CROSSLINKABLE POLYMER

PURPOSE:To obtain a crosslinkable polymer which is injection-moldable and is improved in heat resistance and mechanical properties under high-temperature conditions comprising specified repeating units. CONSTITUTION:A crosslinkable polymer having a basic skeleton selected from among a polyarylene ether (sulfide), a polyarylene ether sulfoxide and a polyarylene ether sulfone and comprising repeating units of formula III or IV (wherein Z' is S, SO or SO2) is obtained, for examply, by reacting an aromatic dihalogen compound (a) having at least one cyano group of formula I (wherein X, X', Y and Y' are each H, a halogen atom or a cyano, provided that at least one of them is a cyano; and W and W' are each a halogen atom) with about 1mol, per mol of component (a), of a fully dried compound (b) of formula II [wherein Ar and Ar' are each an (un)substituted arylene; Z is O, S, SO, SO2 or CRR'; and R and R' are each H or a 1-3 C alkyl] at 70-200 deg.C in a polar aprotic solvent.