N-Amino Norbornene Imides as Scalable Monomers for Living Ring-Opening Metathesis Polymerization

Ring-opening metathesis polymerization (ROMP) is a well-established polymerization method that uses strained cyclic olefins to produce polymers with controlled molecular weight and dispersity suitable for aggregation in solution, leading to polymerization induced self-assembly (PISA). Herein, we report new norbornene-based monomers for the living ROMP that were synthesized on the multigram scale (20 g) starting from cis-5-norbornene-exo-2,3-dicarboxylic anhydride and hydrazine. Upon further reaction with carboxylic acid chlorides, non-hydrogen-bond-forming derivatives could be obtained. In the presence of Grubbs third generation catalyst (G3), the synthesized monomers could be polymerized to produce well-defined polymers with controlled molecular weights (Mn) and narrow dispersities (Đ). Furthermore, amphiphilic block copolymers were synthesized using a combination of acylated and nonacylated monomers, and the PISA behavior was investigated using dynamic light scattering (DLS). We believe that the self-assembly of the copolymers derived from the new norbornene-based monomers via the living ROMP method described here could be useful for developing advanced functional nanomaterials with various morphologies.