Synergistic Enhancement of Rigidity and Toughness in Polydicyclopentadiene Materials via Copolymerization With Tricyclopentadiene, Cyclooctene or α-Pinene

Polydicyclopentadiene (PDCPD), obtained through the ring-opening metathesis polymerization (ROMP) of Dicyclopentadiene (DCPD), benefits from a highly cross-linked rigid framework that provides superior impact resistance; however, it struggles to meet the increasingly demanding mechanical performance requirements of certain emerging fields. To enhance the performance of PDCPD materials, this study prepared poly (DCPD/TCPD) and poly (DCPD/α-pinene) copolymers via ROMP, incorporating tricyclopentadiene (TCPD) as a secondary monomer and using α-pinene for comparison. The introduction of these secondary monomers effectively increased the rigidity of PDCPD. Specifically, with the addition of 5% α-pinene, the tensile strength of PDCPD increased from 52.1 to 58.9 MPa; similarly, the addition of 10% TCPD raised the tensile strength to 61.3 MPa. To achieve a synergistic optimization of stiffness and toughness, cyclooctene (COE) was further introduced as a third monomer. The resulting ternary copolymers exhibited superior rigidity and toughness compared to pure PDCPD. When the DCPD/TCPD/COE ratio was 80/10/10, the poly (DCPD/TCPD/COE) composite achieved a tensile strength of 55.1 MPa, a flexural strength of 91.3 MPa, an elongation at break of 66.3%, and an impact strength of 6.8 kJ/m 2 . Highlights DCPD, TCPD, and COE undergo ternary copolymerization via ROMP. A cross-linked network with a stable structure and no macroscopic phase separation was formed. The polymer achieved a balanced enhancement in mechanical properties.