Abstract: A resin composition comprising a polyphenylene ether having, on the average, 0.01 to 10 terminal structures of the formula (1): ##STR1## wherein R.sub.1 to R.sub.5 are each hydrogen, halogen, a substituted or unsubstituted alkyl, alkenyl or alkynyl group, or a substituted or unsubstituted aryl group, R.sub.6 is a substituted or unsubstituted alkylene group, and R.sub.7 to R.sub.11 are each hydrogen, halogen, an alkyl group, an alkoxy group, a phenyl group, a phenoxy group, a nitro group or a cyano group per 100 phenylene ether units, and a primary aliphatic monoamine having an aromatic substituent, which composition has good thermal stability.

Abstract: A process for producing a polyphenylene ether is disclosed, comprising oxidatively polymerizing a phenol in an organic solvent in the presence of a catalyst for oxidative polymerization, finely dispersing the resulting polyphenylene ether containing the organic solvent in an aqueous dispersion medium containing an acid compound, and heating the aqueous dispersion to remove the solvent from the polyphenylene ether. The resulting polyphenylene ether has excellent powder properties and contains a reduced amount of a catalyst residue.

Abstract: A process for producing a plyphenylene oxide is disclosed, comprising oxidative polymerization of a nucleus-substituted phenol with an oxygen-containing gas in an organic solvent in the presence of a catalyst system comprising a manganese compound containing at least one divalent manganese salt, at least one basic compound selected from hydroxides, alkoxides or phenoxides of the group IA metals of the Periodic Table and hydroxides or oxides of the group IIA metals of the Periodic Table, an alkanolamine represented by formula (I)R.sup.1 --NH--R.sup.2 --OH (I)wherein R.sup.1 represents a hydrogen atom, an alkyl group having from 1 to 12 carbon atoms, or a hydroxyl-substituted alkyl group having from 1 to 12 carbon atoms; and R.sup.2 represents an alkylene group having from 2 to 12 carbon atoms, and an amine represented by formula (II)R.sup.3 R.sup.4 NH (II)wherein R.sup.3 and R.sup.