Preparation of polyethers via proton acid catalyzed transetherification reactions

An approach for the preparation of polyethers by a transetherification rout e has been developed. This approach involves the melt condensation of a dio l with a specifically designed diether in the presence of a catalyst to yie ld polyethers with the exclusion of two moles of a low boiling alcohol, in this case methanol. The diether monomers are designed so as to contain two labile benzyl methyl ether linkages that can readily undergo a transetherif ication process. These diether monomers (5a and 5b) readily undergo transet herification polycondensation with di-, tri- and tetraethylene glycols as w ell as with a variety of aliphatic diols to yield polymers of moderately hi gh molecular weights. The glass transition temperatures (T-g) of the polyme rs decrease with increasing length of the diol. Melting transitions (T-m) a re observed only in some polymers containing aliphatic units but those with the oligo(ethylene oxide) units are completely amorphous. Preliminary ioni c conductivity studies indicate that the polyethers with oligo(ethylene oxi de) units could serve as excellent candidates in solid polymer electrolyte applications.