| 摘要 |
1,130,269. Stabilizing polyphenylene oxides. GENERAL ELECTRIC CO. 1 Aug., 1967 [8 Aug., 1966], No. 35380/67. Heading C3R. Polyphenylene oxides of improved resistance to oxidative degradation at elevated temperature are obtained by contacting solutions of the polyphenylene oxides with ketenes of formula where R<SP>1</SP> and R<SP>2</SP> are hydrogen atoms or alkyl radicals containing 1 to 6 carbons atoms, and recovering the stabilized polyphenylene oxides from the solutions. In examples poly-(2,6- dimethyl-1, 4-phenylene) oxide is stabilized by contact with butylethylketene and with unsubstituted ketene, and poly-(2-methyl-6- phenyl-1, 4-phenylene) oxide and poly-(2,6- diphenyl - 1,4-phenylene) oxide are stabilized by contact with butylethylketene; triethylamine is present as a catalyst. Other stabilizers, e.g. 2-mercaptobenzimidazole dibenzoate, phenylneopentyl phosphite, a 2-mercaptobenzothiazole or a 2-mercaptobenzoxazole benzoate, may be used in combination with the ketene.
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