Cation binding properties of polyesters with photodimerizable groups and oxyethylene units. Effect of photocrosslinking with template cations

Abstract

Polyesters with p-phenylene diacrylate units as photodimerizable groups and oxyethylene units as cation binding sites were prepared, COCHCHC 6H 4CHCHCOO+CH 2CH 2O+ m . The numbers m of repeating oxyethylene units in the oligoethylene glycols were 4, 5, 6 and 7. The alkali cation binding ability of the polymers increased with increases of m for all alkali metal cations examined. The cation selectivity order was found to be K + ≈ Rb + > Cs + > NH 4 + > Na + for all the polymers used. On irradiation with u.v. light, the polymers became insoluble. The polymer ( m = 7) which was crosslinked photochemically in the presence of potassium acetate as a template showed enhanced cation binding ability for alkali cations, especially for K + and Rb + cations, compared with the photocrosslinked polymers without templates.