Cation binding properties of poly(crown ethers) with photodimerizable groups

Abstract

AbstractPolymers that have crown ether groups as cation binding sites and cinnamic acid ester groups as photodimerizable groups were prepared by the cationic polymerizations of 2‐vinyloxyethyl 4′‐(2,3‐benzo‐1,4,7,10,13‐pentaoxa‐2‐cyclopentadecene)acrylate and 2‐vinyloxyethyl 4′‐(2,3‐benzo‐1,4,7,10,13,16‐hexaoxa‐2‐cyclooctadecene)acrylate. When irradiated with ultraviolet (UV) light the cinnamic acid ester groups of the polymers caused dimerization in dilute solution without the formation of insoluble materials. The irradiation was carried out in a dioxane solution and an aqueous solution in the presence and absence of salts. The effect of phototransformation of polymers on the cation binding properties was investigated by a method of picrate salts extraction. The binding ability of the phototransformed polymers for alkali and alkaline earth metal cations was higher than that of the native polymer. Furthermore the cation binding ability of the phototransformed polymers was less sensitive to temperature than that of the native polymer. The effect of the degree of photodimerization of the polymers and the concentration of KCl that exists during irradiation on the cation binding ability was also investigated.