General Electric Company

Carol B Berman

Thomas L Evans

John Jeffrey Talley

Substituted phenols and phenyl carbonates derived therefrom, such as 2,4-dinitrophenol and 2,4-dinitrophenyl carbonate, are employed to inhibit the formation of linear polycarbonates from cyclic polycarbonate oligomers. Inhibition of polymerization initiated by impurities in the cyclics is noted. When polymerization is effected by basic polycarbonate formation catalysts, the phenols or phenyl carbonates decrease reaction rate.

Cyclic polycarbonate oligomers: inhibition of polymerization to linear

Lewis acids such as triphenyl borate, triphenylborane and aluminum isopropoxide are employed to inhibit or control the formation of linear polycarbonates from cyclic polycarbonate oligomers. Inhibition of polymerization initiated by impurities in the cyclics is noted. When polymerization is effected by basic polycarbonate formation catalysts, the Lewis acids can act as reaction rate accelerators or inhibitors depending on reaction parameters.

Cyclic polycarbonate oligomers: inhibition and control of polymerization

Cycle polycarbonate oligomers: inhibition and control of polymerization

Cyclic polycarbonate oligomers are polymerized to linear polycarbonates by contact with a catalyst comprising a polymer containing alkali metal phenoxide moieties. Said polymer is preferably a polycarbonate and the alkali metal is preferably lithium. The catalyst polymer may be prepared by the reaction of a polymer with phenolic moieties with an alkali metal base such as lithium phenoxide at a temperature in the range of about 200.degree.-300.degree. C.

Method for polymerizing cyclic polycarbonate oligomers with catalyst

Flame retardant blends of styrene and polyphenylene oxide are provided resulting from the use of a mixture of zinc oxide and a triorganothiophosphate.

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Schenectady, NY, United States of America

Carol B Berman