Dynamic Cross-Linking of Catalytically Synthesized Poly(Aminonorbornenes)

Amine-functionalized polymeric materials have a wide variety of applications; however, the preparation of these materials is often plagued by laborious, multistep synthetic routes. Herein, a modified and improved synthetic protocol utilizes the hydroaminoalkylation reaction to catalytically assemble amine-functionalized monomers on a gram scale with 100% atom economy. Combined with ring-opening metathesis polymerization (ROMP), amine-functionalized polymers with varying electronic properties have been synthesized. Extensive theological characterizations show that modification of the electronic properties of the amine substituent influences the bulk material properties through modification of hydrogen bonding and pi-stacking interactions to afford dynamic cross-linking within the polymeric material. Tertiary amine-containing polymers display distinct rheological properties that differ from those of polymers with pendant hydrogen-bond-donating secondary amines. The profound viscoelastic effects that result from the incorporation of tunable dynamic interactions are presented.