SYNTHESIS AND PROPERTIES OF OXYMETHYLENE-LINKED OXYETHYLENE OXYPROPYLENE STYRENE MULTIBLOCK COPOLYMERS

Oxymethylene-linked multiblock copolymers with two or three components (oxyethylene-oxypropylene-styrene) (EO-PO-St) were synthesized by cou pling polyethylene glycol with polypropylene glycol and/or telechelic dihydroxyl polystyrene, using dichloromethane as coupling agent and KO H 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 multiblo ck copolymers. D.s.c. and wide angle X-ray diffraction indicated the c rystallinity 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 copoly mer increases with polystyrene and PEO content as well as with the mol ecular weight of PEO blocks. The LiClO4 complex of the multiblock copo lymer (EO/PO = 95/5) shows very good room temperature conductivity, wh ich 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.