Oxymethylene-linked multiblock copolymers with two or three components (oxyethylene-oxypropylene-styrene) (EO-PO-St) were synthesized by coupling polyethylene glycol with polypropylene glycol and/or telechelic dihydroxyl polystyrene, using dichloromethane as coupling agent and KOH as catalyst. The copolymers were purified, characterized by i.r., H-1 n.m.r., g.p.c. and membrane osmometry, and were shown to be multiblock copolymers. D.s.c. and wide angle X-ray diffraction indicated the crystallinity of the copolymer, which depended on the molecular weight and content of polyoxyethylene (PEO) blocks. The multiblock copolymers exhibit good emulsifying properties and good phase transfer catalyst properties in Williamson reactions. The tensile strength of the copolymer increases with polystyrene and PEO content as well as with the molecular weight of PEO blocks. The LiClO4 complex of the multiblock copolymer (EO/PO = 95/5) shows very good room temperature conductivity, which reaches 5.8 x 10(-4) S cm-1 at 25-degrees-C and 1.2 x 10(-3) S cm-1 at 30-degrees-C.