Difunctional oxazoline resins, which may be produced in a convenient one-step reaction from an arylalkylene dinitrile by reaction with an amino alcohol, are used in compositions with an additional curable compound or resin containing one or more carbon to carbon double bonds. The composition can be cured to a thermoset material, the curing mechanism occurring by the zwitterion polymerization of the bisoxazoline resin with the resin containing the one or more carbon to carbon double bonds. The reaction occurs without the need for curing initiators.(I) ##STR00001##