A low molecular weight polyether with B15-C-5 in the side chain was synthesized by the reaction of hydroxymethyl benzo(15-crown-5) with a copolymer of β-iodoethyl glycidyl ether and THF. This polymeric crown ether possess good coordination ability with K+

Na+ and is an effective phase-transfer catalyst for some organic reactions. In addition

this polye-ther is a brown viscous oil

having reactive hydroxyl groups

and can be vulcanized with toluene diisocyanate to form a elastic film or immobilized on silica gel.