Upgrading of thermosets and composites via sequential frontal ring-opening metathesis polymerization and radical reactions

Frontal ring-opening metathesis polymerization (FROMP) of dicyclopentadiene (DCPD) shows promise for manufacturing thermosets and composites. To widen the applications, this work develops a novel approach for the upgrading of polydicyclopentadiene (PDCPD) and fiber-reinforced composites via sequential FROMP and radical reactions to achieve high performance. Herein, we mixed DCPD, Grubbs catalyst and radical initiators in one pot, and initiated FROMP, a self-perpetuating reaction, to obtain FROMP-prepared PDCPD. Then, the further radical reactions were carried out at elevated temperature. With our strategy, the performances of PDCPD and its composites were dramatically upgraded. For instance, the T g of PDCPD could be significantly improved from ~171 °C to ~240 °C. The T g , flexural strength and modulus of FROMP fabricated composite were successively increased from 141 °C, 135.3 MPa and 36.9 GPa to 262 °C, 467.1 MPa and 43.2 GPa, respectively. We believe that this novel strategy will greatly improve the performance of PDCPD and composites, and open new avenues to apply FROMP to wider applications. Graphical Abstract