Preparation Of Anion-exchange Resins Research Articles

Preparation of Anion Exchange Resin Loaded with Ferric Oxide for Arsenic (V) Removal from Aqueous Solution

Preparation of Anion Exchange Resin Loaded with Ferric Oxide for Arsenic (V) Removal from Aqueous Solution

Preparation of anion exchange resin by recycling of waste printed circuit boards

The treatment of the non-metal components of waste printed circuit boards (WPCBs) is very difficult because they are inflexible and insoluble, and thus a new method to convert them into anion exchange resin was studied.

Polymeric anion exchangers for recovery of precious metals

The paper is a literature review concerning the recycling of precious metals: Au, Pt and Pd with particular focus on the possibility of using synthetic polymeric anion exchangers as an alternative method of recovery of metal traces from the solutions. The advantages resulting from the use of anion exchangers in the recycling process in terms of global demand for precious metals have been discussed. Commercial anion exchange resins offered by worldwide companies for the recovery of Pt, Pd and Au were described. The results of authors' studies on the preparation of anion exchange resins based on vinylbenzyl chloride copolymers for the sorption of precious metals have been presented.

Preparation of Anion-Exchange Resin Based on Styrene-Divinylbenzene Copolymer Obtained by Suspension Polymerization Method

Macroporous beads were prepared by suspension polymerization in a batch reactor. The chloromethylated PS-DVB copolymers were aminated through two methods. In the first, the chloromethylated PS-DVB copolymer aminated with two kinds of tertiary amines, in which a first tertiary amine having higher alkyl moieties, preferably trioctylamine, was substituted at chloromethylated sites, and the second tertiary amine, having lower alkyl moieties, preferably triethylamine, was substituted at unreacted chloromethyated sites, which was the lowest accessible in comparison to the first amine. At the second, the chloromethylated PS-DVB beads had aminated with 45% aqueous trimethylamine. Structures of polymers were identified using DSC, TGA, SEM and FT-IR spectroscopy.

Synthesis and Properties of Anion Exchangers Derived from Chloromethyl Styrene Codivinylbenzene and Their Use in Water Treatment

Amination of vinylbenzyl chloride-divinylbenzene (VBC-DVB) copolymers is an effective method for preparation of ion-exchange resins. Conventionally, the starting polymer is produced by chloromethylation of a styrene-divinylbenzene copolymer that utilizes chloromethyl methyl ether, a known carcinogen. An alterative approach is to copolymerize vinylbenzyl chloride with divinylbenzene to generate the necessary VBC-DVB. This method provides precise control over the density of the ion-exchange groups. The regiochemistry of the vinylbenzyl chloride methods was realized using solvent-ion exchange groups. In this investigation, an improved solvent system was found for the preparation of anion exchange resins by the vinylbenzyl chloride route. The effectiveness of amination of the intermediate VBC-DVB polymers with a variety of trimethylamine reagents was investigated, and ethanolic trimethylamine produced the highest degree of amination. These resulting ion-exchange polymers were characterized by a variety of techniques such as analytical titrations, nitrogen analysis, Fourier transform infrared spectroscopy and thermal gravimetric analysis. Testing of these copolymers for breakthrough was performed. The results indicate that these anion exchangers have a meaningful increase in thermal stability over commercial anionic exchange beads.

Preparation of anion-exchange resins from pine sulfuric acid lignin, one of the acid hydrolysis lignins

To utilize acid hydrolysis lignin effectively, chemical conversion to anion-exchange resin was investigated by two methods. Sulfuric acid lignin (SAL) was selected as a typical acid hydrolysis lignin in this experiment. Because it is less reactive, SAL was phenolated with sulfuric acid catalyst to yield reactive phenolized SAL (P-SAL) with p-hydroxyphenyl nuclei. One method was the restricted resinification of P-SAL followed by the Mannich reaction with formaldehyde and dimethylamine to yield a weakly basic anion-exchange resin with an ion-exchange capacity of 2.4 mEq/g. Another method was to react resinified P-SAL with glycidyltrimethylammonium chloride to yield a strongly basic anion-exchange resin with an ion-exchange capacity of 2.0 mEq/g. The reaction of a simple P-SAL model compound with an epoxide suggested that the phenolic hydroxyl group of the p-hydroxyphenyl nucleus had slightly higher reactivity than that of the guaiacyl nucleus.

Anion exchange resins prepared from polystyrene crosslinked via a Friedel–Crafts reaction

AbstractThe preparation of anion exchange resins from polystyrene crosslinked via a Friedel–Crafts reaction is investigated. Chloromethylation of a highly swollen styrene–hexahydrotriacrylolyl‐s‐triazine copolymer with a mixture of chlorosulfonic acid and methylal is accompanied by the crosslinking of the initially flexible copolymer. The crosslinking efficiency is dependent on the conditions (temperature, nature of solvent) of chloromethylation and can be explained by cationic postpolymerization of polystyrene or poly(benzylchloride), which takes place concurrently with the chloromethylation.

(297)イオン交換樹脂に関する研究 (第3報) 重金属吸着用アニオン交換樹脂の製造

(297)イオン交換樹脂に関する研究 (第3報) 重金属吸着用アニオン交換樹脂の製造