Block copolymers of polyphenylene oxides and sterically-hindered aromatic polycarbonates

A block copolymer of a polyphenylene oxide and a sterically hindered aromatic polycarbonate consisting of chemically combined

• (i) polyphenylene oxide blocks of the formula, ##STR7## wherein --(OEO)-- is a divalent quinone residue, E is a divalent arene radical, either a or b is a number at least equal to 1 and the sum of a plus b is at least equal to 10, R is a member selected from hydrogen, a hydrocarbon radical, a halohydrocarbon radical, a hydrocarbonoxy radical or a halohydrocarbonoxy radical,
• (ii) sterically hindered aromatic polycarbonate blocks of the formula, ##STR8## wherein R.sub.f is a member selected from an alkylene, alkylidene, cycloalkylene, cycloalkylidene, arylene linkage and a mixture thereof, a linkage selected from the group consisting of ether, carbonyl, amine, a sulfur or phosphorus containing linkage, Ar and Ar' are arene radicals, Y is bromine, chlorine or a monovalent alkyl or alkoxy group, d represents a whole number up to a maximum equivalent to the number of replaceable hydrogens substituted on the aromatic rings comprising Ar or Ar', subject to the proviso that at least two Y groups are ortho-positioned relative to each --OH group of each arene radical, X is bromine, chlorine or a monovalent hydrocarbon group selected from the class consisting of alkyl, aryl and cycloalkyl including mixtures thereof, e represents a whole number of from 0 to a maximum controlled by the number of replaceable hydrogens on R.sub.f, aa, bb and cc represent whole numbers including 0, when bb is not zero, neither aa nor cc may be zero, otherwise either aa or cc but not both may be 0, when bb is zero, the aromatic groups can be joined by a direct carbon bond, x is a number at least equal to 30, and
• (iii) carbonyl radicals of the formula ##STR9##