ABSTRACT
1,2-epoxides, or vicinal epoxides, include the alkylene oxides, the simplest of which is ethylene oxide. The mechanism of the ferric chloride-propylene oxide complex-initiated polymerization has been considered to be a coordinate anionic polymerization in which monomer, propylene oxide, first coordinates with iron, followed by nucleophilic attack of the alkoxide group on one of the oxirane carbons. Osgan and Price did extensive work with both the 1-propylene oxide and the d, 1-propylene oxide in both potassium hydroxide and ferric chloride/propylene oxide-initiated polymerizations. Most ring-opening polymerizations present no difficulties in ascertaining the configuration of the polymer produced. The configuration is evident from the monomer and polymerization mechanism. Stereospecific olefin polymerizations are generally of the latter type, while both types probably have been observed with the alkylene oxides. Considerable confusion arises in the literature concerning the stereochemistry of the polymerization of epoxides because of an early error in the assignment of the configuration of 1-propylene oxide.
