| 摘要 |
1,241,612. Stabilizing poly-(phenylene oxides). GENERAL ELECTRIC CO. 10 Oct., 1969 [23 Dec., 1968], No. 49960/69. Heading C3R. In a process for stabilizing poly-(phenylene oxides) wherein the hydroxyl groups of the polymer are capped by reaction with suitable materials to form substituents inert to an oxygen-containing atmosphere, the colour of the polymer is reduced by also reacting the polymer in solution with a reducing agent comprising metallic zinc, tin, aluminium, cadmium or magnesium alone or in conjunction with benzoic acid or an alkanoic acid, the reaction with the reducing agent being carried out prior to or simultaneously with, but not later than, the capping reaction. In examples, solutions of poly - (2,6 - dimethyl - 1,4 - phenylene oxide), poly - (2,6 - diphenyl - 1,4 - phenylene oxide) and a copolymer of poly-(2,6-dimethyl-1,4- phenylene oxide) and poly-(2-methyl-6-phenylethyl-1,4-phenylene oxide) are capped by reaction with acetic anhydride and also reacted with zinc and acetic acid to improve the colour. Other reactants are mentioned.
|
