In the field of structural materials, highly cross-linked polymeric solids are desirable due to their superior mechanical strength, durability and solvent resistance. In addition to these attributes, however, there also exist drawbacks: these materials experience a loss of re-cyclability and are usually brittle and rigid. Upon exposure to constant external stress, these systems experience thermal and mechanical fatigue that result in the formation of microcracks. When left untreated, these cracks propagate and enlarge through the sample, resulting in catastrophic failure.

A strong desire, therefore, exists to address the problem of microcrack formation and propagation before total failure of the system occurs. This has led to the recent development of re-mendable and self-healing polymer systems. To allow for repeat mending cycles, it is advantageous to employ materials that incorporate the re-formation of chemical bonds, such as the Diels-Alder (DA) and retro Diels-Alder (rDA) reactions. The energy required to break the DA adducts is much lower than the energy required to break the remaining covalent bonds in the molecule. This allows for rebonding of the intermonomer linkages after crack formation. In this dissertation, a novel single component system that utilizes the rDA reaction to achieve multiple cycles of mending will be presented. These materials are hard, colorless, and transparent at room temperatures, and can be custom-tailored to fit a range of desired working temperatures.