Production of high‐molecular amphoteric compounds by means of polymer‐analogous conversions

Abstract

AbstractPolymer‐analogous transformations of styrene and divinylbenzene (DVB) copolymers permit us to obtain sulfonic cation‐ and anion‐exchange resins of a different basicity. In the last few years, new methods for the production of complex‐forming resins for nonferrous metals have been intensively developed. This paper is also devoted to this problem. Among the series of complexing resins, those derived from the ion‐exchange resins are the best known; they contain aminocarboxylic groups obtained by thermal treatment of an ion‐exchange resin with monohaloacetic acid in a low‐alkaline medium: magnified imageFor the improvement of the complexing ability, the presence of iminodiacetic acid groups is desirable. In our opinion, the simplest among many possible variants is oxidation of the ion‐exchange resin with diethanol amine groups. An acid solution of sodium dichromate may be applied as the oxidant. Other oxidizing agents tested do not give the desired results. The oxidation process requires great skill; otherwise, the resulting product could not be completely or excessively oxidized. An amphoteric ion exchanger of this type has been successfully used for the copper pulp process: magnified imageThe 2,5 methyl vinyl pyridine (MVP) and DVB copolymer can be transformed by two‐stage synthesis into an amphoteric ion exchanger containing an α‐picolinic acid group: magnified imageThe degree of transformation in the oxymethylation stage amounts to 85%; that in the oxidation stage ranges from 92 to 100%. To obtain a better complexing ability of the result‐ ing amphoteric ion‐exchange resin, it is necessary to use a macroporous modilkation.Anion‐exchange resins containing secondary amino groups can be converted into ion exchangers with dithiocarbamate groups if processed by carbon disulfide: magnified imageIn this case, the capactiy of the exchanger with respect to silver, mercury, and molybdenum greatly increases.Interaction of the high‐molecular hydrocarbon compound with chlorosulfonic acid and subsequent treatment of the resulting polysulfochloride with aliphatic diamines or poly‐ amines yielded compounds with cation‐ and anion‐exchange amino groups: magnified image