Frontal Ring-Opening Metathesis Polymerization of Exo-Dicyclopentadiene for Low Catalyst Loadings

Abstract

Polydicyclopentadiene (PDCPD) is a polymer of growing importance in industrial applications. Frontal ring-opening metathesis polymerization (FROMP) offers a means to rapidly cure PDCPD with minimal input energy owing to a propagating reaction wave sustained by the exothermic polymerization. Previous examples of FROMP have required the use of relatively high concentrations of costly ruthenium catalyst, negating many of the benefits of FROMP synthesis. In this contribution, we demonstrate that by using the highly reactive exo-dicyclopentadiene isomer for FROMP the concentration of catalyst is reduced over 3-fold, while maintaining a high frontal velocity. Reducing the amount of ruthenium required for FROMP makes this technique attractive for the production of large PDCPD structural components.

Advanced Polymer Designs for Direct‐Ink‐Write 3D Printing

“…introduced frontal polymerization to cross‐link monomers during DIW. Frontal polymerization is a self‐propagating exothermic reaction where the polymerization‐generated heat subsequently initiates the surrounding monomers . The frontal‐polymerization‐based ink is composed of three key compounds: 1) a dicyclopentadiene as the monomer for ring‐opening metathesis polymerization, 2) a second‐generation Grubbs catalyst that can be thermally activated, and 3) an alkyl‐phosphite inhibitor with optimized concentration to control the polymerization rate and subsequently the rheological profile of the ink .…”

Grubbs‐inspired metathesis in the Moore group

“…(a)] . As previously discussed, exo ‐DCPD has a much higher reactivity with Grubbs' catalyst than endo ‐DCPD . Thus, ROMP of exo ‐DCPD is able to release the same amount of heat as ROMP of endo ‐DCPD with less catalyst loading.…”

“…To address the challenge of high catalyst loading, we investigated exo ‐DCPD as an alternative monomer [Fig. (a)] . As previously discussed, exo ‐DCPD has a much higher reactivity with Grubbs' catalyst than endo ‐DCPD .…”

“…These traits allow control over pot life and frontal velocity by simply varying the catalyst and inhibitor concentrations. As such, exo ‐DCPD was shown to frontally polymerize with catalyst loading as low as 10 ppm, which has great potential for large‐scale materials manufacturing . The greatest challenge for FROMP of exo ‐DCPD, however, is its limited pot‐life.…”

Synthesis and thermal properties of linear polydicyclopentadiene via ring‐opening metathesis polymerization with a third generation grubbs‐type ruthenium‐alkylidene complex

“…DCPD is an inexpensive by‐product of the naphta cracking process and hence, those polymers are highly attractive from a commercial standpoint. There have been reports of polydicyclopentadiene (PDCPD) syntheses in emulsion, high internal phase emulsion, or in bulk during frontal ring‐opening metathesis polymerization (FROMP) for applications in latexes, as low‐density materials or for self‐healing material purposes …”