A method of rapidly forming an elastomer with tunable properties is described herein. The method includes preparing a monomer solution comprising a catalyst and one or more monomers including 1,5- cyclooctadiene (COD). The one or more monomers may further include dicyclopentadiene (DCPD), and each of the COD and the DCPD may be present in the monomer solution at a predetermined volume percentage. A region of the monomer solution is activated to initiate an exothermic polymerization reaction and generate a self-propagating polymerization front, which moves through the monomer solution and polymerizes the one or more monomers. Thus, an elastomer having predetermined properties is rapidly formed.
