A method for producing three-dimensionally crosslinked poly phenylene oxides

摘要

Cross-linked polyphenylene oxides are obtained by reacting amino-substituted polyphenylene oxides with polyfunctional organic compounds capable of reacting with the amino groups to form cross-linking bridges. The polyfunctional compounds may be di- or polyisocyanates, di- or poly-acid anhydrides, di- or poly-acid halides, di- or poly-esters of polyfunctional acids, di- or poly-glycidyl ethers or epoxy resins. There may be from 1 amino group per repeating unit of the polyphenylene oxide to 1 amino group per 100 repeating units. When an epoxy resin is used it may constitute from 1 to 99% by weight of the total material. In examples polyphenylene oxides containing amino groups are obtained by reacting nitric acid with poly-(2,6-dimethyl-1,4-phenylene)-oxide and then reducing the resulting nitro groups with stannous chloride to amino groups, and by reacting poly-(2,6-dimethyl-1,4-phenylene)-oxide containing bromine substituents on the methyl groups and on the aromatic rings, with potassium cyanide and then hydrogenating the nitrile groups to amino groups; the amino-substituted poly-(2,6-dimethyl-1,4-phenylene)-oxides are then cross-linked by heating with a diglycidyl ether of 2,21-bis-(4-hydroxyphenyl)-propane, with pyromellitic di-anhydride, with toluene di-isocyanate, with 4,41-di-isocyanate-3, 31-dimethyl-diphenyl, with dimethyl terephthalate, with phthalic anhydride and with trimellitic anhydride.