) and PVC were used in the alkylation performed either in an organic swelling solvent or in an aqueous suspension under phase transfer catalysis conditions. Yields in the alkylation step depend largely on the type of the alkylating group, hydrolysis yields are essentially quantitative.

A metal sorbent with an unbound complexing agent: polyethylenimine-bead cellulose

SummaryA sorbent was prepared with branched polyethylenimine fixed on bead cellulose without chemical reaction. The “jack-in-the-box” effect was used by means of which a part of the originally adsorbed PEI remains, after treatment with strong acid, almost irreversibly fixed to cellulose. The sorbent contains 1.4–3.0 mmol N/g of dry matter and is able to bind some double-charged cations from acid solutions, both from buffered media (pH 2–4) and from hydrochloric acid (1–4 M).