PREPARATION AND CHARACTERIZATION OF PHOSPHORIC-ACID CATION-EXCHANGE RESINS.
Item
-
Title
-
PREPARATION AND CHARACTERIZATION OF PHOSPHORIC-ACID CATION-EXCHANGE RESINS.
-
Identifier
-
AAI8302543
-
identifier
-
8302543
-
Creator
-
SELZER, RUSSELL B.
-
Contributor
-
Darryl G. Howery
-
Date
-
1982
-
Language
-
English
-
Publisher
-
City University of New York.
-
Subject
-
Chemistry, Physical
-
Abstract
-
Cation-exchange resins containing phosphoric-acid-monoester (PME) and phosphoric-acid-diester (PDE) groups based on a styrene/divinylbenzene copolymer matrix are prepared and characterized. These materials are used to investigate the interactions of the phosphate groups with cations.;The synthesis involves conversion of the styrene/DVB copolymer to 2-polystyrylethanol (alcohol resin) through a five-step reaction sequence. The copolymer side chain is formed through chloromethylation and nitrile formation. The nitrile resin is converted to the alcohol resin through hydrolysis and reduction. Condensation of the alcohol resin with a phosphate monoester under the action of trichloroacetonitrile produces the phosphate exchangers. Thus, reaction with monoethyl phosphate produces the PDE resin and reaction with 2-cyanoethyl phosphate produces the PME resin. The specific experimental conditions required to effect these reactions are discussed. The resins are stable under a variety of conditions.;The results of several physicochemical characterizations, including the capacities, water contents, equilibrium selectivities, infrared spectra and electrical conductivities of several ionic forms of each resin, are reported. One PME resin has a total capacity of 2.69 meq/g and consists of stronger-acid groups (pK = 1.9) and weaker-acid groups (pK = 7.5), each accounting for fifty percent of the total cation-exchange capacity. One PDE resin consists of moderately strong-acid groups (pK = 2.5) and has a capacity of 1.26 meq/g. The water contents of ten ionic forms of the PME resin and six forms of the PDE resin are measured. Typical water contents (%H(,2)O) are: for the PME resin, 22.3 for the H('+)-form and 39.1 for the Na('+)-form; for the PDE resin, 17.9 for the H('+)-form and 28.8 for the Na('+)-form. The equilibrium isotherms for ten cation pairs for the PME resins and five cation pairs for the PDE resins are determined. The resins are highly selective for the proton and for polyvalent cations.;(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI).;The infrared spectra of 14 ionic forms of each resin are recorded. The IR spectra are typical of ionized phosphate groups, and the differences among the spectra are used to distinguish the mode of bonding by the various cations. Interactions are ionic for the Group IA cations while associative interactions govern the bonding in the other ionic forms. The electrical conductivities of 4 ionic forms are measured and are found to be particulary low for the Ca('2+)- and Cu('2+)-forms.
-
Type
-
dissertation
-
Source
-
PQT Legacy CUNY.xlsx
-
degree
-
Ph.D.
-
Program
-
Chemistry
