Abstract: There is provided a thermoset resin comprising a reactive compound bearing at least two functional groups F, identical or different from one another, per molecule and a hardener comprising at least two functional groups E, identical or different from one another, that react with functional groups F, per molecule, wherein the reactive compound is an insertion polyrnorbornene comprising said at least two functional groups F and/or the hardener is an insertion polynorbornene comprising said at least two functional groups E.