Survey of Catalysts for Frontal Ring-Opening Metathesis Polymerization

Recent advances in frontal ring-opening metathesis polymerization (FROMP) have enabled the rapid and energy-efficient fabrication of high-performance and thermoset materials. The second-generation Grubbs complex [(SIMes)RuCl2(PCy3)] is the most exploited FROMP catalyst to date despite the availability of several other commercial variants. Changes in the nature of the catalytic species may provide potential advantages for controlling FROMP conditions, polymer microstructure, and monomer selectivities. Herein, nine catalysts are employed for the FROMP of dicyclopentadiene and ethylidene norbornene mixtures to generate copolymers, and the associated polymerization process parameters (front temperatures and velocities) are measured for each system. Dynamic mechanical analysis, differential scanning calorimetry, and quasistatic tensile testing reveal significant differences in the mechanical and material properties of the resultant polymers.