The present invention provides a method for improving the structural integrity of polymers using a combination of high energy radiation and improved crosslinking agents. The crosslinking agents are 1,3-butadiene, three carbon cyclic compounds, three membered heterocyclic organic compounds, or linear analogues of three carbon cyclic compounds and three membered heterocyclic organic compounds, which are compact enough to diffuse to a suitable depth within the polymeric network. Preferred cyclic crosslinking agents are cyclopropane and ethylene oxide. Preferred linear crosslinking agents include propylene, 1,3-butadiene, dimethyl ether, and propane. A preferred form of high energy radiation is a beam of energetic low mass ions.