The Na2CO3-promoted polymerization of 1,3-dioxolan-2-one (I) to afford poly
(ethylene glycol)III was reinvestigated. The reaction appeared to involve a
nucleophilic attack against the carbonyl and methylene groups of I to affo
rd poly(carbonate) II with poly(ethylene glycol) Linkages and ethylene oxid
e IV as a side product (10-22%). As the reaction progressed, poly(carbonate
) If decreased and poly(ethylene glycol) III increased. Under some conditio
ns, poly(ethylene glycol)s V and VI with vinyl ether terminal groups were f
ormed unexpectedly. The formation of unsaturated products during the polyme
rization of I/EO (ethylene oxide) has not been reported in the literature.
We believe that vinyl ethers were formed from the degradation of poly(carbo
nate)s and were accompanied by a reduction in molecular weight. The structu
res of vinyl ethers V and VI were confirmed by hydrogenation of the double
bond into the ethyl ether group in VIT and Vm, respectively. (C) 2000 John
Wiley & Sons, Inc.